科研之友
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摘要
This study investigates the growth and survival of Zygosaccharomyces rouxii (a xerotolerant yeast) in the glycerol-based intermediate moisture food (IMF) pineapple model systems (0.87a(w)/pH4.1 GLY/CPB/BM and 0.87a(w)/pH4.5 GLY/CPB/BM) containing various levels of chemical preservatives (sodium benzoate, potassium metabisulphite and potassium sorbate) used singly or in combination. Comparing the two different levels used singly, the three preservatives were more effective in inhibiting yeast growth at a higher 0.1% (w/w) than at a lower 0.01% (w/w) level of the preservative, with potassium metabisulphite showing most inhibitory effect at 0.1% (w/w) level. When the combinations of two to three preservatives at 0.01% (w/w) level were evaluated, a synergistic growth inhibitory effect was achieved. Combination of three preservatives was more effective compared to a combination of any of the two preservatives. At different pH values, preservatives used singly or in combination were shown to be more effective in inhibiting growth at lower pH value of 4.1 than at a higher pHvalue of 4.5. Taste evaluation of six formulated acidified 0.87a(w)/pH3.7 glycerol-based IMF pineapple products showed all formulations to be acceptable. However, microbial challenge studies showed that of all the six taste-acceptable glycerol-based IMF pineapple products, only the product that contained 0.1 % (w/w) potassium metabisulphite was shelf-stable up to 6 months of storage at 30C and may be commercially viable. Practical ApplicationsThe results of this study will benefit the food industry wherein preservation of intermediate moisture pineapple-based products or other intermediate moisture products is required to overcome contamination problems, especially from xerotolerant yeasts.
- 出版日期2015-2
