Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan.
J Dairy Sci. 2013 Aug;96(8):5174-83. doi: 10.3168/jds.2012-5963. Epub 2013 Jun 13.
Understanding the influence of regional dietary factors on the flavors of milk and dairy products will provide consumers with more options and promote the conservation of regional resources and the original terroir. The objective of this study was to evaluate the influence of regional differences in feeding systems on the composition, fatty acid content, and flavor of pasteurized milk at the farm level. Nine dairy farms using grass silage (GS), 6 farms using maize silage (MS), and 4 farms using by-products (BP) as the characteristic feed components were chosen for this survey. Fresh milk was sampled once per month from September 2008 to February 2009 at each dairy farm. The percentages of GS, MS, and BP (soybean curd residue or brewer's grain) in the feed were 32.4, 22.1, and 15.1%, respectively. The milk fat, protein, and lactose contents did not differ among the milks from farms with different feeding systems. Fatty acids with chain lengths of less than C16 and saturated fatty acids were present at higher concentrations in the milks from the GS and MS farms than in the milk from the BP farms; conversely, fatty acids with chain lengths greater than C18 and unsaturated fatty acids (UFA), including mono- (MUFA) and polyunsaturated fatty acids (PUFA), were present at higher concentrations in the milks from the BP farms than in the milks from the GS farms. No significant differences were detected in milk flavor, evaluated as sweetness, body, texture, aftertaste, and palatability, between the milks from the farms with different feeding systems. The proportion of BP in the cow's diet was positively correlated with the concentrations of fatty acids with chain lengths greater than C18 and with UFA, MUFA, and PUFA. In contrast, the proportion of GS in the diet was positively associated with the levels of milk fat, protein, fatty acids with chain lengths less than C16, and SFA. The MUFA, PUFA, UFA, and fatty acids with chain lengths greater than C18 were not associated with any of the milk flavors. These results suggest the regional differences in feeding systems contribute to the differences in the fatty acid compositions of milk at the farm level. However, these differences do not influence the flavor of pasteurized milk. Thus, more specific feed profiles will be required to provide a specific regional flavor to pasteurized milk.
了解区域性饮食因素对牛奶和乳制品风味的影响，将为消费者提供更多选择，并促进区域性资源和原产地风味的保护。本研究旨在评估不同养殖系统的区域差异对农场水平巴氏杀菌奶组成、脂肪酸含量和风味的影响。选择了 9 个使用青贮饲料（GS）、6 个使用青贮玉米（MS）和 4 个使用副产品（BP）作为特色饲料成分的奶牛场进行这项调查。从 2008 年 9 月至 2009 年 2 月，每个奶牛场每月采集一次新鲜牛奶。饲料中 GS、MS 和 BP（豆腐渣或啤酒糟）的比例分别为 32.4%、22.1%和 15.1%。不同养殖系统的牛奶中的乳脂、蛋白质和乳糖含量没有差异。GS 和 MS 农场的牛奶中短链（小于 C16）和饱和脂肪酸含量较高，而 BP 农场的牛奶中长链（大于 C18）和不饱和脂肪酸（UFA）含量较高，包括单不饱和脂肪酸（MUFA）和多不饱和脂肪酸（PUFA）。不同养殖系统的牛奶的风味没有显著差异，甜味、口感、质地、回味和口感评价结果一致。奶牛日粮中 BP 的比例与长链大于 C18 的脂肪酸和 UFA、MUFA 和 PUFA 的浓度呈正相关。相反，日粮中 GS 的比例与乳脂、蛋白质、短链小于 C16 的脂肪酸和 SFA 的水平呈正相关。MUFA、PUFA、UFA 和长链大于 C18 的脂肪酸与任何一种牛奶风味都没有关系。这些结果表明，养殖系统的区域差异导致了农场水平牛奶脂肪酸组成的差异。然而，这些差异不会影响巴氏杀菌奶的风味。因此，需要更具体的饲料配方来为巴氏杀菌奶提供特定的区域风味。
