改性麦芽糊精的酶法制备及其在烘焙制品中的应用

Enzymatic preparation of modified maltodextrin and its application in bakery products

该研究旨在酶法制备一种改性麦芽糊精,其能应用于面包制作中并有效改善面包品质。选用分支酶与4,6-α-葡萄糖基转移酶复配并优化酶反应条件制备改性麦芽糊精,将得到的产物以不同比例添加到面包制作中,研究其对面包品质的影响。结果表明,将能特异性转移DP6~10麦芽寡糖形成支链的分支酶(CyBE),与能转移单个葡萄糖生成连续α-1,6-糖苷键连接的异麦芽多糖的4,6-α-葡萄糖基转移酶(GTF13),复配得到的改性麦芽糊精,以添加量5%(质量分数)加入面包制作中,能使面包硬度降低71.01%,长期贮存中明显延缓面包老化;同时提高了面包的抗氧化自由基能力,其中对DPPH自由基、ABTS阳离子自由基和羟自由基的清除率分别提高了2、8、4倍。该研究结果为酶法改性的麦芽糊精应用于面包品质的改良提供了一种新的技术思路。

Maltodextrin is an intermediate product in the process of starch hydrolysis and has excellent functional characteristics,thus it is widely used in food baking.This study aims to prepare a modified maltodextrin by enzymatic method,which can be used in bread making and effectively improve the quality of bread.Branching enzyme and 4,6-a-glucosyltransferase were selected to compound and prepare modified maltodextrin.Reaction conditions were optimized and the product was added to bread making in different proportions.The improvement of modified maltodextrin on bread′s quality was studied.The results showed that with branching enzyme(CyBE),which can specifically transfer DP 6-10 malt oligosaccharides to form branched chains,and the 4,6-a-glucosyltransferase,which can transfer single glucose to produce isomaltopolysaccharide linked with continuousα-1,6-glycosidic bonds(GTF13),compounding,the modified maltodextrin obtained could reduce the hardness of bread by 71.01%,and obviously delayed the aging of bread during long-term storage,when added to bread making at 5%addition amount.At the same time,the ability of the bread to resist oxidation free radicals was improved,and the scavenging rate of DPPH,ABTS cation ion and hydroxyl free radicals was increased by 2,8,and 4 times,respectively.This study provided a new technical idea for the application of enzymatically modified maltodextrins in the improvement of bread quality.