Progr. in Nutr. - Vol. 17 - N. 3 - September 2015 | ISSN 1129-8723 progress in nutrition Journal of Nutrition and Internal Medicine Indexed in Science Citation Index Expanded (SciSearch®); Journal Citation Reports/Science Edition; Excerpta Medica/Embase, ISI Web of Science Impact Factor: 0,143 Mattioli 1885 are ottobre 2015 mp ma - Finito di sta Par B C D ma 1, m n. 46) art. 1, co n L. 27/02/2004 D.L. 353/2003 (conv. i P. - A. n Sped. i Poste Italiane s.p.a. - mestrale - Pubblicazione tri 00-COPERTINA 3-2015 DIGITALE.indd 1 28/10/15 15:13 PR_Natale_200x270.indd 1 26/10/15 15:33 P n rogress in utrition Journal of nutritional and internal medicine Organo Ufficiale della Società Italiana di Scienza dell’Alimentazione (S.I.S.A.) Con il patrocinio dell’Associazione Ricercatori di Nutrizione e Alimenti (A.R.N.A.) Fondatore / Founding editor PreSidente / PreSident Massimo Cocchi andrea Strata Scottish Agricultural College, Edinburgh Università di Parma direttore SCientiFiCo / editor direttore reSPonSaBiLe / Leone arsenio JournaL direCtor Azienda Ospedaliera Universitaria di Parma Federico Cioni CoMitato SCientiFiCo / exeCutive editorS F. arfini t. Leighton Università di Parma Berkeley University d. atkinson M.C. Mancini Scottish Agricultural College, Edinburgh Università di Parma g. Ballarini r. Marchelli Università di Parma Università di Parma S. Bernasconi P. Migliaccio Università di Parma Università Sapienza di Roma g. Bertoni a.L. Mordenti Università di Piacenza Università di Bologna S.e. Carlson K. Mullis Kansas City University Premio Nobel per la Chimica 1993 F. di Lisa S.M. nabavi Università di Padova Baqiyatallah University of Medical Sciences, Tehran, Iran g. Fatati F. nicastro Università di Terni Università di Bari n.g. Frega r.C. noble Università di Ancona Scottish Agricultural College of Edinburgh C. galli g. riccardi Università di Milano Università di Napoli C. giacomini C.M. rotella Università di Parma Università di Firenze g.M. Halpern Hong Kong Polytechnic University PuBLiSHer Mattioli 1885 srl Casa editrice Strada di Lodesana, 649/sx, Loc. vaio 43036 Fidenza (Pr), italy tel. ++39 0524 530383 Fax ++39 0524 82537 e-mail: [email protected] www.progressinnutrition.it 01-Board.indd 181 28/10/15 15:03 Index Volume 17 / n. 3 September 2015 Mattioli 1885 srl - Strada di Lodesana 649/sx Review Loc. Vaio - 43036 Fidenza (Parma) 183 Leone Arsenio, Sergio Bernasconi, Federico Cioni, Marco Nocetti tel 0524/530383 Parmigiano Reggiano cheese: general and metabolic/nutritional aspects from fax 0524/82537 tradition to recent evidences www.mattioli1885.com 198 Wissam Zam Direzione Generale Structured lipids: methods of production, commercial products and nutraceutical Direttore Generale Paolo Cioni characteristics Vice Presidente e Direttore Scientifico Federico Cioni Original articles 214 A. Pleşea-Condratovici, C. Pleşea-Condratovici, N. Rosoga, N. Nedelcu Direzione Editoriale Efficacy and tolerability of a novel food supplement (Turbofer®) containing Editing Manager microencapsulated iron in liposomal form, in female iron deficiency anaemia Anna Scotti Editing Valeria Ceci 220 Attilio Luigi Mordenti, Nico Brogna, Flavia Merendi, Giorgia Canestrari, Foreign Rights Massimo Dall’Olio, Giacomo Biagi, Andrea Formigoni Nausicaa Cerioli Effect of feeding whole soybean and linseed on milk and Parmigiano Reggiano cheese lipid fraction Marketing e Pubblicità Direttore Commerciale 231 Carlo Pinna, Eleonora Nannoni, Giulia Rigoni, Monica Grandi, Marco Spina Carla Giuditta Vecchiato, Caterina Spiezio, Camillo Sandri, Giacomo Biagi Responsabile Area ECM Simone Agnello Effects of yogurt dietary supplementation on the intestinal ecosystem of a Project Manager population of Emperor tamarins (Saguinus imperator) Natalie Cerioli Massimo Radaelli 238 Govindasamy Chandramohan, Khalid S. Al-Numair, Chinnadurai Veeramani, Responsabile Distribuzione Mohammed A. Alsaif, A. Madi Almajwal Massimiliano Franzoni Protective effect of kaempferol, a flavonoid compound, on oxidative mitochondrial damage in streptozotocin-induced diabetic rats 245 Asad Ali, Fatma Hussain, Muhammad Shahid Investigation of the wound healing potential of Onosma hispidum root extract in rabbit models PROgRESS IN NuTRITION Registrazione Tribunale di Parma 250 Abdullah Aslan, Muhammed Ismail Can N. 4 del 21/1/1999 The effect of orange juice against to HO stress in Saccharomyces cerevisiae 2 2 Spedizione in abbonamento postale Abbonamento annuale euro 57 255 Seyed Fazel Nabavi, Seyed Mohammad Nabavi, Akbar Hajizadeh Moghaddam, Claire Hellio, Mohammad Ali Ebrahimzadeh I dati sono stati trattati elettronicamente e Antihypoxic, nephroprotective and antioxidant properties of hydro-alcoholic utilizzati dall’editore Mattioli 1885 spa per extract of loquat flowers la spedizione della presente pubblicazione e di altro materiale medico scientifico. Ai sen- 262 Ki Bae Hong, Eun Young Jung, Jae Hwan Kim, Un Jae Chang, Hyung Joo Suh si dell’Art. 13 L. 675/96 è possibile in qual- Yeast hydrolysate as a functional anti-obesity ingredient: appetite suppressive siasi momento e gratuitamente consultare, modificare e cancellare i dati o semplice- effects of yeast hydrolysate in food-deprived mice mente opporsi all’utilizzo scrivendo a: Mat- tioli 1885 srl - Casa Editrice, Strada della Lodesana 249/sx, Loc. Vaio, 43036 Fidenza (PR) o a [email protected] Progress in Nutrition is indexed by: Scien- ce Citation Index Expanded (SciSearch®); Journal Citation Reports/Science Edition; Excerpta Medica/Embase, ISI Web of Science; Scopus Impact Factor (released in June 2015): 0,143 02-indice.indd 182 27/10/15 10:40 Progress in Nutrition 2015; Vol. 17, N. 3: 198-213 © Mattioli 1885 R e v i e w Structured lipids: methods of production, commercial products and nutraceutical characteristics Wissam Zam Department of Analytical and Food Chemistry, Faculty of Pharmacy, Al-Andalus University for Medical Sciences, Al-Quadmous, Tartous, Syrian Arab Republic Summary. Structured lipids (SLs) are generally defined as triacylglycerols (TAGs) that have been modified to change the fatty acid composition and/or their positional distribution in glycerol molecules by chemical and/or enzymatic reactions and/or by genetic engineering processes. They are designed for obtaining TAGs with im- proved functional properties (i.e. fats with specific physical properties for food applications) and/or for medical and nutritional applications, especially to meet for the growing need for healthier foods and to prevent obesity, cancer and cardiovascular disease cardiovascular disease. Production methods of SLs and commercial products examples are discussed in this review. Moreover, nutritional and medical uses of SLs and their effect on human health are also reviewed in this paper. Key words: Structured lipids, methods of production, commercial products and nutraceutical characteristics. Introduction A high-fat diet poses at least two risks to one’s health. First, fats produce a relatively large amount of Lipids have long been recognized for the richness energy when metabolized, nine calories per gram, com- they impart to foods as well as their satiety value in the pared with four calories per gram for carbohydrates diet. Lipid is an important component of the diet, be- and proteins (5). Second, saturated fats and trans fatty cause it provides both energy and essential fatty acids acids are believed to be responsible for an increase in (EFAs). It is the most concentrated energy source in LDL cholesterol levels and decrease of HDL choles- the diet, with an average energy value of 9 kcal/g com- terol levels which, in turn, have been implicated with pared to 4 kcal/g for carbohydrates and proteins. They an increased risk for heart disease (6, 7). serve several important biological functions including: The guidelines for a healthy diet issued in vari- 1) acting as structural components of all membranes; ous countries recommend to lower the diet fat content 2) serving as storage form and transport medium of to 20-35% of total energy content (5). A reduction of metabolic fuel; 3) serving as a protective cover on the energy intake through a reduction of dietary fat in- surface of several organisms; and 4) being involved as take is easier said than done because fat contributes cell-surface components concerned with cell recog- strongly to the sensory characteristics of our food such nition, species specificity and tissue immunity (1, 2). as taste, appearance and texture. New developments The role of dietary lipids in health and disease -no- in food technology now allow the partial replacement tably coronary heart disease, obesity, hyperlipidemia, of dietary fat with substitutes called structured lipids diabeties and cancer- is one of the most active areas of (SLs), which combine unique characteristics of com- research in modern food science, nutrition, and bio- ponent fatty acids such as melting behavior, digestion, chemistry (3, 4). absorption, and metabolism to enhance their use as 04-Zam.indd 198 27/10/15 10:39 Structured lipids: methods of production, commercial products and nutraceutical characteristics 199 functional lipids and as nutraceuticals of much lower essential fatty acids to hospital patients (15). Basic energetic value and many health benefits. strategies for developing structured lipids are essen- Structured lipids are generally defined as triacyl- tially based on one of the following approaches: glycerols (TAGs) that have been modified by the in- • replacement of glycerol moiety of triacylglycer- corporation of new fatty acids, restructured to change ols with alternative alcohols such as carbohydrates, the positions of fatty acids, or synthesized to yield novel sugar alcohols or polyols such as sucrose fatty acid TAGs aiming at obtaining some desirable properties esters; (Figure 1) (8, 9). Various fatty acids, including different • replacement of long-chain fatty acids with alterna- classes of saturated, monounsaturated, and n-3 and n-6 tive acids such as short-, medium and long-chain polyunsaturated fatty acids (PUFAs) or their mixtures fatty acids esterified to glycerol. may be used in this process, depending on the desired To produce SLs, chemical or enzymatic reactions metabolic effect (10). Lipids can be restructured to meet such as direct esterification, acidolysis, alcoholysis, or essential fatty acid requirements or to incorporate spe- interesterification can be used depending on the types cific fatty acids of interest. SLs may offer the most ef- of substrates available. ficient means of delivering target fatty acids for nutritive Chemical interesterification is a random reaction or therapeutic purposes as well as to alleviate specific conducted at relatively high temperature and produc- disease and metabolic conditions. Structured lipids can ing complete randomization of the fatty acid moieties also be produced to obtain TAG with modified physi- in the triacylglycerol backbones (16). Chemical inter- cal and/or chemical features, including melting point, esterification seems to be attractive due to the low cost iodine and saponification values. They can be produced and large scale application. However, under the per- via inter-esterification reactions of fats, oils, or mixtures spective of producing lipids with very specific compo- thereof, either chemically or enzymatically (11-14). sitions aiming at functional and medical applications, Much attention is being paid to SLs due to their enzymatic interesterification is far more interesting potential biological functions and nutritional perspec- (17). With this respect, the enzymatic interesterifica- tives. The aim of this review is to focus on the com- tion has the advantage of allowing a greater control of ponent fatty acids, production strategies, medical and the positional distribution of fatty acid moieties in the food applications and future prospects for research and final product due to both selectivity and regiospecific- development in this field. ity of lipases (16, 18). Many factors can influence the synthesis of SLs such as the type of lipase and the lipase/substrate ratio Methods of SLs production (19), the reaction medium (19), substrate concentra- tions, content of water (20), temperature (19), and op- Chemical or enzymatic reactions. SLs can pro- erational mode (21-23). vide medium-chain fatty acids (MCFA) as a quick Lipases occur widely in nature and are active at energy source and long-chain fatty acids (LCFA) as oil/water interface in heterogenous reaction system. They catalyze the hydrolysis of triacylglycerols into monoacylglycerols, diacylglycerols, free fatty acids and glycerol, under macroaqueous conditions (24). In ad- dition to acylglycerol ester hydrolysis, lipases can also catalyze a wide variety of esterification, transesterifica- tion, and polyesterification reactions (24). The set of transesterification reactions includes acidolysis, inter- esterification, and alcoholysis (24, 25). Most lipases have their substrate selectivity ac- Figure 1. General structure of structured lipids. cording to chain length, unsaturation, and positional S, M, and L is for short-chain, medium-chain, and long-chain fatty acids, respectively. distribution (26, 27). Many different types of lipases 04-Zam.indd 199 27/10/15 10:39 200 W. Zam have been investigated for the enzymatic modification nate, and produce fatty acid isomers not normally found of oils and fats. Commercial lipases are available from in common sources of edible oils. Plant engineers are microbial, plant, and animal sources. Among those, now trying to incorporate the principles used in chemi- microbial lipases are the most attractive ones and their cal and enzymatic synthesis of “tailor-made” structured utilization has been described extensively (28). Lipases lipids into their genetic engineering techniques. are enzymes that preferentially catalyze the hydrolysis Since oleic acid (18:1) appears to have a similar and synthesis of esters and TAG. Some lipases exhibit effect on cholesterol as linoleic acid (18:2 n-6) and is substrate selectivity. Lipase from Penicillium camem- not as susceptible to oxidation, researchers increased bertii U-150 can hydrolyze mono- and diacylglycerols the ratio of monounsaturated fatty acids (MUFAs) to but not TAG (29). TAG with lower molecular weight PUFAs in soybean and canola oil by modifying the fatty acids were hydrolyzed more easily with lipase activity of a microsomal membrane-bound oleate de- from Penicillium caseicolum than those with higher mo- saturase (39). Trans fatty acids are produced during the lecular weight fatty acids (30). Lipase from Geotrichum hydrogenation process used by food companies and candidum has shown preference to the unsaturated their presence become a major health concern for con- substrates with a double bond at the 9-position (31). sumers. Several companies are actively pursuing the When cis- and trans- form of 18:1 in l-elaidate-2,3- development of seed oils that contain levels of satu- dioleate were compared for lipolysis, lipase from Ge- rated fatty acids high enough to permit the elimina- otrichum candidum preferentially hydrolyzed the cis- tion of the need for hydrogenation, and, subsequently, form to free fatty acid (32). the production of trans fatty acids (40). Cloning and Among the currently available methods for modi- characterizing genes for a family of thioesterases was fying lipids, lipase-catalyzed reactions are better than the 1st step toward the goal of incorporating MCFAs conventional chemical methods since lipases mimic into oil seed crops that naturally do not contain such natural pathways, which concern mild reaction condi- fatty acids. A gene from the California bay tree that tions, high catalytic efficiency, and the inherent selec- produces MCFAs in its seeds was incorporated into tivity of natural biocatalysts (33, 34). Typical applica- canola plants. The transgenic canola now accumulates tions of lipase-catalyzed interesterification reactions up to 65% more lauric acid in their seed TAGs (41). include the production of cocoa butter substitutes, hu- The sn-2 acyltransferase has a high degree of specific- man milk fat substitutes, partial acylglycerols, modi- ity for an unsaturated fatty acid; therefore, most of the fied fish oil products, margarines, structured lipids, and oleic acid found in these TAGs is at the sn-2 position. several lipid products (35, 36). This oil was marketed as Laurical® (Table 1). Genetic engineering. Genetic modification of oilseed crops to improve quality, pest and disease resis- tance and yield has expanded in recent years to include Commercial products examples of structured lipids modification of the fatty acid composition of oils for food use. Caprenin. Caprenin is a common name for cap- The main method of fatty acid profile modifica- rocaprylobehenin, a structured lipid containing C8:0, tion is the cloning and transfer of a gene from one C10:0, and C22:0 fatty acids esterified to glycerol plant species into another species to produce the de- moiety (Figure 2) (42). It is manufactured by Procter sired levels of specific fatty acids. As well, naturally & Gamble’s (Cincinnati, Ohio, U.S.A.) from coconut, occurring enzymes can be modified or new ones can palm kernel, and rapeseed oils by a chemical trans- be introduced to modify the fatty acid profile of the esterification process. The MCFAs are obtained from oilseed (37). Genes from bacterial, animal and yeast the coconut oil and the LCFAs from rapeseed oil. Be- sources have also been incorporated into oilseeds for cause behenic acid is only partially absorbed and capric fatty acid modification (38). and caprylic acids are more readily metabolized than Genetic codes are available to introduce double other longer chain fatty acids, caprenin provides only bonds, elongate carbon chains, synthesize eicosapentae- 5 kcal/g (43, 44). 04-Zam.indd 200 27/10/15 10:39 Structured lipids: methods of production, commercial products and nutraceutical characteristics 201 Procter & Gamble filed a Generally Recognized as Safe (GRAS) affirmation petition to the U.S. Food and Drug Administration (FDA) for use of caprenin in soft candies such as candy bars, and in confectionery coatings for nuts, fruits, cookies, and so on. Caprenin has a bland taste, is liquid or semisolid at room tem- perature, and is fairly stable to heat. It can be used as a cocoa butter substitute. Caprenin, in combination with polydextrose, was commercially available briefly Figure 2. Caprenin chemical structure. in reduced-calorie and reduced- fat chocolate bars (45). Swift et al. (46) showed that Caprenin fed as an SL diet to male subjects for 6 days did not alter plasma as Benefat® by Cultor Food Science (Ardsley, N.Y., cholesterol concentration but decreased HDL-chol U.S.A.). Benefat is produced by base-catalyzed inter- by 14%. However, the medium chain triacylglycerol esterification of highly hydrogenated vegetable oils (MCT) diet raised plasma TAGs by 42% and reduced with TAGs of acetic and/or propionic and/or butyric HDL-chol by 15%. acids (48). Salatrim/Benefat. Salatrim (an acronym derived Benefat is a low-calorie fat like Caprenin, with a from short and long acyl triglyceride molecule) is the caloric availability of 5 kcal/ g. Stearic acid is poorly or generic name for a family of structured triglycerides only 50% absorbed (49), whereas acetyl and propionyl comprised of a mixture containing at least one short groups in Benefat are easily hydrolyzed by lipases in chain fatty acid (primarily C2:0, C3:0, or C4:0 fatty the stomach and upper intestine and readily converted acids) and at least one long chain fatty acid (predomi- to carbon dioxide (50). Nabisco filed a Generally Rec- nantly C18:0, stearic acid) randomly attached to the ognized as Safe (GRAS) affirmation petition to the glycerol backbone (Figure 3) (47). U.S. Food and Drug Administration (FDA) in 1994 Salatrim was developed by the Nabisco Foods for use of Benefat in baking chips, chocolate-flavored Group (Hanover, N.J., U.S.A.) but now marketed coatings, baked and dairy products, dressings, dips, Table 1. Commercial Sls containing polyunsaturated fatty acids and their applications. Brand name Fatty acid composition Application Betapol C16:0 (45%) Infant food formulation Impact Interesterification with high lauric acid oil Pharmaceuticals for patients suffering from and high linoleic acid oil trauma or surgery, sepsis or cancer Laurical C12:0 (40%) and unsaturated fat Medical nutrition and confectionery coating, (C18:1, C18:2 and C18:3) coffee whiteners, whipped toppings and filling fats Neobee C8:0, C10:0 and LCFA (n–6 and n–3) Nutritional or medical beverages Structolipid LCT (63%) and MCT (37%) – Intravenous fat emulsion as a rapid source of caprylic (27%), capric (10%), energy for patients and parenteral nutrition palmitic (7%), oleic (13%), linoleic (33%) and α-linoleic acid (5%) Captex C8:0, C10:0, C18:2 Captex diet resulted in increased heat production and altered energy metabolism in obese Zucker rats. It also improved absorption of 18:2 n-6 when administered to cystic fibrosis patients. LCFA: Long chain fatty acid, LCT: Long chain triacylglycerol, MCT: Medium chain triacylglycerol. 04-Zam.indd 201 27/10/15 10:39 202 W. Zam and sauces, or as a cocoa butter substitute in foods. The consistency of Benefat varies from liquid to semisolid, depending on the fatty acid composition and the num- ber of short chain fatty acids (SCFAs) attached to the glycerol molecule. Olestra/Olean®. Olestra is an acylated sucrose polyester with six to eight fatty acids obtained from vegetable oil (e.g., soybean, corn, sunflower) as shown in figure 4. It is prepared by interesterifying sucrose and Figure 3. Salatrim chemical structure. edible oil methyl esters in the presence of an alkali cata- lyst, at 100-140°C (51). Sucrose polyester (SPE) devel- opment dates back to the year 1880, when a derivative of sucrose was prepared by acetylation to sucrose octa- acetate. In 1952 the concept of sucrose fatty acid polyes- ter (SPE) production was initiated for use in detergents. The other concept was to come up with a fatlike mol- ecule that would significantly reduce fat calories by pre- venting their hydrolysis and absorption. This led to the discovery of a non-digestible and non-absorbable fatlike molecule called sucrose fatty acid polyester, now known as olestra, by Mattson and Volpenhein while working on the absorption of fats by infants (52). Olestra has the organoleptic, and thermal prop- erties of fat. Is not hydrolyzed by gastric or pancre- atic enzymes because the large size and number of the nonpolar fatty acids, thus it is nondigestible, hence noncaloric; it is also nontoxic, yet nutritional concerns Figure 4. Olestra chemical structure. potentially exist (53). Its functionality is dependent on the chain length and unsaturation of the esterified fats, as with normal lipids (54). Olestra made from highly made up of only capric acid (57). Neobee 1095 is a unsaturated fatty acids is liquid at room temperature; solid product. Therefore, this product may be suitable olestra made from highly saturated fatty acids is solid in certain applications which require solid fats. Neobee (55). Because of its unique properties, olestra can serve 1814 is an MCT derivative made by interesterification as a zero-calorie replacement (up to 100%) for conven- of MCT with butter oil (58); it contains half of the tional fat in a variety of foods. It can be exchanged for long-chain saturated fatty acids found in conventional fats in products such as ice cream, margarine, cheese, butter oil and is suitable to replace butter oil in a vari- and baked goods, and it can be blended with vegetable ety of applications. Neobee 1814 may serve as a flavor oil (56). Olestra’s configuration also makes it possible carrier and functions as a textural component for low- for the substance to be exposed to high temperatures, fat food products (57). such as frying. Structured lipid containing polyunsaturated Neobee. Neobee is another caloric reduced fat, it fatty acids (PUFA). Nowadays, the most familiar is composed of capric and caprylic acids and produced types of low-calorie lipids are triacylglycerols with by Stepan Company (Maywood, N.J., U.S.A.). This short- and long-chain acyl residues (SLCTs), triacyl- class of specialty lipids includes different products. glycerols with medium- and long-chain acyl residues For example, Neobee 1053 and Neobee M-5 contain (MLCTs) and diacylglycerols (DAGs) (59). To act as both capric and caprylic acids, while Neobee 1095 is an ideal lipid substitute, the products should contain 04-Zam.indd 202 27/10/15 10:39 Structured lipids: methods of production, commercial products and nutraceutical characteristics 203 unsaturated fatty acids, especially essential fatty ac- Structured triacylglycerols (ST) enriched in eicos- ids, and have no harmful effects. SLs containing n–3 apentaenoic acid (EPA) in position 2 of the triacylg- highly unsaturated fatty acids were produced with im- lycerol (TAG) backbone were synthesized by acidolysis mobilized sn–1,3 specific and non-specific lipases as of a commercially available EPA-rich oil and caprylic biocatalysts. Highly unsaturated fatty acids, such as acid, catalyzed by the 1,3-specific immobilized lipase eicosapentaenoic (EPA, 20:5 n–3), docosahexaenoic lipozyme IM (66). (DHA, 22:6 n–3), linolenic (18:3 n–3) and gamma Table 1 summarize some commercial SLs con- linolenic (18:3 n–6) acids, are important in foods, nu- taining polyunsaturated fatty acids and their food and trition, and pharmaceutical applications (60). SLs con- medical applications (67). taining these fatty acids and medium-chain fatty acids Despite the health benefits of SLs containing may be desirable as ‘nutraceuticals’ for supplementa- polyunsaturated fatty acids, they are highly prone to tion in infant formula or as food supplement for adults oxidative deterioration and thus require adequate pro- to enhance overall health (61). tection to deter their oxidation (68). Some studies For the most part, the position of the highly un- have shown that the rate of autoxidation and melting saturated fatty acid in the glycerol moiety is key to properties of TAGs can be affected by the position of their functionality in foods and absorption when con- unsaturated fatty acids on the glycerol molecule (69). sumed. Perhaps, these designer lipids may replace con- TAGs having unsaturated fatty acids at the 2-position ventional fats and oils in certain specialty applications of glycerol are more stable toward oxidation than those because of their structure-health (nutraceutical or linked at the 1- and 3-positions (70). medical lipids) and structure-function (functional lip- Further research are conducted in order to opti- ids) attributes. In most cases, insertion of the desired mise the SLs’ stabilisation and storage by use of appro- highly unsaturated fatty acid at the sn–2 position will priate antioxidants and packaging technologies. provide maximum nutritional benefits (60). Specific In Nagachinta and Akoh study (71), Maillard re- structured lipids were designed with PUFA residues action products, obtained from heated whey protein at the sn-2 position and MCFA residues at the sn-1,3 isolates and corn syrup solids solution, were used as positions. In this form, the PUFA residues are pro- encapsulants for microencapsulation of 2 enzymati- tected against oxidation by the two saturated MCFA cally synthesized SLs for infant formula applications. residues. Hamam et al. (62) showed that the presence The encapsulated SL powders had low peroxide and of palmitate in the sn-2 position of the TAG, in in- thiobarbituric acid-reactive substances values. fant formula instead of conventional fats, improved digestibility of the fat and absorption of other impor- tant nutrients such as calcium. In a study conducted by Nutraceutical characteristics of SLs Decker (63), saturated fatty acids at the sn-2 position have been found to be beneficial in terms of providing Functional SLs increased caloric intake through infant formula and The interesterification and genetic engineering enteral supplements. processes have been used in the production of struc- An SL made by reacting tripalmitin with unsatu- tured lipids with specific physical properties such as rated fatty acids using an sn-1,3 specific lipase closely having a desired melting point, slow rancidification, mimicked the fatty acid distribution of human milk and also for the production of functional structured was commercially developed for application in in- lipids possessing specific compositions and nutritional fant formulas under the trade name Betapol (Loders properties. Table 2 summarize the potential uses of Croklaan, Glen Ellyn, Ill., U.S.A.) (64). functional structured lipids. Structured lipids (SL) enriched with omega 6 Margarine fats. Chemical and enzymatic inter- PUFA were synthesized from coconut oil triglycerides esterification has been specially employed in the for- by employing enzymatic acidolysis with free fatty acids mulation of margarines and shortenings with no trans obtained from safflower oil (65). FAs while still maintaining physical properties, taste 04-Zam.indd 203 27/10/15 10:39 204 W. Zam and stability. The vegetable oils including corn, palm, the need for hydrogenation to be used in bakery goods peanut, cottonseed, canola, and sunflower oils can be and for frying. The oil also has a healthier FA composi- randomly interesterified with fully hydrogenated soy- tion. High-oleic sunflower oil having better oxidative bean oil or fully hydrogenated cottonseed hard fats to stability in deep frying applications and extended shelf produce desirable fat compositions for margarines and life compared to traditional sunflower oil has been de- shortenings (72). veloped using selective breeding and mutagenesis (75). Cocoa butter equivalents. Due to high cost and Other example includes canola oil seed mutants with fluctuations in the supply and demand of cocoa butter, low linolenic/high oleic acid content (76). cocoa butter equivalent (CBE) with a TAGs composi- Breast milk fat substitute. Lipids are the major tion similar to cocoa butter is used as an alternative source of energy in human milk or infant formulas. source. Recently, vegetable oils such as Mahua, Kokum Hence, modification of fats and oils for infant formulas and mango fats, palm oil, tea seed oil, and olive oil in order to obtain not only the correct fatty acid (FA) have been used to prepare CBE through enzymatic composition but also the same positional distribution catalyzed interesterification until a similar composi- as in human milk fat (HMF) via interesterification tion of cocoa butter is obtained. The triacylglycerol had been widely investigated. Christensen and Hol- composition of oils was redesigned so that properties mer (77) prepared a HMF analogue using a Rhizomu- such as the melting point, solid fat content and fat cor miehei lipase-catalyzed modification of butter oil. crystal network microstructures of the structured oil Unilever produced a milk fat substitute named Betapol and cocoa butter were very much similar (73). for infant formulas (64). Also, Yang et al. (78) modi- Frying oils. Genetic engineering process had been fied lard by lipase to produce HMF substitutes. used for the production of modified oils that have a lot of benefits which include high oxidative stability, zero Health benefits of SLs trans-fat and low saturated FAs, non-hydrogenated, One of the earliest uses of SL was in enteral high oleic content, liquid at room temperature, and ex- and parenteral nutrition followed by its application cellent taste and flavor (74). Recently, genetically mod- in a range of clinical settings including prevention of ified soybean oil has been introduced that eliminates thrombosis, improved nitrogen balance, and enhanced Table 2. Potential uses of functional structured lipids. Potential uses SL related to food application References Margarine, butter, spreads, Benefat, Neobee and Olestra 48, 56, 58 shortening, dressings, dips, and sauces Cocoa butter equivalents Caprenin and Benefat 45, 50 Confectioneries and soft candies Caprenin and Laurical 41, 45 Baking chips, baked goods Benefat and Olestra 48, 56 Snack foods Caprenin, Captex 45 Low caloric food Caprenin, Benefat, Neobee 43, 49, 57 Frying oil Genetically modified soybean oil, 75, 76 high-oleic sunflower oil and canola oil seed mutants with low linolenic/high oleic acid content. Infant food formulas SLs containing EFAs and 61, 64 MCFAs such as Betapol Dairy products Benefat 50 04-Zam.indd 204 27/10/15 10:39
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