Impact of freezing methods on the physicochemical and sensory qualities of frozen carrot (<em>Daucus carota</em>) (Cape Market variety) dices

Abstract

Carrots (Daucus carota) are root vegetables that contain carotenoids, flavonoids, polyacetylenes, vitamins, and minerals. They are high in antioxidants, anticarcinogens, and immune enhancers making them excellent for the eyes. Carrots suffer from significant postharvest losses in Sri Lanka due to their perishable nature, as well as rejections due to their odd morphologies. Even though demand for carrot is high all around the country, losses are unavoidable. Freezing techniques play a vital role in maintaining freshness and avoiding deterioration simultaneously. The goal of the present study was to find the best freezing method among blast freezing (-30 °C) and conventional (-18 °C) freezing circumstances for a superior quality of frozen carrot dice. Blanched (90 °C for 3min) carrot dice (Cape market variety) were frozen and thawed, then physicochemical parameters like drip loss (%), pH and colour, and other aspects including length ratio, hardness and cutting shearing strength and sensory parameters like colour, odour, texture and overall quality changes during freezing were analyzed. The blast frozen-thawed carrot dices showed the best quality of fresh colour, 8.50 ± 2.83 of colour change, 5.573 ± 0.555 % of drip loss, 0.0333 ± 0.007 length ratio, 21.53 N ± 3.78 hardness, 0.1366 J ± 0.0361 cutting and shearing strength, and 5.6867 ± 0.01 pH than conventional frozen-thawed dices. Mann Whitney U test resulted that blast frozen carrot dices had significantly (p<0.05) higher consumer preference than conventionally treated samples during the sensory analysis.