In Situ Increased Reducing Sugar of Nang Lae Pineapple Juice

Nang Lae pineapple, (Ananas comosus (L) Merr.), has planted in Chiang Rai Province, could be used to prepare juice and achieved 35.5?2.0 mL per fresh fruit (100 g). The reducing sugar of six pineapple juice samples were determined using DNS method, which contained 42.22?14.23 mg/mL. Baker's yeast (5% w/v) was immobilized by entrapment method using 0.5% ( w/ v) sodium alginate. Yeast alginate entrapment bead was applied to pineapple juice and it could increase reducing sugar three times within 24 h by sucrose hydrolyzed enzyme. Activity of extracellular enzyme produced in 50 mM calcium chloride at 30 oC established 0.32 U/mL. Application of 5 and 10% (v/v) extracellular enzyme in pineapple juices could increase high content of reducing sugar within 20 min.南莱菠萝（Ananas comosus (L) Merr.）种植于泰国清莱府，其可用于制备果汁，每100克鲜果的出汁量可达35.5±2.0 mL。采用二硝基水杨酸（DNS）法对6份菠萝果汁样品的还原糖含量进行测定，结果显示样品还原糖含量为42.22±14.23 mg/mL。以0.5%（质量体积比，w/v）海藻酸钠为包埋载体，采用包埋法对5%（w/v）的面包酵母进行固定化。将海藻酸钠包埋酵母微球应用于菠萝果汁中，通过蔗糖水解酶的催化水解作用，可在24小时内将还原糖含量提升至初始值的3倍。在30℃、50 mM氯化钙体系中制备得到的胞外酶活性可达0.32 U/mL。向菠萝果汁中添加体积分数为5%和10%（v/v）的胞外酶，可在20分钟内显著提升还原糖含量。