Study on the technology of brewing red raspberry wine by using new immobilized yeast technology

The aim of the present study was to establish a new process for brewing red raspberry wine with immobilized yeast and improve the value of red raspberry. Using the spore filaments of P. chrysogenum as a carrier to co-culture with yeast to obtain immobilized yeast. And the preparation method of immobilized yeast was optimized by single-factor experiment and orthogonal experiments. And the red raspberry wine was brewed in these conditions. The result shows that the optimal preparation conditions for the immobilized yeast of P. chrysogenum were 5 g/L gluconic acid, 5 g/L yeast extract, and the addition amount of P. chrysogenum spores 1 × 10⁵ cfu/ml. Compared with free yeast, the immobilized yeast of P. chrysogenum has better fermenting ability, can better keep the anthocyanins and polyphenols and other active ingredients of red raspberry. The quality of the wine was improved due to increase in aroma components such as alcohols and esters. The immobilized yeast of P. chrysogenum maintained good fermentation performance after three consecutive fermentations.