Abstract: Purpose: To develop a peptide-rich beverage from skim milk powder and waxy maize. Methods: The bitterness flavor of dry waxy maize was removed and then pretreated sequentially with α-amylase and gluco-amylase before being mixed with reconstructed milk and the starting cultures used were a mixture of Streptococcus thermophilus TA40 and Lactobacillus helveticus LH100 (1:1, m/m). Results: The optimal pretreatment conditions were established for waxy maize. The optimal fermentation conditions were determined as 4% (m/m) of whey protein added into reconstituted milk with a skim milk powder to water ratio of 1:0.8:13 (m/m), 4 g/L inoculum size, and fermentation at 37 ℃ for 8 h. The peptide content of the resulting beverage was measured to reach 4.6658 mg/mL. Sensory evaluation and physiological analysis showed that the pH, acidity and viscosity were 3.94, 132.7 oT and 5.276 Pa?s, respectively, and the beverage had a mixed flavor of waxy maize and yogurt but exhibited no obvious whey syneresis.

Key words: waxy maize; skim milk; whey protein; fermentation; yogurt; physiochemical properties

摘要： 目的:以脱脂奶粉和干糯玉米为主要原料,研制糯玉米酸奶.方法:对玉米进行脱苦处理,然后用嗜热链球菌TA40和瑞士乳杆菌LH100质量比为1∶1复配菌种进行发酵制备富含肽的糯玉米酸奶.结果:确立了最佳的干糯玉米预处理方法,并确立了富含肽的最佳发酵条件为糯玉米:脱脂奶粉:水1:0.8∶13(m/m),按4％(m/m)量加入乳清蛋白,接种量4 g/L,在37℃条件下发酵8h,经检测,发酵饮料中含肽4.6658mg/mL;对所制备的发酵饮料进行感官评定和理化性质分析表明,该发酵制品pH值为3.94,酸度为132.7°T,黏度值为5.276 Pa·s.无明显乳清析出,兼具糯玉米和酸奶香味.结论:制备富含玉米肽、乳肽等生物活性肽的发酵饮料,实现植物蛋白和动物蛋白的互补,产品具有较高的营养价值,同时提高了农作物附加值.

关键词: 糯玉米；奶粉；乳清蛋白；发酵；酸奶；理化性质