Use of chlorogenic acid as target to optimize the formula of vinegar fermented with eucommia leaves

Presented a novel way to manufacture vinegar product with the supplement of eucommia leaves hydrolysates containing chlorogenic acids to wheat bran.Release of chlorogenic acids was used to evaluate the quality of the eucommia- leave vinegar.Cellulose enzyme was firstly added to the mixture of pretreated eucommia leaves and water that was hold at 45℃ for 2h. The enzyme used amounted to 0.8% of the total dry weight of eucommia leaves.The ratio of powdered eucommia leaves to water was 1∶10.In this case, the level of chlorogenic acids released reached 592.1μg /mL after 2h- incubation at 45℃.1 ∶ 1 of eucommia leaves hydrolysates to bran was mixed, and then the eucommia- hydrolysates bran mixture was blended with water by 1 ∶ 7 of solid-liquid ratio, with a 10% of glucose supplement and 1% pre- culture for alcohol fermentation, and 14% strain AS.14l for subsequent acetic acid fermentation.After fermentation, the level of chlorogenic acids was 131.1 μg /mL in the final eucommia- leaves vinegar product.The quality of the eucommia- leaves vinegar product totally met the Chinese national standards regulated by Goverment. Moreover, the eucommia-leaves vinegar scavenged DPPH · to 97.3% , and showed better antioxidant activity than the normal marketed vinegar products did. In summary, the development of eucommia-leaves vinegar should be helpful for the integrated and long-term utilization of eucommia resources.