Preservation Methods Impacted Phenolic, Flavonoid and Carotenoid Contents and Antioxidant Activities of Carrots (D aucus carota L.)

Abstract

Minimal processing methods could result in a very short product shelf life due to microbial and quality deteriorations. This study was undertaken to investigate the influence of blanching, freezing, dehydration and canning on the phenolic, flavonoid and carotenoid contents and antioxidant activities of carrots during storage. Carrot blanching resulted in a significant improvement in the phenolic, flavonoid and carotenoid contents and a reduction in DPPH (1,1-diphenyl-2-picrylhydazyl) inhibition activity compared with fresh carrot. Flavonoid and carotenoid contents of blanched carrot, e.g., were significantly (P < 0.05) increased from 0.029 in fresh samples to 0.038 (μg/g) and from 148.2 to 275.6 (μg/g), respectively. Phenolic, flavonoid and carotenoid content retention decreased from 70.8, 51.7 and 47.9% during the first month of storage to 57.3, 41.4 and 11.8% during the third month of storage. Carrot blanching resulted in a significant increase in the retention of phenolic, flavonoid and carotenoid contents from 100% to 113.5, 131.0 and 186.0%, respectively. Practical Applications Minimally processed carrots have gained interests for their nutritional value and sensory attributes. However, due to the limited shelf life of these processed products, various heat treatments are in practice. Contradictory information on the effect of various processing on the phenolic, flavonoid and carotenoid contents and antioxidant activities of carrots during storage are currently available in the literature. With the increasing consumer demand for minimal processed food, results would provide essential information for consumer selection of processed carrots.