Comparative Analysis of Texture Characteristics, Sensory Properties, and Volatile Components in Four Types of Marinated Tofu.

In this study, three different brands of commercially available marinated tofu were analyzed and compared with homemade products to explore the effect of key flavor substances on their sensory quality, sensory properties, texture characteristics, and volatile components. The texture characteristics and flavor substances of the three brands of commercially available marinated tofu were significantly different from those of homemade products. A total of 64 volatile components were identified by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), mainly including 11 hydrocarbons, 11 alcohols, 10 ketones, 15 aldehydes, 4 esters, 1 acid, and 12 other volatile substances. Among these, nine key flavor compounds (ROAV > 1, VIP > 1) were identified using the relative odor activity value (ROAV) combined with a partial least squares discriminant analysis (PLS-DA) and variable importance in projection, including α-Pinene, ß-Myrcene, α-Phellandrene, 1-Penten-3-one, Butanal, 3-Methyl butanal, acetic acid ethyl ester, 1,8-Cineol, and 2-Pentyl furan. The correlation heatmap showed that sensory evaluation was positively correlated with hardness, gumminess, chewiness, and springiness while negatively correlated with 2-Pentyl furan, α-Pinene, resilience, α-Phellandrene, 1-Penten-3-one, acetic acid ethyl ester, and 1,8-Cineol. Overall, this study provides a theoretical reference for developing new instant marinated tofu snacks.

Changes in flavor substances during the processing of boneless cold-eating rabbit meat.

Cold-eating rabbit is a traditional Chinese delicacy made by the process of pickling and frying. To explore the relationship between the flavor of cold-eating rabbit and the production process, this study investigated the changes of nucleotides, free amino acids, fatty acids, and volatile flavor substances in diced, marinated for 10 min, marinated for 20 min, fried for 5 min, re-fried for 10 min, re-fried for 15 min, re-fried for 20 min, seasoned and fried, and in the finished product, and analyzed the changes of flavor substances in deboned rabbit at different processing stages. Results showed that the content of 5'-inosine monophosphate (IMP) increased significantly (p < .05), indicating that the degradation pathway mainly involved IMP. In total, 17 free amino acids were detected, the contents of which increased significantly (p < .05). In addition, 27 medium- and long-chain fatty acids were detected. The total concentration of free fatty acids decreased in the fresh rabbit meat-marinated 20 min stage (p < .05), then increased in the fried 5 min-fried 20 min stage (p < .05), and finally decreased in the fried with spices-finished stage (p < .05). Seventy-seven volatile flavor substances were detected, and the 15-minute frying stage was key in producing the volatile flavor substances.

Potential Correlation between Microbial Diversity and Volatile Flavor Substances in a Novel Chinese-Style Sausage during Storage.

A novel Chinese-style sausage with Chinese traditional fermented condiments used as additional ingredients is produced in this study. The aim of this study was to investigate the microbial community's structure, the volatile flavor substances and their potential correlation in the novel Chinese sausage. High-throughput sequencing (HTS) and solid-phase microextraction-gas chromatography-mass spectrometry (GC-MS) were, respectively, used to analyze the microbial diversity and volatile flavor substances of the novel Chinese-style sausage during storage. The results showed that Firmicutes, Proteobacteria and Actinobacteria were the predominant bacterial genera, and Hyphopichia and Candida were the predominant fungal genera. A total of 88 volatile flavor substances were identified through GC-MS, among which 18 differential flavor compounds were screened (VIP > 1), which could be used as potential biomarkers to distinguish the novel sausages stored for different periods. Lactobacillus exhibited a significant negative correlation with 2,3-epoxy-4,4-dimethylpentane and acetoin and a significant positive correlation with 2-phenyl-2-butenal. Hyphopichia significantly positively correlated with ester. Leuconostoc significantly positively correlated with ethyl caprate, ethyl palmate, ethyl tetradecanoate and ethyl oleate while it negatively correlated with hexanal. This study provides a theoretical basis for revealing the flavor formation mechanisms and the screening of functional strains for improving the flavor quality of the novel Chinese-style sausage.

Effects of Cherry (Prunus cerasus L.) Powder Addition on the Physicochemical Properties and Oxidation Stability of Jiangsu-Type Sausage during Refrigerated Storage.

Effects of different levels (1%, 3% and 5%) of cherry powder on the physiochemical properties and antioxidant activity of Jiangsu-type sausages were investigated at 4 °C for 30 days. The results show that the sensory evaluation values and physicochemical properties of the sausages had no significant differences compared to the control group when cherry powder addition was 1%, and the alcohols, aldehydes and esters were increased after the addition of cherry powder improved the flavor of sausages. However, higher concentration of cherry powder (3% and 5%) exerted adverse influences on sensory evaluation values and physicochemical properties of sausages compared with the control. The addition of cherry powder could better inhibit lipid and protein oxidation of sausages, and the cherry powder concentration has a positive correlation with its effect on the inhibition of lipid and protein oxidation. In addition, cherry powder could effectively control TVB-N values of sausages during chilled storage. All these results indicate that 1% cherry powder could not only guarantee the physicochemical properties of sausages, but also inhibited the oxidation of sausages during chilled storage.

Determination of volatile flavor compounds in raw and treated duck meats of different body parts.

The compounds in volatile flavor substances in duck meats of three different body parts (breast, leg, and wing) were extracted by headspace solid-phase micro-extraction and determined by gas chromatography-mass spectrometry. A total of 16 main volatile compounds including 4 hydrocarbons, 4 alcohols, 2 acids, 3 aldehydes, and 3 others (N-containing, S-containing) were identified in raw duck meats from three different body parts. The hydrocarbon compounds account for more than 50% of all volatile substances in all three body parts. And the percentage of hydrocarbon compounds in raw duck breast meat reaches 82.76%. A total of 81 volatile compounds including 15 hydrocarbons, 10 alcohols, 7 acids, 12 aldehydes, 4 esters, 19 S-containing and N-containing compounds, and 14 others were isolated and identified in 1 hr-marinated and cooked duck meats. A total of 101 kinds of volatile flavor compounds including 13 hydrocarbons, 14 alcohol, 7 acids, 8 aldehydes, 12 esters, 23 S-containing and N-containing compounds, and 24 others were detected in 3 hr-marinated duck meats of the three body parts. It was proved in this study that under the same conditions, the volatile compounds in duck legs are more than those in duck breasts and wings, and the types of volatile flavor substances increase significantly in duck meats after cooked. PRACTICAL APPLICATIONS: Prepared and cooked duck meat, especially wings and legs are popular food in China. The results suggest that Pickling makes duck meat more flavory while proper pickling time is less than 3 hr. Duck wings are better for marinating and cooking compared with duck breasts and legs. The acceptance study of duck meat from different body parts and the analysis of volatile flavor compounds are beneficial for optimizing utilization of whole parts of duck meat.