Development of shelf stable intermediate moisture carrot (Daucus carota) shreds using radiation as hurdle technology

Carrot (Daucus carota) is highly perishable and difficult to preserve fresh for long periods at ambient temperature and humidity. Shelf-stable intermediate moisture (IM) carrot shreds were developed based on ‘hurdle technology’ [HT] which included the combination of the factors like drying by two methods - Infrared drying (IR) / Tray drying (TD) to reduce water activity [aw] to 0.6, pre-treatments and packaging. The product was stored in 400 gauge polyethene and treated with low doses of gamma radiation 0.5 kGy as a major hurdle technology and observed for shelf life stability at ambient conditions (30°C and 65% RH). Infra red dried vegetables treated with gamma radiation (IRR) were found to be stable up to 6 months without substantial loss of flavor, taste, colour and texture than the other treatments. IRR yielded IM carrot shreds with improved rehydration potential, appearance and with the nutrient retention up to 52% of β-carotene, 59.8% of total carotenoids and 25.3% of vitamin C more than the tray dried IM carrot shreds. The product was microbiologically safe throughout the study. Infrared drying using radiation as hurdle technology could be suggested as a potential method for obtaining high quality IM products with optimum sensory, microbial and nutritional quality.