MSc

The study entitled “Postharvest handling for extending shelf life of amaranthus (Amaranthus tricolor L.)” was conducted at Department of Processing Technology, College of Agriculture, Vellayani, during 2013-15, with the objective to extend the shelf life of amaranthus (var. Arun) with minimum nutritional loss through postharvest handling practices.
Amaranthus (var. Arun) raised as per Kerala Agricultural University packages of practices was harvested 30 days after sowing and 25-30 cm long stem with leaves after removing root portion were taken for the study.
Effectiveness of sanitizing agents for surface decontamination of harvested amaranthus was evaluated by analyzing microbial, physiological and visual parameters. The results revealed that amaranthus sanitized with 2 ppm ozonised water had highest microbial reduction (85.68 %), lowest physiological loss in weight (25.63 %), highest relative water content (63.11 %) and score for visual parameters which was followed by those treated with 30 ppm sodium hypochlorite.
When amaranthus sanitized with 2 ppm ozonised water was subjected to different pretreatments and conditions, it was observed that dipping in 10 ppm Benzyl Adenine with moist cotton plugging of cut stem end had lowest physiological loss in weight (21.35 %), highest relative water content (70.22 %) and acceptability which maintained a shelf life up to 48 h of storage at room temperature (30±2˚C).
Amaranthus surface sanitized with 2 ppm ozonised water and pretreated with 10 ppm Benzyl Adenine with moist cotton plugging of cut stem end was packaged in different materials and stored at room temperature (30±2˚C) and refrigerated conditions (10±2˚C) and analysed for physiological, nutritional and visual qualities. The results revealed that prepackaging of sanitized and pretreated amaranthus in 100 gauge macro ventilated polypropylene without absorbent paper had shelf life up to 72 h with highest retention of freshness and nutritional qualities when stored at room temperature and up to 120 h in refrigerated storage. Amaranthus had lowest
physiological loss in weight (17.29 %) and highest relative water content (67.91 %) at 120 h of refrigerated storage.
Nutritional parameters of sanitized and pretreated amaranthus were analyzed and recorded 18.55 to 19.05 mg/100g of ascorbic acid, 5.31 to 5.34 mg g-1 of total chlorophyll, 6.25 to 6.26 μg/100g of β-carotene, 6.36 to 6.45 % of calcium and 0.16 to 0.17 % of iron before storage. At the end of shelf life of 120 h of refrigerated storage, amaranthus prepackaged in macro ventilated PP (100 gauge) without absorbent paper recorded maximum retention of ascorbic acid (10.78 mg/100g), total chlorophyll (4.42 mg g-1), β-carotene (5.34 μg/100g), calcium (5.99%) and iron (0.09%) content with lowest microbial population.
Surface sanitization of harvested amaranthus (var. Arun) with 2 ppm ozonised water and dipping in 10 ppm Benzyl Adenine, each for five minutes, followed by moist cotton plugging of cut stem end and prepackaging in macro ventilated polypropylene (100 gauge) without absorbent paper could extend shelf life up to 120 h when stored under refrigerated condition.