Enzymatic Synthesis of Low-trans Fats Containing Conjugated Linoleic Acids and Their Physicochemical Characteristics

Scale-up production of low-trans fat containing conjugated linoleic acid (CLA-TFO) was performed through lipase-catalyzed synthesis. Blend of fully hydrogenated soybean oil, olive oil containing conjugated linoleic acid and palm oil with 1:2:7 ratio was interesterified through Lipozyme RM IM in the 1 L-batch type reactor at $65^{\circ}C$ for 12 hrs, and the physicochemical and melting properties of CLA-TFO were compared with conventional (high trans fat) or commercial low-trans fat shortening. The trans fatty acids content in the conventional shortening (48.8 area%) was much higher than that of low-trans shortening (0.4 area%) and CLA-TFO (0.3 area%+CLA; 7.6 area%). Acid, saponification and iodine values of CLA-TFO were 0.4, 173.9 and 59.0, respectively. Their ${\alpha}$-, ${\gamma}$-tocopherol contents showed 4.7, 1.0 mg/100 g. Differences were observed in the solid fat contents (SFC), melting point of the conventional or low-trans fat and CLA-TFO. Each SFC of conventional, low-trans fat and CLA-TFO was 32.0, 29.3 and 30.4% with melting point of 38.5, 43.0 and $39.5^{\circ}C$ at $35^{\circ}C$, respectively. In texture profile analysis, hardness of conventional, low-trans fat and CLA-TFO was 111.7, 75.2 and 63.8 g.

Conjugated Linoleic Acid(CLA)를 함유한 기능성 저트랜스 유지의 효소적 합성 및 이화학적 특성 연구

One liter stirred-tank batch reactor에서 기질들의 부피 비율을 1:2:7(fully hydrogenated soybean oil : SL-olive+CLA : palm oil)하고 RM IM lipase를 사용하여 CLA를 함유한 재구성 지질을 합성하였다. 합성된 재구성지질은 총 CLA를 7.6 area% 함유하였고, 주요 지방산 조성은 oleic acid (38.1 area%), palmitic acid(33.1 area%), stearic acid(12.2area%) 및 linoleic acid(7.3 area%)로 분석되었으며 트랜스지방산은 분석한계 미만(0.1 area%)으로 검출되었다. Reversed-phase(RP) HPLC 분석 결과, 재구성 지질의 TAG 형태는 PN=44(1.52 area%), PN=46(21.79 area%), PN=48(53.71 area%) 및 PN=50(11.1 area%)의 범위로 나타내었다. 합성된 지질의 토코페롤 함량을 분석한 결과는 ${\alpha}$, ${\gamma}$-토코페롤이 각각 4.7, 1.0 mg/100 g로 반응기질보다 감소하였고, 이의 산가, 비누화가, 요오드가의 측정 결과는 각각 0.4, 173.9, 59.0이었다. 재구성 지질의 융점은 세 개의 피크를 보이며 각각 8.7, 25.3 및 $40.9^{\circ}C$으로 나타났고 결정화점은 각각 0.7, $18.2^{\circ}C$로 분석되었다. 또한 고체지 함량은 31.8%($25^{\circ}C$), 22.3%($30^{\circ}C$), 13.9%($35^{\circ}C$)를 나타내어 상업적인 쇼트닝과 유사한 물성을 보였다. 재구성 지질의 녹는점은 $39.8^{\circ}C$로 측정되었고, hardness value는 63.8 g로 분석되었다.