MSc

The study entitled “Standardization of minimal processing of amaranthus (Amaranthus tricolor L.)” was conducted in Department of Processing Technology, College of Agriculture, Vellayani, during 2014-16 with the objective to standardise minimal processing technology for the development of ready-to-use amaranthus with extended shelf life and nutritional quality.
Amaranthus (var. Arun) harvested after 30 days of sowing were subjected to sanitisation treatments, after removing root portion and effectiveness of sanitising agents was determined for leaves and stem separately by analysing microbial, biochemical and visual parameters. The study revealed that surface decontamination with 2 ppm ozonised water had the highest percentage of microbial reduction (40.53 per cent for leaves and 39.15 per cent for stem), highest retention of ascorbic acid, anthocyanin and mean score for visual parameters.
After surface sanitisation of amaranthus with 2 ppm ozonised water, effect of pre-treatments was analysed separately for leaves and stem and it was observed that pre-treatment with sodium benzoate + citric acid (0.1%) recorded the lowest physiological loss in weight, highest relative water content, membrane integrity, mean score for visual parameters, ascorbic acid, anthocyanin content, antioxidant assay and lowest microbial population for both amaranthus leaves and stem which was followed by calcium chloride (1%).
Amaranthus surface sanitized with 2 ppm ozonised water and pre-treated with sodium benzoate + citric acid (0.1%) were shredded in to uniform size and subjected to pre-packaging and storage studies. Fresh cut amaranthus, packed as two different proportions of leaves and stem (1:1 and 1:2 (w/w) in different packaging materials and stored at ambient and refrigerated conditions were analysed for physical, physiological, biochemical, microbial and sensory qualities. Fresh cut amaranthus packaged in 150 gauge micro ventilated polyethylene had lowest physiological loss in weight, highest relative water content, membrane integrity, mean score for visual parameters viz. colour, texture and overall acceptability with lower score for wilting, highest retention of ascorbic acid, anthocyanin, antioxidant activity and lowest microbial load for both proportions under ambient as well as refrigerated storage. The results revealed that pre-packaging and storage of sanitized and pre-treated fresh cut amaranthus (leaves : stem as 1:1) packaged in 150 gauge micro ventilated polyethylene had shelf life up to eight days with highest retention of freshness and nutritional qualities under refrigerated storage and four days shelf life when stored at room temperature. Sensory analysis of the standardised technology revealed that there was no difference in sensory attributes of the sanitised, pre-treated, pre-packaged ready-to-use amaranthus from the freshly harvested amaranthus.
Surface sanitization of amaranthus (var. Arun) with 2 ppm ozonised water and pre-treatment with sodium benzoate + citric acid (0.1%) and pre-packaging in micro ventilated polyethylene could extend the shelf life of minimally processed amaranthus up to eight days when stored under refrigerated condition and four days under ambient conditions.