Utilization of high‐melting palm stearin in lipase‐catalyzed interesterification with liquid oils

Abstract

Palm stearin with a melting point (m.p.) of 49.8°C was fractionated from acetone to produce a low-melting palm stearin (m.p. = 35°C) and a higher-melting palm stearin (HMPS, m.p. = 58°C) fraction. HMPS was modified by interesterification with 60% (by weight) of individual liquid oils from sunflower, soybean, and rice bran by means of Mucor miehei lipase. The interesterified products were evaluated for m.p., solid fat content, and carbon number glyceride composition. When HMPS was interesterified individually with sunflower, soybean or rice bran at the 60% level, the m.p. of the interesterified products were 37.5, 38.9, and 39.6°C, respectively. The solid fat content of the interesterified products were 30-35 at 10°C, 17-19 at 20°C, and 6-10 at 30°C, respectively. The carbon number glyceride compositions also changed significantly. C 48 and C 54 glycerides decreased remarkably with a corresponding increase of the C 50 and C 52 glycerides. All these interesterified products were suitable for use as trans acid-free and polyunsaturated fatty acid-rich shortening and margarine fat bases. JAOCS 74, 589-592 (1997). KEY WORDS:High-melting palm stearin, low-melting palm stearin, Mucor miehei lipase, palm stearin.Palm stearins, produced in commerce from palm oil by fractionation, have limited use due to their high melting points. A great deal of work has already been done in utilizing palm stearin by interesterification and by blending in mixtures with liquid oils (1). Nutritional quality of these interesterified products (2) and blended products (3) has also been evaluated.Palm stearin can be further fractionated (4) to produce a low-melting palm stearin (LMPS) and a higher-melting palm stearin (HMPS). The LMPS fraction of melting point 35°C will be more useful than palm stearin as such. The HMPS fraction with melting point of about 58°C cannot be used as such in fat-based edible products due to its high melting point. However, HMPS can be used after some modification by lipase-catalyzed interesterification with other liquid oils.The present study aims at utilizing HMPS by lipase-catalyzed interesterification with individual liquid oils, such as from sunflower, soybean and rice bran, to produce fatty materials suitable for the production of trans-free shortening and margarine. MATERIALS AND METHODS Refined, bleached, and deodorized (RBD) palm stearin was provided by PORIM (Kuala Lumpur, Malaysia). RBD sunflower oil was supplied by ITC (Agro-Tech) Ltd. (Hyderabad, India); RBD soybean oil and rice bran oil were supplied by K.N. Oil Industries (Raipur, India). 1,3-Specific Mucor miehei lipase was a kind gift of NOVO Industry (A/S Copenhagen, Denmark). Except otherwise specified, all other chemicals and solvents (A.R. Grade) were purchased from S.D. Fine Chemicals (Calcutta, India).Fractionation of palm stearin. Palm stearin was fractionated from acetone (5 mL/g palm stearin) at 35°C for 3 h to get 19% by weight of HMPS and 81% by weight of LMPS. These two fractions were collected after removal of acetone.Lipase-catalyzed int...

Application of palm olein in the production of zero‐trans Iranian vanaspati through enzymatic interesterification

“…Increases in SMP that occurred after interesterification may be attributed to the increase of CN 48 (trisaturated) TAG. The results are in contrast with Ghosh and Bhattacharyya [17] who found that the enzymatic interesterification of high-melting point palm stearin with liquid oils resulted in a decrease of the melting point of non-interesterified blends. All the interesterified blends had SMP lower than 40 7C, so they met the ISIRI specifications.…”

“…2, as the portion of POL increases, a decrease in IV is observed. This is due to the increase in the amount of SFA and the decrease in unsaturated fatty [17] reported that interesterification of binary blends of high-melting point palm stearin with sunflower, soybean and rice bran oil with 10% Mocur miehi lipase at 60 7C for 5 h causes a decrease in CN 48 and CN 54 TAG and an increase in CN 50 and CN 52 TAG of the blends, which is different from the changes observed in the blends studied in the present work.…”

Enzymes as biocatalysts in the modification of natural lipids

“…The product contained polyunsaturated fatty acids and was virtually free of trans acids. 111 When lard and high-oleic sun¯ower (60:40) were interesteri®ed (Candida antarctica, 55°C, 24 h) the product was superior to that obtained by blending alone and had solid content resembling that of a soft margarine at a range of temperatures. 112 From the examination of a ternary mixture of canola oil, hydrogenated canola oil, and palm stearin Cho and deMan 113 concluded that the interesteri®cation product crystallised in the desirable b' form and could be used to produce margarine with trans levels lower than conventional products made from hydrogenated oils even though trans acids were still present.…”

Challenges of Utilizing Healthy Fats in Foods

“…To overcome this problem, interesterification can be used to produce a fat with a gradual melting profile. In this process, a blend of lipids high in saturated (e.g., tropical or 100% hydrogenated fats) and unsaturated FAs is mixed with a catalyst such as sodium methoxide (23) or various lipase sources (24). This process initially produces a diacylglycerol anion (2).…”