| Pueraria lobata (Willd) Ohwi is a perennial leguminous vine of the genus Pueraria DC. It was formally listed in the "food and drug" items by Chinese Ministry of Health in 1998. Pueraria lobata (Willd) Ohwi contains many kinds of phenol components and nutrients such as isoflavone, starch, dietary fiber, protein and minerals, which implies its great value in developing nutritional supplement. Pueraria is widely planted in China, but their utilization is very limited. Currently, extraction of isoflavones, starch and producing traditional Chinese medicine are the major ways to utilize it. However, the three ways were indenpent,and the utilization of pueraria was not efficient. The vinegar brewing technology is an effective way to use all components and increase the value of pueraria. In this study, we used vinegar brewing technique to make the major components of pueraria being biologically transformed. The effectiveness of this biological transformation was evaluated.ObjectiveTo make full use of pueraria by the technology of brewing vinegar, evaluate the nutrition value of pueraria vinegar, and to offer scientific basis for the rational conversion of pueraria.Methods1. The solid-state fermentation method was used to brewe pueraria vinegar and part of foxtail millet was replaced by pueraria. The raw materials proportion (foxtail millet: pueraria) in three kinds of pueraria vinegar were 1:1,3:1 and 1:0 respectively.2. The Kieldahl method was used to determine the content of protein in the three vinegar products.3. Flame atomic absorption spectrophotometry was used to determine the contents of copper, zinc, iron, calcium and magnesium in the vinegar products, the content of selenium in the vinegar products were measured by fluorescence method.4. The colorimetry method was used to determine contents of polyphenols and flavonoids in the vinegar products. 5. Contents of puerarin in pueraria and pueraria vinegar were measured by high performance liquid chromatography.6. The clearance rates of the three kinds of vinegar to·OH, O2-·and DPPH·were measured by colorimetry.IC50 was used to evaluate.Results1. The contents of protein in the three kinds of vinegar were between 2.69%～2.91%, there were no significant differences in the three kinds of vinegar (P>0.05).2. There were significant differences in calcium and selenium content in pueraria vinegar and foxtail millet vinegar, and pueraria vinegar's were higher than that of the foxtail millet vinegar (P< 0.05). The contents of copper, zinc, iron and magnesium of rice vinegar were higher than that of the pueraria vinegar, and the differences were significant(P< 0.05).3. There were significant differences in the contents of polyphenols and flavonoids in the three kinds of vinegar (P< 0.05). The result of LSD-t analysis was pueraria vinegar 1>pueraria vinegar 2>foxtail millet vinegar(P< 0.05).4. The contents of puerarin in pueraria vinegar 1, in pueraria vinegar 2 and in pueraria were 36.54 mg/L,12.61 mg/L and 2.09% respectively.5. The transformation efficiencies of puerarin in pueraria vinegar 1 and in pueraria vinegar 2 were 1.39% and 1.07% respectively.6. The IC50 of·OH in pueraria vinegar 1, pueraria vinegar 2 and foxtail millet vinegar were 13.54 mg/L,14.84 mg/L and 19.32 mg/L respectively, the IC50 of O2-·in pueraria vinegar 1, pueraria vinegar 2 and foxtail millet vinegar were 17.03 mg/L, 20.03mg/L and 24.03 mg/L respectively, the IC50 of DPPH·in pueraria vinegar 1, pueraria vinegar 2 and foxtail millet vinegar were 26.95 mg/L,33.90 mg/L and 36.78 mg/L respectively.Conclusions1. With the increasing proportion of pueraria in raw material, the contents of calcium, selenium, puerarin, polyphenols and flavonoids were increased accordingly. The vinegar brewing procesing can implement the biological transformation of pueraria effectively.2. The nutrition value of pueraria vinegar was higher than that of foxtail millet vinegar, with the increasing proportion of pueraria in raw material, the clearance rate of the vinegar to·OH, O2-·and DPPH·was up-regulated.
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