乳清分离蛋白纤维和典型抗氧化剂对罗伊氏乳杆菌TMW 1.656在常温贮藏胁迫下存活的影响

Effects of Whey Protein Isolate Fibrils and Typical Antioxidants on the Survival of Spray-Dried Lactobacillus reuteri TMW 1.656 during Ambient Storage

为研究新型纳米材料乳清分离蛋白纤维(whey protein isolate fibrils,WPIF)和典型抗氧化剂对益生菌常温贮藏氧胁迫的保护影响,采用乳清分离蛋白(whey protein isolate,WPI)和WPIF为壁材,添加不同质量浓度的典型抗氧化剂表没食子酸儿茶素没食子酸酯(epigallocatechin gallate,EGCG)和谷胱甘肽(glutathione,GSH),采用喷雾干燥法制备干态菌粉。结果表明,在常温贮藏期间,益生菌的贮藏稳定性按照WPIF≈WPI>WPI+0.5 mg/mL EGCG>WPI+0.5 mg/mL GSH>WPI+5.0 mg/mL EGCG>WPI+5.0 mg/mL GSH的顺序下降。WPIF保护菌体的效果与WPI相差不大,其原因可能是高温使得纤维发生分解和聚集,从而导致没有发挥纤维优越的效果;抗氧化剂EGCG和GSH在抑菌实验和贮藏实验中都显著加速了益生菌的死亡,且具有质量浓度依赖性,这可能与其本身的抗菌活性或氧化产物的细胞毒性有关。

To investigate the protective effects of the novel nanomaterial whey protein isolated fibrils(WPIF)and typical antioxidants against oxidative stress in probiotics during ambient storage,spray-dried probiotic powders were prepared using whey protein isolate(WPI)or WPIF as wall material alone or in combination with different concentrations of epigallocatechin gallate(EGCG)or glutathione(GSH)in this study.The experimental results suggested that the viability of probiotics during ambient storage decreased in the following order:WPIF≈WPI>WPI+0.5 mg/mL EGCG>WPI+0.5 mg/mL GSH>WPI+5.0 mg/mL EGCG>WPI+5.0 mg/mL GSH.There was no significant difference in the probiotic survival between the WPI and WPIF groups,which may be because the high temperature during spray drying allowed the fibrils to break down and aggregate.Interestingly,EGCG and GSH concentration-dependently accelerated the death of probiotics during ambient storage,which might be related to the antimicrobial activity or the cytotoxicity of the oxidative products of EGCG and GSH.