Hiệu lực của nội dung ban đầu sulfur dioxide trong phải vào động lực học của quá trình lên men rượu vang chính, sử dụng nấm men cố định trong gel alginate canxi đã được kiểm tra. Ban đầu lưu huỳnh dioxide nội dung trong phải được điều chỉnh từ 12ppm để 312ppm. | TẠP CHÍ PHÁT TRIỂN KH CN TẬP 11 SÓ 09 - 2008 EFFECT OF INITIAL SULFUR DIOXIDE CONTENT IN MUST ON THE KINETICS OF WINE PRIMARY FERMENTATION USING YEAST IMMOBILIZED IN CALCIUM ALGINATE GEL Ton Nu Minh Nguyet Le Ngoc Lieu Nguyen Thi Hien Luong Le Van Viet Man University of Technology VNU-HCM Manuscript Received on June 10th 2007 Manuscript Revised April 29th 2008 ASTRACT Effect of initial sulfur dioxide content in must on the kinetics of wine primary fermentation using yeast immobilized in calcium alginate gel was examined. Initial sulfur dioxide content in must was adjusted from 12ppm to 312ppm. Our experimental results indicated that the maximum specific growth rate of the immobilized yeast was 1-2 times less than that of the free yeast. On the contrary the sugar uptake rate and ethanol production rate of the immobilized yeast were times and times respectively more than those of the free yeast. The volatile acid content and pH value of the final wine fermented by immobilized yeast were lower. Thus the organoleptic properties and biological stability of the wine were ameliorated. In general the yeast immobilized in calcium alginate gel was more resistant to sulfur dioxide than the free yeast. Key words alginate immobilization fermentation sulfur dioxide yeast 1. INTRODUCTION Cell immobilization in alcoholic fermentation is a rapidly expanding research area because of its attractive technical and economic advantages compared to the free cell system such as enhanced fermentation productivity feasibility of continuous processing cell stability and lower costs of recovery and recycling processing as well as tolerance to disadvantage factors 5 6 8 . Although many immobilization supports have been proposed for use in wine-making industrial application of the technology is still uncertain and should be investigated. This is mainly due to difficulty in finding a low-cost material that is abundant durable of food-grade purity and has the ability to be .
