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• The germination of cannabis treatments varied with landrace and treatments. • H 2 SO 4 , GA 3 , and KNO 3 enhanced the germination capacity of cannabis landraces. • Control produced vigorous seedlings compared dormancy-breaking pre-treatments. The current study evaluated the effectiveness of different pre-treatments for dormancy breaking and seed germination of five cannabis landraces. These landraces were collected from local growers in three regions of KwaZulu-Natal Province in South Africa, namely, Bergville (B), Hammersdale (H), and Ladysmith (L). Each genotype was assigned an alphabet and number based on where the seed material was collected. The five landraces were as follows, 'B1', 'K1', 'H1', 'L1', and 'L2'. The study was conducted using various pre-treatments, including potassium nitrate (KNO 3), hydrochloric acid (HCL), hot water (HW) at 70 °C, nitric acid (HNO 3), dry prechilling at 10 °C, gibberellic acid (GA 3), sulfuric acid (H 2 SO 4), and water, which served as the control. Before the germination test, the seed viability of cannabis landraces was assessed using the tetrazolium chloride (TCC) test. Afterward, the seeds were germinated in Petri dishes with cotton pads moistened with distilled water for five (5) days. The study was later validated under tunnel conditions. The parameters such as germination percentage, germination rate, seedling length, and seed vigour index of the germinated seeds were then measured. The landraces, dormancy breaking treatments, and their interactions showed significant differences (p < 0.001) in germination percentage, germination rate index, seedling length, and seed vigour index under both laboratory and tunnel conditions. In summary, GA 3 , KNO 3 and prechilling were the most effective pre-treatments to improve the germination and seedling growth of cannabis genotypes and breaking seed dormancy. Therefore, it was concluded that cannabis genotypes had physiological dormancy. [ABSTRACT FROM AUTHOR]

• Phytohormonal changes in relation to citrus rind disorder was examined postharvest. • Fruit were harvested from inside and outside canopy position of the tree. • Endogenous levels of cytokinins (CK), auxins, isomers and conjugates were analysed. • Cis -zeatin-type CK concentrations were higher in outside canopy fruit postharvest. The role of phytohormones in mitigating or enhancing the incidence of non-chilling rind physiological disorder of citrus fruit is largely unknown. Therefore, this study attempted to elucidate cytokinins (CK) and auxin changes in 'Nules Clementine' mandarin fruit rind from different canopy positions during postharvest non-chilling cold storage regarding rind breakdown disorder (RBD). Fruit from the inside canopy (IC) and outside canopy (OC) positions of citrus trees were harvested at commercial maturity from Eastern Cape (EC) and Western Cape (WC) provinces of South Africa, respectively. Endogenous levels of CK, auxins, their isomers, and conjugates were analysed using ultra-performance liquid chromatography coupled with a triple quadrupole mass spectrometer (MS/MS) equipped with an electrospray interface. Cis -zeatin-type cytokinins were significantly higher in the OC fruit than in the IC fruit from both provinces during cold storage. Whereas dihydrozeatin concentration (the most abundant CK) was significantly higher in fruit from IC (326.10 and 29.38 nmol kg−1) than in OC (65.75 and 17.72 nmol kg−1) fruit before cold storage, respectively. Fruit without rind disorder had lower CK - conjugates than fruit with the disorder. The IAA concentration was higher in the IC fruit (344.15 nmol kg−1) than in the OC fruit (194.20 nmol kg−1) from EC at week 0 while the IAA concentration of OC fruit from WC was below the limit of detection and IC fruit had 53.20 nmol kg−1 at week 0. Fruit without the disorder had more IAA concentration than fruit with RBD while indole-3-acetylaspartic acid (IAAsp) was higher in fruit with RBD than fruit without the disorder, indicating the preventive role of IAA in the incidence of the disorder. This study is the first to record the negative effect of IAAsp in RBD and revealed the crucial role and synergistic role of CK, IAA and their isomers in RBD of 'Nules Clementine' fruit. [ABSTRACT FROM AUTHOR]

Climacteric fruits continue to ripen postharvest, characterized by an increase in respiration and ethylene. Thus, the shelf-life, quality, and marketability of these fruits is reduced rapidly. One of the most important postharvest technology used to reduce the effect of exogenous and endogenous ethylene and extend the shelf-life of climacteric fruits is 1-methylcyclopropene (1-MCP). Currently, the application of 1-MCP on certain climacteric fruits is not commercially feasible due to the variable effects associated with this technology. In this review, factors that influence 1-MCP efficacy in climacteric fruits such as fruit maturity, concentration, genotypes, storage temperature and atmospheres, packaging material and application timing are critically discussed. In addition, current techniques used to mitigate the 1-MCP variability such as combined application with other postharvest treatments are briefly described and discussed. This review will provide an important information on the utilization of 1-MCP to prolong shelf-life in various climacteric fruits and help in the development of protocols for unregistered genotypes. [ABSTRACT FROM AUTHOR]

Cannabis sativa L. is the utmost consumed, grown, and produced illicit drug worldwide. The psychotropic activity of the component (-)- trans -∆9-tetrahydrocannabinol (∆9-THC), however, led to the banning of cannabis worldwide for many centuries. Besides being the most popular crop for recreational purposes, cannabis is grown globally as a multifunctional agricultural crop for its oily seeds and long, durable fibers. These properties have led to cannabis application in various industries, including agriculture, textile, bio-composite, papermaking, automotive, construction, and biofuel. Furthermore, medicinal cannabis constitutes of high concentration of cannabinoids, which have been discovered relevant in the pharmaceutical industry. As a result, various countries worldwide have relaxed regulations on cannabis. However, the cannabis products' final use depends on the cultivar. Yet, the crop has hundreds of cultivars owing to constant breeding and human selection, which has altered the original plant with the spread of the crop worldwide. Generally, these cultivars possess chemical composition that varies genetically, and with the growing environmental conditions. Therefore, the current descriptive review of literature highlights the techniques available for classifying cannabis varieties, given the ongoing debate over classifying cultivars into distinct taxonomic groups. The effect of intrinsic and extrinsic factors on cannabis germination and seedling establishment are also highlighted. • Classification of varieties assist determine the end-use product. • Seed morphology appears prospective to solve cannabis taxonomy-related issues. • Traditional methods are still mostly used in cannabis seed quality assessment. • The effect of intrinsic and extrinsic factors in germination varies with species • Physiology and biochemistry studies on cannabis germination are still very limited. [ABSTRACT FROM AUTHOR]

Effect of canopy position on rind biochemical properties of 'Marsh' grapefruit during postharvest non-chilling cold storage was evaluated on fruit harvested from different orchard locations. Inside canopy (IC) and outside canopy (OC) fruits were harvested at commercial maturity from two commercial farms located at KwaZulu-Natal (KZN) and Limpopo (LMP), South Africa, during two seasons. Rind biochemical analyses including color indices, total phenolic concentration, and sugars were performed on harvested grapefruit after Weeks 0, 3, 6, and 9 of cold storage at 7.5 ± 0.5°C. Canopy position showed a high significant (p <.001) effect on rind biochemicals while significant (p <.05) influence of orchard locations was observed on the same parameters. Reducing sugars were more concentrated in IC fruit harvested from both orchard location than OC fruit at Weeks 0 and 3, but inverse results occurred at Weeks 6 and 9. Orchard location significantly (p <.001) influenced vitamin C (14.4, 14.2, 14.4, 14.8 g kg−1) and (12.3, 16.1, 15.9, 14.6 g kg−1) of fruit rind at Weeks 0, 3, 6, and 9 from KZN and LMP, respectively. This study revealed that canopy position can influence rind biochemical properties of 'Marsh' grapefruit during non-chilling postharvest cold storage. However, further studies are required to formulate and provide the citrus industries with adequate advice. [ABSTRACT FROM AUTHOR]

1-methylcyclopropene (1-MCP) extends shelf-life of banana fruit, however, it induces uneven ripening. The strong effect 1-MCP has on ethylene receptors probably condition the fruit to ripen unevenly. Combined application of 1-MCP and ethephon has been reported to alleviate this negative effect. However, limited work reported the effect of the treatment at cold storage. Hence, the present study determined whether the combined application of 1-MCP and ethylene prolongs banana green-life during cold storage and induces uniform ripening during shelf-life. The study comprised four treatments: control (untreated), gaseous 1-MCP at 400 nL L−1 and combination of 400 nL L−1 1-MCP with liquid ethephon at 50 or 100 µL L−1 concentrations. The treatments were arranged in a completely randomized design (CRD) with 4 replicates. The treated fruit were cold stored at 14°C for 30 d and thereafter 23°C to simulate shelf-life for 9 d. The results showed that 400 nL L−1 1-MCP and combined with 50 and 100 µL L−1 ethephon prolonged green-life and delayed ripening during cold storage compared to the control. In addition, there was more softening, yellow color development, and accumulation of soluble sugars in fruit treated with 1-MCP+ethephon compared to 1-MCP during shelf-life. The combined application of 1-MCP and ethylene is an effective strategy that prolongs banana green-life during cold storage and induces uniform ripening during shelf-life. This strategy has potential to be used when banana fruit are exported to distant markets, since it also prolongs green-life for a long time. [ABSTRACT FROM AUTHOR]

Effect of canopy position on rind biochemical properties of 'Marsh' grapefruit during postharvest non-chilling cold storage was evaluated on fruit harvested from different orchard locations. Inside canopy (IC) and outside canopy (OC) fruits were harvested at commercial maturity from two commercial farms located at KwaZulu-Natal (KZN) and Limpopo (LMP), South Africa, during two seasons. Rind biochemical analyses including color indices, total phenolic concentration, and sugars were performed on harvested grapefruit after Weeks 0, 3, 6, and 9 of cold storage at 7.5 ± 0.5°C. Canopy position showed a high significant (p < .001) effect on rind biochemicals while significant (p < .05) influence of orchard locations was observed on the same parameters. Reducing sugars were more concentrated in IC fruit harvested from both orchard location than OC fruit at Weeks 0 and 3, but inverse results occurred at Weeks 6 and 9. Orchard location significantly (p < .001) influenced vitamin C (14.4, 14.2, 14.4, 14.8 g kg-1) and (12.3, 16.1, 15.9, 14.6 g kg-1 ) of fruit rind at Weeks 0, 3, 6, and 9 from KZN and LMP, respectively. This study revealed that canopy position can influence rind biochemical properties of 'Marsh' grapefruit during non-chilling postharvest cold storage. However, further studies are required to formulate and provide the citrus industries with adequate advice. [ABSTRACT FROM AUTHOR]

• Photosynthetic efficiency of leaves from different positions of avocado trees was assessed. • Outside leaves had higher photosynthetic rate and stomatal conductance. • The high photosynthetic efficiency of outside fruit was linked fruit maturity. • Outside fruit matured earlier with mesocarp DM content of 23.2% compared to 22.3% on inside fruit. Physiological changes associated with leaf chlorophyll fluorescence and gas exchange are the key components towards understanding performance of fruit trees. In this study, the photosynthetic efficiency of leaves from inside and outside canopy positions of avocado trees was assessed during the fruit growing season. The aim was to determine to what extent photosynthesis and gas exchange of the leaves correlates with the position of the leaf inside canopy and outside canopy of an avocado tree, and how does that affect fruit maturity. The study was conducted in a commercial orchard at Everdon Estates in the KwaZulu-Natal, South Africa during 2017/18 season. A total of fifteen 8-year old avocado trees (cv. 'Carmen') were selected in a completely randomised design with three replicates and each replicate consisting of five trees. Data was collected bi-weekly from full bloom to fruit physiological maturity (25% dry matter content). Measured variables included gs, C i, T , A , F 0 , F m , Fv/Fm , ΦPS II , qP, qN, ETR, 1- qP and DM content, were estimated within and outside canopy. Results showed that leaves from the outside position had higher A (22.28 mol CO 2 m−2 s−1) , gs (0.22 mol CO 2 m−2 s−1) , ΦPS II (0.35), and qP (0.57) compared to those on the inside position of the canopy with lower values of 14.19 mol CO 2 m−2 s−1, 0.14 mol CO 2 m−2 s−1, 0.047 and 0.071, for A, gs, ΦPS II and qP respectively. Conversely, Fo', Fm' , Fv', Fv'/Fm' , and 1- qP were about two times higher on the inside canopy than on the outside. The high photosynthetic efficiency of outside fruit was linked fruit maturity with fruit from the outside maturing earlier with an average mesocarp dry matter content of 27.6% compared to 26.5% on fruit from the inside canopy. The findings suggest that the high sunlight interception by leaves from the outside position improved photosynthetic efficiency, increased rate of dry matter accumulation and maturation of avocado fruit. There is a strong sink demand within the outside canopy demanding more carbohydrates, and thus commanding leaves from the outside canopy to photosynthesize more efficiently leading to fast maturity. [ABSTRACT FROM AUTHOR]

Abstract Rind biochemical properties play major roles in defence mechanisms against the incidence of rind physiological disorders of citrus fruit during cold storage. Hence, multivariate calibration models were developed to rapidly and non-destructively determine rind biochemical properties of citrus fruit from visible to near-infrared (Vis/NIR) spectra acquired by Vis/NIR spectroscopy using partial least square regression algorithm. To achieve optimum models for determination of each rind biochemical property, several mathematical pre-processing methods were explored, including no pre-treatment. However, special emphases were given to the best model statistics in terms of coefficient of determination (R2) and residual predictive deviation (RPD). Models were performed by critical examination of different wavelength ranges (visible, near-infrared and full regions) and combinations of fruit harvested from different production regions and acquired before (week 0) and after (week 9) cold storage. Results obtained showed excellent models for determining parameters such as sucrose (R2 = 0.99 and RPD = 11.42), total flavonoids (R2 = 0.99 and RPD = 12.37), and chlorophyll b (R2 = 0.97 and RPD = 5.67). This study reported the first application of Vis/NIR and chemometrics in determining the rind biochemical properties of 'Marsh' grapefruit rapidly and non-destructively. [ABSTRACT FROM AUTHOR]

The physicochemical properties of citrus fruit play critical roles in its maturity and quality determination. Hence, this study investigated the effect of canopy position on physicochemical properties of ‘Marsh’ grapefruit across different production regions at harvest and after storage at 7.5 °C for 3, 6, and 9 weeks. The study also evaluated the use of BrimA as an adoptable internal quality and maturity parameter for ‘Marsh’ grapefruit. Fruit from inside canopy (IC) and outside canopy (OC) were harvested from KwaZulu-Natal (KZN) and Mpumalanga (MP) provinces in South Africa. Titratable acidity was determined by titration and calculation of the sugar/acid ratio (TSS/TA) was established while BrimA was derived from sugar and acid with tongue sensitivity index. Colour indices were measured using calibrated colorimeter while sugars were measured using high performance liquid chromatography (HPLC). At harvest, IC fruit from MP province were more luminous than the OC fruit while inverse results were recorded for fruit from KZN. At harvest, IC fruit had higher percentage of titratable acidity (TA) (2.73%) than OC fruit (2.40%) from MP, with opposite results from KZN. The BrimA showed a strong and positive correlation with TSS/TA (r = 0.9364). Overall, our result suggested that canopy position affect some physicochemical properties of ‘Marsh’ grapefruit. However, harvested fruit displayed a high level of maturity and quality over the period of cold storage. BrimA could potentially be used as an index of internal quality of grapefruit but further studies into the subject is required. [ABSTRACT FROM AUTHOR]

This study evaluated the effectiveness of a low-cost evaporative cooling system and its effect on postharvest storage potential and physicochemical quality properties of tomatoes. The performance of the cooling system was evaluated in terms of temperature drop, increase in relative humidity (RH) and cooling efficiency. Two tomato cultivars (‘9065′ jam and round) were harvested from smallholder farms in Umsinga, South Africa (28˚45′56.45′'S, 30˚33′42.37′'E). Tomatoes were assigned to one of the three storage conditions namely; evaporative cooling system (ECS), cold room (CR) and room temperature (RT). Quality parameters evaluated included mass loss, respiration rate, colour, firmness, total soluble solids and titratable acids for both tomato cultivars. ECS reduced temperature to 19.8 °C which was 13% lower than RT (23.0 °C). RH increased from 63.59% in RT to 83.91% in the ECS with an average cooling efficiency of 67.17%. Storage treatments and time had significant ( p  <  0.05) effect on fruit quality. Fruit in the CR retained colour, mass, firmness, respiration rate, TA and TSS of both cultivars longer than the other treatments. However, the ECS was able to preserve the freshness of tomatoes for 20 days and had a slower rate of change in mass, respiration, colour, firmness, TA and TSS compared with those stored at RT. This suggested that the evaluated ECS is capable of maintaining postharvest quality and increasing shelf-life of tomatoes. Therefore, ECS has a potential as a low-cost and energy-free system for preserving quality and reducing postharvest losses under smallholder farming systems. [ABSTRACT FROM AUTHOR]

Rind biochemical concentrations and radical-scavenging activities of ‘Nules Clementine’ mandarin could play a significant role in the susceptibility of the fruit to various forms of physiological rind disorders. This study examined the effect of fruit position within tree canopy on biochemical concentrations and radical-scavenging activities of ‘Nules Clementine’ mandarin fruit rind after harvest at week 0 and after 3, 6 and 9 weeks of postharvest cold storage at 7.5 ± 0.5 °C. Biochemical concentrations and radical-scavenging activities of flavedo and albedo tissues of the rind were also examined. Fruit from inside canopy (IC) and outside canopy (OC) were harvested at commercial maturity in May 2015 and 2016 from Unifruiti and Swartvelei Farms located at Eastern Cape (EC) (33° 27′ 32″ S, 25° 34′ 79″ E) and Western Cape (WC) (19° 02′ 33.8″ S, 33° 41′ 17.24″ E) provinces of South Africa, respectively. Results showed that canopy position played a significant ( p < 0.001) role on total carotenoids, total phenolics and total flavonoids as well as rind dry matter, with OC fruit often characterised by higher biochemical concentrations than IC fruit during cold storage. The study further showed that production region influenced radical-scavenging activities and carbohydrate content of OC and IC fruit rind during cold storage. Radical-scavenging activities of OC fruit (61.2%) were higher than IC fruit (52.5%) from EC whereas radical-scavenging activities of IC fruit (67.1%) were higher than those of OC fruit (58.2%) from WC at harvest. Overall, this study revealed that fruit position within tree canopy influenced its rind biochemical concentrations and radical-scavenging activities. [ABSTRACT FROM AUTHOR]

This study investigated the potential of edible carboxyl methylcellulose (CMC) containing moringa leaf and seed extracts as a novel postharvest treatment for maintaining storage quality and controlling diseases in ‘Hass’ and ‘Gem’ avocado fruit. The study also investigated the antifungal activity of methanolic and ethanolic moringa plant extracts. Briefly, 1% CMC was blended with 2% of moringa leaf (MLE) or seed extract (MSE). After the fruit was dipped in either CMC + MLE or CMC + MSE, it was stored at 5.5 °C (95% RH) for 21 days. After cold storage, fruit were stored at ambient conditions (21 ± 1 °C) and 60% RH to simulate retail conditions. Postharvest quality attributes such as ethylene production, respiration rate and fruit firmness were measured. Both coatings were also tested against postharvest fungi in reference to potato dextrose agarose (PDA). Coated fruit had lower mass loss, ethylene production and respiration rate compared to the uncoated fruit. Ethanolic leaf extract had an inhibition of 43.6% and 42.9% against C. gloeosporioides and A . alternata , respectively. Scanning electron microscopy analysis revealed damaged hyphal structures for all pathogens exposed to coatings while such structures remained intact in uncoated fruit. Ethanolic moringa leaf extracts proved to have higher antimicrobial activity compared to methanolic extracts. The findings reported in this study demonstrated that CMC containing moringa extract suppresses diseases, prolongs the shelf-life and maintain the overall quality avocados during postharvest supply chain. The CMC blended with moringa extracts could potentially be commercialized as a new organic edible coating for avocado fruit industry. [ABSTRACT FROM AUTHOR]

Vitamin C is widely regarded as one of the most important antioxidants in citrus fruits. The rapidly growing demand for fresh citrus fruits and their derivative products has prompted researchers to study factors affecting the vitamin C content. This review discusses postharvest factors influencing vitamin C content of citrus fruits. Vitamin C content in citrus fruits can be influenced by several factors such as postharvest treatment, storage conditions as well as oxidative stress. Postharvest treatments such as surface coating, heat treatments, irradiation, and ethylene degreening lead to better vitamin C retention. Additionally, improper temperature management may negatively affect the nutritional quality of the stored produce; vitamin C loss is intensified at higher storage temperatures. Although storage conditions favorable to water loss are known to accelerate vitamin C loss, the effect of low relative humidity (RH) on vitamin C content of citrus fruits has not yet been fully elucidated. Vitamin C retention is also improved when citrus fruits are stored in modified atmosphere packaging and controlled atmosphere (CA). Although the effect of postharvest treatments on vitamin C content has been intensively studied, the influence of chemical treatments warrants more research. [ABSTRACT FROM AUTHOR]

Citrus fruits are an important diet for human health by providing some nutritional and antioxidant components, especially ascorbic acid (AsA). As the major antioxidant compound, the concentration of AsA is an important nutritional quality indicator for citrus fruit and its derivative products. Although the emphasis is on vitamin C content of harvested citrus fruit, this review of literature focuses on preharvest factors affecting this nutritional quality variable. The literature reviewed in this study showed that the content of AsA in citrus fruits is influenced by numerous preharvest factors including genotype, cultural practices, climatic conditions, fruit maturity and postharvest management. To better understand the mechanism underlying the vitamin C content of different citrus fruits, the introduction of this paper will first provide an overview of major proposed biosynthetic pathways and genes encoding for enzymes involved in AsA biosynthesis and oxidation. The review will then concentrate on the current state of knowledge regarding inherent genetic, environmental, fertilization, maturity and harvesting factors affecting AsA of citrus fruits. Some suggestions for future research are also highlighted. [ABSTRACT FROM AUTHOR]

The rapidly growing organic food market has prompted many researchers to compare numerous aspects of organically and conventionally grown foods. This review of literature provides an overview of empirical studies comparing postharvest quality of organically and conventionally produced fruits. The emphasis is on key postharvest quality parameters including physicochemical properties, postharvest storage performance, microbiological, sensory and nutritional quality. The study showed that physicochemical and nutritional properties relating to the contents of vitamins, phenolics and antioxidants are higher in organically produced fruits. It is also showed that production system has little effect on sensory quality. The better taste of organic produce as perceived by consumers is only due to the ‘halo effect’ of the organic label. The differences identified could be largely attributed to the different fertilization systems between organically and conventionally managed soils. The microbial contamination due to improper use of manure and compost in organically managed soils is a major concern in organic fruits. High levels of pesticide residues and nitrates in conventionally grown fruits is also a cause of concern. Several important problems in organic fruits are yet to be addressed, bacterial and fungal contamination of organic fruits warrants more intensive research. Future research should also investigate the effect of production system on storage potential. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy (NIRS) is an alternative analytical method that can be used to quantify protein content in sweetpotato. It is relatively cheaper and efficient than other methods. This study was conducted to develop NIRS-based models for quantifying protein content of sweetpotato for selection or wide-area production of recommended varieties. A pool of 104 sweetpotato varieties were sampled and roots scanned using NIR spectrometer. Calibration models were developed by subjecting spectral and reference datasets to partial least squares regression. Several pre-processing methods were investigated. Models that yielded the highest coefficient of determination (R 2 ), residual predictive deviation (RPD) and lowest root mean square error of calibration (RMSEC) and prediction (RMSEP) were selected. Optimal model performances were obtained using second derivative pre-processing, showing the highest values of R 2 v , RMSEP and RPD v of 0.98, 0.29, and 4.0, respectively. The regression analysis indicated that informative NIR bands for quantifying protein content of sweetpotatoes ranged between 1600 and 2200 nm. The results demonstrated that NIRS is capable of predicting protein content on sweetpotatoes, rapidly and accurately. Therefore, the NIRS model developed in this study may help to quantify protein composition of sweetpotato for rapid screening of germplasm in breeding programs with high throughput and accuracy. [ABSTRACT FROM AUTHOR]

Sub-Saharan Africa is faced with the challenge of improving current food security on highly degraded land. At the same time, the region has to develop strategies to ensure future food security for the increasing population under worsening climate change. Conventional tillage (CT) has for many years resulted in the deterioration of soil quality through depletion of soil organic matter. This review of literature provides an overview of the impact of conservation agriculture (CA) on soil quality with particular emphasis on key soil physical, chemical and biological properties. This paper also discusses impact of CA on yield, highlighting South African research gaps since the adoption is still very low in the country. The review of numerous studies indicated that soil quality and yield improvements are possible in CA although some negative results have also been reported under contrasting environments. Yield under CA were recognised to be resilient to seasonal rainfall variability compared with CT because of its ability to conserve water. CA is particularly relevant to the South African maize production given high levels of soil degradation, water scarcity and low soil fertility status. This review of literature demonstrated that CA can have substantial positive environmental, financial, social and health benefits for South Africa and the world. However, more research on CA is required from different agroecological zones and socio-economic contexts since maize is the biggest produced crop in South Africa. [ABSTRACT FROM AUTHOR]

Conventional methods for extracting and quantifying phenolic compounds in citrus rinds are time consuming. Rapid methods for extracting and quantifying phenolic compounds were developed by comparing three extraction solvent combinations (80:20 v/v ethanol:H2O; 70:29.5:0.5 v/v/v methanol:H2O: HCl; and 50:50 v/v dimethyl sulfoxide ( DMSO):methanol) for effectiveness. Freeze-dried, rind powder was extracted in an ultrasonic water bath at 35°C for 10, 20, and 30 min. Phenolic compound quantification was done with a high-performance liquid chromatography ( HPLC) equipped with diode array detector. Extracting with methanol:H2O: HCl for 30 min resulted in the optimum yield of targeted phenolic acids. Seven phenolic acids and three flavanone glycosides ( FGs) were quantified. The dominant phenolic compound was hesperidin, with concentrations ranging from 7500 to 32,000 μg/g DW. The highest yield of FGs was observed in samples extracted, using DMSO:methanol for 10 min. Compared to other extraction methods, methanol:H2O: HCl was efficient in optimum extraction of phenolic acids. The limit of detection and quantification for all analytes were small, ranging from 1.35 to 5.02 and 4.51 to 16.72 μg/g DW, respectively, demonstrating HPLC quantification method sensitivity. The extraction and quantification methods developed in this study are faster and more efficient. Where speed and effectiveness are required, these methods are recommended. [ABSTRACT FROM AUTHOR]

The determination and quantification of sugars is important for quality control and assurance of horticultural produce. This review discusses analytical methods for determination of sugars and sweetness of fresh and processed fruit and vegetables, including the use of destructive and non-destructive instrumental techniques to evaluate sugar composition and characterize taste profile or sweetness. From the standard hand-held refractometer to the hydrometer, electronic tongue and high pressure liquid chromatography (HPLC) equipped with different detectors, a wide range of devices have been used to determine sugar composition and sweetness of many fruit and vegetable products. Although chromatographic techniques are very accurate and useful, they require extensive sample preparation based on solvent extraction and hence are generally time-consuming and expensive. Visible to near infrared spectroscopy (vis/NIRS) has been proposed as an interesting alternative to traditional methods due to its rapidity, simplicity, cost effectiveness and potential for routine analysis if proper calibration and validation steps were developed. Current trends favour analytical methods that are simple to use, quick and non-destructive. The prospects for using emerging technologies such as hyperspectral imaging and nuclear magnetic resonance for non-destructive assessment of sugar content and sweetness of fresh and processed horticultural food products are also discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fruit from inside the canopy were more susceptible to RBD disorder than outside fruit. [•] Vis/NIRS PLS models predicted rind fructose, glucose and sucrose with accuracy. [•] Vis/NIRS PCA model was able to non-destructively classify fruit based on tree canopy. [•] Models based on pre-storage spectra gave better prediction of RBD than post-storage. [Copyright &y& Elsevier]

Highlights: [•] X-ray CT was used to non-destructively evaluate internal structures of pomegranate fruit. [•] Image analysis algorithm to compute volume of arils, albedo and air spaces was developed. [•] Characterization of fruit with and without chilling injury was achieved using X-ray CT. [Copyright &y& Elsevier]

Highlights: [•] Vis/NIRS models for prediction of mandarin postharvest rind quality were validated. [•] Rind carbohydrates associated with rind breakdown disorder were predicted. [•] Spiking of models with few samples from prediction set improved model performance. [•] The robustness of PLS models across two seasons and four orchards was demonstrated. [•] Models developed using collective data of all orchards and seasons performed better. [Copyright &y& Elsevier]

Highlights: [•] A link between fruit canopy position and rind biochemical profile was established. [•] Bagged fruit inside the canopy had higher incidence of rind breakdown disorder. [•] Shaded fruit had lower rind dry matter and higher postharvest weight loss. [•] Vis/NIRS PCA displayed clusters that separated fruit according to canopy position. [Copyright &y& Elsevier]

Highlights: [•] The mechanism of citrus rind breakdown (RBD) disorder was studied. [•] Reduced light inside tree canopy exacerbated RBD incidence. [•] Fruit inside canopy with low sugar concentrations in the rind were more susceptible to RBD. [•] Postharvest water loss is an important factor leading to RBD. [Copyright &y& Elsevier]

The objective of this study was to determine drought tolerance of diverse potato (Solanum tuberosum L.) genotypes. The physiological and morphological responses of eight potato genotypes were assessed under well-irrigated (Wi) and deficit irrigation (Di) conditions across four different growth stages, namely, the Vegetative (VG), Tuber Initiation (TI), Tuber Bulking (TB) and maturity (MAT) stages, using an 8 × 4 × 2 factorial treatment structure with three replications. Data were collected on morphological traits such as Plant Height (PH), the Number of Leaves (NL), Tuber Yield (TY) and Total Above-Ground biomass (TAG), as well as the physiological traits such as stomatal conductance (gs), Transpiration rate (Tr), the rate of photosynthesis (A), Water Productivity (WP), Chlorophyll Content Index (CCI) and Relative Water Content (RWC). A significant (p < 0.05) genotype x water condition x growth stage effects were observed for A , Tr, WP, RWC, CCI, PH, NL, TY and TAG, which indicated the varied responses of the genotypes to the water conditions across the growth stages. This is useful when recommending the growth-stage specific and drought tolerant potato genotypes for production. Correlation analysis revealed significant and negative association between gs and WP with TY (r = −0.81; r = −0.77) at the VG stage, positive association between PH, Tr, A and WP with TY (r = 0.92; r = 0.65; r = 0.95; r = 0.88) at the TI stage.CCI positively correlated with TY (r = 0.71) at the MAT stage, and a negative association was observed between TAG with TY (r = −0.85) at the MAT stage, under Di conditions. Principal component bi-plot identified that the all-rounder genotypes that are resistant to drought in all stages include the Challenger, Sifra and Tyson. These genotypes are recommended for cultivation in water-restricted environments. • Drought tolerance of potato genotypes was evaluated by imposing water deficit. • Varied responses of genotypes to water deficit across growth stages were observed. • Genotypes with higher water use efficiency and high yield were the most tolerant. • Bikini and Challenger had higher tuber yield regardless of growth stage for water deficit. • Bikini and Challenger are recommended for cultivation in water-restricted conditions. [ABSTRACT FROM AUTHOR]

Selection of drought-tolerance (Solanum tuberosum L.) genotypes is essential to enhance tuber yield and quality for food and processing. The aim of the study was to evaluate effect of water deficit on tuber yield, quality and drought-tolerance of selected potato genotypes at different growth stages. Tuber quality of eight potato genotypes were evaluated under well-watered (Ww) and water-deficit (Wd) conditions at four different growth stages, namely, vegetative (VG), tuber initiation (TI), tuber bulking (TB) and maturity (MAT) stages using an 8 × 4 × 2 factorial treatment with three replications. Data was collected on morphological traits such as tuber yield (TY), number of tubers (NT), tuber size distribution (TSD) and dry matter content (DMC). Significant (p < 0.05) genotype x water condition x growth stage effect were observed for TY, NT, TSD and DMC, indicating varied responses of genotypes to water conditions across growth stages. Correlation analysis shown significant and positive associations among medium tubers and yield (r = 0.76; p = 0.05), between large tubers and number of tuber (r = 0.42; p = 0.05) at VG stage, DMC and yield (r = 0.79; p = 0.010) at TI stage and highly significant negatively correlated with NT (r = -0.94; p = 0.001) at TB stage. Mondial and Sifra produced high percentage of medium (35-55 mm) and large tubers (>55 mm) across all growth stages. Genotypes Bikini, Mondial, Sababa and Sifra were identified as drought tolerance genotypes due to high yield observed under water deficit conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] A non-destructive method for evaluating microstructures of citrus rind was developed. [•] Real-time image acquisition was achieved with optical coherence tomography (OCT). [•] Rind breakdown disorder was associated with the progressive collapse of oil glands. [•] Image processing procedures to compute volume and 3D models of oil glands were demonstrated. [Copyright &y& Elsevier]

Highlights: [•] NIR methods for non-destructive composition analysis of oranges was investigated. [•] NIR with emission head gave best predictions of mass, colour index and vitamin C. [•] Using an integrating sphere gave best prediction of TSS. [•] NIR with emission head can evaluate external and internal characteristics. [ABSTRACT FROM AUTHOR]

The dynamics of nitrogen availability in soil result from the net amount of organic and inorganic inputs undergoing decomposition, mineralization, and immobilization. This varies with soil type, climate, and cropping system management practices. Hence, the interaction of these factors in a specific environment is important for nitrogen management and availability in any cropping system. This study evaluated the concentration of nitrate (NO3−) and ammonium (NH4+) in a maize monocropping system in a long-term trial under different tillage practices, i.e., no-till (NT), conventional tillage (CT), and rotational tillage (RT), and with different nitrogen (Urea) fertiliser application rates (0, 100, and 200 kg/ha N). The experimental area was a split plot with randomized tillage strips as the main plots, with the nitrogen fertiliser application rates forming the subplots. The results found the highest concentration of NO3− (7.728 mg/kg) and NH4+ (0.762 mg/kg) under the NT (p < 0.05) compared to the other treatments. CT recorded the lowest amount of NH4+ (0.648 mg/kg) (p < 0.05) compared to RT (0.758 mg/kg), while the concentration of NO3− (6.755 mg/kg) under the CT was relatively higher than under the RT (4.720 mg/kg). The results also showed that the 0–10 cm depth had a significantly (p < 0.05) higher concentration of NO3− (6.787 mg/kg) and NH4+ (0.851 mg/kg), followed at the 20–30 cm depth with 6.229 mg/kg NO3− and 0.832 mg/kg NH4+. Soil samples taken at 10–20 cm depth recorded the lowest NO3− (6.188 mg/kg) and NH4+ (0.485 mg/kg). The study also found the highest NO3− concentration (0.452 mg/kg) with 200 kg/ha N (p < 0.05), while the highest concentration of NH4+ (0.954 mg/kg) was found with 0 kg/ha N. The lowest concentrations of both NO3− (6.333 mg/kg) and NH4+ (0.561 mg/kg) were found with 100 kg/ha N. the no-till also had a significantly (p < 0.05) higher NO3− (8.518 mg/kg) concentration with 200 kg/ha N compared to the CT (6.005 mg/kg) and RT (4.833 mg/kg). On the other hand, more NH4+ (1.478 mg/kg) was found with 0 kg/ha N under the NT compared to the CT (0.717 mg/kg) and the RT (0.669 mg/kg). The concentration of NH4+ was relatively low with 200 kg/ha N in the NT (0.545 mg/kg) and CT (0.598 mg/kg) but higher in the RT (0.813 mg/kg). In conclusion, the NT favoured the availability of NO3− and NH4+ in the studied cropping system; however, the concentration of these was affected by fertiliser application rate and depth. This suggested that each tillage system should be compatible with the type and the rate of inorganic nitrogen fertiliser for better crop production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Vis-NIR spectroscopy can detect gluten protein adulteration in green banana flour. • PCA exploration showed 100% classification between adulterated and unadulterated banana flour samples. • PLSR model predicted gluten adulteration with high accuracy. The demand for gluten-free banana flour has led manufactures to enforce strict measures for quality control. A need has arisen for the development of more sensitive and reliable methods to test the quality of green banana flour (GBF). The objective of this study was to develop rapid visible to near-infrared (Vis-NIR) based spectroscopic models to detect gluten concentration, as a biomarker to detect wheat flour adulteration in green banana flour (GBF). Spectroscopic data were acquired using a desktop (FOSS®) Vis-NIR spectroscopy ranging from 400 to 2500 nm of the electromagnetic spectrum. The spectral and reference data were submitted to principal component analysis (PCA) and partial least squares regression (PLSR) for the development of gluten adulteration detection models. Calibration models were constructed based on a full cross-validation approach, consisting of 51 samples for the calibration set and 21 samples for the test set. PCA scores plot discriminated gluten adulterated and unadulterated GBF samples with 100% accuracy for the first two principal components (PCs). The optimal prediction model was obtained after a combination of baseline (offset and baseline linear correlation) and standard normal variate (SNV) pre-processing technique. This model showed a 94% coefficient of determination of cross-validation (R2 cv) and prediction (R2 p); root mean square error of cross-validation (RMSECV) of 3.7 mg/kg, root mean square error of prediction (RMSEP) of 3.9 mg/kg; and RPD value of 4. This work has demonstrated that Vis-NIRS method is a robust and feasible technology that may be used to ensure the safety of banana flour and that this product stays gluten-free by providing good and reliable gluten detection and quantification prediction models. [ABSTRACT FROM AUTHOR]

• Resistant starch is a reliable biomarker to detect adulteration of banana flour with wheat. • Vis-NIR models for quantifying resistant starch in banana flour were developed. • Optimized models accurately quantified resistant starch with more than 93 % accuracy. This study investigated the effect of nine different wheat adulteration levels (10 %, 20 %, 30 %, 40 %, 50 %, 60 %, 70 %, 80 % and 90 % added wheat) on the concentration of resistant starch (RS) of green banana flour (GBF). The study further evaluated the potential application of visible to near infrared (Vis-NIR) spectroscopy with multivariate analysis to detect changes in the concentration of resistant starch of GBF caused thereof by wheat adulteration. Principal component analysis (PCA) and partial least squares (PLS) regression independently paired with 2nd derivative Savitsky-Golay (with 21 smoothing gaps, 2nd order polynomial); Detrend and the combination of these spectral pre-treatments were applied to compare the distribution of spectral data; model and predict the concentration of RS. A significant reduction trend in the concentration of RS of GBF samples was observed as the advancement of wheat adulteration from 38.65 ± 1.27 g/100 g (pure GBF) to as low as 5.37 ± 0.47 g/100 g (with 90 % added wheat). PCA was able to clearly group samples and gave 93 % accuracy based on RS concentration variation. The optimal PLS models obtained after the combination 2nd derivative Savitsky-Golay (with 21 smoothing gaps, 2nd order polynomial) + Detrend demonstrated high accuracy with the coefficient of determination for prediction (R2 p) of 0.97; root mean square error of prediction (RMSEP) of 2.43; residual predictive deviation (RPD) of 6.24 and a range error ratio (RER) of 14.27. Based on the research findings, wheat adulteration is a nutritional threat to the production and marketing of green banana flour. There is a strong potential for the tested Vis-NIR technique to rapidly monitor banana flour nutritional changes or deteriorations caused by wheat on RS concentration. This research could provide the banana flour industry with a novel quality index to determine GBF authenticity. [ABSTRACT FROM AUTHOR]

This study evaluated the feasibility of using bio-markers to develop statistical models for predicting time to maturity of avocado fruit. The experiment used ‘Mendez#1ʹ and ‘Hass’ as model cultivars. Fruit was sampled bi-weekly from two positions within the tree canopy, namely, inside and outside canopy. Nine fruits per canopy position were sampled from fifteen trees of each cultivar. Mesocarp dry matter content (DM), oil content (OC), D-mannoheptulose and perseitol were assessed from 182 to 294 days after full bloom. Simple and multiple linear regression models were successfully developed to predict the maturity parameters of ‘Mendez#1ʹ and ‘Hass’ avocado fruit. Oil content was the most reliable index for predicting the DM due to the strongest positive and significant correlation (r = 0.76; p < .001). Furthermore, OC remained the only best fit in the DM model after backward elimination that was performed. The DM and oil content (OC) were the most successful variables with a strongest positive and significant (r > 0.7; p < .001) correlation with the number of days to reach maturity, suggesting that these parameters can be used to predict the days to maturity. Therefore, a farmer who keep a record of time after full bloom can use the number of days to predict DM and OC, before starting actual maturity tests. The predictive models from this study can be used to predict OC, DM and time (days) to maturity. D-mannoheptulose and perseitol had non-significant predictive values (p > .05), thus did not fit in both models of predicting avocado maturity. [ABSTRACT FROM AUTHOR]

• Growth and yield response of hydroponic tomato to wastewater nutrient sources was investigated. • Plants fertilized with the commercial hydroponic mix had higher growth rate and low harvest index. • Fertigation with wastewater improved physiological performance and leaf nutrient composition. Disposal of human excreta derived materials (HEDM), particularly domestic wastewater, presents a challenge in areas served with on-site sanitation systems, most particular in informal settlements. The use of HEDM for agricultural food production represents a couple of opportunities such as improved sanitation, household food security as well as the generation of informal income. In this study, tomato seedlings 'Monica' cv were grown in a hydroponic system and irrigated with HEDM (effluents from decentralized wastewater treatment system and nitrified urine concentrate). A commercial hydroponic fertilizer mixture was used concurrently as a control treatment. All the treatments were applied to the plants through fertigation using a drip irrigation system. Plant growth (plant height, stem diameter, leaf area index, root:shoot ratio and plant dry matter), physiological (photosynthesis and chlorophyll), yield components (fruit number, fruit mass, harvest index and crop yield), leaf nutrient composition (N, P, K, Mg, Ca, Cu, Mn, Fe, Zn and Na) and microbiological (Aerobic count, coliforms and faecal coliforms) parameters were measured to assess the potential of these HEDMs as nutrient sources for hydroponically produced tomatoes. The results showed that irrigating the tomatoes with HEDM increased harvest index relative to crops irrigated with a commercial hydroponic fertilizer mix. Tomato plants irrigated with a commercial hydroponic fertilizer mix achieved the highest growth and yield, however, irrigation with human excreta based sources improved plant physiological performance and leaf nutrient composition compared to crops irrigated with commercial fertilizer mix. In terms of microbiological analysis, tomatoes harvested from plants treated with HEDM recorded the highest population of bacterial count as compared to the commercial hydroponic fertilizer mix.These results showed that nutrients derived from human excreta can be a good source of nutrients for hydroponically grown tomatoes. Moreover this practice can effectively address the challenges of human waste disposal while at the same time providing the much-needed resources for increased food production through urban agriculture. However, further research on the effect of heavy metals, pathogens on tomato fruit quality is still needed for the adaptation of wastewater as nutrients sources for hydroponically grown tomatoes. [ABSTRACT FROM AUTHOR]

• Photosynthetic response of hydroponic tomato to waste-based nutrient sources was investigated. • Plants fertilized with the commercial hydroponic mix had higher leaf area index. • Tomato treated with nitrified urine concentrate had higher chlorophyll content. • Leaves of tomatoes treated with DEWATS effluent had higher photosynthetic rate. There is increasing interest and wide recognition of the potential use of human-excreta derived materials (HEDM) as fertilizer to supply essential nutrients needed for crop production. However, most work on HEDM has focussed on yield responses using soils and very little done on soil-less media using hydroponics. Further, physiological responses of plants to different HEDM in a hydroponic production system is currently not well-understood. This study investigated the effect of Decentralized Waste-water Treatment System (DEWATS) effluents and Nitrified Urine Concentrate (NUC) on leaf gas exchange, photosynthetic efficiency and mineral content of hydroponically-grown tomato. The experiment was conducted in a polyethylene tunnel using a complete randomised design comprising of three treatments namely: DEWATS effluent, NUC and commercial hydroponic fertilizer mix (CHFM). Sampling conducted both before and after flowering showed significant differences (P < 0.05) among different nutrient sources for all physiological parameters (leaf gas exchange and chlorophyll fluorescence) and mineral content. Leaf N and P were significantly (P < 0.05) higher in NUC treatment whereas Ca and K were high in the CHFM treatment. The current study demonstrated that HEDM such as NUC and DEWATS effluent could be an effective source of nutrients of agricultural crops in hydroponic systems with results comparable to commercial fertilizer mix. [ABSTRACT FROM AUTHOR]

• The effect of canopy position on biochemical compounds regulating avocado maturity and ripening was evaluated. • Outside fruit had higher dry matter (DM) and oil content resulting in earlier maturity. • Higher concentrations of C7 sugars were recorded on inside canopy fruit, coinciding with late maturity and ripeness. • The minimum maturity of fruit from the inside canopy guarantees the maturity of outside canopy fruit. In the current study, biochemical changes of avocado fruit cv. 'Carmen' and 'Hass' were evaluated during growth, development and maturation. The aim was to determine if exposure of fruit to sunlight could vary the biochemical compounds associated with maturity, and hence be among the causes of uneven maturity, and ripening. The current study also seeks to evaluate if the mesocarp C7 sugars, oil and DM content have a relationship with fruit maturity. The study was conducted in a commercial orchard at Everdon Estates in the KwaZulu-Natal, South Africa. Nine avocado fruit (cv. 'Carmen' and 'Hass' avocado) per canopy were sampled bi-weekly for assessment of mesocarp dry matter (DM), oil content, D -mannoheptulose, perseitol and total C7 sugars. The significantly (p < 0.001) higher DM and oil content in fruit that were sampled from the outside canopy in both cultivars suggested an early maturity, and vice versa inside canopy. The higher D- mannoheptulose and perseitol in fruit sampled inside canopy as a storage reserve was associated with the rate of respiration, which is slower inside canopy due to cooler temperatures. This results in accumulation of higher overall C7 sugars that are slowly used up as a substrates of respiration for synthesis of overall DM, oils, proteins, C6 sugars and other biochemical constituents associated with ripening. In terms of maturity, higher D -mannoheptulose and perseitol implies that fruit from the inside canopy will take longer to mature and to reach edible ripeness when harvested. This then causes uneven maturity of fruit, only characterized by uneven ripening. [ABSTRACT FROM AUTHOR]

• Photoprotection mechanisms of avocado leaves from tree canopy positions were assessed. • Photochemistry was high outside of and low within the tree canopy. • Photoprotection mechanisms were stronger within the canopy and poorer outside the canopy. • High photochemistry outside the canopy was linked to early fruit maturity. • High chlorophyll fluorescence and heat dissipation within the canopy delayed fruit maturity. A reduction in photosynthesis results in a reduced CO 2 assimilation rate and availability of carbohydrates essential for fruit growth and development. This study determined photosynthetic efficiency and photoprotection mechanisms within and outside leaf canopy positions in 'Gem' avocado orchards and their relationship with avocado fruit maturity. The study was conducted in a commercial orchard at Everdon Estate in KwaZulu-Natal, South Africa. A total of 15 eight-year-old avocado trees (cv. Gem) were selected in a completely randomised design with three replicates, with each replicate consisting of five trees. Data were collected bi-weekly on photosynthetic rate (A), effective quantum efficiency of photosystem II (ϕPSII), stomatal conductance (gs), transpiration rate (T), electron transport rate (ETR), minimum fluorescence (Fo'), maximum fluorescence (Fm'), variable fluorescence (Fv'), intrinsic water use efficiency (WUE i), instantaneous water use efficiency (WUE ins), intercellular CO 2 concentration (Ci) and photochemical quenching (qP) from full bloom to fruit physiological maturity (∼25 % dry matter content (DM)). The results showed that leaves from the outside position had higher A (29.46 mol CO 2 m−2s-1); gs (0.078 mol CO 2 m−2s-1); ΦPS II (0.32); and qP (0.52) compared to those within the canopy position with lower A (19.27 mol CO 2 m−2s-1); gs (0.0037 mol CO 2 m−2s-1); ΦPS II (0.044) and qP (0.075), respectively. Contrastingly, chlorophyll fluorescence and photoprotection parameters were higher within the canopy than on the outside, suggesting that the greater proportion of energy accumulated within the canopy was used for photoprotection other than photochemistry. Photosynthetic rate (A) , gs, Ci, T, WUEi and WUE ins , correlated significantly with mesocarp dry matter (DM), while all other parameters correlated poorly. The high photosynthetic efficiency of leaves from outside the canopy resulted in an average DM of 28.9 % compared to 26.9 % of fruit within the canopy. The present findings suggest that reduced photosynthetic efficiency of 'Gem' avocado within the canopy position does not compromise fruit DM by reserving more energy for photoprotection; however, it delays maturity by about two weeks. [ABSTRACT FROM AUTHOR]

Water scarcity, nutrient-depleted soils and pollution continue to be a major challenge worldwide and these are likely to worsen with increasing global populations particularly, in urban areas. As a result, environmental and public health problems may arise from the insufficient provision of sanitation and wastewater disposal facilities. Because of this, a paradigm shifts with regard to the sustainable management of waste disposal in a manner that could protect the environment at the same time benefits society by allowing nutrient recovery and reuse for food production is required. Hence, the use of urban wastewater for agricultural irrigation has more potential, especially when incorporating the reuse of nutrients like nitrogen and phosphorous, which are essential for crop production. Among the current treatment technologies applied in urban wastewater reuse for agriculture, hydroponic system is identified as one of the alternative technology that can be integrated with wastewater treatment. The integration of hydroponic system with municipal wastewater treatment has the advantage of reducing costs in terms of pollutants removal while reducing maintenance and energy costs required for conventional wastewater treatment. The efficiency of a hydroponic system with regard to municipal wastewater reuse is mainly linked to its capacity to allow continuous use of wastewater through the production of agricultural crops and the removal of pollutants/nutrients (nitrogen and phosphorus), resulting to increased food security and environmental protection. Moreover, the suitability of hydroponic system for wastewater treatment is derived from its capacity to minimize associated health risks to farmers, harvested crop and consumers, that may arise through contact with wastewater. Unlabelled Image • Wastewater disposal is exacerbated by the increasing population and rapid urbanization. • A paradigm shift towards sustainable management of waste disposal was identified. • Nutrient recovery and use for food production in hydroponic system is an alternative. • Advances of technologies to recover nutrients for food crop production is provided. [ABSTRACT FROM AUTHOR]

This study was conducted to identify reliable science-based maturity indices for 'Lamb Hass' avocado fruit and evaluate the effect of harvest maturity on the fruit postharvest performance. Fruits were harvested from outside and inside canopy positions at early and mid-season for quality assessment. The results showed that the canopy position had a highly significant effect (p <.001) on all maturity parameters: dry matter (DM) content, moisture content (MC) and oil content (OC). The outside canopy fruit were more mature (30% DM, 70% MC, 14.9% OC) than those harvested from the inside canopy (28.9% DM, 71.1% MC, 11.75% OC) at minimum maturity. However, fruit DM and MC did not differ significantly (p >.05) between the early and mid-season fruit, whilst significant differences in OC were found between the two harvesting stages. In both harvesting stages, the canopy positions did not affect the rate of fruit mass loss. Nonetheless, the overall analysis showed that early season fruit had a significantly (p <.001) higher fruit mass loss rate than the mid-season fruit. Notably, fruit maturity did not have a significant effect (p >.05) on the fruit softening rate as insignificant differences between the two harvesting stages were observed. In both the harvesting stages, inside canopy fruit were characterized by a higher concentration of mannoheptulose and perseitol than the outside canopy fruit. The early and mid-season fruit also differed significantly (p <.05) in phenolic content; with the mid-season fruit having a high phenolic content (2.7 µm/g) than the early season fruit (1.8 µm/g), suggesting the possibility of increased mesocarp discolouration with the advancement in maturity. These findings will be a valuable tool to assist growers in assessing fruit readiness for harvest and understanding the influence of maturity on the fruit postharvest behavior. [ABSTRACT FROM AUTHOR]

Mango is the third most important fruit in the tropics due to its nutritional properties and delicious flavor. The fruit is exceptionally perishable due to its climacteric nature, which decreases the quality and shelf-life. Preserving fruit quality and preventing losses during postharvest is one of the critical solutions in sustaining human dietary demands. Postharvest treatments such as 1-Methylcyclopropene, edible coatings, and hot water treatment have shown to be effective in preserving fruit quality. However, developing environmental-friendly postharvest technologies that ensure the safety of consumers remains a challenge. Gaseous ozone, controlled atmosphere (CA), and pulsed electric field (PEF) are some of the emerging technologies with great potential for the mango fruit industry. The use of such technologies has been demonstrated to be effective in maintaining the sensory, nutritional, and physicochemical quality of the mango fruit. However, the mode of action of the emerging technologies is not yet understood. This review provides of an overview of various postharvest techniques used to preserve mango fruit quality. The potential of the emerging postharvest technologies to maintain mango fruit quality during storage and shelf-life is also discussed. [ABSTRACT FROM AUTHOR]

Some of the major processed horticultural commodities subjected to adulteration are powders, edible oils and juices. This review covers the recent application in the field of vibrational spectroscopic techniques (near and mid-infrared spectroscopy, Raman spectroscopy and hyperspectral imaging) for the determination of authenticity and adulteration in processed horticultural products with an emphasis on powders, edible oils and juices. The review highlights fundamental concepts, limitations and constraints associated with each spectroscopic technique in evaluating the authenticity and adulteration of processed horticultural products. Our findings suggest that the application of infrared spectroscopy (near and mid) is highly suitable for the assessment of powders, oils and juices, while Raman spectroscopy has shown potential in evaluating powders and edible oils. However, these spectroscopic tools still require improvement on measurement accessories and dynamic analytical methods for modern food inspection. Overall, the review of literature suggests that vibrational spectroscopy has the potential to fulfil the industrial need for quality control and authenticity assessment. [ABSTRACT FROM AUTHOR]

Near infrared (NIR) and mid infrared (MIR) spectral acquisition modes were compared for predicting organoleptic and phytochemical quality attributes of pomegranate juice. Three Fourier transform infrared (FT-IR) spectrometers namely, a FT-NIR spectrometer, FT-MIR spectrometer in attenuated total reflection mode and FT-MIR spectrometer in transmission mode were used. Calibration models were constructed by subjecting the spectral data to partial least squares regression analysis. The models were assessed based on their overall performance (lower root mean square error of prediction, the number of latent variables and residual predictive deviation). The predictive abilities of the instruments for juice quality attributes were statistically compared using Bland and Altman, and Passing-Bablok. The outcomes are critically discussed, which showed the suitability of the FT-MIR spectrometer in transmission mode for predicting selected quality attributes of pomegranate juice. [ABSTRACT FROM AUTHOR]

Fourier transform near infrared (FT-NIR) diffuse reflectance spectroscopy as a non-destructive method for the development of calibration models has been investigated as a means of assessing the quality of whole pomegranate fruit. FT-NIR diffuse reflectance spectrometers with different spectral acquisition modes were evaluated using direct contact between the sample and the integrating sphere (IS), or by a contact-less measurement using an optic fibre coupled emission head (EH) to scan fruit over a distance of 170 mm. Fruit weight, firmness and colour components (a*, Chroma, hue angle), total soluble solids (TSS), pH, titratable acidity (TA), sugar to acid ratio (TSS:TA), BrimA, total phenolics, total anthocyanin and vitamin C. The best prediction statistics obtained from calibration models of the EH were firmness (R 2  = 83.0, residual predictive deviation (RPD) = 2.43), fruit colour components (a*: R 2  = 90.9, RPD = 3.34); Chroma: R 2  = 83.0, RPD = 2.43, TSS (R 2  = 78.1, RPD = 2.17), TA (R 2  = 76.8, RPD = 2.12), BrimA (R 2  = 76.2, RPD = 2.08), total phenolics (R 2  = 88.0, RPD = 2.91) and vitamin C (R 2  = 76.2, RPD = 2.06). The best prediction obtained from calibration models of IS were colour component Hue (R 2  = 83.9, RPD = 2.50), TSS:TA (R 2  = 86.8, RPD = 2.72) and total anthocyanin (R 2  = 62.6, RPD = 1.64). Overall, good prediction was observed for both the EH and IS; however, better prediction performance was obtained with the EH which gave the best prediction for 9 of the 13 quality parameters evaluated. These findings have demonstrated that the EH (a contactless option of the Matrix-F) can be implemented as an online tool for the analysis of pomegranate fruit quality. [ABSTRACT FROM AUTHOR]

Postharvest RP is a progressive rind physiological disorder affecting citrus fruit during postharvest storage, reducing external quality of the fruit. The disorder develops 3–5 weeks after harvest, making it difficult to detect during grading and sorting in commercial packing lines. The Vis/NIR spectroscopy and associated chemometric analytical methods were explored for non-destructive prediction of ‘Marsh’ grapefruit ( Citrus x paradisi MacFad) susceptibility to rind pitting. Reflectance Vis/NIR spectral data was acquired from fruit, just after harvest, using a laboratory bench-top monochromator NIR System equipped with a quartz halogen lamp and lead sulfide detector. Reference measurements for calibrating and validating PLS models included visual scores of RP and rind physico-chemical variables related to the disorder. The spectral data was correlated to RP scores and rind physico-chemical properties after eight weeks in cold storage and a week in shelf life. Good prediction of RP was obtained (R 2 p  = 0.78; RPD = 2.03; RMSEP = 1.41). Prediction models for rind physicochemical properties successfully developed and validated included rind total antioxidant capacity (R 2 p  = 0.95), β carotene (R 2 p  = 0.99), total carotenoids (R 2 p  = 0.92), chlorophyll a (R 2 p  = 0.89), chlorophyll b (R 2 p  = 0.93), dry matter (R 2 p  = 0.88), sucrose (R 2 p  = 0.91), glucose (R 2 p  = 0.93) and fructose (R 2 p  = 0.94). Principal component analysis successfully segregated fruit based on canopy position and susceptibility to rind pitting disorder. The ability of Vis/NIR spectroscopy coupled with chemometric analysis to cluster fruit based on canopy position is recommended as a secondary approach to discriminate fruit with high susceptibility to RP since RP occurrence was high on fruit from outside canopy. [ABSTRACT FROM AUTHOR]

Fruits with thick rind have been reported to interfere with the measurement of internal quality of non-destructive near infrared spectroscopy. This review provides an overview of issues related to the use of near infrared spectroscopy for measuring internal and external quality attributes of horticultural produce with thick rinds. The use of other non-destructive techniques for assessing internal and external quality thick rind fruit, such as hyperspectral and multispectral imaging systems, X-ray micro-computed tomography, nuclear magnetic resonance and Raman spectroscopy are also discussed. A concise summary of research and potential commercial application for each of the techniques is highlighted. [ABSTRACT FROM AUTHOR]

Fruits with thick rind have been reported to interfere with the measurement of internal quality of non-destructive near infrared spectroscopy. This review provides an overview of issues related to the use of near infrared spectroscopy for measuring internal and external quality attributes of horticultural produce with thick rinds. The use of other non-destructive techniques for assessing internal and external quality thick rind fruit, such as hyperspectral and multispectral imaging systems, X-ray micro-computed tomography, nuclear magnetic resonance and Raman spectroscopy are also discussed. A concise summary of research and potential commercial application for each of the techniques is highlighted. [ABSTRACT FROM AUTHOR]

In this study, X-ray computed tomography (CT) was used as a non-destructive technique to characterise and quantify the internal structure of pomegranate fruit (cv. Wonderful). A commercial X-ray system with a radiation source of 245 kW and electron current of 300 μA was used to generate two-dimensional (2D) radioscopic images which were reconstructed into three dimensional (3D) images for the quantification and volume estimation of internal structural components of fruit. Segmentation of the internal fruit components (arils, peel, kernel, juice content, air space) and single arils was achieved using StudioMax volume graphics software. The calculated volume of each fruit fraction were 162.5 ± 16.2, 163.9 ± 21.4, 16.4 ± 1.8, 10.9 ± 2.6 mL for arils, peel, kernel and air space, respectively which accounted for 48.1, 48.3, 4.9 and 4.1% of total fruit volume. Furthermore, the calculated volume of juice content was 146.1 ± 16.3 mL per fruit which was equivalent to an average of 89.8% of total aril weight, while a single aril (0.3 ± 0.04 mL) accounted for only 0.09% of whole fruit volume. Destructive validation measurements of each fruit fraction showed similar results to non-destructive data, with volumes of 163.3 ± 15.2, 161.8 ± 20.6, 15.1 ± 1.6, and 12.3 ± 4.4 mL for arils, peel, kernel, air space, respectively, while volumes of juice and single aril were 142.7 ± 16.4 and 0.3 ± 0.09 mL per fruit, respectively. Furthermore, the results showed that fruit physical attributes such as length, diameter and peel thickness were underestimated by an average of 0.14%, 1.13% and 5.27%, respectively, while fruit radius was overestimated by 1.75%. Nevertheless, no significant differences were observed for length, diameter, radius and peel thickness between X-ray CT predicted values and actual measurements. This work has demonstrated the capability of X-ray CT as a non-destructive technique to suitably estimate the fruit volume and its fractions which could be employed for fruit quality systems. [ABSTRACT FROM AUTHOR]

The application of microfocus X-ray computed tomography (μCT) with a density calibration with homogenous polymeric materials ranging from 910 to 2150 kg m −3 and its accuracy for differentiating fruit fractions (albedo and arils) and the effects of detecting false codling moth and blackheart disease in pomegranate fruit was investigated. A commercial microfocus X-ray (μCT) system in combination with image analysis techniques was used to generate two-dimensional (2-D) radioscopic images which were reconstructed into three dimensional (3-D) images. Optimum μCT settings were obtained using an isotropic voxel size of 71.4 μm based on a radiation source generated from a voltage of 100 kV with the electric current set at 200 μA. The density of whole pomegranate fruit, its fractions (arils and albedo), false codling moth, and blackheart infected portions were successfully determined within the calibration range. Furthermore, the density of larva moth (9400 ± 40 kg m −3 ) were found to be significantly ( p < 0.0001) lower than whole fruit (1070 ± 20 kg m −3 ) and fruit fractions (arils 1120 ± 40 kg m −3 and albedo 1040 ± 30 kg m −3 ). Similarly, the differentiation between healthy and blackheart affected fruit was successfully accomplished. The density of healthy fruit was significantly ( p < 0.0001) higher (1070 ± 20 kg m −3 ) than that of fruit affected by blackheart which ranged from 870 to 1000 kg m −3 . The results thus demonstrated that X-ray μCT with associated algorithm can be used to accurately detect and quantify internal defects caused by false codling moth and blackheart disease in pomegranate fruit. [ABSTRACT FROM AUTHOR]

Harvest maturity of avocado fruit is currently determined using indices such as mesocarp oil content, dry matter (DM) or moisture content (MC), both measured destructively using representative samples of a batch in an orchard. Although useful, destructive techniques are time-consuming and results reflect properties of specific produce evaluated. In this study, the feasibility of near-infrared spectroscopy (NIRS) as a rapid non-destructive method for predicting maturity parameters of individual avocado fruit was evaluated. NIRS prediction results showed that MC and DM were predicted accurately, with residual predictive deviation (RPD) of 2.00 and 2.13 respectively. However, models for predicting oil content, though promising, were not accurate, with RPD value of less than 1.0. The good prediction statistics between NIRS predicted MC and DM content demonstrated the potential of this system for non-destructive evaluation of avocado fruit maturity status. The stability and accuracy of models developed over two seasons, 2013 and 2014, to predict maturity parameters of avocado fruit demonstrated model robustness. NIRS combined with PLS models developed in this study are recommended for non-destructive evaluation of individual avocado fruit maturity status. [ABSTRACT FROM AUTHOR]

Owing to their health-boosting properties and other appreciable properties, citrus fruit is widely consumed and commercialized worldwide. Destination markets around the world vary in their fruit quality requirements and are also highly influenced by climatic conditions, agronomical and postharvest practices. Hence, harvesting decisions are arduous. Maturity indices in citrus fruit are highly variable and dependent on the species and varieties, growing regions, and destination markets. For decades, determination of the maturity of citrus fruit and predicting the near time of harvesting was a challenge for producers, researchers, and food safety agencies. Thus, the current review provides a correlation between maturity and internal components and an overview of techniques of maturity determination for citrus fruits. Also, stress has been given to the destructive and nondestructive methods to determine the maturity level of different citrus species. The techniques presented in this review portray continuous productiveness as an excellent quality assessment, particularly as ripening and maturity analysis tools for citrus fruits. Traditional techniques are time-consuming, laborious, costly, destructive, and tedious. Thus, these nondestructive techniques hold great potential to replace conventional procedures. [ABSTRACT FROM AUTHOR]