Effect of osmotic dehydration on physico-chemical properties and pigment content of carrot (Daucus carotaL) during preserve manufacture

Abstract

Osmotic dehydration affected physico-chemical properties and carotenoids content during preserve making in red and orange carrots. The initial soluble solid contents of 5.29°B and 9.53°B increased to 67°B and 69°B in the final product of red and orange carrots, respectively. Total carotenoids content reduced from 15.28 to 9.34 mg/100 g for red carrot and 24.5 to 22.12 mg/100 g for orange carrots due to thermal degradation. The lycopene content also got decreased in both carrots when cooked in sugar syrup. Red carrot has higher lycopene content as compared with orange carrot. The L value decreased during preserve making due to darkening. The “a” value and “b” value also decreased which means reduction in redness and yellowness. Reducing sugars increased during processing because of inversion of sucrose in the presence of citric acid. Practical applications The current focus of the food processing is to study the functional constituents. Pigments are important phyto-chemicals having health promoting properties. Carrot is a very economic source of carotenoids that gets converted into vitamin A. Preserve is an important product that can be used as a mean to supplement vitamin A. This study has been carried out to know the fate of pigments during processing. The preserve manufacturers, nutritionists and consumer may get the precise amount of pigment in the final product.