Effect of whey protein isolate coating with cardamom essential oil on shelf life of white cheese

Cheese packaging as one of the processes has an important effect on increasing the shelf life and quality of cheese. The aim of this study was to package Iranian white cheese using edible coating based on whey protein isolate (WPI) containing different levels of cardamom (Elettaria cardamomum L.) essential oil (CEO) (0, 1, 1.5 and 2%) during storage. Samples were examined for physicochemical, microbial and sensory changes during 60 days of storage. The chemical compounds of CEO were also identified by GC-MS. In the analysis of the chemical composition of CEO, two main compounds including α-terpenyl acetate (46.705%) and 1.8-cineole (27.415%) were identified. Examination of pH changes showed that the pH of all samples decreased significant during storage (P<0.05). On the last day of storage, the lowest amount of peroxide was in the cheese sample coated with 2% CEO (0.97±0.21 meq O2/kg). The results of changes in TBARS in coated white cheese samples during storage showed that two samples of white cheese coated with WPI enriched with 1.5 and 2% CEO had the lowest Thiobarbituric acid reactive substances levels were from the 7th day to the end of the storage period. In microbiological analysis, the lowest population of total bacteria on the last day of storage was in the white cheese sample enriched with 2% CEO (2.431±0.56 Log cfu/g). The results of sensory evaluation showed that the edible coating based on WPI containing 1.5% of CEO had more desirable sensory properties than other coatings. According to the results of the present study, it can be stated that edible coatings containing plant essential oils can be used in packaging and coating of white cheese to increase its quality and safety.