共查询到18条相似文献,搜索用时 93 毫秒
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新型酸奶发酵剂的研究 总被引:12,自引:3,他引:9
研究了具有不同粘度,风味和保健功能的新型酸奶发酵剂,首先通过对专用酸奶菌种嗜热链球菌和保加利亚乳杆菌不同菌株的组合筛选,优选出具有不同粘度和风味的3种组合;其次,酸奶的疗效保健作用来源于嗜酸乳杆菌,通过研究缓冲盐,生长促进物质对该菌生长的影响,确定了适宜的培养基成分和发酵剂中菌种的配比。 相似文献
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酸乳后酸化影响因子的初步研究 总被引:4,自引:1,他引:4
酸乳在贮存、运输、销售、食用前这一过程中发生后酸化现象,导致酸乳无法长期贮存,酸乳贮存期短这一缺陷一直困扰着酸乳的消费。文中从酸乳发酵时保加利亚乳杆菌与嗜热链球菌比例的改变、弱后酸化发酵剂的筛选和酸乳发酵后添加乳酸链球菌素等方面探讨了控制酸乳后酸化的措施。通过改变嗜热链球菌与保加利亚乳杆菌的比例、酸乳发酵后添加乳酸链球菌素对控制酸乳后酸化有一定的效果,但成本较高。控制酸乳后酸化的最好方法是选育在高温条件下产酸较强,在低温条件下产酸甚微的菌株作为发酵剂,并发现采用汉森公司的YF-L812发酵的酸乳后酸化程度很小,在6℃条件下贮存30 d时酸度仅上升了14.5°T。 相似文献
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Xinhui Wang Hongyang Ren Dayu Liu Bing Wang Wenyou Zhu Wei Wang 《Journal of food science》2013,78(2):M297-M302
Continued acid production by Lactobacillus delbrueckii subsp. bulgaricus during the chilled storage of yogurt is the major cause of postacidification, resulting in a short shelf life. Two H+‐ATPase defective variants of L. delbrueckii subsp. bulgaricus were successfully isolated and their H+‐ATPase activities were reduced by 51.3% and 34.3%, respectively. It was shown that growth and acid production of variants were remarkably inhibited. The variants were more sensitive to acidic condition and had a significant rate for inactivation of H+‐ATPase by N, N‐dicyclohexylcarbodiimide (DCCD), along with a low H+‐extrusion, suggesting that H+‐ATPase is direct response for H+‐extrusion. In addition, the variants were also more sensitive to NaCl, while H+‐ATPase activities of variants and parent strain were significantly enhanced by NaCl stress. Obviously, H+‐ATPase might be involved in Na+ transportation. Furthermore, variants were inoculated in fermented milk to ferment yogurt. There was no significant difference in flavor, whereas the postacidification of yogurt during chilled storage was remarkably inhibited. It is suggested that application of L. delbrueckii subsp. bulgaricus with reduced H+‐ATPase activity in yogurt fermentation is one of effect, economic and simple avenues of inhibiting postacidification of yogurt during refrigerated storage, giving a longer shelf life. Practical Application: During yogurt fermentation, continued acid production by Lactobacillus delbrueckii subsp. bulgaricus during the chilled storage of yogurt leads to milk fermentation with high postacidification, resulting in a short shelf life. In this work, 2 acid‐sensitive variant strains of L. delbrueckii subsp. bulgaricus were isolated. The characteristics related to H+‐ATPase were compared and it was observed that milk fermented by the variants had lower postacidification, giving a longer shelf life. Application of L. delbrueckii subsp. bulgaricus with reduced H+‐ATPase activity in yogurt fermentation might be one of effect, economic and simple avenues of inhibiting yogurt postacidification during chilled storage, giving a longer shelf life. 相似文献
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搅拌型酸奶后酸化控制的初步研究 总被引:1,自引:0,他引:1
文中针对搅拌型酸奶成熟后在贮存、运输、销售、食用前出现的后酸化现象(postacidification)文中进行了初步研究。在无水乙醇抑制后酸化的实验中,4%的无水乙醇能明显抑制乳酸菌的进一步产酸,且不影响其优良的感官指标。进一步研究发现,每40mL酸奶制品分别添加1.4mL酒精度为38%的汾酒、1.0mL酒精度为62%的高度酒均可明显抑制后酸化现象。文中还尝试了酵母菌抑制后酸化的效果,结果发现,1株从牧区家庭自制酸奶中分离的酵母菌以2.0×107个/mL的浓度,每40mL酸奶制品添加0.1mL不仅可抑制后酸化现象,而且轻微的乙醇发酵改善了酸奶的口味,提高了酸奶的感官品质。经细胞形态、菌落特征、生理生化及产孢子类型可初步判断该酵母菌为异酒香酵母。 相似文献
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以直投式乳酸菌为实验菌,研究富含ACE抑制活性肽的酪蛋白双酶水解物及其超滤物对乳酸菌的生长及发酵酸乳的影响。添加不同质量浓度的水解物和超滤物培养乳酸菌,检测对乳酸菌生长的影响,确定对乳酸菌生长无抑制作用的添加量,并将其应用于酸乳发酵。检测对酸乳的酸度、硬度、黏性、弹性等指标的的影响,结合感官评价,确定对酸乳的影响。结果表明:水解物的添加量为4g/100mL,分子质量在6000u以下的超滤物添加量为0.3g/100mL对乳酸菌的生长有促进作用,并且对发酵酸乳的感官质量无显著影响。水解物质量浓度≥5g/100mL、超滤物质量浓度≥0.35g/100mL对乳酸菌的生长起到抑制作用。 相似文献
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游离与微胶囊化益生菌对酸奶感官性质的影响 总被引:1,自引:0,他引:1
对游离益生菌与微胶囊化益生菌(嗜酸乳杆菌和双歧杆菌)的存活率、pH、胞外多糖的产生进行了比较,且对添加这两种形式的益生菌酸奶,在贮存7周后的感官性质进行了评定。结果表明,微胶囊有助于提高益生菌在酸奶中存活率,且添加游离或包埋益生菌的酸奶在贮存期间,其外观、色泽、风味及酸度并无显著变化,但酸奶的质地(光滑程度)变化显著。 相似文献