Characteristic flavor of Antarctic krill (Euphausia superba) and white shrimp (Penaeus vannamei) induced by thermal treatment

Insight into the correlation of key taste substances and key volatile substances from shrimp heads at different temperatures

This study aimed to investigate taste substances of shrimp heads stored at 20 °C, 4 °C, -3 °C, and - 18 °C, and the correlation between taste substances and 25 key volatile substances. Notably, samples stored at 20 °C showed significant changes in bitter amino acids and hypoxanthine, and quickly deteriorated. Samples stored at 4 °C for 14 d or - 3 °C for 30 d facilitated the development of umami amino acids, sweet amino acids, and IMP. Furthermore, samples stored at -18 °C for 30 d demonstrated no significant changes in taste profile. Changes in taste substances through quantitative analysis were consistent with changes in taste profile through e-tongue analysis. Based on the results of O2PLS (VIP > 1), Cys, Arg, Glu, Ser, Val, Ala, Ile, ADP, and IMP were correlated with 25 key volatile substances. This study provides fundamental data for the storage, transportation, and value-added utilization of shrimp heads.

Effects of different high temperature-pressure processing times on the sensory quality, nutrition and allergenicity of ready-to-eat clam meat

Investigating technologies to control the allergenicity of seafood is particularly important to safeguard consumer health, but there is currently a dearth of research focused on reducing the allergenicity of clam meat. This study aimed to investigate the effects of high temperature-pressure (HTP) processing times (121 °C, 0.14 MPa; 5, 10, 15, 20 min) on the sensory quality, nutrition, and allergenicity of ready-to-eat clam meat. With the extension of HTP time, the hardness of clam meat gradually decreased, the chewiness decreased initially and then increased, and the meat became tender. HTP processing endowed clam meat with abundant esters and aldehydes. Among all the processing groups, the umami and saltiness were better at 15 min, correlating with the highest overall acceptability. Ready-to-eat clam meat contained high-protein nutritional value. Compared with raw clam meat, the tropomyosin allergenicity of clam meat treated with HTP for 15 and 20 min was significantly reduced by 51.9 % and 56.5 %, respectively (P < 0.05). However, there was no significant difference between these two groups. Appropriate HTP processing time might be an efficient condition to reduce the tropomyosin allergenicity of ready-to-eat clam meat and improve its quality, particularly for the time of 15 min. The results of this study could provide a reliable theoretical basis for the development of hypoallergenic clam foods.

Novel synergistic cross-linking ameliorate ready-to-eat sea cucumber deterioration and its quantum chemical analysis

Synergistic cross-linkers could improve the taste acceptability of ready-to-eat sea cucumber (RSC). Besides, the hardness of RSC was increased by 331.00% and 266.87% after synergistic cross-linking. Synergistic cross-linking treatment could ameliorate the non-enzymatic degradation of RSC collagen and polysaccharides. Gaussian calculations results showed that dipeptides containing asparagine residues may have different reaction pathways. The main cleavage pathways of CH3CO-Asn-Gly-NHCH3 (NG) might be water-assisted side chain cyclization, stepwise cyclamide hydrolysis via a Gemdiol Intermediate, deamination, and peptide bond breakage. The relative free energy of cyclamide hydrolysis process of NG was increased by 8.2 kcal/mol after synergistic cross-linking. The mass spectrometry results showed that typical peptides could cleavage at NG, CH3CO-Asn-Lys-NHCH3 (NK) and CH3CO-Asn-Leu-NHCH3 (NL) sites after heating, which justified the breakage pattern of peptides in Gaussian calculations. It can offer a comprehensive theoretical basis for the processing of the ready-to-eat sea cucumber with storage stability.

Effect of different thermal processing methods on sensory, nutritional, physicochemical and structural properties of Penaeus vannamei

The aim of this study was to investigate the effect of different thermal processing methods on the nutritional and physicochemical qualities of Penaeus vannamei. Three different thermal processing methods, namely, drying (DS, 120 °C/40 min), steaming (SS, 100 °C/2 min), and microwaving (MS, 600 W/2 min) were used to treat the shrimps. Low-field nuclear magnetic resonance data indicated that fixed water was the main component of Penaeus vannamei. The ratio of fatty acids in MS and DS samples was more in line with the FAO/WHO recommended health requirements; The myofibrillar protein carbonyl group increased, whereas sulfhydryl content decreased after thermal processing, indicating that the proteins were oxidized by thermal processing. The magnitude of oxidation is: MS > SS > DS. Different thermal processing methods can exert great influence on color texture and nutrition to Penaeus vannamei, which can provide a theoretical knowledge for consumers to choose the appropriate processing method.

Insights into the effects of steaming on organoleptic quality of salmon (Salmo salar) integrating multi-omics analysis and electronic sensory system

The effect of steaming treatment on salmon quality was explored by different multi-omics and electronic sensory system in this study. A comparison between conventional steaming (CS) and anaerobic steaming (AS) was conducted in organoleptic quality of salmon. Twelve key volatile compounds were identified, which contributed to the flavor difference. The concentrations of hexanal, (E)-2-octen-1-al, and decanal in AS salmon were significantly lower than in CS salmon, which account for 68.9-80.5 % of the latter. During steaming, the fatty acids and diacylglycerols decreased significantly by 37.4 % and 57.9 %, respectively. Anaerobic steaming limited the degradation of some oxidized lipids, further reduced some volatile secondary oxidation products. Nucleotides and derivatives, succinic acid, glutamic acid, hydroxyproline and betaine contributed to the saltness, umami, richness of steamed salmon. Metabolomics data revealed that the higher creatinine, Ala-Ala and Ala-Leu provided more umami and less bitterness to AS salmon.

GC-MS, GC-IMS, and E-Nose Analysis of Volatile Aroma Compounds in Wet-Marinated Fermented Golden Pomfret Prepared Using Different Cooking Methods

The cooking method is extremely important for the production of low-salt, wet-marinated, fermented golden pomfret because it strongly influences its flavor components and organoleptic quality. There are also significant differences in flavor preferences in different populations. The present study analyzed differences in the aroma characteristics of wet-marinated fermented golden pomfret after boiling, steaming, microwaving, air-frying, and baking using a combination of an electronic nose, GC-IMS, and SPME-GC-MS. Electronic nose PCA showed that the flavors of the boiled (A), steamed (B), and microwaved (C) treatment groups were similar, and the flavors of the baking (D) and air-frying (E) groups were similar. A total of 72 flavor compounds were detected in the GC-IMS analysis, and the comparative analysis of the cooked wet-marinated and fermented golden pomfret yielded a greater abundance of flavor compounds. SPME-GC-MS analysis detected 108 flavor compounds, and the results were similar for baking and air-frying. Twelve key flavor substances, including hexanal, isovaleraldehyde, and (E)-2-dodecenal, were identified by orthogonal partial least-squares discriminant analysis (OPLS-DA) and VIP analysis. These results showed that the cooking method could be a key factor in the flavor distribution of wet-marinated fermented golden pomfret, and consumers can choose the appropriate cooking method accordingly. The results can provide theoretical guidance for the more effective processing of fish products and the development of subsequent food products.

Optimization of ultrasonic-assisted extraction of flavor compounds from shrimp by-products and characterization of flavor profile of the extract

This study aimed to optimize the ultrasonic-assisted extraction conditions of flavor compounds from white shrimp heads (WSHs). The effects of sonication amplitude, sonication time, and solvent-to-solid ratio on the extraction yield (EY) of flavor compounds and the degree of protein modification (DPM) were evaluated by Box-Behnken design and response surface methodology (RSM). The optimum EY (40.87 %) and DPM (26.28 %) were obtained at amplitude, time, and solvent-to-solid ratios of 63.2 %, 20.5 min, and 20.8 mL/g, respectively. The optimum DPM value indicates that sonication markedly influenced the protein denaturation, as evidenced by the higher TCA soluble protein content. Further, we also investigated the taste active composition of ultrasonic extract of shrimp head (USH). Results show that the equivalent umami concentration (EUC) value was significantly (p < 0.05) increased in the ultrasonic extract of shrimp head (USH) (55.44 ± 3.25 g MSG/100 g) compared to the control shrimp head extract (CSH) (8.32 ± 1.07 g MSG/100 g). This study also deals with the development of shrimp flavor concentrate (SFC) using USH by the conventional heating process. Sensory evaluation of SFC revealed that the shrimp-like aroma and umami taste characteristics were predominant. Thus, USH's improved umami taste composition demonstrates its potential utilization for producing SFC with higher EUC.

A comparative study on the taste quality of Mytilus coruscus under different shucking treatments

Shucking is an indispensable step in the preparation of cooked mussel products, as it facilitates the detachment of meat from the shell. In this study, we comprehensively investigated the effects of boiling, steaming, and microwaving on taste constituents in half-cooked mussel meat. Two-dimensional correlation spectroscopy revealed the key differential taste components of the different shucking groups. Structural equation modeling (SEM) indicated the positive effects of saltiness and bitterness on umami taste, while sweetness and sourness had negative effects on umami taste in half-cooked mussel meat. Furthermore, Glu, Asp, Ala, Arg, betaine, malic acid, succinic acid, glycogen, Cl^-, Na⁺, K⁺, and PO3- 4 were quantitatively determined as the main taste compounds. The steaming shelling group had the most enriched taste components, with the highest equivalent umami concentration compared to the other shelling groups. Hence, steaming shucking may be favored due to abundant tastes and nutrients.

Effect of Drying Process on the Formation of the Characteristic Flavor of Oyster (Crassostrea hongkongensis)

Oysters are nutritious and tasty but difficult to store. Drying can extend the storage period of oysters and give them a unique flavor. In this study, the effects of four drying procedures, namely, vacuum freeze drying (VFD), vacuum drying (VD), natural sun-drying (NSD), and hot air drying (HAD), on the flavor characteristics of oysters (Crassostrea hongkongensis) were investigated using blanched oysters as a control (CK). Results showed that HAD produced more free amino acids than the other methods, but VFD retained the most flavor nucleotides. Compared with cold drying (VFD), hot drying (VD, NSD, and HAD) increased the abundance of organic acids, betaine, and aroma substances. Glutamic acid, alanine, AMP, hexanal, octanal, heptanal, (E, E)-2,4-heptadienal, (E)-2-decenal, nonanal, etc., are defined as the characteristic flavor compounds of dried oysters, with umami, sweet, green, fatty, and fruity aromas being the main organoleptic attributes of dried oysters. Glutamic acid, glycine, betaine, IMP, pentanal, ethyl heptanoate, (E, Z)-2,4-nonadienal, 1-octen-3-one, 2-hexenal, 2-octenal, hexanal, decanal were defined as markers to distinguish different drying methods. Overall, HAD showed improved flavor qualities and characteristics and was better suited for the highly commercialized production of dried oysters.

Effect of orange solid waste diet on flesh quality and metabolic profile of common carp (Cyprinus carpio)

In this study, we aimed to evaluate the effects of solid waste of Citrus sinensis (SWC) supplementation in diet on common carp (Cyprinus carpio) flesh quality and the potential mechanisms underlying these effects. Four diets, each with different levels of SWC (0%, 5%, 10%, and 15%), were formulated and administered to C. carpio (48.83 ± 5.59 g) for 60 days. The results showed that SWC diet significantly enhanced specific growth rate, muscle sweetness (via sweet amino acids and sweet molecules), and the nutritional value of fish meat (increased protein, α-vitamin E, and allopurinol). Chromatography-mass spectrometry analyses indicated that SWC supplementation increased the essential amino acid content in the diet. In addition, SWC diet promoted biosynthesis of non-essential amino acids in muscle by enhancing glycolysis and the tricarboxylic acid cycle. In conclusion, SWC could be a cost-effective solution for providing nutritious and flavourful aquatic products.

Effect of gamma irradiation treatment on microstructure, water mobility, flavor, sensory and quality properties of smoked chicken breast

Effect of gamma irradiation on quality, flavor and sensory properties of smoked chicken breasts were investigated. Results indicated irradiation doses >3 kGy were effective for sterilization, while also produced a significant effect on overall quality of smoked chicken breast. Irradiation treatment could inhibit protein oxidation and accelerate lipid oxidation of smoked chicken breasts. High irradiation doses could increase the instability of free and bound water, as well as increase muscle fiber gap and juice loss significantly. Irradiation treatment also promoted free fatty acids and taste-presenting nucleotides degradation, effectively increased fresh-tasting amino acids contents and decreased bitter and sweet-tasting amino acids contents. The types and relative contents of volatiles, especially aldehydes, alcohols, aromatic hydrocarbons, and phenolic compounds, also changed after irradiation, while tartaric, pyruvic, and malic acids decreased. Results obtained can provide valuable reference data for improving the quality and flavor of smoked chicken breasts using gamma irradiation technology.

Enhancing the AI-2/LuxS quorum sensing system in Lactiplantibacillus plantarum: Effect on the elimination of biofilms grown on seafoods

The biofilm clustered with putrefying microorganisms and seafood pathogens could cover the surface of aquatic products that pose a risk to cross-contaminating food products or even human health. Fighting biofilms triggers synchronous communication associated with microbial consortia to regulate their developmental processes, and the enhancement of the quorum sensing system in Lactiplantibacillus plantarum can serve as an updated starting point for antibiofilm-forming strategies. Our results showed that the exogenous 25 mM L-cysteine induced a significant strengthening in the AI-2/LuxS system of Lactiplantibacillus plantarum SS-128 along with a stronger bacteriostatic ability, resulting in an effective inhibition of biofilms formed by the simplified microbial consortia constructed by Vibrio parahaemolyticus and Shewanella putrefaciens grown on shrimp and squid surfaces. The accumulation of AI-2 allowed the suppression of the expression of biofilm-related genes in V. parahaemolyticus under the premise of L. plantarum SS-128 treatment, contributing to the inhibition effect. In addition, strengthening the AI-2/LuxS system is also conducive to eliminating preexisting biofilms by L. plantarum SS-128. This study suggests that the enhancement of the AI-2/LuxS system of lactic acid bacteria enables the regulation of interspecific communication within biofilms to be a viable tool to efficiently reduce and eradicate potentially harmful biofilms from aquatic product sources, opening new horizons for combating biofilms.

In Vitro and In Situ Characterization of Psychrotrophic Spoilage Bacteria Recovered from Chilled Chicken

Spoilage bacteria play a remarkable role in the spoilage of chilled chicken. In this paper, a total of 42 isolates belonging to 16 species of four genera were isolated from chilled chicken and displayed different characterizations of psychrotrophic spoilage. Six isolates of J7, J8, Q20, Q23, R1, and R9 with differences in proteolytic capabilities were further characterized for in situ spoilage potential evaluation. Pseudomonas lundensis J8 exhibited the strongest spoilage potential in situ, displaying a fast growth rate, increased pH velocity, high total volatile basic nitrogen, and high peptide content in the chicken samples. The volatile flavor analysis of chicken samples via electronic nose indicated that the content of characteristic odors representing spoilage, including sulfides, organic sulfide, and hydride, increased during storage. Additionally, the principle component and correlation analyses revealed that the spoilage odors produced by different species of bacteria were significantly different and positively correlated with the results of protease activity in vitro. The characteristics of spoilage bacteria in chilled chicken provided a comprehensive insight into microbial assessment during storage.

Ready-to-Eat Fish Cake Processing Methods and the Impacts on Quality and Flavor

This study aimed to compare tilapia fish cake drying and sterilization conditions (105, 115, and 121 °C) on the quality of the cakes. The impacts of volatile flavor substances, the chroma value, quality and structure characteristics, microscopic structure, and the types and content of volatile flavor substances were also analyzed. The results showed that after drying and sterilization, the L* value, W value and delta-E value of fish cakes decreased significantly from 77.12 to 64.77, 66.21 to 52.57, 10.46 to 24.50, respectively. However, a* value and b* value increased significantly from 0.30 to 6.97 and 24.85 to 30.89, respectively. The elasticity, hardness, and chewiness increased significantly with the drying process but decreased significantly with the increased sterilization temperature. Scanning electron microscopy results showed that the internal pores of the fish cakes became smaller, and the tissue structure was closer after drying. Gas chromatography-ion mobile spectrometry analysis identified a total of 36 volatile flavor compounds. Among these, ketones comprised the largest content, aldehydes represented the largest variety, and all volatile compounds contributed significantly to the flavor of fish cake. PCA results and nearest-neighbor fingerprint analysis showed that there were obvious differences in volatile flavor compounds between different treatments. In summary, this study conducted a detailed comparative analysis of the quality and flavor of fish cakes subjected to different processing methods. These findings contribute suggestions for sterilization temperatures in industrial production processes.

Effects of High Hydrostatic Pressure and Storage Temperature on Fatty Acids and Non-Volatile Taste Active Compounds in Red Claw Crayfish (Cherax quadricarinatus)

The effects of high hydrostatic pressure (treated with 200, 400 and 600 MPa) and storage temperatures (4 °C and −20 °C) on the fatty acids and flavor compounds of red claw crayfish were studied. HHP decreased the PUFA, GMP, IMP and AMP, citric and lactic acids, and PO43− contents, but the FAA, Ca2+ and Cl− contents increased in HHP-treated crayfish compared to untreated crayfish at 0 d. Storage at −20 °C could restrain the fatty acids and flavor contents compared to those stored at 4 °C. The GMP, AMP, citric acid and PO43− contents decreased, and Ca2+ and Cl− contents increased after storage at 4 °C for 15 d (p < 0.05). HHP at 200 and 400 MPa increased EUC on 0 d. No significant changes in EUC were observed after storage at −20 °C for 15 d, significant decreases were noted at 4 °C than the crayfish stored for 0 d (p < 0.05), except for the untreated group. Generally, HHP at 200 or 400 MPa, and storage at −20 °C is beneficial according to the shelling rates and EUC of crayfish.