关键词: 浆水, 直投式增香发酵剂, 制备工艺, 真空冷冻干燥, 异常汉逊酵母

Abstract: A strain of producing fragrant yeast —— Hansenula anomala Y16 was used as the tested strain, which was isolated from the traditionally fermented Jiangshui (Tianshui, Gansu). After being high-density fermented, the preparation technology of its aroma-enhancing yeast starter was optimized by using Plackett-Burman test, steepest ascent test and response surface methodology (RSM). The results showed that the cell density of Y16 could reached 9.2×1010 CFU/mL after high-density culturing. And the optimum centrifugation conditions for collecting Y16 fermentation broth was being centrifuged at 1 600 g for 10 min, after that the centrifugal sedimentation rate of living cells was 95.5%. While the optimal combination of protective agent for the yeast starter was 11% skim milk powder, 9% sucrose and 12% trehalose, and under this condition, the yeast survival rate of lyophilizing inoculum was up to 91.54%. This flavoring starter prepared by the above process still had good storage stability after the storage period of 3 months. In addition, the result of simulated fermentation test of Jiangshui showed that the product had good flavor. The research result could provide a source of aroma-enhancing starter for Jiangshui industrial production.

Key words: Jiangshui, direct vat aroma-enhancing yeast starter, preparation technology, vacuum freeze-drying, Hansenula anomala