The effect of nuruks and crude amylolytic enzyme on free amino acid and volatile components of brown rice vinegar prepared by static cultures was investigated. Five groups consisted of AV (100% nuruk without crude amylolytic enzyme), BV (75% nuruk; 25% crude amylolytic enzyme), CV (50% nuruk; 50% crude amylolytic enzyme), DV (25% nuruk; 75% crude amylolytic enzyme) and EV (100% crude amylolytic enzyme without nuruk). Free amino acid content in AV vinegar (132.06 mg%) was lower than the others (184.56-191.22 mg%). Acetic acid, 3-methyl butyl acetate, acetoin and isoamyl alcohol were major volatile components as analyzed using gas chromatography-mass spectrometry after headspace solid-phase microextraction. Acetic acid in AV and EV samples represented 67.56% and 55.53% of total GC peak area, respectively. E-nose provided different patterns in each case showing variation in sensory properties.

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This study investigated the quality characteristics of brown rice vinegar (agitated culture and static culture) derived from brown rice Takju with different types of yeasts. The alcohol content by yeast was the highest in B (brown rice Takju produced by S. cerevisiae GRJ) at 14.3% and the titratable acidity was less than 0.6% in all ranges. When quality characteristics of agitated and static culture brown rice vinegar using them were compared, acidity of agitated culture vinegar recorded the highest level or 6.05% at 7 day of fermentation DV (brown rice vinegar produced by S. kluyveri DJ97) with the initial acidity of 1.0% and the initial pH of 3.9～4.0, and AV (brown rice vinegar produced by S. cerevisiae JK99), CV (brown rice vinegar produced by S. cerevisiae H9) and BV (brown rice vinegar produced by S. cerevisiae GRJ) recorded as 5.64, 5.55 and 5.32%, respectively. In addition, acidity of static culture vinegar increased continuously to 5.01～5.31% until the 14 day of fermentation and then tended to decrease slightly from the 16 day of fermentation. Difference in acidity and pH of brown rice vinegar according to types of yeast was not significant. Comparison of free amino acid of brown rice vinegar showed that for agitated culture brown rice vinegar, the content of total free amino acid was higher in the order of BV, DV, AV and CV and the content of essential amino acid was the highest in BV by recording over 1,000 ppm. The content of total free amino acid of static culture brown rice vinegar was higher than that of agitated culture vinegar in all ranges and especially static culture brown rice vinegar contained more serine, alanine, valine, isoleucine, leucine and γ-aminobutyric acid than agitated culture vinegar. In particular, γ-aminobutyric acid recorded over ten times higher level or 456.91～522.66 ppm. From these results, quality characteristics of brown rice vinegar was affected by acetic acid fermentation methods rather than types of yeast. However, as future aging process is expected to change flavor components and sensory characteristics, studies on various quality factors of vinegar are needed.

Quality properties of red ginseng prepared with different cultivation years of fresh ginseng produced in Punggi region were investigated. Fresh ginseng cultivated for 4, 5, or 6 years was steamed for 3.5 hr and dried for 24 hr at 60～65 o C and subsequently for 3～4 days at 40 o C under commercial conditions. Compared to 6 years-old roots, the five years-old roots showed similar or some lower quality properties in terms of color, appearance, diameter, and inside quality, but higher ones in length and yield of prepared red ginseng. In particular, the levels of ginsenoside Rg3 and Rh2, which are known as specific components in red ginseng, were the highest in 5 years-old roots. The result shows that fresh ginseng of 5 years-old roots produced in Punggi region can be utilized as a raw material for the manufacture of high-quality red ginseng.

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