Effects of harvest maturity on the storage life of Japanese type plums

Abstract

Summary. Plums are highly perishable and once harvested have a short commercial life. Hence, this crop would benefit from the determination of conditions which permit extended storage. This study investigates the effects of fruit maturity at harvest on the physical and chemical characteristics of the plum cultivars, Radiant, Gulfruby and Shiro, after periods of cool storage. Fruit from these cultivars were separated into 3 maturity categories according to either skin colour at harvest or time after pit hardening. The storage disorders, internal breakdown and gel breakdown, were measured after periods of storage at 0°C and subsequent ripening at 20°C. Skin colour, flesh firmness, concentration of soluble solids and titratable acidity were measured at harvest and after ripening. Internal breakdown and gel breakdown, symptoms of chilling injury, developed after 2 weeks cool storage in Gulfruby and Shiro and after 4 weeks in Radiant. These symptoms were most severe in the oldest fruit. Significant differences were also found in skin colour, firmness, soluble solids and acidity during ripening and after cool storage. Fruit harvested at an earlier maturity withstand cold storage better than more mature fruit. However, these less mature fruit initially have a poorer quality than those which are more mature. Therefore, it is important for the grower to be able to determine the precise stage of crop development in order to allow harvesting at a time which is optimal for the storage process.

Comparison of antioxidant levels and cell membrane composition during fruit development in two plum cultivars (Prunus salicina Lindl.) differing in chilling resistance

“…The higher oleic/linoleic acid ratio, higher total and reduced ascorbic acid concentrations and total phenolic concentration in all probability render 'Angeleno' plums much more CI resistant under long term cold-storage conditions compared to 'Sapphire' plums. The results of this study confirm the observation of Abdi et al (1997) that fruit with a long fruit development period are less susceptible to CI compared to fruit with a short fruit development period. In our study it was found that the longer fruit development period causes 'Angeleno' to experience higher average day temperatures than 'Sapphire' which, in turn, causes higher levels of MUFA instead of PUFA to accumulate in the 'Angeleno' fruit.…”

The Changes of Polyphenols, Flavonoids, Anthocyanins and Chlorophyll Content in Plum Peels during Growth Phases: from Fructification to Ripening

“…Kader et al (1999) observed a linear decrease of chlorophyll during the last development period of plum fruit, for both varieties researched, which is agreement with horticultural knowledge of fruits ripening. In another study, Abdi et al (1997) reported a similar chlorophyll degradation pattern, the studied plum varieties changed the color from green to yellow.…”

“…Kader et al (1999) have observed a linear decrease in chlorophyll absorption in the last development of plum fruit on the tree for both varieties studied, which corresponds physiologically and horticulturally with the growth and maturation of the fruit. Abdi et al (1997) stated that green-to-yellow color change for prunes in its research is associated with chlorophyll degradation during fruit baking. A decrease of the chlorophyll content by 41% during 12 days of ripening, was also reported for the peel of 'Qingnai' plums (Prunus salicina Lindl.…”

Controle do escurecimento interno de ameixas durante o armazenamento pelo manejo do ponto de colheita e do etileno

“…Segundo Crisosto et al (2004), ameixas 'Blackamber', quando colhidas precocemente, são mais suscetíveis a dano por frio manifestado, como polpa escurecida, e, quando colhidas tardiamente, são mais suscetíveis a dano por frio manifestado, como polpa translúcida. Outros estudos, com várias cultivares de ameixas, mostram que, em frutos colhidos em estádio avançado de maturação, o dano por frio manifesta-se na forma de polpa gelatinosa (ABDI et al, 1997).…”