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Effect of different drying methods on chlorophyll, ascorbic acid and antioxidant compounds retention of leaves of Hibiscus sabdariffa L.
Author(s) -
Kumar Sandopu Sravan,
Manoj Prabhakaran,
Shetty Nandini P,
Giridhar Parvatam
Publication year - 2015
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.6879
Subject(s) - hibiscus sabdariffa , chemistry , ascorbic acid , antioxidant , food science , anthocyanin , flavonoid , postharvest , nutraceutical , chlorophyll , bioactive compound , botany , organic chemistry , biochemistry , biology
Abstract BACKGROUND Use of the indigenous, easily accessible leafy vegetable roselle ( Hibiscus sabdariffa L.) for value addition is gaining impetus as its nutritive and nutraceutical compounds are exposed by investigations. Being a perishable, storage is challenging, hence different methods of drying have been an attractive alternative for its postharvest usage in foods without much compromising its quality and antioxidant potential. RESULTS Room‐ and freeze‐dried samples were found to have best quality in terms of colour, total flavonoid content (18.53 ± 2.39 and 18.66 ± 1.06 g kg −1 respectively), total phenolic content (17.76 ± 1.93 and 18.91 ± 0.48 g kg −1 ), chlorophyll content (1.59 ± 0.001 and 1.55 ± 0.001 g kg −1 ) and ascorbic acid content (11.11 ± 1.04 and 8.92 ± 0.94 g kg −1 ) compared with those subjected to infrared, crossflow, microwave, oven or sun drying. Samples treated by room and freeze drying retained maximum antioxidant potential as shown by the phosphomolybdate method and the 2,2‐diphenyl‐1‐picrylhydrazyl free radical‐scavenging activity and ferric‐reducing antioxidant power assays. Cold water and hot water extracts showed significantly higher total phenolic content and total antioxidant activity owing to the greater solubility of phenolics and destruction of cellular components in polar solvents than in organic solvents. CONCLUSION The data obtained show the potential for retaining quality parameters of roselle leaf under suitable drying methods. © 2014 Society of Chemical Industry