Quality evaluation of vegetables cultivated through aquaponics

Abstract

The project entitled “Quality evaluation of vegetables cultivated through aquaponics” was carried out at the Department of Community Science, during 2018-2020. The objective of the study was to compare the quality characteristics of selected green leafy vegetables cultivated through aquaponics (T1) and conventional methods (T2). The capacity of the grow bed of the aquaponics unit selected was 400 L and that of the fish tank was 500 L.tuberless colocasia, water spinach and malabar spinach were the selected green leafy vegetables.Hundred tilapia fishes were grown with the plants. After the plants attained maturity, the physical characteristics, sensory qualities, nutrient composition, nutraceutical composition and shelf life of the two treatments of these leafy vegetables were studied. Except for water spinach, yield of malabar spinach and tuberless colocasia were comparable in both the treatments. Dry matter production of T1tuberless colocasia(119.5g/plant) was higher than T2 (45.25g/plant). Higher values for sensory qualities in both fresh and cooked samples of T1were obtained with respect to colour, appearance, texture, taste and flavor. In the case of water spinach, the higher scores obtained for appearance and colour of fresh leaves were significantly different (z value-3.023 and 2.305 respectively). Nutrient analysis revealed significant differences in the moisture content and fibre content of malabar spinach among the treatments. Statistical analysis revealed significant difference among the treatments cultivated in aquaponics and conventional systems for tuberless colocasia and malabar spinachwith respect to total minerals and acidity content. Nutrient analysis revealed significantly highervalues for soluble sugars, vitamin C, beta carotene, calcium and Iron for T1. In nutraceutical profile analysis, except for oxalate content, there was significant differences among the treatments. 138 Shelf life studies revealed that tuberless colocasia (T1) remained fresh for 7 days when packed in newspaper, while T2tuberless colocasia, kept only for 6 days in similar packing. water spinach had the least shelf life in ambient conditions -T1 had 4 days and T2 had 3 days, when packed in news paper. Physiological loss of water was not found to be significantly different in any of the treatments of these vegetables. Shelf life of leaves were not seen to show differences among the treatments. Packing in PP covers were generally seen to be ideal for all the three leaf varieties. Overall analysis of the results revealed that, physical characteristics, sensory qualities, nutrient composition, nutraceutical composition and shelf life parameters of T1were on par with T2, or even higher in most cases, indicating the scope of raising these vegetables successfully in households for Food and Nutrient security.