Department of Food, Bioprocessing and Nutrition Sciences, Southeast Dairy Foods Research Center, Box 7624, North Carolina State University, Raleigh 27695-7624.
Department of Food Science, Northeast Dairy Foods Research Center, Cornell University, 311 Tower Road, Ithaca, NY 14853.
J Dairy Sci. 2022 Apr;105(4):3004-3018. doi: 10.3168/jds.2021-20826. Epub 2022 Jan 25.
Schools participating in federal meal programs are limited to serving skim or low-fat (≤1%) flavored and unflavored milk. Few studies have directly addressed child perceptions and preferences for milk containing different amounts of milkfat. The objective of this study was to determine whether children can differentiate between flavored and unflavored fluid milk containing varying levels of milkfat and whether preferences for certain levels of milkfat exist. Flavored and unflavored milks containing 4 different percentages of milkfat (≤0.5, 1, 2, and 3.25%) were high-temperature, short-time processed, filled into half-gallon light-shielded milk jugs, and stored at 4°C in the dark. Milks were evaluated by children (ages 8-13 yr) following 7 d at 4°C. Acceptance testing and tetrad difference testing were conducted on flavored and unflavored milks with and without visual cues to determine if differences were driven by visual or flavor or mouthfeel cues. Child acceptance testing (n = 138 unflavored; n = 123 flavored) was conducted to evaluate liking and perception of selected attributes. Tetrad testing (n = 127 unflavored; n = 129 flavored) was conducted to determine if children could differentiate between different fat levels even in the absence of a difference in acceptance. The experiment was replicated twice. When visual cues were present, children had higher overall liking for 1% and 2% milks than skim for unflavored milk and higher liking for chocolate milks containing at least 1% milk fat than for skim. Differences in liking were driven by appearance, viscosity, and flavor. In the absence of visual cues, no differences were observed in liking or flavor or mouthfeel attributes for unflavored milk but higher liking for at least 1% milk fat in chocolate milk compared with skim was consistent with the presence of visual cues. From tetrad testing, children could visually tell a difference between all unflavored pairs except 2% versus whole milk and could not detect consistent differences between milkfat pairs in the absence of visual cues. For chocolate milk, children could tell a difference between all milk fat pairs with visual cues and could tell a difference between skim versus 2% and skim versus whole milk without visual cues. These results demonstrate that in the absence of package-related flavors, school-age children like unflavored skim milk as well as milk with higher fat content in the absence of visual cues. In contrast, appearance as well as flavor and mouthfeel attributes play a role in children's liking as well as their ability to discriminate between chocolate milks containing different amounts of fat, with chocolate milk containing at least 1% fat preferred. The sensory quality of school lunch milk is vital to child preference, and processing efforts are needed to maximize school milk sensory quality.
参与联邦膳食计划的学校仅限于供应脱脂或低脂(≤1%)风味和非风味牛奶。很少有研究直接探讨儿童对含不同脂肪量的牛奶的感知和偏好。本研究的目的是确定儿童是否可以区分含有不同脂肪量的风味和非风味液体牛奶,以及是否存在对某些脂肪量的偏好。含有 4 种不同脂肪百分比(≤0.5、1、2 和 3.25%)的风味和非风味牛奶经过高温短时间处理,装入半加仑避光牛奶罐中,并在 4°C 的暗处储存。在 4°C 下储存 7 天后,儿童(8-13 岁)对牛奶进行评估。对有和没有视觉提示的风味和非风味牛奶进行接受性测试和四元差异测试,以确定差异是由视觉、风味还是口感提示驱动的。对选定属性的儿童接受性测试(无风味 138 人;风味 123 人)进行了测试,以评估喜好和感知。四元测试(无风味 127 人;风味 129 人)用于确定即使在接受度没有差异的情况下,儿童是否能够区分不同的脂肪水平。该实验重复了两次。当有视觉提示时,与脱脂牛奶相比,儿童更喜欢 1%和 2%的牛奶,而对含有至少 1%牛奶脂肪的巧克力牛奶的喜爱程度高于脱脂牛奶。喜好的差异是由外观、粘度和风味驱动的。在没有视觉提示的情况下,无风味牛奶的喜好、风味或口感属性没有差异,但与脱脂牛奶相比,巧克力牛奶中至少 1%的牛奶脂肪含量较高的喜好是一致的。从四元测试中可以看出,儿童可以通过视觉分辨出所有无风味的牛奶之间的差异,除了 2%与全脂牛奶之间的差异,并且在没有视觉提示的情况下,无法检测到牛奶脂肪之间的一致差异。对于巧克力牛奶,儿童可以通过视觉分辨出所有脂肪含量的牛奶之间的差异,并且可以在没有视觉提示的情况下分辨出脱脂与 2%和脱脂与全脂之间的差异。这些结果表明,在没有与包装相关的风味的情况下,学龄儿童喜欢无风味的脱脂牛奶以及脂肪含量较高的牛奶,而在没有视觉提示的情况下则没有。相比之下,外观以及风味和口感属性在儿童的喜好以及他们区分含有不同脂肪量的巧克力牛奶的能力中起着重要作用,含有至少 1%脂肪的巧克力牛奶更受欢迎。学校午餐牛奶的感官质量对儿童的偏好至关重要,需要进行加工努力以最大限度地提高学校牛奶的感官质量。