科学素养与现象阐释·英语30篇（6）
17 / 30
正在确认阅读权限…
Lactic Acid Fermentation as a Redox-Neutral Preservation Strategy in Dairy Matrices
乳酸发酵作为乳基质中氧化还原中性防腐策略
-
Milk sours not through spoilage but via targeted microbial fermentation—primarily by Lactobacillus and Streptococcus species converting lactose into lactic acid.牛奶变酸并非因腐败，而是由微生物定向发酵所致——主要是乳酸杆菌和链球菌将乳糖转化为乳酸。
-
This process maintains redox neutrality: electrons removed during sugar oxidation are exactly balanced by protons consumed in acid formation, avoiding reactive oxygen species generation.该过程维持氧化还原平衡：糖氧化脱下的电子恰好被产酸时消耗的质子所平衡，因而不会产生活性氧。
-
The resulting pH drop below 4.6 denatures casein micelles, inducing coagulation and inhibiting pathogens like Salmonella and E. coli that cannot tolerate acidic environments.pH值降至4.6以下使酪蛋白胶束变性，引发凝结，并抑制沙门氏菌、大肠杆菌等无法耐受酸性环境的致病菌。
-
Unlike chemical preservatives, fermentation enhances nutritional value—increasing bioavailable B vitamins and generating antimicrobial peptides called bacteriocins.与化学防腐剂不同，发酵可提升营养价值——增加B族维生素的生物利用率，并生成具有抗菌作用的细菌素。
-
Temperature and inoculum concentration precisely control acidification kinetics: rapid fermentation at 42°C yields yogurt, while slower mesophilic cultures produce farmhouse cheeses.温度与接种量精准调控酸化动力学：42°C快速发酵制得酸奶，而较慢的常温发酵则产出农家奶酪。
-
Crucially, fermentation preserves energy content—lactic acid retains nearly all the caloric potential of lactose, unlike aerobic spoilage which wastes energy as CO₂ and heat.关键在于，发酵保留了能量：乳酸几乎完全保留了乳糖的热量潜力，而好氧腐败却以CO₂和热的形式浪费能量。
-
Modern dairy safety standards rely on monitoring titratable acidity and viable culture counts rather than merely checking for 'off' odors or textures.现代乳品安全标准依赖滴定酸度和活菌计数监测，而非仅凭异味或质地等感官指标判断。
-
Probiotic functionality further depends on strain-specific adhesion to intestinal epithelia—a trait selected during centuries of artisanal fermentation practice.益生功能还取决于菌株特异性地黏附肠道上皮的能力——这一特性在数百年手工发酵实践中被自然筛选出来。
-
This ancient biotechnology thus represents a sophisticated metabolic engineering solution predating laboratory microbiology by millennia.这项古老生物技术实为一种高度成熟的代谢工程方案，比实验室微生物学早出现数千年。
-
Its robustness stems from self-limiting feedback: accumulated acid eventually inhibits the very microbes producing it, halting fermentation predictably.其稳健性源于自我限制型反馈：积累的酸最终抑制产酸菌自身，使发酵可预测地终止。
-
Understanding this mechanism reframes 'spoilage' as context-dependent functional transformation.理解这一机制，便能将‘腐败’重新定义为依情境而定的功能性转化。
-
Dairy science today seeks to harness similar redox-balanced pathways for plant-based analogues using engineered lactic acid bacteria.当今乳品科学正致力于利用基因工程乳酸菌，在植物基替代品中复现类似的氧化还原平衡代谢通路。