Study On Reducing Sulfur Dioxide In Perry And The Optimal Fermenting Process

As a necessary additive in wine fermentation, Sulphur dioxide has theability to prevent or delay spoilage and control wine oxidative browning.However, concerns over its ability to induce severe allergic reactions havecreated a great need for its reduction or replacement in recent years. Vast interritory, China has abundant herbs, most of which have anti-oxidative activityand antimicrobial activity, and has been increasingly used in food industry. Theaim of this work was to screen potential antimicrobials and antioxidants.Antimicrobial and antioxidant effects, as well as the effects to the yeast’s growthcurve, were tested to choose the best herb combination, the antioxidantmechanism of which has been preliminary considered. Bacillus LicheniformisSH003was added in the fermentation to lower the acidity of perry, the additiontime and volume were also investigated. Furthermore, fermentation technologyof perry was studied. The results are as follows:Two herbs, Shepherdspurse Herb and Trichosanthes kirilowii Maxim, wereselected out of53Chinese herbs.3%of single herb extracts added in perry gotthe highest antimicrobial efficacy. Herbs compounding experiment showed,when mixed with other herbs, Giant Knotweed and Spina Date Seed had higheractivity than single herb.Nine kinds of traditional Chinese medicine, screened from40kinds ofChinese herbal medicine though in vitro antioxidant experiment, were used inperry. Results showed that, the peanut shells, cloves and Savia Miltiorrhiza hadhigher antioxidant effect in perry, and they could be used as antioxidativealternatives of sulfur dioxide in perry.Potential antibacterial alternatives and potential antioxidant alternativeswere mixed and used in perry. Results showed that the mixture of Spina DateSeed and clove, the mixture of Giant Knotweed and Savia Miltiorrhiza, as well as the mixture of Trichosanthes kirilowii Maxim and clove had better effect thanother mixtures.Compared with the other two mixtures, lower impact of Saccharomcescerevisiae DJ02was caused by the mixture of Spina Date Seed and clove. It hadthe same antimicrobial activity with sulfur dioxide, and could replace70%ofsulfur dioxide in terms of antioxidant activity.Result showed that the mixture of Spina Date Seed and clove lowered theredox potential of perry, and suppressed the polymerization of polyphenols inperry to achieve the effect on preventing polyphenol oxidation.Aroma compositions detection showed, samples added herb extracts hadsimilar characteristic aroma constituents and similar taste with samples addedsulfur dioxide, and the two samples had similar aroma components and contents.Acidification experiment showed that addition time of BacillusLicheniformis SH003had significant effect to the acid-reducing volume. Whenadded on the fourth day, the lowest acid content would be got.Through single factor and orthogonal experiments，the optimal conditionsof perry fermentation were: fermentation temperature20℃, yeast inoculationvolume12%, Bacillus Licheniformis SH003inoculation volume12%.