Chemical Changes in Okra Stored in Air and Controlled Atmosphere

Okra (Abelmoschus esculentus L. Moench) pods stored In a controlled atmosphere (CA) of 5% O2 and 10% CO2 at 11 ± 1C and in air at the same temperature (RA) were compared to determine the effects of the two storage environments on changes in sugars, organic acids, proteins and amino acids, and ascorbic acid contents within the tissue. Pods were sampled at 3-day intervals for 12 days. CA-stored pods generally had greater retention of sugars, soluble proteins, and amino acids than RA-stored pods. Citric, malic, and ascorbic acids contents of CA pods also declined more slowly than those of RA pods. Okra is well-adapted to hot, humid conditions and is a popular vegetable in most tropical countries. Okra not only serves as a thickening agent for soups and stews, but is an important source of nutrients in the diet (8, 9). Fresh okra pods have a short postharvest life, being prone to physical and physiological changes that reduce quality (18). Postharvest treatments such as hydrocooling (6), chemical sprays (11), and modified atmospheres (MA) (1) have been used to extend the postharvest life and maintain the quality of fresh okra. Modified or controlled atmosphere (CA) in conjunction with low temperatures is particularly attractive, since this stor- age method is generally considered effective in reducing the respiration rates of fresh vegetables and in maintaining quality while leaving no harmful residues. The effects of MA or CA storage on physical and physiological changes in fresh com- modities are variable and there are even conflicting reports on the effects of CA storage on a given commodity in some cases