Post harvest evaluation of bitter gourd as influenced by growing condition, harvest maturity, prepacking and storage

Abstract

The present investigation on “Postharvest evaluation of bitter gourd as influenced by growing condition, harvest maturity, prepackaging and storage” was carried out at the Department of Processing Technology, College of Agriculture, Vellayani during 2011-2013, with the objective to determine the stage of harvest maturity and its influence on postharvest life along with prepackaging and storage condition for organically and conventionally grown bitter gourd (var. Preethi) and to develop a postharvest package for extended shelf life with minimum nutritional loss.

The experiment was conducted in three continuous phases such as determination of harvest maturity, precooling treatments, prepackaging and storage. Growth and development studies conducted for determining harvest maturity revealed that fruit length, width, weight and flesh thickness increased periodically till 15 days of flowering and percentage of increase was negligible 15 days after flower opening. But conventional fruits recorded higher values for all these physical characters at all the stages of maturity. Considering the development of both external and internal fruit characters, 14 and 15 days after flower opening were selected as optimum harvest maturity for further postharvest studies.

Hydrocooling of harvested fruits with 150 ppm sodium hypochlorite was found as the best sanitizing treatment for maintaining the postharvest quality and increased shelf life for both harvest maturities (14 and 15 days) and growing conditions (organic and conventional).

Prepackaging and storage trials revealed that prepackaging treatments, growing conditions and storage temperature had significant influence on shelf life and nutritional qualities of fruits. Fruits with 14 days maturity, grown organically, prepackaged in micro ventilated polyethylene and stored under refrigerated condition had resulted in lowest PLW.

Nutritional parameters of fruits viz, protein, acidity, fibre, calcium, magnesium, iron and ascorbic acid were analysed before storage and at the end of shelf life. Before storage, none of the factors except growing conditions had significantly influenced the nutritional parameters. Fruits grown conventionally had higher protein and organic fruits exhibited high fibre, Ca, Mg, Fe and ascorbic acid content. Storage studies revealed that refrigerated storage after prepackaging in micro ventilated PE had lower nutritional and physiological changes during storage.

From the study it can be concluded that bitter gourd (var. Preethi) fruits can be harvested at 14 days maturity for export and long distance market and 15 days for domestic market grown under both organic and conventional system in order to reduce the postharvest losses. Harvested fruits precooled with water containing 150 ppm sodium hypochlorite, prepackaged in micro ventilated polyethylene and stored under refrigerated condition was effective for extending the shelf life with minimum nutritional loss.