Yangilar, Filiz

Effects of the edible films coated with natamycin (N) solutions and enriched with essential oils (EOs) were investigated on the chemical (e.g., the rates of pH, dry matter, fat, acidity, salt, protein, water soluble nitrogen, ripening index (RI), 12% trichloroacetic acid-soluble nitrogen, and pH 4.6 soluble-nitrogen), microbial (e.g., total number of aerobic mesophilic bacteria, lactic acid bacteria in MRS, lactic acid bacteria in M17, coliform and mould) and sensory properties of Kashar cheese during ripening time (3rd, 30th, 60th and 90th days) in the present study. Antimicrobial effectiveness of the films against moulds was measured on 30th, 60th, and 90th days of storage. The highest and lowest mould counts were determined for the C (2.87 log cfu/g) and N5 (1 log cfu/g) samples, respectively, at 90 days of ripening. Compared to other cheese samples, C and N3 coated cheese samples represented higher levels of water-soluble nitrogen and RI at the end of storage. N3 coated cheese samples were preferred more by the panellists while N5 coated cheese samples received the lowest scores. Practical applications: Antibacterial and antioxidant activities of essential oils have received considerable attention in food preservation. During Kashar cheese storage, the edible film incorporating oregano and rosemary essential oils coating process showed reducing effect on the microbial growth and extended the shelf-life of Kashar cheese.

Oğuzhan Yıldız, Pınar; Yangılar, Filiz

The present study aimed to investigate the effect of whey protein isolate (WPI) coating enriched with essential oils (ginger and chamomile) on rainbow trout fillets during storage at 4°C. Samples were analyzed at 0, 3, 6, 9, 12, and 15 days for microbiological (total aerobic mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria, Pseudomonas), chemical analyses (pH, thiobarbituric acid reactive substances-TBARS, total volatile base nitrogen-TVB-N, peroxide value [PV]) and sensory quality (odor, taste, tissue, appearance). Bacterial growth was inhibited in samples with high concentrations of essential oils due to its antimicrobial activity. During the storage period, TVB-N, TBARS, and PVs content gradually increased in all groups, and significant differences were found between the groups (p <.05). In conclusion, the addition of of ginger and chamomile essential oils to WPI coatings showed a positive effect on the rainbow trout shelf-life. Practical applications: Whey protein is a by-product of the cheese-making industry and is already known as an excellent barrier to oxygen, aroma, and oil and can be used as a coating material for improving the oxygen barrier property of food packaging. The use of an essential oil in fresh fish preservation may be considered an alternative “natural” additive, extending the shelf life of the product. Our study has clearly shown that addition of ginger and camolime essential oil and whey protein isolate coating in fish resulted in longer shelf life, and this method could be commercially used.