Sustainable usage of carrot discards in food processing

Abstract

The Processed carrot discards (PCDs) separated during the primary processing of carrots are partially utilized towards animal feed and the remaining end in the landfills. The study was undertaken to evaluate the prospects of using the PCDs towards preparation of carrot puree. PCDs were procured from the processing unit in Ontario, Canada. These were processed into carrot puree (with and without thermal pretreatment). The prepared purees were evaluated for the physical and nutraceutical properties, and the most desirable among these was compared with the commercially available carrot purees. Carrot puree processed from steam blanched PCDs reported β-carotene (94.56µgg-1), α-carotene (86.62µgg-1), Total Soluble Solids (5.50 °Brix) and color values with L (36.40), a (22.90) and b (30.00). The regression model correlated the presence of β-carotene to color values (a, b) and particle size D (0.9) with R2(0.9939) and p-value (0.0091 < 0.05). Comparing the properties of carrot puree prepared from PCDs with commercially available carrot purees, significant differences (p ≤ 0.05) were recorded in color, β-carotene and α-carotene content. No significant difference (p≤0.05) was recorded for the particle size, density, sedimentation index and moisture content. The study concluded that the thermally pretreated PCDs can be used for carrot puree preparation. It is suggested to include some percentage of graded carrots with PCDs to enhance the nutraceutical properties of the carrot puree.