The aim of this study was to clarify the quality characteristics of Wenchang chicken cooked with coconut water, so as to provide an effective basis for the research on the interaction mechanism of Wenchang chicken and coconut water components and the standardized production.

With Wenchang chicken and Hainan green coconut as the main raw materials, the odor substances of Wenchang chicken, Wenchang chicken breast meat, and chicken leg meat cooked with coconut water were analyzed and compared using an electronic nose and gas chromatography-mass spectrometry (GC-MS), combined with odor activity value (OAV) and principal component analysis (PCA). The taste substances of chicken breast meat and chicken leg meat were analyzed using electronic tongue, free amino acid, and nucleotide detection techniques. The physical and chemical indexes of chicken and coconut water, as well as the cooking loss and texture indexes of coconut-boiled chicken and water-boiled chicken, were determined to clarify the changes in the quality characteristics of Wenchang chicken after cooking with coconut water.

The protein content in chicken leg meat was 21.0 g/100 g, and the fat content was 3.08 g/100 g. The protein content in chicken breast meat was 23.6 g/100 g, and the fat content was 1.29 g/100 g. The content of reducing sugar in coconut water was 4.75 g/100 g. The cooking loss of chicken cooked with coconut water was the highest compared with that boiled with water, and there was no significant correlation between the two texture indicators (P>0.05). After cooking with coconut water, five new aldehydes were produced in the chicken, namely 2-heptanal, (E)-2-octenal, (E)-2-nonenal, 2, 5-dimethyl benzaldehyde, and 2-undecenal. The electronic nose was able to distinguish the volatile substances in boiled chicken legs from those in coconut water. After cooking with coconut water, the content of sweet amino acids in chicken legs and chicken soup increased, but the content of savory amino acids in boiled chicken legs, chicken breasts, and broth was higher than that in chicken cooked with coconut water. The contents of 5'-AMP, 5'-IMP, and 5'-GMP in chicken cooked with coconut water were higher than those in boiled chicken.

The fat content in the chicken leg and protein content in the chicken breast differed in various parts of the Wenchang chicken. Boiling Wenchang chicken with coconut water increased the nucleotide content in the muscles and the free amino acid content in the chicken leg meat, significantly enhancing the taste. Boiling Wenchang chicken with coconut water increased the types of aldehydes in the thigh meat, and resulted in better flavor formation than the breast meat.

This study aimed to clarify the effects of adding tomatoes on the quality characteristics, lipid and protein oxidation inhibition of stewed beef, so as to provide insights into the interaction mechanism between tomato and beef components, thereby contributing to the development of a standardized production process.

Tomato was added to the stewed beef in proportions of 0, 50%, 100%, 150%, and 200%, respectively, and which were stewed for 20 min. The quality characteristics of stewed beef, including pH value, color, and tenderness, were measured. The content of amino acids, nucleotides, and the taste of stewed beef brisket with tomato were determined and evaluated. Besides, the degrees of lipid and protein oxidation in beef were studied as well.

With higher ratios of added tomato, the pH value and L* value of beef significantly decreased (P<0.05), while the a* value increased. On the other hand, the shear force of beef significantly decreased and the myofibrillar fragmentation index (MFI) increased (P<0.05), which positively affected the color and tenderness of beef. Higher content of aspartic acid, glutamic acid, and proline in the soup and higher content of free amino acids such as glutamic acid and histidine in beef were observed as tomato added, while the content of 5′-AMP, 5′-GMP and 5′-IMP in beef were decreased (P<0.05). The addition of tomato resulted in a reduction in the levels of beef Schiff base (SB), TBARS, and the total sulfhydryl group. However, it increased the free sulfhydryl content. There was no significant effect on the carbonyl content. It could be assumed that tomatoes could inhibit the lipid oxidation and protein oxidation of stewed beef. The tomato addition ratios of 100%, 150%, and 200% had no significant effect on sensory acceptability. However, combining the content of free amino acids, nucleotides and the lipid and protein oxidation of beef, it was found that adding 200% tomato during beef stew resulted in better edible quality and greater oxidation inhibition ability.

The addition of tomato stew could increase the redness, tenderness, and free amino acid content, and accelerate the release nucleotides of beef. Addition of tomatoes could inhibit the lipids oxidation and proteins oxidation of beef. Overall, addition of tomatoes results in beef with good overall acceptability and suppress oxidation.