Timlin Mark, Brodkorb André, Harbourne Niamh, O'Callaghan Tom F, Drouin Gaetan, Pacheco-Pappenheim Sara, Hennessy Deirdre, O'Donovan Michael, Pierce Karina M, Corrigan Bernard M, Murphy John P, Pismennõi Dmitri, Taivosalo Anastassia, Lints Taivo, Kriščiunaite Tiina, Vilu Raivo, Fitzpatrick Ellen, McCarthy Kieran, Sheehan Jeremiah J
Teagasc, Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland P61 C996; School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland D04 V1W8; Food for Health Ireland, University College Dublin, Dublin 4, Ireland D04 V1W8.
Teagasc, Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland P61 C996; Food for Health Ireland, University College Dublin, Dublin 4, Ireland D04 V1W8.
J Dairy Sci. 2024 Dec;107(12):10310-10327. doi: 10.3168/jds.2024-24745. Epub 2024 Aug 8.
The objective of this study was to examine the effect of stage of lactation (early, mid, and late) and proportion of pasture in the cow's diet (high: GRS, medium: PMR, and no: TMR) on the composition and quality of Cheddar cheese. Triplicate trials were carried out in each stage of lactation, and milk protein and fat contents were standardized for Cheddar cheese manufacture at pilot scale. Because cheese milks were standardized for milk fat and protein contents, gross composition did not differ as a result of diet. Fatty acid profiles of GRS cheese were significantly different from TMR, while PMR profiles were less distinct and more similar to both GRS and TMR profiles, as illustrated by partial least squares discriminatory analysis. Fatty acids including CLA C18:2 cis-9,trans-11, C22:1 n-9, and C18:3 n-3 were most influential in this separation of profiles. Fatty acid profiling revealed that GRS-derived cheese contained higher proportions of nutrients considered beneficial for human health including higher proportions of unsaturated fatty acids and omega-3 fatty acids. A biomarker model utilizing the proportions of 5 fatty acids was constructed and was effective at distinguishing between cheese of GRS, TMR, and PMR feeding systems. Proportions of ρ-κ-CN, α-CN and α-CN in cheese also differed among diets while proportions of ρ-κ-CN, α-CN, and β-CN were lowest in late lactation cheese. The effect of diet was less influential compared with that of stage of lactation on the ripening characteristics of cheese. An index of primary proteolysis was highest in late lactation cheese. The peptides derived from the proteolysis of κ-CN and β-CN and levels of secondary proteolysis, in particular, the proportions of 12 free AA were most influenced by stage of lactation. Overall this study demonstrated the effects of increasing pasture allowance and wstage of lactation on the nutritional quality and ripening properties of Cheddar cheese.
本研究的目的是考察泌乳阶段（早期、中期和晚期）以及奶牛日粮中牧草比例（高：青草青贮料，中：多年生黑麦草，无：全混合日粮）对切达干酪成分和品质的影响。在泌乳的每个阶段进行了三次重复试验，并在中试规模下对用于生产切达干酪的牛奶蛋白质和脂肪含量进行了标准化。由于用于制作奶酪的牛奶在脂肪和蛋白质含量方面进行了标准化，日粮对总成分没有影响。偏最小二乘判别分析表明，青草青贮料奶酪的脂肪酸谱与全混合日粮奶酪有显著差异，而多年生黑麦草日粮奶酪的脂肪酸谱差异较小，与青草青贮料和全混合日粮奶酪的脂肪酸谱更相似。包括共轭亚油酸C18:2顺-9,反-11、C22:1 n-9和C18:3 n-3在内的脂肪酸在这种谱图分离中影响最大。脂肪酸分析表明，源自青草青贮料的奶酪含有更高比例对人体健康有益的营养成分，包括更高比例的不饱和脂肪酸和ω-3脂肪酸。构建了一个利用5种脂肪酸比例的生物标志物模型，该模型能够有效区分青草青贮料、全混合日粮和多年生黑麦草饲喂系统下生产的奶酪。奶酪中ρ-κ-酪蛋白、α-酪蛋白和α-酪蛋白的比例在不同日粮间也存在差异，而ρ-κ-酪蛋白、α-酪蛋白和β-酪蛋白的比例在泌乳后期奶酪中最低。与泌乳阶段相比，日粮对奶酪成熟特性的影响较小。初级蛋白水解指数在泌乳后期奶酪中最高。κ-酪蛋白和β-酪蛋白水解产生的肽以及二级蛋白水解水平，特别是12种游离氨基酸的比例受泌乳阶段影响最大。总体而言，本研究证明了增加牧草供应量和泌乳阶段对切达干酪营养品质和成熟特性的影响。
