挤奶阶段对羊乳中微生物的影响
Influence of milking stage on microorganisms in goat milk
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摘要: 对奶山羊挤奶过程中不同挤奶阶段的乳样中微生物变化规律进行了研究。结果表明,不同挤奶阶段乳中微生物数量有明显变化,挤出的前期乳样中微生物数量最高,中期乳样次之,末期乳样最低。前期乳样的菌落总数、大肠菌群、嗜冷菌、嗜热菌、蛋白分解菌和脂肪分解菌的数量分别高达3×106、1.4×104、3.3×104、1.3×103、1.5×105和1.3×105cfu/mL,明显高于中期乳样和末期乳样(p<0.05),尤其是前期乳样中的菌落总数已高出GB19301-2010中收购生鲜乳的微生物指标(2×106cfu/mL)。因此在挤奶过程中,应尽可能的弃去前期乳样,以提高原料羊乳的卫生质量。Abstract: The change of the bacterial numbers in goat milk samples at different milking stage were studied in this paper. The results showed that the number of the total bacterial count, coliform, psychrotrophilic bacteria, thermophilic bacteria, proteolytic bacteria and lipolysis bacteria was higher in the pre- milk samples, which was also obviously higher than that of the middle and the end milk samples ( p < 0.05) . These bacterial numbers had reached 3 × 10 6 、1.4 ×10 4 、3.3 × 10 4 、1.3 × 10 3 、1.5 × 10 5 and 1.3 × 10 5 cfu /mL, respectively, the pre- milk samples of the total bacterial count had exceed national standard ( GB19301-2010) for purchase fresh milk in the microbial index.So the pre-milk samples should be abandoned in milking process as far as possible to improve the sanitary quality of raw goat milk.