Journal of Biotechnology ( IF 4.1 ) Pub Date : 2020-09-17 , DOI: 10.1016/j.jbiotec.2020.09.009 Yuriy Kryachko 1 , Barkhas Batbayar 1 , Takuji Tanaka 1 , Michael T Nickerson 1 , Darren R Korber 1
Suspensions of pea protein enriched flour (PP) inoculated with Lactobacillus plantarum NRRL B-4496 and uninoculated PP suspensions were incubated in vials covered with airtight caps. Organic compound compositions of fermented and unfermented PP suspensions (F-PP and U-PP, respectively) were analyzed using solid phase microextraction (SPME) coupled with gas chromatography – mass-spectrometry (GCMS). Acetic acid was detected in all samples; pH dropped from pH 6.5 to pH 4.1 in L. plantarum F-PP and to pH 5.3 in uninoculated F-PP. Abundance of acetic acid and minuscule presence of lactic acid in L. plantarum F-PP suggested that fermentation proceeded preferentially via the pyruvate formate lyase (PFL) pathway. Nonetheless, glycerol appeared to be the most abundant compound in L. plantarum F-PP samples; colorimetric analysis indicated that its average concentration in these samples was 1.05 g/L. A metabolic switch from the PFL pathway to glycerol production might occur due to acidity tolerance limitations of L. plantarum, glycerol production being associated with the release of phosphate, which can act as a buffer. Fermentation of PP by L. plantarum also led to formation of hexamine, which is a known food preservation agent. Presence of naturally formed hexamine and glycerol in food products may render using chemical additives needless.
中文翻译:
植物乳杆菌 NRRL B-4496 生产甘油和豌豆蛋白粉发酵过程中六胺的形成。
用植物乳杆菌NRRL B-4496接种的富含豌豆蛋白的面粉 (PP)悬浮液和未接种的 PP 悬浮液在盖有密封盖的小瓶中孵育。使用固相微萃取 (SPME) 结合气相色谱 - 质谱 (GCMS) 分析发酵和未发酵 PP 悬浮液(分别为 F-PP 和 U-PP)的有机化合物组成。所有样品均检出乙酸;pH 在植物乳杆菌F-PP 中从 pH 6.5 降至 pH 4.1,在未接种 F-PP 中降至 pH 5.3。植物乳杆菌中大量的乙酸和极少的乳酸F-PP 表明发酵优先通过丙酮酸甲酸裂解酶 (PFL) 途径进行。尽管如此,甘油似乎是植物乳杆菌F-PP 样品中含量最高的化合物;比色分析表明其在这些样品中的平均浓度为 1.05 g/L。由于植物乳杆菌的耐酸性限制,可能会发生从 PFL 途径到甘油生产的代谢转换,甘油生产与磷酸盐的释放有关,磷酸盐可以充当缓冲剂。植物乳杆菌对 PP 的发酵也导致了六胺的形成,这是一种已知的食品保鲜剂。食品中天然形成的六胺和甘油的存在可能导致无需使用化学添加剂。