STUDIES ON THERMAL PROCESSING OF SOME FOODS

Abstract

Canning and thermal processing are the major section of the food industries in Egypt. This study was carried out for : I- Studying changes that occur in chemical, microbial and sensory attributes during blanching of green beans, peas and okra. II- Isolation and identification of aerobes isolates (Bacillus spp.)

i.e .. B. subtilis, B. coagulans, B. stearothermophilus, B. cereus

0 and B. licheniformis from green beans, peas and okra Decimal reduction time (D-values) and Z-values for these isolates were determined. III- Studying heat penetration of canned green beans, peas and okra either in brine solution or in tomato sauce and find out thermal constant parameter (fh, jh, jc). IV- Studying the optimum thermal process time.

The results can be summarized as follows :

1- Blanching of green beans, peas and okra in boiling water for 1, •

c 3 and 5 minutes decreased the chemical constituents.

2- All major constituents of green beans, peas arid okra i.e. protein, ash, fat and fiber were decreased after canning process. However, the higher a decremental reduction was observed when brine solution l .5o/o was used compared with canning in tomato sauce.