Applications of Palm-Based Interesterified Fats Johari Minal*
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Applications of Palm-Based Interesterified Fats Johari Minal* INTRODUCTION not only low, but consisted of mainly positional and geometric The physical characteristics of oils and fats are determined by their chemi- fatty acid isomers, with hence, very cal properties, i.e., the chain length and unsaturation of the fatty acids as little essential fatty acid activity. In well as their distribution among the three hydroxyl groups of glycerol. By an animal study by Majumbar and changing them through hydrogenation, fractionation, blending or inter- Bhattacharyya (1986), it was rev e a l - esterification (IE), the physical properties can be changed as well, hence, ed that rats fed with an interesteri- widening the spectrum for usage and application of the oils/fats. For fied fat showed more essential fatty instance, by applying IE, palm stearin can be incorporated in various types acids in their tissue lipids compared of margarine and at the same time, increase its proportion in the formula- to the rats fed with hydrogenated tions. Without IE, only very small amounts of palm stearin can be incorpo- fats. The coefficients of digestibility rated in a table margarine formulation but the percentage can be increased of 94.7%-96.92% of interesterified to more than 50% when IE is employed. vanaspati prep a r ed from palm stearin and soyabean, rice bran, rapeseed and mustard oils, were also much There are cases where IE is exchange raw materials with the higher than the 93.6% of hydro- used to deal with the problems of ones that are the most cost effec- genated vanaspati. The triglyceride plastic fat products such as granular tive at the point of production levels were lower than in the hydro- development, texture breakdown, because some of the physical prop- genated vanaspati but with more or lumpy appearance, post hardening, erties of randomized samples can less similar levels of total choles- etc. Nor Aini and Noor Lida (2003) be, to a certain extent, predicted by terol. In another study, they also measured the consistency of palm- their fatty acid composition. Coran- found that the erythrocyte mem- based shortenings over a period of domized mixtures of similar fatty brane isolated from the rats fed two months. It was found that the acid composition, irrespective of the interesterified fats contained more interesterified shortenings were type or fraction of fat from which phospholipids and less cholesterol softer than the non-uninteresteri- these mixtures are formulated, will compared to that of hydrogenated fied ones and showed minimal have similar physical properties. IE, vanaspati (Majumbar and changes in consistency during stor- therefore, is a very useful process Bhattacharyya, 1985). age. IE, especially the enzymatic for substituting one fat with other The nutritional benefits of using one, can also be used to design a in the formulations of most of the IE fats in comparison to hydrgena- fat of specific triglyceride structure fat-based products, e.g. margarine, ted fats can be achieved by maxi- such as in the production of cocoa shortening, vanaspati, specialty mizing the use of natural fats such butter extenders (CBEs) and infant fats, etc. as palm stearin. The use of fully formula fats. Nutritionally, IE contributes in hydrogenated fats as the hardstock The source fat for IE is obtain- many ways; apart from eliminat- for IE may give similar adverse able at low prices. For example, ing/reducing trans fatty acids, the effects as those of hydrogenated palm stearin, the hard fraction of amount of polyunsaturated fatty fats. Sundram et al. (2003) studied palm oil, is probably the cheapest acids in the cis form is higher, pro- the effects of an interesterified fat edible vegetable fat readily and viding higher essential fatty acid of a fully hydrogenated oil with its commercially available throughout activity. A comparison of the fatty native oil in comparison with a the world. Palm stearin can be used acid composition of a commercial hydrogenated fat and palm oil. It in margarines, shortenings and vanaspati with an IE vanaspati was appeared from the study that the IE other plastic fats, hence, becoming made by Kheiri et al. (1989) as and hydrogenated fats increased a saving to the manufacturers. IE shown in Table 1. In the commer- the lipoprotein associated CHD risk will also enable manufacturers to cial product, only 5% polyunsatu- factors in normocholesterolemic rated fatty acids were available humans compared to natural palm * Malaysian Palm Oil Board, compared to 23.5% in the IE sam- P. O. Box 10620, oil-based solid fat. ple. The essential fatty acids level in 50720 Kuala Lumpur, In terms of food safety, the the hydrogenated vanaspati was Malaysia possibility of having trace metal 11 Palm Oil Developments 39 TABLE 1. FATTY ACID COMPOSITION OF COMMERCIAL AND INTERESTERIFIED VANASPATI IE blend Commercial SBO:HPOs vanaspati (40:60) I.V. 51.4 72.4 Total saturated fatty acids 46.9 42.7 Total unsaturated fatty acids 53.1 57.3 Total monounsaturated fatty acids 48.1 33.8 Total polyunsaturated fatty acids 5.0 23.5 Total trans fatty acids 13.5 12.5 Unsaturated/saturated ratio 1.13 1.34 Polyunsaturated/saturated ratio 0.10 0.55 Notes: IE – Interesterification; I.V.= Iodine value. Source: Kheiri et al. (1989). residues in IE fats, as is the case sumption and minimal oil loss, and fatty acids for the formation of b’ with hydrogenation, can be totally as such, is a feasible option to stable fats (DeMan, 2000). IE, on eliminated. hydrogenation in solid fats produc- the other hand, helps stabilize and tion. increase the amounts of b’ crystals APPLICATIONS OF INTERESTERIFI- which are needed for a smooth tex- CATION (IE) FATS Margarine, Shortening and ture and functional properties. An Vanaspati IE blend of palm stearin and sun- IE was introduced in the 1940s and flower oil had comparatively more co m m e r cialized in the 1950s (Hamm, Palm stearin interesterified with b’ crystals than the direct blend of 2000). Since then, its applications unhdrogenated liquid vegetable oils the two (Nor Aini and Noor Lida, in food have more or less been is an excellent fat for margarines, 2003). Similarly, the products of IE established. The major development shortenings and vanaspati. The between palm stearin and palm by IE has been in the improvement advantages of using palm stearin kernel oil or its fractions have high- of processing technology to higher not only lies on its low price but er solid fat contents at ambient efficiency through lower utility con- also the change length diversity of temperature with excellent melting TABLE 2. SOME INTERESTERIFICATION (IE) FATS FOR MARGARINES, SHORTENINGS AND CONFECTIONERY FAT IE blends Fat (%) POs PKO PKOO RSO CSO SBO SMP (°C) Tub 1a 40 20 - 40 -- 29.3 Margarines 2a 60 - 40 --- 34.3 Packet 3a 70 - 30 --- 36.2 Margarines 4a 75 25 ---- 32.5 Table margarine 5a 60 - 20 -- 20* 38.5 Bakery 5b 70 ---- 30 44.0 Shortenings 6b 60 --- 40 - 43.5 Note: * Sunflower oil. Sources: a-Teah et al. (1992); b-Noor Lida and Yusof (1995). 12 Applications of Palm-Based Interesterified Fats TABLE 3. POSSIBLE FAT SPREAD FORMULATIONS USING SIMPLE AND INTERESTERIFICATION (IE) BLENDS OF PALM STEARIN, SUNFLOWER OIL AND PALM KERNEL OIL Spread type Simple blend IE blend POs (%) SFO (%) PKOo (%) POs (%) SFO (%) PKOo (%) Temperate tub spread 16.2 – 22.5 57.5 – 81.2 0 – 22.5 Not suitable Tropica tub spread 20.0 – 25.0 32.5 – 60.0 18.8 – 47.5 41.2 – 53.1 35.0 – 51.2 0.0 - 23.8 Block spread Not suitable 47.5 – 52.5 37.5 – 47.5 0.0 – 15.0 Source: Noor Lida et al. (2001). properties due to the presence of incorporated (Teah et al., 1992). blends of palm stearin, sunflower lauric acid. Such products are Since no hydrogenated fat is oil and palm kernel olein and found excellent base fats for both packet involved, the products are free from that more palm stearin and palm and tub margarines. In direct blend- trans fatty acids. Some formula- kernel olein can be incorporated in ing, only 10%-15% of palm stearin tions for margarines and shorten- fat spreads compared to the simple can be used in the formulation of ings are given in Table 2. blend of the three oils. The results table margarines. With IE, a much Noor Lida et al. (2001) studied are summarized in Table 3. higher level of palm stearin can be the characteristics of tertiary IE TABLE 4. INTERESTERIFICATION (IE) FATS-BASED FORMULATIONS FOR VANASPATI Fat blend Fat (%) HPO POs RSO RBO SBO CSO SMP (°C) Appearance. 1a - 70 -- 30 - 37.5 Uniform homogenous granulation, no phase separation. 2b - 60 --- 40 42.0 - 3a - 50 - 50 -- 36.5 Homogenous granulation, relatively soft, no phase separation. 4c - 80 -- 20 - 41 Firm consistency, no phase separation. 6a - 70 30 --- 37.5a Uniform homogenous granulation, no phase separation. 6a - 60 - 40 -- 38.5 Granular mass almost like ghee, no phase separation. 7c - #60 -- 40 - 38.6 Firm consistency, no oil separation. 8c 70-75 --- 25-30 -- Firm consistency, no oil separation. 9d - 60 - 40 -- 39.0 Uniform homogenous granulation with no phase separation. 10d - 70 - 30 -- 39.4 Uniform homogenous granulation with no phase separation. Note: # hydrogenated palm stearin. So u r ces: a- Majumbar and Bhattacharyya (1986); b- Noor Lida and Yusof (1995); c- Kheiri et al. (1989); d-Yusof and Teah (undated). 13 Palm Oil Developments 39 A granular fat product is popu- lar in the Indian Subcontinent and TABLE 5. CONFECTIONARY FATS FROM A BLEND OF HPKO AND IEHPKO Middle East. It is called vanaspati in SFI (%) the former and popularly known as samna in the latter.