Akoh C C
Department of Food Science and Technology, University of Georgia, Athens 30602-7610, USA.
Crit Rev Food Sci Nutr. 1995 Sep;35(5):405-30. doi: 10.1080/10408399509527707.
Fats and oils account for 38% of the total calories in the diet of Western populations, especially in the U.S. They provide the most concentrated source of energy, 9 kcal/g of a triacylglycerol molecule compared with 4 kcal/g provided by carbohydrate and protein. In response to consumer demands for low-calorie or calorie-free fats and their reluctance to give up the taste of fat, current research efforts have been directed toward the development of lipid-like fat substitutes. These fat substitutes contain the fatty acids found in conventional fats and oils, with all the physical and organoleptic properties of fats, but provide few or no calories in the diet. Some of the fat substitutes are modified triacylglycerols (glycerol backbone) with reduced digestion and absorption; others are digestible and nondigestible carbohydrate fatty acid esters and polyesters, respectively. Sucrose polyester (Olestra), a sucrose molecule esterified with six to either fatty acids, is the most studied of the lipid-based fat substitutes containing a carbohydrate backbone. If approved by the FDA, sucrose polyester will find application in almost all fat-containing foods. Specialty fats or fat substitutes targeted to certain individuals with special needs are being developed. Among these are the medium-chain triacylglycerols and structured lipids (glycerol backbone), or ¿nutraceuticals¿ with reduced absorption and medical applications. Enzyme biotechnology is another tool available to lipid chemists to selectively modify, esterify, transform, transesterify, and interesterify fats and oils or synthesize new lipids such as structured lipids of food, nutritional, and medical importance. These designer fats may be the trend in the future to produce medical lipids that do not occur normally in nature. The different types of lipid-based fat substitutes are reviewed with respect to their synthesis, analysis, metabolism, potential applications/uses, and the future of fat substitutes.
脂肪和油类占西方人群饮食中总热量的38%，在美国尤其如此。它们是最浓缩的能量来源，三酰甘油分子每克提供9千卡能量，而碳水化合物和蛋白质每克仅提供4千卡能量。为了满足消费者对低热量或无热量脂肪的需求，同时又不想放弃脂肪的味道，目前的研究工作致力于开发类似脂质的脂肪替代品。这些脂肪替代品含有传统油脂中的脂肪酸，具备脂肪的所有物理和感官特性，但在饮食中提供很少或不提供热量。一些脂肪替代品是消化和吸收能力降低的改性三酰甘油（甘油主链）；其他的分别是可消化和不可消化的碳水化合物脂肪酸酯和聚酯。蔗糖聚酯（奥利司他）是一种蔗糖分子与六个脂肪酸酯化而成的物质，是对含碳水化合物主链的基于脂质的脂肪替代品研究最多的一种。如果获得美国食品药品监督管理局（FDA）的批准，蔗糖聚酯将应用于几乎所有含脂肪的食品中。针对有特殊需求的特定个体的特种脂肪或脂肪替代品正在研发中。其中包括中链三酰甘油和结构化脂质（甘油主链），或吸收减少且具有医学应用的“营养保健品”。酶生物技术是脂质化学家可用的另一种工具，用于选择性地改性、酯化、转化、酯交换和酯基转移油脂，或合成新的脂质，如具有食品、营养和医学重要性的结构化脂质。这些特制脂肪可能是未来生产自然界中通常不存在的医用脂质的趋势。本文就不同类型的基于脂质的脂肪替代品的合成、分析、代谢、潜在应用/用途以及脂肪替代品的未来发展进行了综述。
