• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.594-600
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• 2009

Quality characteristics of white lotus leaf tea (LLT) fermented with or without mycelial Paecilomyces japonica were investigated. Extraction yield and browning index of hot water extract from non fermented and fermented LLTs were higher than those of ethanol extract (p<0.05). In all LLTs, nutritional components such as total free sugar, free amino acids and minerals of hot water extracts were higher than those of ethanol extracts except for total organic acids (p<0.05). Contents of total free sugar and organic acids were markedly increased through fermentation process of mycelial Paecilomyces japonica. in the same solvent extracts (p<0.05). Contents of most taste components of fermented LLT were increased by mycelial solid fermentation (p<0.05), but total free amino acids of two extracts were decreased in the range of $37.1{\sim}67.2%$ as compared to non-fermented LLT. Fifty-nine volatile compounds were identified by GC and GC-MS, including 11 aldehydes, 14 alcohols, 11 ketones, 11 hydrocarbones and 12 acids. Aldehyde and ketone compounds were more identified in fermented LLT than in non-fermented LLT being abundant alcohol compounds by simultaneous steam distillation and extraction. The most abundant compounds of LLT identified in this study were curcumene followed by 2,6-bis(1,1-dimethylethyl)-4-methyl-phenol and cyclohexen. Main compounds of fermented LLT were 2,6-bis(1,1-dimethylethyl)-4-methyl-phenol, butanoic acid, furfural, benzaldehyde, hexanoic acid and 2(3H)-furanone.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.133-141
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• 2016

The physicochemical properties, antioxidant capacities, and sensory optimization of taro (Colocasia esculenta) under different aging conditions were investigated to develop black taro. Black taro was processed in three steps (steaming: $95{\pm}3^{\circ}C$ for 1 h; aging: 85, 90, $95^{\circ}C$ for 20, 40, and 60 h; drying: $60^{\circ}C$ for 24 h) and ground into a powder for all experiments. Black taro showed an increased crude fiber content and browning index compared to raw taro. Calcium oxalate contents, reducing sugar contents, moisture contents, and lightness values were decreased during the processing of taro. Improvements in total polyphenol content and antioxidant activity (DPPH, ABTS, FRAP) were observed in the black taro samples aged at higher temperature. Response surface methodology was used for sensory optimization, and the optimum aging conditions with the highest acceptance values were found to be $88.73^{\circ}C$ for 39.50 h for taste, and $88.82^{\circ}C$ for 42.60 h for overall acceptance.