Effect of acidification on quality and shelf-life of carrot juice

Abstract

Yu, L. J. and Rupasinghe, H. P. V. 2012. Effect of acidification on quality and shelf-life of carrot juice. Can. J. Plant Sci. 92: 1113–1120. This study compared the effects of different acidification methods for processing carrot juice: blanching of carrot with 20 and 40 g L−1 of citric acid, 20 and 40 g L−1 of lactic acid and blending carrot juice with cranberry juice in 80:20 and 70:30 ratios. The quality was measured in terms of changes in pH, titratable acidity (TA), total soluble solids (TSS), turbidity, antioxidant capacity, beta-carotene content and total aerobic colony count (TAC) during a 21-d storage at 4°C. Water blanched carrot juice was selected as the control. During storage, the pH, TA, TSS and turbidity values were much more stable for all acidified juices than for water blanched juice. The highest value and stability of antioxidant capacity measured by ferric reducing antioxidant power (FRAP) belonged to a carrot-cranberry juice blend in a 70:30 ratio. The highest beta-carotene value belonged to 40 g L−1 lactic acid blanched juices. Carrot-cranberry juice blend in an 80:20 ratio gave the maximum stability for beta-carotene. All acidification methods prolonged the shelf-life of carrot juice in terms of TAC. Blanching with 40 g L−1 of lactic acid or citric acid provided 3–4 log reduction TAC and was among the most effective methods for extending the shelf-life of carrot juice.