直鏈澱粉聚合度影響直鏈澱粉脂肪酸複合物之形成

Degree of Polymerizations of Amylose Affects the Formation of Amylose-Fatty Acid Complex

張皓崴(Hao-Wei Chang)

指導教授 ： 葉安義

國立臺灣大學/生物資源暨農學院/食品科技研究所/碩士(2017年)

https://doi.org/10.6342/NTU201702029

摘要

直鏈澱粉能與脂肪酸形成具熱穩定性與酵素消化抗性的直鏈澱粉脂肪酸複合物 (ALC)，本研究探討不同直鏈澱粉聚合度 (DP) 與ALC的形成和物化特性。
使用初始水解斜率0.93 glucose equivalent conc./hr，水解速率適中的2.5 U ß-amylase以pH 5.5、55 ℃水解0 hr、0.25 hr、1 hr、4 hr 與9 hr，從馬鈴薯直鏈澱粉製得DP 809、702、485、364與207的直鏈澱粉水解物 (hydrolysate, HYD)，與用isoamylase去枝馬鈴薯枝鏈澱粉製得DP 38的澱粉水解物，並與棕梠酸複合形成直鏈澱粉脂肪酸複合物 (水解物平均聚合度-ALC)。未複合脂肪酸的直鏈澱粉 (809-HYD) 型態為棉絮狀，DSC圖譜中觀察不到ALC的熱解離峰、偏光顯微鏡觀察下無發光、2θ值4^。~〖30〗^。之XRD圖譜中也無波峰，故判斷809-HYD無ALC形成也無結晶生成，體外消化結果顯示平衡水解率94.51 %，澱粉水解率上升快速 (水解動力常數k = 7.62)，快消化性澱粉 (RDS)、慢消化性澱粉 (SDS) 與抗性澱粉 (RS) 分別佔73.95 %、20.55 %與5.50 %，且預估升糖指數 (eGI) 達92.53。
ALC型態為50~100 μm的顆粒，偏光下發光，有結晶生成。702-ALC、485-ALC與364-ALC複合指數約70 %，DSC圖譜觀察到Type I ALC與Type II ALC波峰， 809-ALC、207-ALC與38-ALC只觀察到Type I ALC波峰，以38-ALC的波峰熱解離溫度與焓值最低。二次熱掃描後，38-ALC的波峰消失，其他ALC則波峰焓值都變小，起始解離溫度T_0增加約8 ℃。XRD圖譜顯示38-ALC圖形下積分面積與結晶度最小，其餘ALC無顯著差異，因此38-ALC消化抗性差，平衡水解率為107.46 %、RS為2.36 %、eGI值為86.98。702-ALC、485-ALC與364-ALC平衡水解率約65 %、RS約35 %、eGI值約75，809-ALC與207-ALC的RS含量分別為24.35 %與30.67 %。結果顯示DP 809因分子鏈太長，鏈之間纏繞，干擾ALC形成，水解至DP 702、485、364能形成熱穩定性與消化抗性佳的ALC，DP 207與38因鏈太短，複合物消化抗性變差。

關鍵字

聚合度 ； 直鏈澱粉脂肪酸複合物 ； DSC ； XRD ； eGI

並列摘要

Amylose and fatty acid can form a complex, which is heat stable and enzyme resistant amylose lipid complex (ALC), the purpose of this study was to explore the formation of amylose-lipid complex (ALC) and its physicochemical properties with different degree of polymerizations (DP) of amylose.
amylose hydrolysate (HYD) DP 809, 702, 485, 364 and 207 were prepared from potato amylose being hydrolyzed with an initial slope of 0.93 glucose equivalent conc./hr using 2.5 U ß-amylase (pH5.5, 55 ℃) for 0 hr, 0.25 hr, 1 hr, 4 hr and 9 hr. DP 38 hydrolysate was made from debranched potato amylopectin by isoamylase. The hydrolysate was complexed with palmitic acid to form amylose lipid complex (Average DP of starch hydrolysate-ALC). Potato amylose without complexation (809-HYD) was cotton-like and didn’t display any endothermic peaks, no luminescent observed under polar light and no peaks found in the XRD in the range of 2θ value 4^。~〖30〗^。. Thus, the in vitro digestion showed a high final hydrolysis percentage of 94.51 %, with kinetic constant of 7.62 min^(-1). Rapidly digestible starch, slowly digestible starch and resistant starch contents were 73.95 %, 20.55 % and 5.50 %, respectively, and the estimated glycemic index (eGI) was 92.53.
ALCs exhibited luminesce under the polarized light, indicating that crystals were formed during the amylose lipid complexation. Complex index of 702-ALC, 485-ALC and 364-ALC were about 70 % and showed both the dissociation peaks of Type I ALC and Type II ALC in the DSC thermogram. Nonetheless, only dissociation peaks of Type I ALC were observed for 809-ALC, 207-ALC and 38-ALC. Among all groups of ALCs, 38-ALC has the lowest dissociation temperature and enthalpy. After rescan, endothermic peaks were disappeared or declined in 38-ALC or other ALCs and the onset temperatures of Type I ALC were raised about 8 ℃. 38-ALC showed the least crystallinity among all ALCs, and thus exhibited a relatively high equilibrium starch hydrolyzed ratio of 107.46 % with eGI value of 86.98 and RS contents of approximately 2.36 %. Nevertheless, 702-ALC, 485-ALC and 364-ALC exhibited relatively low equilibrium starch hydrolyzed ratio of about 65 % with eGI value of 75 and RS contents of about 35 %. RS contents of 809-ALC and 207-ALC were 24.35 % and 30.67 %, respectively. Result showed that the long chain of DP 809 might interfere the formation of ALC, because of the chain interaction which caused a steric hindrance for the palmitic acid to complexed into the V helix. Proper chain length of DP 702, 485 and 364 formed ALC, which were heat stable and resistant to digestion. Short chain of DP 207 and 38 exhibited low digestion resistance due to weak van der waal and nonpolar reaction between short chain amylose and fatty acid.

並列關鍵字

degree of polymerizations ； amylose lipid complex ； DSC ； XRD ； eGI

參考文獻

張亙翔。2014。探討以糯性玉米澱粉製備短鏈第五型抗解澱粉。國立宜蘭大學食品科學系碩士論文。

鄭光哲。2016。預煮處理對稻米理化特性與消化性之影響。國立台灣大學食品科技研究所碩士論文。

林奕廷。2014。油脂對米飯理化特性及澱粉消化性之影響。國立台灣大學食品科技研究所碩士論文。

黃建豪。2015。七種米澱粉微細結構與理化性質之解析。國立台灣大學食品科技研究所碩士論文。

Feng, Q., Liang, S., Jia, H., Stadlmayr, A., Tang, L., Lan, Z., Zhang, D., Xia, H., Xu, Z., Jie, Z., Su, L., Li, X., Li, X., Li, J., Xiao, L., Huber-Scho¨nauer, U., Niederseer, D., Xu, X., Al-Aama, J.Y., Yang, H., Wang, J., Kristiansen, K., Arumugam, M., Tilg, H., Datz, C., Wang, J. Gut microbiome development along the colorectal adenoma–carcinoma sequence. Nat. Commun. 2015, 6, 6528.