Studies on fruit development stages and adjudging maturity indices of European Plum Cv. Hauszwetschge (Clone: Wolff) for extended postharvest life
Neeraj, M. S. Joon, F. Lippert, G. Noga
Abstracts of 7th International Postharvest Symposium 2012 (IPS2012). 25-29 June, 2012. Putra World Trade Centre (PWTC), Kuala Lumpur, Malaysia. 238 pages.
2012
บทคัดย่อ
Proper picking maturity plays a vital role in determining the storage life of plum fruit. The present study was undertaken with an aim to adjudge optimum harvesting stage of European plum for maximum quality retention and extended shelflife. Harvesting of fruits was initiated at colour breaker stage and concluded at self dropping stage. Harvesting was done at weekly interval and seven harvesting stages were characterized viz. harvesting stage -I (HS-I i.e. colour break stage), HS-II, HS-III, HS-IV, HS-V, HS-VI and H-VII (overripe stage, i.e. 42 days after colour break). Fruit weight, specific gravity, hue angle, total soluble solids, TSS/acid ratio and total sugars increased whereas fruit firmness, saturation index (C*) and acidity content of fruits was found decreasing from HS-I to HS-VII. Development of typical blue-purple colour of European plum was represented by negative b* values (maximum at HS- VII, 2.01±0.27). Regression analysis of respiratory profile showed a strong relation between ethylene produced by fruits and changes in sucrose content (R2=0.885) and loss of firmness (R2=0.774). Oxygen consumed by fruits and CO2 produced was also found strongly related (R2=0.875) indicating active respiration throughout growth period. Correlation studies indicate high significant and positive coefficient value of sucrose with fructose (0.941) and glucose (0.894). Fruit composition of 25.90±0.13 g fruit weight, 1.05±0.01 g cc-1 specific gravity, 58.78±1.78 shore firmness, 15.26±0.72 ml kg-l h-1 CO2 production rate, 1.33±0.14 RQ, 18.86±1.37 m1 kg-1 h-1 ethylene production rate and 13.06±0.86 TSS/acidity ratio gave maximum storage life at 20°C. Among various harvesting stages observed, HS-V (i.e. 28 days after colour break) was adjudged as the optimum harvesting stage for European plum.