Post Harvest Stabilityof Vegetable Amaranthus (Amaranthus Dubius)Combined Low Temperature And Modified Atmospheric Packaging

Abstract

Post-harvest losses of leafy vegetables are estimated to be over 30% and are generally caused by poor handling and storage conditions. In this study, leaf amaranthus variety dubius was used to determine the changes in physico-chemical properties of the vegetable under modified atmospheric storage combined with low temperatures. Leaf amaranth grown at JKUAT farm was harvested at 8 weeks after planting. The vegetables were kept in active bags and stored in cold room at temperatures between 5^o-25^oC and relative humidity of 75%.Initially and after every two days, the vegetable were analyzed for moisture, beta-carotene, ascorbic acid and respiration rates. Ascorbic acid content in the fresh leaf amaranth was 67?g/g. The results indicated that loss of ascorbic acid was greater insamples stored at higher temperatures as compared to samples stored at the lower temperatures. The control sample lost 88% of ascorbic acid in 4 days as compared to 55% loss at 5^oC after 23 days.Beta-carotene content in the fresh leaf amaranth vegetable was 61.4mg/100g. Loss in carotene was slightly higher at room temperature (25°C) and decreased correspondingly with decrease in storage temperature. At the end of the storage, the retentions were 6.86, 19.6, 26.14 and 31.53mg/100g at 25°C, 15°C, and 10°C respectively. Amaranth vegetable exhibited a non-climacteric rise with the peaks of carbon dioxide production. Based on this study, it is suggested that the use of active bag combined with low temperature storage can extend the shelf life and preserve nutrients of vegetable by maintaining quality attributes and external appearance of vegetable amaranth.

Key words: vegetable amaranth, modified atmospheric storage, ascorbic acid, beta-carotene