Study On The Processing Technology Of Persimmon Vinegar With Origin Pulp

New persimmon products development is an important way to raise the benefit. Recently the persimmon vinegar with rich nutrition, bright-colored and special flavor by microorganism fermentation has a good market vista; the base to stable and develop the market is the application of advanced techniques and the enhancement of its quality. In order to study the variation regularity of fruit vinegar production with persimmon pulp, enhance acidification ability, acetic acid content and flavor quality of persimmon vinegar, and provide theoretical foundation for persimmon processing, the systematic research works of persimmon vinegar brewing techniques, measures and technological parameters optimization of different fermentation measures have been conducted with Diospyros kaki L. as the raw material on the base of mass microorganism in nature and traditional nature fermentation technique.Conclusions have been drawn as the following:1,High quality persimmon vinegar which have good acid tastes, aroma and color characteristics of persimmon can be produced with persimmon pulp as raw material on the base of traditional nature fermentation technique. The technology provides theoretical foundation for factorization processing of persimmon vinegar.2,In order to provide theoretical foundation for persimmon vinegar processing, we studied the variation regularity of alcohol, the sugar and the acetic acid content during persimmon vinegar fermentation using natural fermentation method. The results show that remnants of alchol and sugar are high in persimmon vinegar by this fermentation style.3,In order to ensure successful accomplishment of persimmon pulp fermentation using one-step fermentation method of only inoculating activated dry yeast condition to fruit pulp, the technique of adding water to persimmon pulp and stirring persimm pulp during fermentation were applied to process persimmon vinegar. The results show that amount of water is 30% of persimmon pulp weight. We used this technique to process persimmon vinegar and obtained a better effect.4,In order to shorten fermentation time and provide theoretical foundation for persimmon processing, the technology of one-step fermentation was applied to process persimmon vinegar with Diospyros kaki L. as the raw material on the basis of traditional nature fermentation technique. Response surface methodology was applied to study variation regularity of persimmon pulp fermentation and optimize the technical parameters with the three-factor second orthogonal rotation combination experiment. The results show that fermentation temperature has a highly significant influence on acetic acid content (p<0.01) and yeast inoculation quantity has a significant influence on acetic acid content (p<0.05). A quadratic equation has been established (Y = 4.40599 - 0.166403x₁ - 0.121586x₂ -0.154911x₁² - 0.13675x₁x₂- 0.15775x₁x₃-0.148016x₃²) between acetic acid content and the technique parameters by analyzing variation regularity in persimmon pulp fermentation. The optimum fermentation parameters are as follows: fermentation temperature 30.9℃, yeast inoculation quantity 0.87‰and fermentation time178h. Adequacy of the model equation is verified effectively and it is valuable for practical application.5,In order to study the variation regularity of fruit vinegar production with persimmon pulp by using persimmon vinegar fermentation method of inoculating yeast and acetic acid bacillus condition to fruit pulp and provide theoretical foundation for persimmon processing, response surface methodology was applied to optimize the technological parameters of acetic acid fermentation for producing persimmon vinegar with Diospyros kaki L. as the raw material. The results show that both acetic acid bacillus inoculation quantity and fermentation time have noticeably significant effects on acetic acid content (p<0.01), but fermentation temperature has no significant effect on acetic acid content. There is a highly significant correlation between acetic acid content and fermentation temperature, acetic acid bacillus inoculation quantity and fermentation time, in a form of negative quadric curved lines relations. The optimal quadratic equation and fermentation parameters are as follows: Y'=4.876046+0.166609x₅+0.245975x₆–0.124459x₄² -0.379195x₅²-0.282321x₆²; temperature 33.1℃, inoculum of acetic acid bacillus 0.56‰and fermentation time 110h. Under these optimized conditions, the acetic acid content of persimmon vinegar is 4.928 g/(100 mL).The results of multivariate regression analysis show that the model for regressing fermentation temperature, acetic acid bacillus inoculation quantity, fermentation time and acetic acid content is remarkable. Practical production of acetic acid content of persimmon vinegar can be forecasted by applying the model.6,The organic acids are analyzed by reverses phase HPLC. The results show that major organic acid in fermented persimmon vinegar is acetic acid. There are many other organic acids, for example malic acid, tartaric acid, oxalic acid, citric acid, lactic and succinic acid. Organic acids styles and content have correlation to fermentation method, fermentation terminate style, aging and so on.