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Background: Kiwifruit are classified as climacteric since exogenous ethylene (or its analogue propylene) induces rapid ripening accompanied by ethylene production under positive feedback regulation. However, most of the ripening-associated changes (Phase 1 ripening) in kiwifruit during storage and on-vine occur largely in the absence of any detectable ethylene. This ripening behavior is often attributed to basal levels of system I ethylene, although it is suggested to be modulated by low temperature., Results: To elucidate the mechanisms regulating Phase 1 ripening in kiwifruit, a comparative transcriptome analysis using fruit continuously exposed to propylene (at 20 °C), and during storage at 5 °C and 20 °C was conducted. Propylene exposure induced kiwifruit softening, reduction of titratable acidity (TA), increase in soluble solids content (SSC) and ethylene production within 5 days. During storage, softening and reduction of TA occurred faster in fruit at 5 °C compared to 20 °C although no endogenous ethylene production was detected. Transcriptome analysis revealed 3761 ripening-related differentially expressed genes (DEGs), of which 2742 were up-regulated by propylene while 1058 were up-regulated by low temperature. Propylene exclusively up-regulated 2112 DEGs including those associated with ethylene biosynthesis and ripening such as AcACS1, AcACO2, AcPL1, AcXET1, Acβ-GAL, AcAAT, AcERF6 and AcNAC7. Similarly, low temperature exclusively up-regulated 467 DEGS including AcACO3, AcPL2, AcPMEi, AcADH, Acβ-AMY2, AcGA2ox2, AcNAC5 and AcbZIP2 among others. A considerable number of DEGs such as AcPG, AcEXP1, AcXET2, Acβ-AMY1, AcGA2ox1, AcNAC6, AcMADS1 and AcbZIP1 were up-regulated by either propylene or low temperature. Frequent 1-MCP treatments failed to inhibit the accelerated ripening and up-regulation of associated DEGs by low temperature indicating that the changes were independent of ethylene. On-vine kiwifruit ripening proceeded in the absence of any detectable endogenous ethylene production, and coincided with increased expression of low temperature-responsive DEGs as well as the decrease in environmental temperature., Conclusions: These results indicate that kiwifruit possess both ethylene-dependent and low temperature-modulated ripening mechanisms that are distinct and independent of each other. The current work provides a foundation for elaborating the control of these two ripening mechanisms in kiwifruit.

The mango cultivar 'Apple' is an important fruitcrop in Kenya, but it is highly susceptible to russeting. The objective was to establish whether lenticels predispose cv. 'Apple' mango to russeting. Fruit mass and surface area increased in a sigmoidal pattern with time. The frequency of lenticels per unit surface area decreased during development. The number of lenticels per fruit was constant. Lenticels were most frequent in the apex region and least common in the cheek and nak (ventral) regions. The cheek region also had lenticels with the largest core areas, whereas the lenticel core areas in the apex region were significantly smaller. Microscopy revealed stomata became covered over with wax deposits at 33 days after full bloom (DAFB). By 78 DAFB, periderm had formed beneath the pore. At 110 and 161 DAFB, cracks had developed and the periderm had extended tangentially and radially. The presence of lenticels increased the strain released upon excision of an epidermal segment, further strain releases occurred subsequently upon isolation of the cuticle and on extraction of the cuticular waxes. The number of lenticels per unit surface area was negatively correlated with the fruit surface area (r2 = 0.62 **), but not affected by fruit size. Mango cv. 'Apple' had fewer, larger lenticels and more russet, compared with 'Ngowe', 'Kitovu' or 'Tommy Atkins' mango. In cv. 'Apple', the lowest lenticel frequency, the largest lenticels and the most russeting occurred at a growing site at the highest altitude, with the highest rainfall and the lowest temperature. Moisture exposure of the fruit surface resulted in enlarged lenticels and more microcracking of the cuticle. Our results establish that russeting in 'Apple' mango is initiated at lenticels and is exacerbated if lenticels are exposed to moisture. [ABSTRACT FROM AUTHOR]

Summary: Baobab fruit pulp powder (BFPP) is susceptible to economically driven adulteration owing to its incredible nutrient density and rapidly expanding demand worldwide. In this study, a portable NIR spectroscopy (wavelength 900–1700 nm) coupled with chemometrics was used for the detection of BFPP adulteration. BFPP samples separately adulterated with rice flour (RF), wheat flour (WF), and maize flour (MF) at 0%, 1%, 3%, 5%, 10%, 15%, 20%, 25%, 30%, 40%, 50% and 60% concentrations were subjected to NIR spectroscopy. Two‐class models proved to be reliable with sensitivity and specificity of above 0.98 and an error of below 0.01. Four‐class models attained sensitivity and specificity of above 0.68 and an error of below 0.276. The correlation coefficient (R2) and root mean square error (RMSE) of the prediction set were above 0.88 and below 6.20% respectively for PLSR models. The LODs were also below 13.79%. Therefore, NIR spectroscopy has a promising potential for rapid screening of BFPP adulterations. [ABSTRACT FROM AUTHOR]

Purpose: In the rural Kenyan diet, the bioavailability of iron is low and predisposes the population to iron deficiency. Fruit pulp of the indigenous baobab tree contains significant amounts of vitamin C, which enhances non-heme iron bioavailability. We studied the impact of baobab fruit pulp (BFP) consumption on the hemoglobin (Hb) and iron status of Kenyan schoolchildren. Methods: The single-blind randomized controlled intervention trial was implemented daily among apparently healthy schoolchildren aged 6–12 years with hemoglobin level < 12.2 g/dl. For 12 weeks, children in the intervention group (n = 29) received a drink with BFP, while the control group (n = 29) received an isoenergy drink without BFP. At baseline and endline, blood samples were taken. Results: The development of hemoglobin, ferritin (FER) and soluble transferrin receptor (sTfR) did not differ significantly between the intervention and control groups. However, in the intervention group, Hb levels improved slightly (2.2%), while they decreased slightly (1.2%) in the control group. Levels of geometric means of sTfR remained almost unchanged (0.7%) in the intervention group and slightly worsened (2.7%) in the control group. In both the groups, geometric mean of FER levels decreased, yet to a smaller extent in the intervention (17.3%) than in the control (26.0%) group. Conclusion: Even though no significant effects of BFP could be detected in this study, the identification of products such as BFP remains pertinent to help improve non-heme iron absorption in the most vulnerable populations. [ABSTRACT FROM AUTHOR]

An on-farm study was conducted among smallholder mango farmers in Embu County of Kenya to demonstrate the effectiveness of simple harvest and postharvest handling practices to attain cold chain and extend mango shelf life. The recommended cold chain practices were compared with common farmers' practices. 'Apple', 'Ngowe', 'Kent', and 'Tommy Atkins' harvested at the mature green stage were used in the study. To demonstrate proper cold chain, fruits were harvested before 8 am, transported in crates lined with dampened newspapers, precooled in an evaporative charcoal cooler, and then transferred to a Coolbot™ cold room (10 ± 2°C). To demonstrate common farmers' practices, fruits were harvested at noon, transported in open crates, and stored at ambient room conditions (25 ± 7°C, 55 ± 15%RH). The air and fruit pulp temperatures were monitored regularly using HUATO® data loggers. During the storage period, a random sample of 3 fruits (per variety) per treatment was taken after every 3 days to evaluate ripening related changes including physiological weight loss, colour, firmness, and total soluble solids. Proper cold chain practices resulted in low fruit pulp temperature (average 11°C) compared to 25°C for fruits handled using common practices by farmers leading to faster ripening as evidenced by lower peel/pulp colour and firmness, higher physiological weight loss, and higher total soluble solids. For example, flesh firmness of fruits under poor cold chain practices decreased from initial 36.6 N, 45.9 N, 66.5 N, and 46.8 N to 3.1 N, 2.4 N, 3.2 N, and 3.1 N for 'Apple', 'Ngowe', 'Kent', and 'Tommy Atkins' varieties, respectively, at the end of storage while that of fruits under proper cold chain practices reduced to 2.3 N, 1.5 N, 3.9 N, and 2.9 N, respectively, for the four varieties at the end of storage. Overall, proper cold chain management extended mango shelf life by 18 days. Application of simple harvest and handling practices coupled with simple storage technologies can attain and maintain the cold chain required to preserve quality and extend shelf life. This could increase the marketing and storage periods for later selling and processing, respectively, of mango fruits. [ABSTRACT FROM AUTHOR]

Mango is an economically important fruit crop but with a very short shelf life of about 4–9 days in ambient and between 2 and 3 weeks in cold storage. Extending the shelf life and marketing period of mango fruit requires application of quality preservation technologies. This study aimed at evaluating the effect of innovative waxing options on shelf life and postharvest quality of "ngowe" mango fruits stored under different storage conditions. A homogenous sample of mango fruits, variety "ngowe" harvested at mature green stage were subjected to two waxing treatments, namely Shellac or Decco wax™. The waxes were applied by dipping the fruits in wax for five seconds followed by air drying. The waxed fruits were then packed in carton boxes and stored either at ambient room temperature (25°C) or cold room (12°C). Random samples of three fruits from each treatment and storage conditions were taken for measurement of attributes associated with ripening after every 3 and 7 days for ambient and cold storage, respectively. These included cumulative weight loss, respiration, peel firmness, total soluble solids (TSS), total titratable acidity (TTA) and beta carotene content. Results from the study showed that waxing with either Shellac or Decco wax was effective in prolonging shelf life of "ngowe" mango fruits by 3 and 6 days in ambient and cold storage respectively. Untreated fruits in ambient storage lost 5.3% of the initial weight by day 7 compared to an average of 4.5% for the waxed fruit (day 10). Waxed fruits in ambient had low CO2 concentration (59.53 ml/kg hr) compared to a high (88.11 ml/kg hr) CO2 concentration for the untreated fruits. Similarly, other ripening related changes including brix, color, and firmness were significantly slowed down by waxing, especially under cold storage. Findings from this study show the effectiveness of waxing in delaying mango fruit ripening. Waxing can therefore be used to extend the shelf life and marketing period for mango fruit. [ABSTRACT FROM AUTHOR]

In Kenya, the mango (Mangifera indica L) cultivar 'Apple' is commercially important but it often suffers excessive russeting, which both compromises its appearance and impairs its postharvest performance. Together, these effects seriously reduce its market potential. Exposure to surface moisture is implicated in russeting of cv. 'Apple' mango. The objective was to establish the effect of bagging on russeting. Developing fruit were bagged at the onset of the exponential growth phase, using brown paper bags (Blue star®). Un-bagged fruit served as controls. The brown paper bags were selected because of their high permeance to water vapor. At harvest maturity, bagged fruit were larger, less russeted and had smaller lenticels than un-bagged control fruit. Staining with aqueous acridine orange in conjunction with fluorescence microscopy revealed numerous microcracks and larger lenticels on un-bagged control fruit but these were not evident on bagged fruit. Postharvest mass loss (principally water loss) of bagged fruit was lower than of un-bagged control fruit. In the un-bagged control fruit, the skin's water permeance increased as the russeted surface area increased (r2 = 0.88 **). Fruit skins were less permeable to water vapor than the brown paper bags. The brown paper bags contributed not more than 4.2 to 9.1% of the total in-series diffusion resistance of skin + bag. The masses of isolated cuticular membranes, and of dewaxed cuticular membranes, and of wax per unit surface area were higher for un-bagged control fruit than for bagged fruit. Bagged fruit were also greener and showed less blush. There was little difference in skin carotenoid content between bagged and un-bagged control fruit, but skin anthocyanin content was lower in bagged fruit. The rates of respiration and ethylene evolution of bagged fruit were lower than those of un-bagged control fruit. There were no differences between bagged and un-bagged control fruit in their organoleptic and nutritional properties including titratable acidity, total soluble sugars, sucrose, glucose, fructose, vitamin C and calcium content. In conclusion, bagging decreased russeting and increased postharvest performance of fruit of mango cv. 'Apple'. • Bagging increased fruit size and decreased cuticle thickness. • Bagging did not change background color, soluble solids or total acidity. • Bagging decreased anthocyanin content and blush area of the fruit surface. • Bagging reduced cuticular microcracking, russeting and postharvest water loss. [ABSTRACT FROM AUTHOR]

• YSST identified ethylene-dependent and independent genes encoding secreted proteins. • Eight of the identified genes showed different expression in 'La France' and 'Yali'. • Five of the differently expressed genes encoded cell wall modifying proteins. • Three of the differently expressed genes encoded proteins of unknown function. During ripening, European pear (Pyrus communis L. cv. 'La France') fruit undergo dramatic softening in response to increased ethylene production, whereas Chinese pear (Pyrus bretschneideri Rehd. cv. 'Yali') fruit remain firm, despite producing large amounts of ethylene. The molecular basis of this differential softening behavior is not well understood. In this study, we combined a yeast-based signal sequence trap (YSST) and macroarray gene expression analysis to identify putative genes encoding secreted proteins that control pear fruit softening. We identified 22 cDNAs annotated as encoding proteins with diverse cell wall-associated functions that were up- or down-regulated during fruit ripening in 'La France'. Gene expression analysis in fruit that were treated with the ethylene perception inhibitor 1-methylcyclopropene (1-MCP) at 4 d after the onset of ripening revealed that 16 of the targeted genes are ethylene-regulated, while the others appear to be ethylene independent. Comparative gene expression analyses of 'La France' and 'Yali' fruit during ripening suggested that four ethylene-regulated cDNAs encoding cell wall modifying proteins, contig 2 (polygalacturonase 3), contig 15 (expansin), contig 19 (expansin) and contig 55 (pectate lyase) contribute to the different softening behaviors of 'La France' and 'Yali' fruit. Additionally, one ethylene-independent cell wall related gene, contig 36 (expansin), and three genes encoding proteins of unknown function, contigs 1 , 13 and contig 75 showed differential expression between 'La France' and 'Yali' fruit during ripening. The results presented herein represent promising candidates for future functional analysis and elucidation of softening mechanisms. [ABSTRACT FROM AUTHOR]