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'Redson' is a new triploid, red-fleshed pomelo x grapefruit hybrid. The goal of this study was to examine the effects of rainfall, harvest time, tree age, and yield on the postharvest storage performance of 'Redson' fruit. During 2022/23, two postharvest storage trials were conducted with early- and late-harvested fruit. The fruit from the early harvest retained good quality for up to 16 weeks of storage at 7.5 °C plus 1 week at 22 °C, whereas the late-harvested fruit suffered from a high decay incidence. During 2023/24, we expanded the postharvest trials to nine different fruit sets harvested from early season (late October) until the end of the season (January). Fruit quality was examined under the same storage conditions after 6 and 16 weeks, and the results indicated that early- and mid-season fruit retained good quality with minimal decay incidence even after prolonged storage for 16 weeks, whereas the late-season fruit suffered from significant decay incidences of 17–22% and a decline in flavor acceptability. Further analysis revealed strong and significant correlations between various rainfall parameters and harvest time and decay incidences. Overall, early-harvested fruit during the autumn had a superior postharvest storage performance, whereas late-harvested fruit during the rainy winter suffered from decay development. [ABSTRACT FROM AUTHOR]

'Aliza' is a new pomelo × mandarin hybrid (Citrus maxima, cv. Red Chandler × Citrus reticulata, cv. Ora) developed by the Israeli citrus breeding program at the Volcani Institute. Here, we aimed to characterize the quality and flavor of 'Aliza' fruit as compared to other commercial citrus fruit, specifically pomelo (C. maxima), grapefruit (Citrus paradisi), orange (Citrus sinensis) and mandarin (C. reticulata). 'Aliza' fruits have a similar size as grapefruits, but have a thinner peel and a unique yellowish/golden color. 'Aliza' fruits are completely seedless and have especially high juice contents. They also have a unique, highly preferred flavor, characterized by high sweetness and moderate bitterness and acidity, with strong citrusy and tropical fruity aromas. Sensory analyses conducted with the aid of a trained panel and an electronic tongue revealed that the flavor of 'Aliza' fruits is different from the flavors of other citrus species. Consumer acceptance and preference tests revealed that 'Aliza' fruit are highly appreciated and favored. The aroma volatile profile of 'Aliza' fruit was somewhat similar to those of pomelo and grapefruit, but very different from those of orange and mandarin. Overall, 'Aliza' fruits can be distinguished from other citrus fruits by their unique color, high juice content and exceptional, unique flavor. [ABSTRACT FROM AUTHOR]

During the last decade, there has been a continuous rise in consumption and global marketing of fresh, easy-to-peel mandarins, with current annual production of nearly 29 million tons. Nevertheless, most of the existing knowledge on quality traits of citrus fruit comes from research conducted on oranges and grapefruit, which are the main products for the citrus juice manufacturing industry; relatively little is yet known regarding the unique fruit quality traits of mandarins, nor about the great diversity in these traits among the various natural sub-groups and varieties of mandarins. In the present review we discuss the physiological, biochemical, and molecular factors governing key fruit quality attributes of mandarins, including fruit colour, size and shape, ease of peeling, seedlessness, flavour, and nutritional quality. Fruit colour, size, and shape contribute to external appearance; peelability and seedlessness to ease of consumption; and flavour and nutritional quality to internal quality. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND: Mandarins constitute a large, diverse and important group within the Citrus family. Here, we analysed the aromavolatiles compositions of 13 mandarin varieties belonging to seven genetically different natural sub-groups that included common mandarin (C. reticulata Blanco), clementine (C. clementina Hort. ex. Tan), satsuma (C. unshiu Marcovitch), Mediterranean mandarin (C. deliciosa Tenore), King mandarin (C. nobilis Loureiro), and mandarin hybrids, such as tangor (C. reticulata × C. sinensis) and tangelo (C. reticulata × C. paradisi). RESULTS: We found that mandarin varieties among tangors ('Temple', 'Ortanique'), tangelos ('Orlando', 'Minneola') and King ('King') had more volatiles, at higher levels, and were richer in sesquiterpene and ester volatiles, than other varieties belonging to the sub-groups common mandarin ('Ora', 'Ponkan'), clementine ('Oroval', 'Caffin'), satsuma ('Okitsu', 'Owari') and Mediterranean mandarin ('Avana', 'Yusuf Efendi'). Hierarchical clustering and principal component analysis accurately differentiated between mandarin varieties and natural sub-groups according to their aroma-volatile profiles. CONCLUSIONS: Although we found wide differences in aroma-volatiles compositions among varieties belonging to different natural sub-groups, we detected only minor differences among varieties within any natural sub-group. These findings suggest that selecting appropriate parents would enable manipulation of aroma-volatile compositions in future mandarin breeding programmes. [ABSTRACT FROM AUTHOR]

By using immunolocalization and differential extraction methods we show that only apoplastic invertase, but not vacuolar invertase, was present in the mature, sucrose-accumulating L. hirsutum pericarp. In contrast, in the hexose-accumulating L. esculentum fruit, both the apoplastic and vacuolar invertase activities and protein content increase in the mature fruit. Quantitative expression studies of the soluble invertase gene (TIV1) and the apoplastic invertase genes (LINs) showed that only TIV1 gene expression could account for the species and developmental differences of both soluble and insoluble enzyme activity of the pericarp. The expression of the LIN genes encoding for apoplastic tomato invertases was unrelated to the differences in bound enzyme activity and could not account for the rise in bound invertase activity in the mature L. esculentum fruit. Evidence is presented that the bound invertase activity of tomato fruit is also the TIV1 gene product. The presence of apoplastic invertase in the mature sucrose-accumulating L. hirsutum fruit suggests a hydrolysis-resynthesis mechanism of sucrose uptake. In order to test this hypothesis, we studied short- and long-term uptakes of asymmetrically labelled 3H-fructosyl-sucrose accompanied by compartmental analysis of the sugars in attached whole fruits of L. hirsutum and L. esculentum. The results indicate that hydrolysis-resynthesis is slow in the sucrose-accumulating fruit but is not an integral part of an uptake and compartmentation mechanism. [ABSTRACT FROM AUTHOR]