• Food Science and Biotechnology
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• v.17 no.5
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• pp.996-1002
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• 2008

Pickled hen egg dipped in brewed apple vinegar for 7 and 14 days was prepared and changes of weight, pH, viscosity, calcium content, antioxidative effect, and sensory characteristics were determined. During a pickling, the egg weight was increased from 62.03 g at day 0 to 91.13 and 94.93 g at day 7 and 14, respectively. The pH of the egg white and yolk, initially at pH 10.24 and 6.56, was decreased, while that of the pickling solution was increased by the pickling days. Viscosity of the pickled egg white was significantly decreased with the pickling days (p<0.05). Significant antioxidative effect was found from the pickled egg mixture (egg white:yolk=1:1). Calcium content of the egg white after 7 and 14 days of the pickling was 280-300 times higher than the fresh egg white and 1.9 times higher than fresh egg yolk. Addition of plain yogurt and honey improved the sensory quality of a pickled egg and was able to mask the unpleasant sour taste. Results suggest that, in addition to the use of pickled egg by itself, egg-based foods such as mayonnaise with enforced calcium content can be developed using a pickled egg.

• Microbiology and Biotechnology Letters
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• v.41 no.2
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• pp.168-175
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• 2013

In this study we investigated the possibility of preparing brewed brown rice makgeolli, a traditional Korean rice wine, under diverse conditions. For this purpose the physicochemical characteristics of makgeolli brewed at different temperatures, utilizing a variety of nuruks, the traditional Korean fermentation agent, were studied. The alcohol content was seen to be highest when brewing occurred at $30^{\circ}C$, with the nuruk TN producing 16.2%. At $20^{\circ}C$TN produced 14.1% alcohol content. The alcohol content was therefore higher, by about 2%, for $30^{\circ}C$ fermentations than $20^{\circ}C$ fermentations. Similarly, saccharifying activity was influenced by temperature and sugar content, with a higher activity seen at $30^{\circ}C$ than at $20^{\circ}C$. As the fermentations progressed acidification petered out, with titratable acidity being 0.50-0.67% in all end samples. On the Hunter L, a, b scale; the a value decreased slightly, while the b value increased steadily during the fermentation process. Measurements of total organic acids were highest at $30^{\circ}C$, with the nuruk AK, at about 550 mg%. The content of citric acid was the highest at $30^{\circ}C$, being 230-310 mg% in all samples. However, more lactic acid was detected at $20^{\circ}C$ than at $30^{\circ}C$. Total free amino acid was highest at $30^{\circ}C$, with TN at $8,605{\mu}g/ml$, AK at $6,083{\mu}g/ml$, and RJ at $2,381{\mu}g/ml$. Total free amino acid and essential amino acid was shown to be higher at $30^{\circ}C$ than at $20^{\circ}C$. The bioactive substance ${\gamma}$-aminobutyric acid was also higher at $30^{\circ}C$, with TN at $223{\mu}g/ml$. From all of these results, we surmise that brown rice makgeolli manufacturing conditions are optimal at $30^{\circ}C$ fermentation temperatures and using the nuruk TN for brewing vinegar. In addition, the nuruk used clearly affects the quality of brown rice makgeolli and an appropriate method to determine the best nuruk for various purposes should be pursued.