Treatment of germinated wheat to increase levels of GABA and IP6 catalyzed by endogenous enzymes.
We found that the levels of bioactive products from wheat can be increased dramatically by manipulating germination conditions and taking advantage of the activity of endogenous enzymes. The yield of phytic acid (IP(6)) from wheat germinated in the presence of high, controlled levels of dissolved oxygen (188 +/- 28 mg/100 g wheat) was almost three times greater than that from wheat germinated with no supplemental oxygen (74 +/- 10 mg/100 g wheat). The yield of gamma-aminobutyric acid (GABA) from wheat germinated in the presence of uncontrolled levels of dissolved oxygen was 18 +/- 3 times greater than that from nonsupplemented wheat (1 mg/100 g wheat). The concentration of GABA was much greater in wheat germ than in whole wheat, and the yield of GABA from wheat germ processed with supplemental water (163 +/- 7 mg/100 g wheat germ) was notably greater than that from wheat germ processed with no supplemental water (100 +/- 2 mg/100 g wheat germ). In contrast, IP(6) was more concentrated in wheat bran, and the yield of IP(6) from wheat bran processed with supplemental water (3100 +/- 12 mg/100 g wheat bran) was notably higher than that from wheat bran processed with no supplemental water (2420 +/- 13 mg/100 g wheat bran). We conclude that the large amount of GABA extracted from wheat germ is likely due to high glutamate decarboxylase activity and low aminotransferase activity and that the large amount of IP(6) extracted from wheat bran is likely due to high levels of tyrosinase activity. Our findings indicate that bioactive molecules such as GABA and IP(6) can be successfully mass-produced by taking advantage of endogenous enzymatic activities.
Nagaoka
Hiroyuki
H
Sanyo Foods Co., Ltd., Research and Development, 555-4 Asakura, Maebashi, Gunma 371-0811, Japan. nagaoka1@sea.plala.or.jp
D002384:Catalysis; D018525:Germination; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010833:Phytic Acid / Q000378:metabolism*; D000085822:Prolyl Oligopeptidases; D012697:Serine Endopeptidases / Q000378:metabolism; D014908:Triticum / Q000201:enzymology / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid; D010833:Phytic Acid; D014442:Monophenol Monooxygenase; D012697:Serine Endopeptidases; D000085822:Prolyl Oligopeptidases