Quality of physalis (Physalis pubescenss L.) juice packaged in glass bottles and flexible laminated packs during storage at 5°c.

Abstract

Husk tomato (Physalis pubescens L.) is one of the important 100 species in the Physalis genus of the Solanaceae family. Among unexploited tropical fruits, Physalis is a very promising fruit. Physalis is included in the priority list of many governments' horticulture and fruit export plans. It is relatively unknown in importing markets and remains an exotic fruit. The important step toward developing Physalis as a commercial crop was maximizing its technological applications. The objective of our study was to prepare a new processed pasteurized Physalis juice and to study the effects of storage and packaging on its nutritional properties. The pulp was yellowish or orange with a yield of 64%. The fresh juice had a light sweet and acidic taste (pH 3.5). The titratable acidity was 1.43%, polyphenols 76.6mg/100mL and vitamin C 38.8mg/100mL. Physalis juice was rich in carotenoids (70μg/mL). The nutritional and bio-physical characteristics of Physalis juice packaged in glass bottles and flexible laminated packs during storage under refrigeration (5±1°C, 85-90%RH) for 6 months
were studied. Carotenoids, polyphenolic substances and ascorbic acid contents were gradually reduced throughout cold storage, where this reduction was more pronounced in juice packaged in flexible laminated packs. A slight increase in total acidity was observed with cold storage prolongation, especially in juice packaged in flexible laminated packs. Significant differences in color were found between the same juice packaged either in glass bottles or in flexible laminated packs, where the
juice color was darker in flexible laminated packs. It could be noticed that, there was no migration of Na ions from glass bottles to processed juice formulas during the cold storage period. In flexible laminated packs, a slight increase of Al ions throughout the cold storage period but not exceeding the safety limit of Al daily intake (3.5mg/day). It was concluded that Physalis juice packaged in glass bottles had higher storage
stability than that packaged in flexible laminated packs.