Although the yellow mealworm (Tenebrio molitor L.) is a promising alternative protein source, the effects of processing conditions on functional properties are unclear. In this study, a protein extract of yellow mealworm larvae (PEYM) was subjected to different heat temperature (55°C, 75°C, and 95°C) with different time (20, 40, and 60 min) to evaluate the functional properties and protein oxidation. Different heat temperature treatment significantly affected the exposure of surface hydrophobicity of the proteins and protein molecule aggregation, which reached maximum levels at 95°C for 60 min. Protein oxidation was inversely proportional to the temperature. Both the highest carbonyl value (1.49 nmol/mg protein) and lowest thiol value (22.94 nmol/mg protein) were observed at 95°C for 60 min. The heating time-temperature interaction affected several functional properties, including solubility, emulsifying potential, and gel strength (GS). Solubility decreased near the isoelectric point (pH 5 to 6). As the temperature and heating time increased, emulsifying properties decreased and GS increased. The oil absorption capacity and foaming properties decreased and the water absorption capacity increased. These results confirmed that PEYM is a suitable source of proteins for processing and applications in the food industry.

The objective of this study was to determine the antioxidant and quality characteristics of yogurt containing olive leaf hot water extract (CON: 0, OLY1: 0.1, OLY2: 0.2, and OLY4: 0.4% (w/v)) stored at 4°С for 15 days. After storage, the lactic acid bacteria count showed no significant difference between yogurt samples either in the presence or absence of olive leaf extract (p > 0.05). The total phenolic content, DPPH radical scavenging activity, and reducing power increased upon increasing the content of the olive leaf hot water extract. Oleuropein was found to be the most abundant phenolic compounds present in olive leaf, and the oleuropein content in OLY4, as measured by HPLC, decreased gradually to 1.09, 1.00, and 0.96 g/L upon increasing the storage time; however, this reduction was not significant (p > 0.05). In sensory evaluations, OLY1 gave the highest score among the experimental groups. The results of this study thereby demonstrate that olive leaf hot water extract can be used to improve the antioxidant capacity and sensory characteristics of yogurt.

Food Science of Animal Resources (Food Sci. Anim. Resour.) is an international, peer-reviewed bimonthly journal publishing original research and reviews on basic and applied aspects of the use of animal resources including the meat, egg, and dairy product. Food Sci. Anim. Resour. is published and distributed by the Korean Society for Food Science of Animal Resources.

This study was performed to investigate the changes in meat quality characteristics of the sous vide cooked chicken breast during refrigerated storage at 4℃ for 14 d between before and after sous-vide cooking. Cooking loss and shear force were significantly increased, whereas expressible drip was significantly decreased along with reduction in the water holding capacity in both of two groups. Redness of meat juice was significantly (p<0.05) increased during storage, and considerably increased in the refrigerated samples after sous-vide cooked at the 7 to 10 d. The thiobarbituric acid reactive substances (TBARS) was significantly increased and was higher in the refrigerator stored chicken breast samples after sous-vide cooking. The volatile basic nitrogen (VBN) value was significantly increased in both groups, but the VBN value of the stored raw meat sample before sous-vide cooking was increased at an early storage, while the VBN value of the stored sample after sous-vide cooking was increased gradually in this study. Total viable counts and coliform counts were significantly decreased during storage, and coliforms were not detected after 7 d of storage in both groups. Salmonella spp. was not detected during the whole studied period. The outcome of this research can provide preliminary data that could be used to apply for further study of chicken breast using sous-vide cooking method that could be attractive to consumers.