This study aimed to investigate the ultrasound‐assisted extraction of bioactive compounds from persimmon ( Diospyros kaki ) calyx by deep eutectic solvents (DES) with different molar ratios. For this reason, the prepared DES extracts’ total phenolic–flavonoid compounds and antioxidant activities (1,1‐diphenyl‐2‐picrilhydrazyl radical scavenging activity [DPPH•], Cupric Reducing Antioxidant Capacity (CUPRAC), and ferric reducing antioxidant power [FRAP]) were investigated as a result of the experimental design and optimization study conducted for this purpose. A sonication time of 20 min was determined as the optimal condition. Under these conditions, a molar ratio of 1.9:1 (lactic acid:choline chloride) and a water ratio of 70% provided the highest phenolic/flavonoid compounds and antioxidative activity. Correlations among water ratio, molar ratio, and sonication time were determined using principal component analysis (PCA). In conditions where total flavonoid compound, FRAP, and DPPH• are high due to PCA, it can be concluded that the sonication time is at high level; on the contrary, the water and molar ratios are at low level. In conclusion, ultrasound‐assisted extraction using DES proved effective in persimmon calyx. Therefore, it can be recommended to use these environmentally friendly green solvents as an alternative to organic solvents in preparing extracts in various fields. Practical Application: This study shows the effectiveness of the ultrasound‐assisted green extraction method using persimmon calyx specified as waste. These findings are compelling in the food industry in terms of consumers being now aware of green technology and the discovery that calyx is a good source of bioactive compounds.

This study investigated the effects of the addition of Lactobacillus reuteri E81 (LRE) into rations of chukar partridges (Alectoris chukar) fed under heat stress (HS) conditions on fattening performance and meat quality. This study included 256 chukar partridges aged 1 day. The study comprised an adaptation period of 7 days and a fattening period of 35 days and included 8 different groups with 32 animals in each group. Each group was further divided into four subgroups with eight animals in each subgroup. At the end of the study, the best results in terms of fattening performance in the non-HS groups were obtained in the LRE 600 ppm group and in the HS groups, SLRE 200 ppm had the best effect on average live weight and average live weight increase, whereas SLRE 400 ppm had the best effect on FCR (p<0.05). The analysis of the samples collected from chukar partridges on day 21 showed that, there was no effect on the colour parameters and Thiobarbituric acid reactive substances (TBARS) level in the LRE in the HS and non- HS groups, whereas the meat pH level decreased in the SLRE 400 ppm group (p<0.05). The analysis of the samples collected on day 42 showed that there was no effect on colour parameters in the HS and non-HS groups. TBARS level decreased at the dose of LRE 200 ppm in the non-HS group, and the meat pH level decreased in both HS and non-HS groups (p<0.05).