Thermal processing of aonla juice
Loading...
Date
2007
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
The study was conducted on aonla juice to standardize a
time-temperature combination for thermal processing of aonla juice with
minimum losses in ascorbic acid content. The various physico-chemical
characteristics of fresh aonla juice, heat treated aonla juice and stored
juices were studied. The aonla fruit yielded about 32% pulp and 52%
clarified juice with 9.9% TSS, 2.9% acidity, 3.2% tannins, 426 mg/100g
ascorbic acid and a pH of 2.45. This aonla juice was heat treated at
different temperatures viz. 600C, 700C, 800C and 900C for different time
periods viz. 5, 10, 15 and 20 min. for 600C & 700C and 1, 3, 5 and 10
min. for 800C and 900C. These heat treated juices were analyzed for
various physico chemical characteristics and yeast and mold count. On the basis of this study two best combinations were selected viz. 800C/3
min. and 700C/15 min. which had minimum losses in ascorbic acid
content upon thermal processing and negligible yeast and mold growth.
These combinations were used for storage study of 2 months at room
temperature. During storage, ascorbic acid and acidity decreased
whereas browning increased. There was no significant growth of yeast
and mold even after two months of storage of heat treated juices. Thus
the study indicated that considering the destruction of yeasts and molds
and retention of vitamin C content of the juice, processing of aonla juice
at 800C/3 min. and 700C/15 min. were found suitable.
Description
Keywords
Aonla juice, Thermal processing, Time-temperature combinations, Heat treatment