Contribution of phospholipase B to the formation of characteristic flavor in steamed sturgeon meat

Sensory analysis and untargeted lipidomics were employed to study the impact of phospholipase B (PLB) on lipid oxidation and flavor in steamed sturgeon meat, revealing the inherent relationship between lipid oxidation and flavor regulation. The research verified that PLB effectively suppresses fat oxidation and improves the overall taste of steamed sturgeon meat. Furthermore, the PLB group identified 52 compounds, and the content of odor substances such as isoamyl alcohol and hexanal was reduced compared with other groups. Finally, lipid substances containing eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) were screened out from 32 kinds of differential phospholipids. Through Pearson correlation analysis, it was observed that certain differential phospholipids such as PC (22:6) and PC (22:5) exhibited varying correlations with odor substances like hexanal and isovaleraldehyde. These findings suggest that PLB specifically affects certain phospholipids, leading to the production of distinct volatile substances through oxidative degradation.

The effect of instant tea on the aroma of duck meat

Tea products, such as instant tea, have been shown to improve the aroma of meat products. However, the mechanisms by which tea products enhance meat aroma have not been adequately explained. In this study, we analyzed the impact of instant tea on the aroma of duck meat. Our results showed that treatment with instant tea led to increases in floral, baked, and grassy notes while reducing fishy and fatty notes. Several alcohols, aldehydes, ketones, indole and dihydroactinidiolide exhibited significantly increased OAVs. Conversely, certain saturated aldehydes, unsaturated aldehydes and alcohols displayed significantly decreased OAVs. The enhanced floral, baked and grassy notes were attributed to volatile compounds present in instant tea. The reduction in fishy and fatty notes was linked to polyphenols in instant tea interacting with nonanal, undecanal, (E)-2-octenal, (E)-2-nonenal, (E)-2-decenal, and 2,4-decadienal through hydrophobic interactions and electronic effects. This study enhances our understanding of how tea products improve meat aromas.

Insights into application progress of seafood processing technologies and their implications on flavor: a review

Seafood tends to be highly vulnerable to spoilage and deterioration due to biochemical reactions and microbial contaminations, which requires appropriate processing technologies to improve or maintain its quality. Flavor, as an indispensable aspect reflecting the quality profile of seafood and influencing the final choice of consumers, is closely related to the processing technologies adopted. This review gives updated information on traditional and emerging processing technologies used in seafood processing and their implications on flavor. Traditional processing technologies, especially thermal treatment, effectively deactivate microorganisms to enhance seafood safety and prolong its shelf life. Nonetheless, these methods come with limitations, including reduced processing efficiency, increased energy consumption, and alterations in flavor, color, and texture due to overheating. Emerging processing technologies like microwave heating, infrared heating, high pressure processing, cold plasma, pulsed electric field, and ultrasound show alternative effects to traditional technologies. In addition to deactivating microorganisms and extending shelf life, these technologies can also safeguard the sensory quality of seafood. This review discusses emerging processing technologies in seafood and covers their principles, applications, developments, advantages, and limitations. In addition, this review examines the potential synergies that can arise from combining certain processing technologies in seafood processing.

The Interaction Relationship of Aroma Components Releasing with Saliva and Chewing Degree during Grilled Eels Consumption

The interaction perception between aroma and oral chewing during food consumption has always been a hot topic in exploring consumers' preferences and purchase desires. A chewing simulation system was set to find out the effect of key saliva components and chewing time on odorants released with grilled eel meat. Odor release did not always enhance with the degree of chewing, or the amount of saliva released. The breaking up of the tissue structure of the fish meat by the teeth encourages the release of odorants and the participation of saliva partially blocks this process. The release of pyrazine, alcohol, and acid compounds in grilled eel meat peaked within 20-60 s after chewing. Sufficient exposure of saliva to grilled eel meat will inhibit aromatic, ketone, ester, hydrocarbon, and sulfur compounds release. 3-methyl-2-butanol contributed to the subtle aroma differences that arise before and after eating grilled eel meat. Naphthalene, 2-acetylthiazole, 2-decenal, 2-undecanone, 5-ethyldihydro-2(3H)-furanone were the main odorants released in large quantities in the early stages of eating grilled eel and affected the top note. Consequently, the results provided the odorants information in aroma perception during grilled eel consumption and benefited the objective evaluation of grilled eel product optimization.

Characterization of aroma-active compounds in Dongli by quantitative descriptive analysis, gas chromatography-triple quadrupole tandem mass spectrometry, and gas chromatography-olfactometry

Dongli, or frozen pear, is a traditional Chinese snack with a unique flavor. This study identified the aroma-active volatile compounds (VOCs) in Dongli using quantitative descriptive analysis (QDA), gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS), and gas chromatography-olfactometry (GC-O). QDA indicated that Dongli of all cultivars presented increased sweet and wine aromas. A total of 21 VOCs were identified by GC-MS/MS. Bidirectional orthogonal partial least square (O2PLS) analysis, GC-O analysis, detection frequency analysis (DFA), and relative odor activity values (ROAV) showed that: estragole and anethole contributing "anise, green" aromas were the key aromatic VOCs of fresh pears, while ethyl butanoate, butyl acetate, heptyl acetate, benzaldehyde, and geranyl acetone contributing "sweet, fruity, green" aromas were the key aromatic VOCs of Dongli. The results revealed that the repeated freezing treatment promoted a unique aroma in pears. This study would contribute to developing new pear products.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05463-8.

Application of MOS Gas Sensors Coupled with Chemometrics Methods to Predict the Amount of Sugar and Carbohydrates in Potatoes

Five potato varieties were studied using an electronic nose with nine MOS sensors. Parameters measured included carbohydrate content, sugar level, and the toughness of the potatoes. Routine tests were carried out while the signals for each potato were measured, simultaneously, using an electronic nose. The signals obtained indicated the concentration of various chemical components. In addition to support vector machines (SVMs that were used for the classification of the samples, chemometric methods, such as the partial least squares regression (PLSR) method, the principal component regression (PCR) method, and the multiple linear regression (MLR) method, were used to create separate regression models for sugar and carbohydrates. The predictive power of the regression models was characterized by a coefficient of determination (R²), a root-mean-square error of prediction (RMSEP), and offsets. PLSR was able to accurately model the relationship between the smells of different types of potatoes, sugar, and carbohydrates. The highest and lowest accuracy of models for predicting sugar and carbohydrates was related to Marfona potatoes and Sprite cultivar potatoes. In general, in all cultivars, the accuracy in predicting the amount of carbohydrates was somewhat better than the accuracy in predicting the amount of sugar. Moreover, the linear function had 100% accuracy for training and validation in the C-SVM method for classification of five potato groups. The electronic nose could be used as a fast and non-destructive method for detecting different potato varieties. Researchers in the food industry will find this method extremely useful in selecting the desired product and samples.

Dissecting grilled red and white meat flavor: Its characteristics, production mechanisms, influencing factors and chemical hazards

Meat flavor is composed of a complex mixture of volatile compounds developed as a result of heat driven multi-directional reactions. Typical reactions include Maillard reaction, lipid oxidation, as well as nitrogenous compounds degradation. Such complex flavor is characterized by a rich variety of volatile species, and to strongly influence consumer's preference. The objective of this review is to holistically dissect the flavor characteristic for cooked meat products with special emphasis on grilling and the factors that affect their production to ensure best quality and or safety levels. The review also highlights different analytical techniques used for the detection of flavor compounds in grilled meat. This comprehensive literature research critically analyze grilled flavor derived from heat mediated reactions, with a special emphasis on key flavors or hazard chemicals and their production mechanism. The various influencing factors i.e., grilling temperature, meat, food components, animal ante-mortem factors and food additives are summarized.

Influence of thermal processing on flavor and sensory profile of sturgeon meat

Sensory analysis and instrumental techniques were used to investigate the effect of thermal processing on sturgeon meat flavor. A lexicon consisted of 26 descriptors was established for the sensory evaluation of raw and steamed sturgeon meat (4, 8, 12, 16, 20 min at 100 °C). Ten odor attributes generated by Check-all-that-apply and Free Choice Profiling methods were selected as characteristic descriptors, which were "fishy, meaty, oily/fatty, salty, umami, ammonia/rancid, grass, fresh, earthy, and visceral". Aroma compounds were extracted by headspace-solid phase micro extraction (HS-SPME). A total of 63 and 62 volatiles were identified by gas chromatography equipped with mass spectrometry and olfactometry (GC-MS-O) and GC-ion mobility spectrometry (GC-IMS). Phospholipids accounted for 67.05% in 173 differential metabolites identified via untargeted metabolomics. 47 kinds of phosphatidylethanolamines were significantly correlated with the formation of aldehydes. This study provides a theoretical basis for regulating the flavor formation of thermal-processed aquatic products.

Differences of characteristic aroma compounds in Rougui tea leaves with different roasting temperatures analyzed by switchable GC-O-MS and GC × GC-O-MS and sensory evaluation

Roasting, an important process to refine Wuyi Rock tea, could impart different types of aroma to the final products. This study focuses on the differences in aroma characteristics among three kinds of refined teas, named light fire (LF), moderate fire (MF), and high fire (HF). A combination of solid phase microextraction (SPME) and a switchable system between GC-O-MS and GC × GC-O-MS was utilized to identify the odorants. In total, 97 aroma-active compounds could be smelled at the sniffing port, comprising alcohols, aldehydes, ketones, esters, heterocycles, and terpenes. However, only 52 obtained r-OAV >1. Significant differences were uncovered by the application of principal component analysis (PCA) and partial least squares regression (PLSR). Thereby, MF and HF had a more similar aroma profile, while in LF samples, alcohols, aliphatic aldehydes and some ketones were responsible for the aroma profile, such as (E,E)-2,4-hexadienal, octanal, hexanal, (E,Z)-2,6-nonadienal, (E)-β-ionone, 3-octen-2-one etc. Strecker aldehydes had a great impact on the aroma of MF, including 2-methylpropanal, 2-methylbutanal, 3-methylbutanal etc. Some N-heterocyclic compounds also affected the overall aroma, for instance, 6-methyl-2-ethylpyrazine. In HF, the majority of aroma compounds increased with increasing roasting temperature, especially N-heterocyclic compounds as well as furfural and 5-methyl-2-furancarboxaldehyde, which are all closely related to the Maillard reaction. Besides, 5-methyl-2-(1-methylethenyl)-4-hexen-1-ol, trans-linalooloxide and 2-nonanone also remarkably influenced the aroma of HF. In addition, it was supposed that most amino acids that participated in the Maillard reaction during roasting were decomposed from the compounds that combined with tea polyphenols and amino acids.

Water dynamics changes and protein denaturation in surf clam evaluated by two-dimensional LF-NMR T1-T2 relaxation technique during heating process

Water dynamics and protein denaturation in surf clam during heating were studied by the two-dimensional low-field nuclear magnetic resonance (LF-NMR) T₁-T₂ relaxation technique. A significant change was found for clam around 80 °C and direct visualization of the water state change was provided by the magnetic resonance imaging. Principal components and heatmap analysis revealed that clam treated at 80-100 °C located at different region from those treated at 40-70 °C. The clams heated at 80 °C showed a maximum water holding capability, and significant microstructure change. The differential scanning calorimetry analysis indicated a denaturation of protein when the temperature was over 80 °C. The hardness and chewiness had a maximum value at 80 and 70 °C, respectively. The color parameter L* showed a significant increase when temperature was over 80 °C. This demonstrated that the T₁-T₂ technique has potential in evaluating water dynamics for surf clam during heating.