熊珊珊,繆 銘,江 波,*
(1.江南大學食品科學與技術國家重點實驗室,江蘇無錫 214122;2.江南大學食品學院,江蘇無錫 214122)
雙酶處理對玉米淀粉鏈結構和消化性的影響
熊珊珊1,2,繆 銘1,江 波1,*
(1.江南大學食品科學與技術國家重點實驗室,江蘇無錫 214122;2.江南大學食品學院,江蘇無錫 214122)
研究雙酶處理形成慢消化淀粉(slowly digestible starch,SDS)的精細結構。采用兩種酶(β-淀粉酶的水解作用和轉苷酶的轉苷作用)對玉米淀粉進行雙重處理以期提高慢消化淀粉含量。實驗結果發現,經過β-淀粉酶水解后的玉米淀粉再經轉苷酶處理,其鏈長分布、碘吸附作用和消化性能有了顯著地變化,并且這種變化隨不同的轉苷處理時間而有明顯差異。原淀粉經過β-淀粉酶處理4h,再經過轉苷酶處理24h后的淀粉樣品SDS最高含量可以達到13.95%,此時的樣品平均鏈長為12.58,分支密度為7.95%。實驗證明酶法改性淀粉可以有效改善淀粉的消化性能。
消化性,鏈長,分支密度,玉米淀粉
Abstract:Fine structure of slowly digestible starch(SDS) formed during dual-enzymes treatment was investigated.Through the hydrolysis of β-amylase and transglycosylation of transglucosidase,higher amount of SDS could be obtained.The result indicated that the chain length distribution,iodine binding and digestibility of starch samples,which were subjected to different time of transglycosylation following β-hydrolysis,changed obviously.After maize starch being treated by β-amylase for 4h,the highest SDS amount of 13.95%was gained when transglucosidase continued to treat for 24h,the average chain length was 12.58,and branch density was 7.95%.The experiment proved that dual-enzymes treatment could improve the digestibility of maize starch effectively.
Key words:digestibility;chain length;branch density;maize starch
淀粉屬于多聚葡萄糖,其分子式通常表示為(C6H10O5)n,n為不定數,可以聚合度DP(degree of polymerization)來表示。淀粉是由直鏈狀和支叉狀兩種分子組成的,脫水葡萄糖單位間經α-1,4糖苷鍵連接,稱為直鏈淀粉(amylose);交叉位置是α-1,6糖苷鍵連接,其余為α-1,4糖苷鍵連接,稱為支鏈淀粉(amylopectin)。由于淀粉是人類膳食中主要的碳水化合物,也是人體能量的主要來源,淀粉消化的方式和速度對人體餐后血糖應答有著很重要的影響[1-2],因此改善淀粉的消化利用有著非常大的研究前景。1992年,英國學者Englyst[3]等提出在體外模擬的條……