高脂肪食物被认为对我们有普遍的吸引力,但人们喜欢和消耗脂肪的程度因个人而异。3月,Journal of Food Science杂志上发表的一项研究证实,两个特定基因(TAS2R38-1——苦味觉受体和CD36——脂肪物质的受体),可能在人们品尝和享受食物中脂肪的能力中发挥作用。通过了解这两个基因的作用,食品科学家可能帮助人们解决无法控制他们摄入多少脂肪的困扰。
大多数食品科学家承认脂肪的品质对影响脂肪在口腔中的口感有很大作用。例如,冰淇淋是典型的“丰厚、圆滑”的。对于某些脂肪而言,科学家已经确定可以通过气味检测其存在。食品科学家最近才探索发现大多数脂肪也有一种味道。目前,研究人员正在研究基因(CD360)是如何能发觉口中脂肪(脂肪酸)味道的存在。
在最近的Journal of Food Science杂志上,研究人员关注于一个有族群限制的遗传变异,这个变异可能会减少人们对脂肪物质的感兴趣程度。他们确检测了300多名非洲裔美国成年人脂肪的喜好程度和体内CD36的状态。纽约肥胖研究中心的研究人员发现21%的非裔美国人存在基因变异,该基因变异与脂肪和油(如沙拉酱、食用油等)的喜爱程度高有关。他们还发现,这种基因变异的研究参与者也更喜爱意大利沙拉酱。
调查研究发现其他基因——TAS2R38是带苦味的化合物的作用受体。约70%的美国成年人和儿童是这些化合物的尝味道者,而其余30%不能品尝带苦味的化合物。结果表明不能品尝这些化合物的人往往不善于区分食品中的脂肪物质,因此,这些无法检测脂肪的存在,进而可能会消耗更高脂肪的食物以弥补这一缺陷。上述现象的原因是由于不能品尝到脂肪存在的人比能品尝到脂肪物质的人有较少的味蕾。虽然研究人员承认肥胖的原因是多方面的,但他们将继续研究这些基因在体重控制中的作用。
食品行业内的基因测试可能不会太遥远。一旦这些研究得到更充分的发展,那么当一新食品种类产生时,测试新产品中的基因分型是很有可能的。此外,食品行业将能够创造出针对特定人群的不同种类的食物。(生物谷:Bioon)
doi:10.1111/j.1750-3841.2011.02585.x
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Genetic Influences on Oral Fat Perception and Preference
Kathleen L. Keller
Research suggests that dietary fat is perceived not only by texture, but also by taste. However, the receptors for chemosensory response to fat have not been identified. We report on 2 genes,TAS2R38 and CD36, that may play a role in fat perception and preference in humans. TAS2R38 is a taste receptor for bitter thiourea compounds, including 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC). Nontasters of these compounds tend to be poor at discriminating fat in foods, even though they prefer higher fat versions of these foods. CD36, a fatty acid translocase expressed on multiple cell types including taste cells, plays a critical role in fat preferences in animals. In studies conducted in our laboratory with African-American adults, we identified a variant in the CD36 gene, rs1761667, that predicts oral responses to fat. Individuals who have the A/A genotype at this site tend to find Italian salad dressings creamier than those who have other genotypes at this site. In addition, A/A individuals report higher preferences for added fats, oils, and spreads (for example margarine). Assuming these data are confirmed in other populations, screening for CD36 genotype may provide helpful information to food companies for developing fat-modified products.