The present research aimed to investigate the preservative effects of a sodium caseinate (SC) coating enriched with Zataria multiflora Boiss. essential oil (ZMEO) at 0.5, 1, or 1.5% on the product life of meat during storage at 4°C. Over a 15-day period, the meat samples were refrigerated and analyzed every five days. The treated samples had markedly less psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae, and total viable counts relative to the control throughout storage. In terms of the sensory, chemical (PV, TBARS, and pH), and microbial characterization, undesirable results were attained in the control sample after 10 days of refrigerated storage, whereas samples coated with SC/ZMEO, especially at higher essential oil concentrations (1 and 1.5%), proved to be significantly more stable (P<0.05). However, high concentration of ZMEO (1.5%) gave an unpleasant effect on sensory attributes of meat samples. Notably, the SC/1% ZMEO coating led to good overall acceptability of the veal specimens even after 15 days of refrigeration. Hence, this coating is recommended as a replacement for synthetic preservatives and flavorings for meat products given that it preserved the quality of refrigerated veal samples for over two weeks.

The effects of incorporating guar gum (GG) and gum arabic (GA) in cheese-making milk with various fat contents (0.4, 0.9, and 1.4 %) on chemical and rheological properties of Iranian white cheese were evaluated by response surface method (RSM). As GG concentration increased, dry matter content of cheese samples decreased due to the high water binding capacity of this gum. A similar trend was also observed for GA at concentrations less than 150 ppm. The higher the GG concentration, the higher was the free fatty acid content of cheese samples. GA at concentrations more than 150 ppm, increased the storage modulus (G'), causing an undesirable hard texture for the product. The G' and stress at fracture (бf) of samples decreased by the increasing concentration of GG incorporated into the cheese-making milk. Response surface minimization of rheological indices for Iranian white cheese showed that combination of two hydrocolloids (GG in the concentration range 75-170 ppm and GA at concentrations <75 ppm) would provide the softest texture.

In our research, a composite film of whey protein isolate (WPI)/chitosan incorporated with TiO2 nanoparticles (NPs) and essential oil of Zataria multiflora (ZEO) was developed. The resulting composite films were evaluated by FTIR, SEM, and XRD, and also the physicochemical characteristics including color, mechanical properties, swelling ratio, and water vapor permeability (WVP) were studied. SEM graphs exhibited that the samples had a uniform and homogeneous structure where TiO2 NPs and ZEO were well dispersed. FTIR and XRD findings also show that the hydrogen bonds and hydrophobic interactions are the main interactions between the composite WPI/chitosan and TiO2. The crystalline nature of the composite samples increased with the increase of NP content. Nevertheless, ZEO had an insignificant effect on the functional groups and the crystallinity of composite samples. The film visual characterization revealed that, by adding and increasing the TiO2 and TiO2-ZEO, sample lightness and opacity significantly increased. Additions of TiO2 remarkably (p<0.05) improved the water vapor and mechanical properties of composite samples, although the loading of ZEO, regardless of TiO2 incorporation, led to a considerable decrement of these properties. Furthermore, composite films containing ZEO combined with 2% of TiO2 compared with 1% of NPs blended with ZEO had strong antimicrobial properties against Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes. Generally, the findings proposed that the addition of TiO2 reinforces the properties of composite films with a synergistic effect of ZEO loading on the antibacterial ability, by which the resulting biodegradable composite samples can be used as a food active packaging material.

The present research aimed to produce Fruit Feta-type cheese and investigate the effects of pomegranate juice on the manufacturing process and characterization of Feta-type cheese during storage. In order to produce Feta-type cheese with pomegranate juice, part of the milk was replaced with pomegranate juice. Therefore, it was necessary to produce Feta-type cheese with whey-less method, which is a good substitute for ultrafiltrated cheese. Initially, whey-less Feta-type cheese was produced. The formula was optimized based on the physicochemical characteristics of the marketed ultrafiltrated Feta cheeses. At the optimal point, the amount of cream, MPC, WPC, and fresh milk were 45.6, 11.7, 2.7, and 40%, respectively. Whey-less Feta-type cheese with these ratios was produced and the effects of different levels of pomegranate juice (0, 5, 10, 15, and 20%) on its physicochemical, textural, microbial, and sensorial properties during 60 days of storage were studied. The results showed that pomegranate juice increased acidity, total phenol, anthocyanin, DPPH inhibition, and a ∗ value, and reduced the pH, peroxide value, thiobarbituric acid (TBA), proteolysis, lipolysis, and L ∗ and b ∗ values. Adding pomegranate juice to cheese reduced all of the textural indices except the adhesiveness. Sensory evaluation of the samples showed that the sample containing 20% of pomegranate juice had a higher score and was selected as the best sample.