효소적으로 합성된 대칭형과 비대칭형 Triacylglycerol 혼합물의 In Vitro Digestion에서의 소화율 비교

Abstract

For developing indigestible lipids, symmetric triacylglycerol (ST) and asymmetric triacylglycerol (AT) were produced by enzymatic interesterification using high oleic sunflower oil, palmitic ethyl ester, and stearic ethyl ester in a shaking water bath. Used enzymes were Lipozyme RMIM for ST and Lipozyme TLIM for AT. To remove ethyl ester from reactants, methanol fractionation (reactant : methanol=1:5, w/v, 25°C) and florisil separation (reactant : florisil=1:8, w/w) were applied. Acetone fractionation (reactant : acetone=1:9, w/v) was implemented to separate triacylglcerol (TAG) species into ST and AT. Fractions I (before fractionation), II (after fractionation, liquid phase) and III (after fractionation, solid phase) were separated from ST, whereas fractions IV (after 1st fractionation, liquid phase) and V (after 2nd fractionation, solid phase) were from AT. From sn-2 fatty acid composition analysis, the sum of palmitic acid (C16:0) and stearic acid (C18:0) was 4.9∼6.5 area% in ST (I, II, III), and 41.9∼43.9 area% in AT (IV, V). In vitro digestion was performed for 0, 15, 30, 60, and 120 minutes at 37°C in a shaking water bath. For the digestion results, hydrolysis of V was only 40% compared to others (I, II, III, IV) at 120 minutes due to its melting point (49°C). However, initially (15 minutes), hydrolysis (%) was as follows: V<III<IV<I, II. This order was similar with that of melting point, and a higher TAG content (two saturated fatty acids) was associated with a higher melting point. On the other hand, fractions III and IV showed similar complete melting points (32.5°C, 31.8°C) and different slip melting points (31.3°C, 19.5°C). Even though IV has a lower TAG content composed of two saturated fatty acids than III, it had a similar melting point.