Different coating application methods: Zein-based edible coating containing Heracleum persicum essential oil for shelf-life enhancement of whey-less cheese.

Abstract

In this research, the efficiency of brushing (Br), dipping (Di), spraying (S), and enrobing (En) methods was compared in three concentrations of 10%, 15%, and 20% of corn zein (Z) edible coating containing 0.5% of Heracleum persicum essential oil (HEO) in the shelf-life improvement of whey-less cheese during 56 days of cold storage. The results of the photography and colorimetric (L*, a*, and b* parameters) of the samples showed that the En method in 20% of Z created a uniform, brilliant, and attractive surface on the cheese pieces compared to the other groups during the storage period, and the S, Br, and Di methods were in the next categories, respectively. The findings of the texture analysis of the samples showed that all of the treatments significantly (p ≤ .05) preserved the hardness of the cheese samples compared to the control group, and the En method containing Z 20% and HEO was the most effective treatment in preventing the hardness loss of the samples during the 56-day storage period. In all treatments, the growth of aerobic mesophilic bacteria, psychrotrophic bacteria, enterobacteriaceae, molds, and yeasts was significantly (p ≤ .05) reduced in comparison with the control sample, and the En method containing HEO and Z 20% was the most efficient in preventing the microbial growth. The rate of moisture loss, fat oxidation, and pH values of the studied samples significantly (p ≤ .05) decreased in the coated treatments containing a higher concentration of Z and HEO compared with other treatments during the storage period. According to the findings of this study, it can be concluded that the En technique containing Z20% and HEO0.5% was the most effective treatment in the shelf-life improvement of whey-less cheese during 56 days of the refrigerated storage period, and the S, Br, and Di methods were in the next ranks, respectively.