EFFECT of MODIFIED ATMOSPHERE PACKAGING ON GLUTATHIONE and ASCORBIC ACID CONTENT of ASPARAGUS SPEARS

Abstract

Asparagus (Asparagus Officinalis L.) spears were packaged in ordinary and microperforated oriented polypropylene (OPP) films and were stored at 15C and 75% RH for up to 10 days. CO2 concentrations ranged from 15.5 to 23% at 10 days of storage. Weight loss was less than 1.2% in microperforated film packages compared with 15% in air storage under similar conditions. Ascorbic acid content was found to be adversely affected at all the O2 levels (1–6%) prevailing in microperforated film packages, but it was retained to the extent of 45–55% of its original concentration in ordinary OPP film packaged asparagus. the O2 concentrations in microperforated film packages were also associated with higher glutathione concentrations in packed asparagus spears. Results of the study indicated that to preserve ascorbic acid and glutathione simultaneously in stored asparagus through MAP under high CO2 and low O2 conditions, O2 concentration levels must be selected between 1 and 6% in such a way so as to get acceptable retention levels of ascorbic acid and glutathione.