Synthesis, physicochemical properties, and health aspects of structured lipids: A review

Abstract

Structured lipids (SLs) refer to a new type of functional lipids obtained by chemically, enzymatically, or genetically modifying the composition and/or distribution of fatty acids in the glycerol backbone. Due to the unique physicochemical characteristics and health benefits of SLs (for example, calorie reduction, immune function improvement, and reduction in serum triacylglycerols), there is increasing interest in the research and application of novel SLs in the food industry. The chemical structures and molecular architectures of SLs define mainly their physicochemical properties and nutritional values, which are also affected by the processing conditions. In this regard, this holistic review provides coverage of the latest developments and applications of SLs in terms of synthesis strategies, physicochemical properties, health aspects, and potential food applications. Enzymatic synthesis of SLs particularly with immobilized lipases is presented with a short introduction to the genetic engineering approach. Some physical features such as solid fat content, crystallization and melting behavior, rheology and interfacial properties, as well as oxidative stability are discussed as influenced by chemical structures and processing conditions. Health‐related considerations of SLs including their metabolic characteristics, biopolymer‐based lipid digestion modulation, and oleogelation of liquid oils are also explored. Finally, potential food applications of SLs are shortly introduced. Major challenges and future trends in the industrial production of SLs, physicochemical properties, and digestion behavior of SLs in complex food systems, as well as further exploration of SL‐based oleogels and their food application are also discussed.

Rhizopus oryzae Lipase, a Promising Industrial Enzyme: Biochemical Characteristics, Production and Biocatalytic Applications

“…Therefore, by modifying the fatty acids composition or its profile, lipids with improved properties might be obtained, the so-called structured lipids (SL). Currently, there are various SLs of commercial interest whose properties have been widely described (Table 6), (i) low caloric and dietetic triacylglycerols that include TAGs with medium-chains (MMM) and TAGs with short-and medium-chain fatty acids in sn-1 and sn-3 and a long-chain fatty acids in sn-2 position, SLS and MLM respectively; (ii) human milk fat substitutes (HMFS), (iii) cocoa butter equivalents (CBE), (iv) transfree plastic fats, (v) triacylglycerols rich in specific long-chain and polyunsaturated fatty acids (PUFAs) and recently, even (vi) diacylglycerols (DAG) and monoacylglycerols (MAG) have been considered as SLs [246,247]. Released M fatty acids can be directly absorbed and provide readily energy in the liver.…”

“…• Promote palmitic acid absorption as 2-monoacylpalmitate • Promote calcium absorption [246,247,250,251] Cocoa butter equivalents (CBE)…”

“…• Desirable polymorph is β form • Similar organoleptic properties to cocoa butter [246,247,252,253] Trans-free plastic fats…”

Thermorheological Characterization of Healthier Reduced-Fat Cocoa Butter Formulated by Substitution with a Hydroxypropyl Methylcellulose (HPMC)-Based Oleogel

“…The emulsion-templated approach for oil structuring is described as an indirect method to obtain oleogels by first creating a water continuous emulsion, followed by removing water and further shearing the dried emulsion [18][19][20]. These oleogels can be considered to be fat analogs as they contain a high concentration (above 97 wt.%) of edible oil [11].…”

Triacylglycerols and Fatty Acid Compositions of Cucumber, Tomato, Pumpkin, and Carrot Seed Oils by Ultra-Performance Convergence Chromatography Combined with Quadrupole Time-of-Flight Mass Spectrometry

“…Among the nutrients in these seeds, lipid is one of the most important components, which contains more than 95% triacylglycerols (TAGs) [ 5 , 8 ]. Recently, increasing evidence has demonstrated that not only the fatty acid compositions, but also their binding positions in TAGs play very important roles in the functionality and nutrition values of seed oils [ 9 , 10 , 11 , 12 ]. For example, binding positions of fatty acids to TAG altered their oxidative stability, calcium absorption, and lipid metabolism [ 11 ].…”