CTA、NaCl和APP浸泡处理对鲜块菌微生物数量及其货架期的影响

Effects of Soaking Treatments with Citric Acid, Sodium Chloride and Apple Polyphenols on Microbial Populations and Shelf Life of Fresh Truffles

考察食品级添加剂柠檬酸(citric acid,CTA)、氯化钠(NaCl)和苹果多酚(apple polyphenols,APP)浸泡处理对鲜块菌微生物数量、感官品质和货架期的影响。在45℃条件下,分别采用不同水平的CTA、NaCl和APP单独或复合浸泡鲜块菌30 min,测定不同处理的细菌总数、霉菌数和酵母菌数并评定感官品质,然后对处理的鲜块菌真空包装后贮藏于4℃条件下进行货架期评估。结果表明,采用不同质量分数的CTA、NaCl和APP单独浸泡能明显降低鲜块菌的细菌总数、酵母数和霉菌数;采用两两复合处理时,CTA、NaCl和APP之间都表现出了较好的协同抗菌效应,同单独处理相比效果明显提高;以感官评价可接受的32分为限,单独处理时CTA、NaCl和APP的最佳使用水平分别为2.5%、5.0%和2.0%;两两组合时以5.0% NaCl+2.0% CTA、2.0% APP+2.5% CTA和2.0% APP+5.0% NaCl的复合处理最佳。基于两两组合实验结果,获得了这3种添加剂的最佳组合为2.0% CTA+5% NaCl+2.0% APP;利用该组合浸泡处理鲜块菌,在真空包装后于4℃贮藏,其货架期延长到49 d。

The effects of soaking treatments with citric acid(CTA), sodium chloride(NaCl) and apple polyphenols(APP) on the populations of bacteria, moulds and yeasts, sensory quality and shelf life of fresh truffles were investigated. Fresh truffles were soaked with CTA, NaCl and APP alone or in combination for 30 min at 45 ℃, and the total bacterial counts, and mold and yeast counts were assayed. In addition, the sensory quality was judged and the shelf-life of un-soaked and soaked truffles of storage in vacuum packaging at 4 ℃ was evaluated. There were noticeable reductions in the populations of bacteria, molds and yeasts in soaked truffles with the individual agents; the combined treatments had marked synergistic antimicrobial effects compared with the summation of the effects of each individual treatment. Taking into account 32 as a threshold value for sensory acceptability, the optimal concentrations f individual treatments were 2.5% CTA, 5.0% NaCl and 2.0% APP. The optimal concentrations for combined treatments were 2.0% APP + 2.5% CTA, 5.0% NaCl + 2.0% CTA and 2.0% APP + 5.0% NaCl, respectively. Based on the experimental results from the combinations, the optimal concentration of CTA + NaCl + APP was 2.0% + 5.0% + 2.0%; the shelf-life of fresh truffles was prolonged to 49 days by this combined treatment.