Search

Processing tomato is an important agricultural crop worldwide suffering from genetic erosion due to a severe genetic diversity reduction and domestication hindrance. In Tunisia, some old underutilized tomato cultivars are increasingly being considered as genetic resources and are marginally used by small farmers constituting a real safety valve for the sustainability of the processing tomato value chain. Those tomato cultivars differ in their biometric, processing and functional quality attributes. Therefore, there is an increasing interest to examine their performances for processing and fresh market quality improvement. Recently, there was also a particular focus on improving the quality of fresh fruit via the introgression of high-pigment genes in processing tomato in order to obtain a high quality processed products. The results are important as large differences are highlighted and the main traits affecting tomato quality are also reported and clearly discussed. This suggest that maintaining of the existing genetic pools among cultivated tomato is as important as creating novel hybrids.

Artichoke (Cynara scolymus L.) is a worldwide popular horticultural crop. Interest in assessing bioactive compounds with potential health benefits in artichoke is increasing. Therefore, in this study, the variability in total phenolic and flavonoid contents of six artichoke cultivars, including five purple namely Brindisie, Opal, Conserto, Romanesco and Rouge de France as well as an ordinary white artichoke variety were investigated. The results showed significant differences in total phenolic and flavonoid contents between artichoke cultivars. Total phenolic content ranged from 17.31 mg GAE/ g DW in the white artichoke variety to 21.31 mg GAE/g DW in Romanesco. Flavonoid content ranged from 4.51 mg RE/g DW in white artichoke to 7.06 mg RE/g DW in Rouge de France. Therefore, the highest total phenolic content was shown by Romanesco. However, the highest flavonoid content was recorded for both Opal and Rouge de France. This study demonstrates the importance of genotypic variability in shaping the levels of total phenolic and flavonoid, emphasizing the need to evaluate artichoke biodiversity in order to improve its nutritional value and to contribute towards increasing the intake of antioxidants.

Postharvest storage conditions frequently affect nutritional quality of fruits and vegetables. Temperature and storage duration are the most important factors to extend shelf life and maintain quality of fresh watermelon. This study was conducted to determine the changes in the antioxidant properties of watermelon during storage. Fruits of the watermelon cultivars were harvested and stored at 5ºC for a period of 15 days. During storage antioxidant contents (lycopene and total phenolics) and total antioxidant activity were evaluated. The objective of this work was to determine the content of the antioxidant properties in different watermelon genotypes at four different postharvest storage periods (0, 5, 10 and 15 days). Furthermore, the nutritional quality is strongly influenced by the storage period. The cv Mahdia was the most suitable for extended storage periods.

Capsicum annuum is among the five domesticated Capsicum species (frutescens, annuum, baccatum, chinense and pubescens) the most cultivated in the world. It adapts quite well, in a dry and warm environment. It is of real socio-economic importance, capable of providing a production of fruit consumed fresh or in the form of products little processed (preserved chilli, dried chilli, spice, etc.) of high nutritional value. The objective of this research was to study the biochemical diversity: capsaicin, dihydrocapsaicin, iron, potassium, magnesium, sodium, zinc, flavonoids and phenolic acids contained in a collection of chillies from different zones of oasis in Tunisia (Gabès, Kbeli and Tozeur). The characterization of these elements was identified using the HPLC method and atomic absorption spectrophotometry. There is considerable variability between localities in terms of chemical richness (coefficient of variation % between 43 and 108%). The recovery of these old sources, which have been replaced by commercial cultivars causing genetic erosion in this crop, should be crucial for the maintenance of sustainable agriculture.

Landraces are considered a crucial component of biodiversity conservation, serving as a reservoir of genetic diversity. Consequently, the collection, cultivation, and detailed characterization of such landraces constitute an inherent aspect of the world's natural resource heritage. This effort holds promise for the development of elite varieties capable of thriving amidst continuous global climate fluctuations. In this context, we conducted a comprehensive assessment of the main agronomic attributes, physico-chemical properties, and functional quality traits of the major hot pepper landraces adapted to diverse climatic conditions in Tunisia. These landraces include 'Dhirat', 'Semmane', 'Beldi', 'Nabeul', 'Jerid', 'Mahdia', 'Cayenne', 'Kairouan', and 'Baklouti'. Most of the pepper landraces exhibited satisfactory yields, ranging from 1163.25 to 1841.67 g plant−1 in 'Jerid' and 'Kairouan', respectively, indicating robust productivity, especially under prevailing climatic changes and high temperatures during both growing cycles. The levels of antioxidants comprising capsaicinoids, carotenoids, phenolics, and tocopherols, as well as radical scavenging activity, emerged as key discriminating factors among pungent pepper landraces. Irrespective of genotype, capsaicin and dihydrocapsaicin constituted the major capsaicinoids, accounting for 44–91% of the total capsaicinoids content. Total capsaicinoids ranged from 1.81 µg g−1 fw to 193.71 µg g−1 fw, with 'Baklouti' and 'Jerid' identified as the most pungent landraces. Total carotenoids ranged from 45.94 µg g−1 fw to 174.52 µg g−1 fw, with 'Semmane' and 'Jerid' exhibiting the highest levels. Considerable variation was observed in β-carotene content, spanning from 3% to 24% of the total carotenoids. α-Tocopherol content ranged from 19.03 µg g−1 fw in 'Kairouan' to 30.93 µg g−1 fw in 'Beldi', exerting a notable influence on the overall tocopherol content. Conversely, the β- and γ-tocopherol isomers were detected at very low concentrations. The total vitamin C content ranged from 132 mg 100g−1 fw in 'Mahdia' to 200 mg 100 g−1 fw in 'Nabeul', indicating relatively low genetic variability. However, large variability was detected in total phenolics content, ranging from 168.58 mg GAE kg−1 fw in 'Beldi' to 302.98 mg GAE kg−1 fw in 'Cayenne'. Landraces such as 'Dhirat', 'Nabeul', 'Semmane', 'Kairouan', 'Cayenne', and 'Mahdia' appear suitable for both fresh consumption and processing, owing to their favorable average fruit weight, soluble solids content, and bioactive content. Among the pepper landraces tested, 'Cayenne' achieved the highest value of radical scavenging activity in both hydrophilic and lipophilic fractions (RSAHF and RSALF), with variations ranging from 59% to 120% for RSAHF and from 4% to 63% for RSALF. This study aims to preserve and enhance the value of local genetic resources and contribute to identify desirable traits for incorporation into breeding programs to develop high-quality, high-yielding landraces and elite lines. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is a staple food widely consumed in Tunisia and represents a source of various secondary metabolites with human health benefits. However, cold storage of potato tuber affects their bioactive properties and functional quality. Despite the importance of this fact, few studies have examined the effects of extended cold storage on potato tubers quality. Therefore, the objective of the present work was to evaluate the effect of cold storage on the main quality traits of different potato genotypes grown in Tunisia. This investigation focused on four cultivated potato varieties including three commercial (Selena, Elbeidha, and Naima) and a selected clone CL27 grown under late cropping season conditions with planting at the beginning of autumn and a winter tuberization. The tubers from this trial were stored for 90 days at 8°C. The results obtained showed that quality traits of potato tubers were strongly influenced by storage at 8°C throughout 90 days. Additionally, disregarding the genotype, total carotenoids, phenolics, and flavonoids contents increased significantly following 90 days storage at 8°C. However, genotypic differences underlying the antioxidant activity in both hydrophilic and lipophilic fractions were detected suggesting their sensibility to cold storage. This study might be useful for breeders working on potato genotypes suitable for extended storage duration and for growers storing their material for extended period under low temperature. Core Ideas: The effect of storage varies according to the considered genotype.Stored tubers at 8°C for 90 days exhibited higher nutritional quality with respect to fresh samples.Appropriate storage can contribute to maintain high‐quality potato tubers. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is a staple food widely consumed in Tunisia and a source of nutrients beneficial for human health. The tubers are, indeed, important source of vitamins, minerals, and bioactive compounds, including carotenoids, polyphenols, and flavonoids. However, data regarding the functional quality of potato varieties grown and consumed in Tunisia are very scarce. For this reason, two field trials were conducted to focus on the effect of the growing season on the functional quality of four potato genotypes (Selena, El Beidha, Naima, and CL07F172.5): a first autumnal trial in Teboulba, Monastir (September 2015–February 2016), which is the late cropping season (LCS) and a second summer cropping season (SCS) in El ksour, El Kef region at an altitude > 1000 m (July 2015–October 2015). Total carotenoids, total phenolics, and flavonoids contents, as well as the hydrophilic radical scavenging activity and lipophilic radical scavenging activity (LRSA) were determined. The obtained results confirmed the importance of potato tubers as a source of bioactive compounds. All quality traits varied significantly among varieties and cropping seasons. Tubers grown under colder weather conditions (LCS: minimum and maximum averages temperatures and relative humidity (RH) ranging between 14.25 and 22.55°C and 25.46% and 83.07%, respectively) accumulated the highest total vitamin C content and exhibited the highest LRSA values. However, temperature and warmer growing conditions (SCS: minimum and maximum averages temperatures and RH ranging between 19.74 and 34.22°C and 35.46% and 87.51%, respectively) probably enhanced the synthesis and accumulation of total carotenoids, total phenolics, and total flavonoids, associated with higher LRSA values. Core Ideas: The development of a new summer cropping season in Tunisia is examined.The production and quality traits are similar to other potato cropping season.Highland potato production is promising and contributes to fill the existing gap. [ABSTRACT FROM AUTHOR]

The tomato as a raw material for processing is globally important and is pivotal in dietary and agronomic research due to its nutritional, economic, and health significance. This study explored the potential of machine learning (ML) for predicting tomato quality, utilizing data from 48 cultivars and 28 locations in Hungary over 5 seasons. It focused on °Brix, lycopene content, and colour (a/b ratio) using extreme gradient boosting (XGBoost) and artificial neural network (ANN) models. The results revealed that XGBoost consistently outperformed ANN, achieving high accuracy in predicting °Brix (R² = 0.98, RMSE = 0.07) and lycopene content (R² = 0.87, RMSE = 0.61), and excelling in colour prediction (a/b ratio) with a R² of 0.93 and RMSE of 0.03. ANN lagged behind particularly in colour prediction, showing a negative R² value of −0.35. Shapley additive explanation's (SHAP) summary plot analysis indicated that both models are effective in predicting °Brix and lycopene content in tomatoes, highlighting different aspects of the data. SHAP analysis highlighted the models' efficiency (especially in °Brix and lycopene predictions) and underscored the significant influence of cultivar choice and environmental factors like climate and soil. These findings emphasize the importance of selecting and fine-tuning the appropriate ML model for enhancing precision agriculture, underlining XGBoost's superiority in handling complex agronomic data for quality assessment. [ABSTRACT FROM AUTHOR]

Tomato landraces have progressively faded into obscurity, making way for new hybrids and elite tomato cultivars. This study presents a comprehensive evaluation of the agronomic attributes, physicochemical properties, and functional traits across seven cultivars, comprising two high-pigment varieties, 'HLT−F81' and 'HLT−F82', as well as five underutilized ancient-tomato genotypes considered as landraces. Most of the studied genotypes exhibited satisfactory horticultural and processing traits. The average fruit weight ranged from 73.3 g in 'Rimone' to 91.83 g in 'HLT−F81', while the soluble solids content ranged from 4.66 °Brix in 'Justar' to 6.08 °Brix in 'HLT−F81'. The functional quality and the content of most antioxidants, as well as the antioxidant activity in both hydrophilic and lipophilic fractions, proved to be the most discriminating parameters among the tomato genotypes. The content of β−carotene and lycopene spanned from 2.94 mg kg−1 fw in 'Rio Grande' to 13.94 mg kg−1 fw in 'HLT−F82' and 227.8 mg kg−1 fw in 'HLT−F81', yielding large variations compared to 'Rio Grande'. The total phenolic content ranged from 139.83 mg GAE kg−1 fw in 'Rimone' to 352.41 mg GAE kg−1 fw in 'HLT-F81', while the flavonoid content varied from 136.16 mg RE kg−1 fw in 'Justar' to 311.23 mg RE kg−1 fw in 'HLT-F82'. The presence of tocopherol isomers was genotype-dependent, with a higher content in lines carrying the high-pigment mutations. Among the tested tomato genotypes, the high-pigment tomato line 'HLT−F81' achieved the highest hydrophilic and lipophilic antioxidant activity values. This study primarily focused on the recovery and valorization of tomato genetic resources and landraces. It also aimed to identify desirable horticultural (yield, low-input, and low-water demand), processing (°Brix and titratable acidity), and quality (rich antioxidant berries) traits for introgression into new tomato cultivars better suited to the evolving climate conditions of the near future. [ABSTRACT FROM AUTHOR]

Managing crop yields and optimizing water use is a global challenge, as fresh water supply decreases rapidly and demand remains high. Therefore, understanding how plants react to varying water levels is crucial for efficient water usage. This study evaluates how tomato plants adapt to varying water levels (100%, 50% of crop evapotranspiration, and non-irrigated control) over two growing seasons in 2020 and 2021. Root images were captured weekly during an 8-week monitoring period in 2020 and 6 weeks in 2021 using a non-destructive CI-600 in-situ root imager at depths between 10 and 70 cm. Under water stress, plants developed deeper, more extensive root systems to maximize water uptake, consistent with prior research. Root depth and architecture varied with soil depth and the severity of water stress. Year-to-year variations were also found, likely due to changes in irrigation levels and environmental conditions such as temperature. SPAD values were higher under control conditions, especially in the 2021 growing season, suggesting reduced chlorophyll degradation, while no significant differences were observed in chlorophyll fluorescence (Fv/Fm) between treatments, suggesting stable photosynthetic efficiency under varied water stress conditions. These findings contribute to our understanding of root zone optimization and drought-resilient cultivar breeding, contributing to more sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

This study investigates the antioxidant components (total carotenoids, lycopene, β-carotene, total phenols, flavonoids, ascorbic acid and total vitamin C) as well as the hydrophilic and lipophilic antioxidant activities (HAA and LAA) of tomato genotypes consisting of one ordinary cultivar Rio Grande and the two high-lycopene breeding lines HLT-F71 and HLT-F72. The correlation of nutritional value to L∗, a∗, b∗ colour indexes and a∗/b∗ ratio was also investigated in whole and fresh cut tomato fruits. Except for β-carotene content, significant differences were found among cultivars for antioxidants. The berries of both HLT-lines recorded higher antioxidant contents, HAA and LAA (TEAC and FRAP assays) than Rio Grande. Under controlled conditions, HLT-F72 reached the highest levels of total carotenoids (165.5 mg β-ca Eq per kg fw), lycopene (150.1 mg per kg fw) and total phenolics (549.7 mg GAE per kg fw). However, HLT-F72 exhibited the highest levels of ascorbic acid (193.3 mg per kg fw), total vitamin C (271.6 mg per kg fw) and flavonoids (450.5 mg RE per kg fw). Line HLT-F71 showed the highest HAA (148.0 µM Trolox per 100 g fw and 4.2 mM FRAP per g fw) and LAA values (258.5 µM Trolox per 100 g fw and 3.2 mM FRAP per g fw respectively). Colour readings in red ripe fresh cut tomato berries particularly a∗, b∗ and the ratio a∗/b∗ could represent an indicator not only for lycopene but also for other phytochemicals and resulting antioxidant activities. HLT-Lines may serve as a starting point for the development of semi-determinate growth habit tomato cultivars with higher functional quality.

Growing conditions and seasonal fluctuations are critical factors affecting fruit and vegetable nutritional quality. The effects of two partially overlapping cropping seasons, early (ECS; January–May) and full (FCS; March–July), on the main carpometric traits and bioactive components of different watermelon fruits were investigated in the open field. Four watermelon genotypes, comprising of three commercial cultivars 'Crimson Sweet', 'Dumara', 'Giza', and the novel hybrid 'P503 F1', were compared. The carpometric traits varied significantly between genotypes. Soluble solids and yield were higher under FCS than ECS. The variation affecting colour indexes between the two growing seasons exhibited a genotype-dependent trend. The antioxidant components and radical scavenging activity of watermelon fruits were also significantly affected by differences in received solar energy and temperature fluctuations during the trial period. The average citrulline, total phenolics and flavonoid contents were 93%, 71% and 40% higher in FCS than in ECS. A genotype-dependent variation trend was also observed for lycopene and total vitamin C between cropping seasons. The hydrophilic and lipophilic radical scavenging activities of the pulp of ripe watermelon fruits of the different genotypes investigated varied between 243.16 and 425.31 µmol Trolox Equivalent (TE) of 100 g−1 of fresh weight (fw) and from 232.71 to 341.67 µmol TE of 100 g−1 fw in FCS and ECS, respectively. Our results, although preliminary, show that the functional quality of watermelon fruits is drastically altered depending on the environmental conditions that characterize the ECS and LCS. [ABSTRACT FROM AUTHOR]

Introduction: Exogenous melatonin (EMT) application has been used to reduce postharvest senescence and improve the quality and antioxidant enzyme activities of papaya fruits during cold storage. Methods: The effects of exogenous melatonin application (1. 5 mM) were investigated on papaya fruits during cold storage (10°C ± 2°C) for 28 days in the present study. Results and discussion: The EMT treatment delayed postharvest senescence significantly with lower maturing status compared with untreated papaya fruits (control). In addition, EMT treatment maintained substantially higher titratable acidity values and ascorbic acid content but significantly lower soluble solids content and lower weight loss compared with the untreated fruits. Concerning the antioxidant capacity, the EMT-treated papaya fruit exhibited markedly higher total phenolic content and, consequently, higher DPPH-radical scavenging activity than the control group. The EMT treatment not only kept a higher enzyme activity of superoxide dismutase, peroxidase, and catalase but also significantly inhibited the accumulation of hydrogen peroxide and malondialdehyde, along with satisfying sensory attributes. Conclusion: The findings of this study indicated that EMT application could be commercially used as an eco-friendly strategy to reduce postharvest senescence and maintain the fresh-like quality traits of papaya fruit during cold storage. [ABSTRACT FROM AUTHOR]

In recent year, the demand for guava fruit has been increasing in domestic and international markets. However, guava fruit is extremely perishable due to the short shelf life and rapid over-ripening of the fruits suggesting the need for practical tools to extend their shelf-life. In the present study, the efficiency of calcium nitrate treatment was investigated on Golla guava fruit. Fruits were treated with different concentrations (0, 1%, 2%, 3% and 4%) for 12 days storage at ambient condition. Among the dipping treatments, 4% calcium nitrate significantly reduced fruit weight loss (FWL), decay percentage, and suppressed the increase of soluble solids content (SSC). Moreover, 4% calcium-treated fruits had higher total titratable acidity (TA), and lower ripening index (SSC: TA ratio) and pH during the storage period. Higher ascorbic acid, total phenolic content (TPC) and higher reducing, non-reducing and total sugars along with retained higher activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) enzymes were observed in (4%) calcium nitrate treated guava fruits. Calcium nitrate (4%) also exhibited higher aroma, taste and flavour among the other treatments. Generally, the pre-storage calcium nitrate dipping treatment of guava fruit-maintained fruit quality for up to 12 days at ambient storage condition and could be suggested as practical solution at commercial levels in extending the shelf life of fresh guava fruits. [ABSTRACT FROM AUTHOR]