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Mango (Mangifera indica L.) is a highly perishable fruit with a short shelf life at ambient conditions, which may lead to post-harvest losses approximated to be 40-45%. This reduces returns to farmers significantly. The problem is compounded by the fact that most farmers do not have access to cold storage facilities. Nutrient management has been shown to affect postharvest characteristics of fruits. Calcium particularly plays a critical role in cell membrane integrity, tissue firmness and delays lipid catabolism. Previous studies have indicated a deficiency of calcium in some mango growing regions in Kenya. A field study was carried out to determine the effect of varied calcium formulations applied at various stages of growth on mango fruits post-harvest quality and organoleptic acceptability. The study was carried out in Embu County Eastern Kenya during seasons 2017/2018 and 2018/2019 using "Van Dyke" cultivar, aged approximately 10 years. The experiment was set up in a randomized complete block design with a split-split plot arrangement, three trees per replication, replicated thrice. Three calcium formulations: calcium chloride, calcium nitrate and Easygro™ were applied at rates of 0%,1.0%, 1.5% and 2.0% at fruit set, 30 days after fruit set and 30 days to physiological maturity. The calcium sources formed the main plots, the timing of application formed the subplots while the rates of application formed the sub-sub plots. Total soluble solids (TSS) and percentage titratable acidity (TA) were assessed at harvest and after 12 days of storage under ambient conditions (25±2°C, 70±5% relative humidity) using standard procedures. Selected fruits' sensory attributes were also evaluated after storage using a hedonic scale. Analysis of data was done using the 14th Edition of the Genstat software. The differences among the means of the treatments were compared using Fisher's Protected LSD test at 5% probability level. Fruits sprayed with calcium chloride, 2.0% at fruit set had higher TSS (6.8 ° brix and 6.3° brix) (10.47 ° brix and 9.10 ° brix), TA (1.29% and 1.27%), (0.77% and 0.675%) than other treatments at maturity and after storage in both seasons, respectively. Calcium chloride at 2.0% level of application led to a superior peel color appearance contrary to calcium nitrate and Easygro™ also applied at 2.0%, which led to an inferior peel color appearance and an inferior taste of fruits. Therefore, calcium nitrate and easy gro should be sprayed at concentration of 1.5% for good taste and peel colour appearance. [ABSTRACT FROM AUTHOR]

Leafy vegetables play a crucial role in the human diet providing numerous nutrients and health benefiting compounds. Leafy vegetables like collard (Brassica oleracea var. acephala) and black nightshade (Solanum nigrum l.) are commonly consumed leafy vegetables in Kenya. However, their high perishability and short shelf life (usually 1-2 days at ambient temperature) limits their utilization resulting in significant high postharvest losses. This study assessed the effect of harvest stage and nitrogen fertilization on the postharvest shelf life of collard and black nightshade. Experiments were conducted at Kabete field station, University of Nairobi, using collard and black nightshade. Field experimental layout was a 4 x 3 factorial arrangement in randomized complete block design with three replicates. Factors were nitrogen levels and harvest stage. Four levels of nitrogen (0, 30, 60 and 90 kg N/ha) were applied on black nightshade and (0, 55.5, 111.1 and 166.6 kg N/ha) in collard where 0 kg N/ha was the control. Collard and black night shade were harvested at three harvest stages: 4 weeks, 6 weeks and 8 weeks after transplanting. The harvested vegetables were kept at ambient room condition (20 °C, 55% relative humidity). Data collection was performed daily for quality related parameters which included color change, wilting index and cumulative weight loss. Results show that there was a progressive deterioration in quality of the collard and black nightshade with storage time regardless of harvest stage and nitrogen level. Harvesting at 8 weeks after transplanting resulted in longer shelf life in collard (three days) and black nightshade (two days) when compared to harvesting at 4 weeks or 6 weeks after transplanting. Collard and black nightshade showed reduced hue angles over storage time at different harvest stages. Black nightshade subjected to 90 kg N/ha and harvested at 4 weeks after transplanting had the highest wilting index of 33%. The highest cumulative weight loss of 29% was recorded in collard that were harvested at 8 weeks after transplanting. Black nightshade subjected to 90 kg N/ha and harvested at 6 weeks after transplanting showed the best color at a hue angle of 145°. Overall, harvesting at 8 weeks after transplanting resulted in the longest shelf life of both black nightshade and collard. These results show that low application of nitrogen fertilizer in black nightshade (30 kg N/ha) and in collard (55.5 kg N/ha) had minimal effects on weight loss and wilting and resulted in good keeping quality. [ABSTRACT FROM AUTHOR]

The high postharvest losses (40 - 50%) reported in the mango value chain are partly attributed to lack of reliable maturity indices. Harvest maturity is dictated by the intended use and the target market for the fruits. The aim of this study was to establish maturity indices of three commercial mango varieties namely 'Van dyke,' 'Kent' and 'Tommy Atkins' in Embu County of Kenya. At least eighteen mango trees (six per variety) were randomly tagged at 50% flowering in each of the three selected smallscale farms in Embu County. Number of days from flowering to different maturity stages were recorded (computational method). For each variety and maturity stage, five fruits were randomly sampled from the pool and analysed for physical (size, density, firmness, colour), physiological (ethylene evolution and respiration rate) and biochemical (obrix/Total Soluble Solids (TSS), total titratable acidity (TTA) and their ratio) indices of maturity. The results showed that although size increased as the fruits developed, it was not a reliable index of maturity since some small-sized fruits attained advanced maturity earlier than others that were large-sized. The weight of the fruits fluctuated as the fruits developed and similar trend was observed on the specific gravity. Flesh firmness decreased gradually with maturity from a mean firmness of 40.54 N to 6.84 N. Tommy Atkins exhibited the lowest firmness levels at stage 4. Kent variety had the lowest ethylene at all stages while Tommy Atkins variety had the highest respiration rate of 21.40 ml/kg/hr at stage 1, which increased gradually to 32.10 ml/kg/hr at stage 4. The highest TSS: TTA values were reported in Kent variety. The results revealed significant differences in maturity indices of the three mango varieties despite similar physical indices. This study confirms the unreliability of physical maturity indices such as size and shape in establishing the right harvest stage of mango fruits. Computational, physiological and biochemical maturity indices should be incorporated in determination of accurate harvest maturity for mango. [ABSTRACT FROM AUTHOR]

Collard (Brassica oleracea var.acephala L.) is a nutritious leafy vegetable that is widely cultivated and consumed in Kenya. However, collard is highly perishable with a shelf life of one to two days at ambient conditions, which limits its consumption. Exploring storage options and packaging methods that can extend the shelf life of collards, can avert quantity and quality losses of the vegetable. This will ensure sustained income to producers and continued vegetable supply to consumers. The study aimed to evaluate the effectiveness of CoolBot® Technology and Modified Atmosphere Packaging (MAP) as options to preserve quality and extend the shelf life of collards. Two experiments were conducted at Kabete and Juja sub-counties using freshly harvested collards from the University of Nairobi Kabete farm. In each experiment, homogenous batch of freshly harvested collards were first divided into four batches. The vegetable batches were then subjected to two storage options (CoolBot® cold room; 5±2 °C, 75±20% RH, and ambient conditions; 25±10 °C, 50±15% RH), which were further split into two packaging treatments (packaged using Xtend® MAP, and unpackaged). The experimental layout was a 2 by 2 factorial arranged in a completely randomized design with three replications. Measurements were performed daily to determine cumulative weight loss, yellowing, wilting and color changes. Biochemical assay was also performed to determine the changes in vitamin C and betacarotene content. Results show that CoolBot® cold storage extended the shelf life of collards by 6 days without MAP and 13 days with MAP, in comparison to collards stored at ambient conditions. The slow rate of deterioration under CoolBot® storage (with or without MAP) was evidenced by delayed yellowing, wilting, and reduced weight loss compared to ambient conditions, in the two experimental sites. The loss in vitamin C content was significantly higher (p = 0.05) in collards under ambient conditions than those under CoolBot® storage. In ambient conditions, unpackaged collards lost 77.7% of their vitamin C content while the packaged collards lost 57.7% by end of shelf life (day four). In CoolBot® storage, packaged collards lost 18.4% whereas the unpackaged lost 26.3% of their initial vitamin C content. In CoolBot® storage, packaged collards lost 26.2% while the unpackaged lost 44.1% of their initial Vitamin C by day seven. These results demonstrate a synergistic effect of CoolBot® cold storage and MAP in preserving quality and extending the shelf life of collards. [ABSTRACT FROM AUTHOR]

Use of loss reduction practices are critical to ensuring losses are reduced significantly along the value chain. This necessitates for the need to assess the factors that influence adoption of the loss reductio practices to have better targeting and development. Therefore, the current study assessed the factors that influence adoption, and multistage sampling technique was employed. The counties and the sub-counties were purposively selected, and the mapping began from Nairobi which is the main market for mangoes. Wholesalers, and retailers were interviewed making use of snowballing, while farmers were randomly selected. A total of 70 farmers were selected, 74 wholesalers, and 98 retailers were sampled. From the study, at the farm level results revealed that about 38.7 % of the farmer respondents prefer use of stick and bag. On the other hand, about 37.1 % of farmers in Machakos had preference of hand picking as the main method of harvesting. Wholesaler preferred the use of cartons in Nairobi, while those in Embu and Machakos had higher preference of use of shades. Result from the empirical model showed that credit was a critical factor to use of the practices at the farm with a 40 % influence on use of multiple practices. Experiencing higher losses influenced adoption of the practices by 4.3 %, and would influence use of multiple practices by 19.2 %. Organized selling was the critical factor for wholesalers and influenced adoption by 43.4 %. Retailers in Embu and Machakos on the other hand, were 19.9 % less likely to take up the practices. The results further showed that higher PHL influence retailer to take up loss reduction practices by 30.2 %, and those that were more experience were 20 % more likely to take up the practices. From the result it was thus concluded that cost effectiveness, ability to reduce losses, and increase of incomes were some of the things actors were interested with before they could take up any loss reduction practice. Through the study it was evident that high PHL less to higher use of the practices, and also positively influence the intensity of use of the practices. It was thus recommended that there is need for upgrading the current low-cost technologies to make them more user friendly so that they are not time-wasting during harvest, and for the traders they are able to carry optimal quantities that lead to profit maximization., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

More than a decade after the World Health Organization Commission on the Social Determinants of Health (SDoH), it is becoming widely accepted that social and economic factors, including but not limited to education, energy, income, race, ethnicity, and housing, are important drivers of health in populations. Despite this understanding, in most contexts, social determinants are not central to local, national, or global decision-making. Greater clarity in conceptualizing social determinants, and more specificity in measuring them, can move us forward towards better incorporating social determinants in decision-making for health. In this paper, first, we summarize the evolution of the social framing of health. Second, we describe how the social determinants are conceptualized and contextualized differently at the global, national, and local levels. With this, we seek to demonstrate the importance of analyzing and understanding SDoH relative to the contexts in which they are experienced. Third, we problematize the gap in data across contexts on different dimensions of social determinants and describe data that could be curated to better understand the influence of social determinants at the local and national levels. Fourth, we describe the necessity of using data to understand social determinants and inform decision-making to improve health. Our overall goal is to provide a path for our collective understanding of the foundational causes of health, facilitated by advances in data access and quality, and realized through improved decision-making., (© 2021. The New York Academy of Medicine.)

Housing is a paradigmatic example of a social determinant of health, as it influences and is influenced by structural determinants, such as social, macroeconomic, and public policies, politics, education, income, and ethnicity/race, all intersecting to shaping the health and well-being of populations. It can therefore be argued that housing policy is critically linked to health policy. However, the extent to which this linkage is understood and addressed in public policies is limited and highly diverse across and within countries. This analysis seeks to describe the linkages between housing policies and health and well-being using examples from three countries at different levels of the wealth spectrum: Singapore, the UK, and Kenya.We conducted a comparative policy analysis across three country contexts (Singapore, the UK, and Kenya) to document the extent to which housing policies address health and well-being, highlighting commonalities and differences among them. To guide our analysis, we used the United Nations (UN) definition of adequate housing as it offers a broad framework to analyze the impact of housing on health and well-being.The anatomy of housing policies has a strong correlation to the provision of adequate housing across Singapore, the UK, and Kenya, especially for vulnerable groups. The paper demonstrates that contextual factors including population composition (i.e., aging versus youthful), political ideologies, legal frameworks (i.e., welfare versus market-based provision of housing), and presence (or absence) of adequate, quality, timely, reliable, robust data systems for decision-making, which are taken up by stakeholders/state, have strong implications of the type of housing policies developed and implemented, in turn directly and indirectly impacting the overall health and well-being of populations.This analysis demonstrates the value of viewing housing policies as public health policies that could significantly impact the health and well-being of populations, especially vulnerable groups. Moreover, the findings highlight the importance of the Health in All Policies approach to facilitate integrated policy responses to address social determinants of health such as housing. This is more critical than ever, given the context of the global pandemic that has led to worsening overall health and well-being., (© 2021. The New York Academy of Medicine.)

This study investigated the effect of pretreatments namely citric acid, lemon juice and blanching on the physical attributes of dried chips from two popular commercial mango varieties grown in Kenya viz 'Apple' and 'Ngowe'. The pretreated mango chips were either subjected to a convective dryer or solar drying. Moisture content, extent of dryness, rehydration characteristics, water activity and color retention were determined to establish the effect of the pretreatments before drying on physical quality attributes of dried mango chips. Moisture content, water activity and color were determined using standard procedures. Equilibrium relative humidity was estimated using Drycard™. Results obtained indicated that optimal drying was achieved with dryer temperatures of 50 °C and 65 °C for 10 and 7 h respectively that reduced moisture content to ~ 11% and water activity to below 0.65 (sufficient for inhibited spoilage). The best color parameters and rehydration characteristics were observed with 1% citric acid and 0.5 v/v lemon acid pretreated samples. Blanched as well as control (untreated) samples showed relatively poor color retention in relation to flesh mango chips and had the least rehydration ratio (1.65 ± 0.01) and coefficient of rehydration (0.33 ± 0.1). As pretreatments before drying affect physical parameters of dried mango chips, the best choice of pretreatments should be made to produce high quality end products. Citric acid and lemon juice pretreatments before drying at 50 °C and 65 °C had the optimal outcome and produced the best physical quality parameters.

Various modes of edible coating application vary in their coat dispersion and film formation, hence the need to determine the most effective mode of application for cassava. Edible surface coatings have been found to be effective in preserving the quality of various food products. However, there are variations in effectiveness among the different coating solutions, hence the need for optimization of the concentrations of the gums used. This study aimed at determining the most efficient coating application method on the cassava postharvest quality. Physiologically mature cassava (variety KME 1) was harvested and divided into seven portions. The various portions were coated using 1.5% xanthan gum, 1.5% xanthan/guar gum, and 2% xanthan/guar gum by both dipping and spraying method. There was no significant difference on the colour, total cyanide, ethylene production, and total phenolic content between the two application methods. The 2% xanthan/guar gum coating showed a significant difference on the dry matter content while the 1.5% xanthan gum coating had a significant difference on the respiration rate and weight loss. The 1.5 xanthan treated roots had a final dry matter content of 72.5% for the sprayed samples and 75.98% for the dipped sample while the 2% xanthan/guar gum treated roots had a final dry matter content of 64.6% and 74.1% for the dipped and sprayed root samples, respectively. The 1.5% xanthan and 2% xanthan/guar gum treated roots showed no significant difference in their action on dry matter content. The 1.5% xanthan/guar dipped and sprayed samples differed significantly on their effect on flesh firmness with final values of 35.4N and 46.1N, respectively, at 20 days after harvest. This study suggested that based on the coating solution and the parameters being observed, there generally was no varying effect of dipping and spraying methods of coating application. The choice of the efficient mode of application to use will depend on other factors such as the easiness of application.

African eggplants ( Solanum aethiopicum L.) are a rich source of bioactive compounds and functional constituents that are beneficial to human health. However, the short shelf life of these vegetables can be a major cause of postharvest losses especially during peak harvesting season. Drying is one of the most convenient technologies for the production of shelf stable food products. However, drying can lead to considerable loss of the available bioactive compounds due to thermal degradation depending on the drying method and temperature conditions. This study investigated the effect of four drying methods (solar, oven, vacuum, and freeze) on the retention of total phenolics, beta-carotene, antioxidant capacity, and lycopene in five African eggplant ( S. aethiopicum ) accessions (sangawili, manyire green, S00047A, AB2, and aubergine blanche). Samples were dried up to ~10% moisture content. The fresh and dried samples were analyzed for total phenolic content, antioxidant capacity, beta-carotene content, and the lycopene content. In the fresh state, beta-carotene, total phenolic content, and free radical scavenging activity ranged between 14.75 ± 0.50 and 29.50 ± 0.77 mg/100 g db, 751.21 ± 1.73 and 1,363.95 ± 2.56 mg/100 g GAE db, and 99.58 and 325.61 mg/ml db IC 50 value, respectively. The accession S00047 showed highest total phenolic content and lowest IC 50 value in the fresh samples. The results also showed that total phenolic content, antioxidant capacity, and beta-carotene contents were significantly ( p  < .05) affected by drying method and drying temperature with freeze-drying presenting the highest retention. Overall, 36.26%s-95.05% (total phenolics) and 31.44%-99.27% (beta-carotene) were retained during freeze-drying. Lycopene was only detected in the dried samples of the accession manyire green but absent in all the fresh samples of all the accessions. This study demonstrates that freeze-drying was the most effective in retaining the highest bioactive compounds in African eggplants.

Background: Drought stress is one of the main abiotic stresses that affect crops. It leads to biochemical changes that can have adverse effects on plant growth, development and productivity. African eggplants are important vegetable and fruit crops reported to adapt and thrive well under drought stress. The diversified metabolites arising due to stress have not been well defined. A gas chromatographic-mass spectrometric metabolomic approach was applied to characterize the effect of drought stress on metabolites at different stages of growth. Nineteen accessions were selected for analysis and drought was imposed by withholding water until soil moisture reached 60% field capacity. Fresh leaf tissues were sampled before stress, 2 and 4 weeks after stress and metabolite profiling done., Results: Significant changes in metabolite content were observed, and potentially important metabolites with respect to stress responses were characterized. Proline, glutamate, sucrose, fructose and tricarboxylic acid cycle metabolites were shown to be positively correlated with stress. Principal component analysis showed a clear discrimination between the different accessions, growth stages and stress/control conditions., Conclusion: The results illustrate that drought stress has a significant impact on the concentrations of some metabolites, such as amino acids, sugars and organic acids, which may contribute to drought stress effects and tolerance. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

African eggplants ( Solanum aethiopicum and S .  macrocarpon ) are among the most economically important and valuable vegetable and fruit crops. They are a major source of biologically active nutritional substances and metabolites which are essential for plant growth, development, stress adaptation and defense. Among these metabolites are the carotenoids which act as accessory pigments for photosynthesis and precursor to plant hormones. Though African eggplants are known to be resistant to various abiotic stresses, the effect of these stresses on secondary metabolites has not been well defined. The objective of this study was to establish the effect of drought stress on carotenoid profiles of nineteen African eggplant accessions selected based on leaf and fruit morphological traits. Stress was achieved by limiting irrigation and maintaining the wilting state of the crops. Fresh leaves were sampled at different maturity stages; before stress, 2 weeks and 4 weeks after stress for carotenoid analysis. The fresh harvested leaf tissues were immediately frozen in liquid nitrogen and ground. Analysis was carried out using a Dionex HPLC machine coupled to Photo Array Detector and Chromeleon software package (Thermo Fisher Scientific Inc, Waltham, Massachusetts, USA). Major carotenoids viz;. Xanthophylls (neoxanthin, violaxanthin, zeaxanthin and lutein) and carotenes ( β -carotene and α -carotene), phytofluene, lycopene, phytoene as well as chlorophylls (chlorophyll-b and Chlorophyll-a) were targeted. The carotenoids increased with maturity stage of the crop. Although the stressed crops reported significantly decreased amount of carotenes, chlorophylls, neoxanthin and violaxanthin, the concentration of zeaxanthin increased with stress whereas lutein had no significant change. Chlorophyll-a was significantly high in all the control accessions. Two accessions reported significantly higher contents of carotenoids as compared to the other accessions. The results of this study indicate that water stress has significant impact on the concentration of some carotenoids and photosynthetic pigments. This will definitely add value to the study of stress tolerance in crops.