Chemical, structural and antioxidant properties of melanoidins in fish sauce.

BACKGROUND: Melanoidins, as a functional component, exhibit antioxidant properties. However, the antioxidant mechanism of melanoidins in fish sauce remains poorly understood. The present study focused on the structural characteristics, microstructure and antioxidant activity of melanoidin substances in fish sauce. RESULTS: Ultrafiltration and color difference analysis were utilized to confirm the main molecular weight composition of melanoidins. The ultrafiltration component > 10 kDa in fish sauce exhibited the darkest and reddest color, along with the highest content of melanoidins (699.5 mg g-1). The spectral characteristics were consistent with typical melanoidins. Gas chromatography-tandem mass spectrometry and Fourier transform infrared spectroscopy analyses revealed that the melanoidins contained a significant number of oxygen-containing groups, amino compounds, carbohydrates, aromatic compounds and carbonyl compounds (CO), pyrrole (CN), among others. In total, 129 alkanes, 71 esters, nine olefins and two alkynes were identified. The melanoidins (> 10 kDa component) had the strongest antioxidant activity, including a reducing power of 0.8, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of 67.7% and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of 92.4%. Additionally, the melanoidins (> 10 kDa component) had the highest total phenolic content at 48.2 µg gallic acid equivalents mL-1. CONCLUSION: Melanoidins are important factors affecting the antioxidant activity of fish sauce. There were differences in the structural properties of melanoidin fractions with different molecular weights. © 2024 Society of Chemical Industry.

Elevated levels of branched chain fatty acids in low-salt fish sauce by co-fermentation: flavor improvement and metabolism analysis.

BACKGROUND: Traditional fish sauce products rely on relatively long fermentation time and high salt concentration, resulting in inconsistent quality and health risks. Branched-chain fatty acids (BCFAs) are associated with nutritional benefits and health-care effects, mainly derived from food fermentation. This study aimed to screen BCFAs-producing bacteria with high protease and aminotransferase activity as starter cultures for fish sauce fermentation. RESULTS: The low-salt fish sauce products were obtained by co-fermentation with three chosen strains. Trichloroacetic acid (TCA)-soluble peptides and amino acid nitrogen concentrations were higher in the co-fermentation group (FH group). The organoleptic evaluation showed co-fermentation optimized flavor composition and endured with rich taste. The levels of BCFAs and branched-chain amino acids (BCAAs) significantly increased by co-fermentation. Volatile metabolomics analysis indicated that BCFAs, branched-chain esters, and pyrazines were the key flavor compounds in the co-fermented group. CONCLUSION: The co-fermentation system with selected strains to ferment low-salt fish sauce has the potential to increase BCFA content and improve flavor and nutrition. © 2024 Society of Chemical Industry.

Microplastics contamination in selected staple consumer food products.

The use of plastics in the manufacturing of food products is of concern as microplastics (MPs, 1 µm to 5 mm) find their way into food which poses risks to human health. This study is the first to report detection of MPs in selected staple food products in the Philippines, specifically sea salt, white and brown sugar, fish sauce, and rice. Raman microspectroscopy was used to identify the MPs and pigment additives. The mean MP concentration was 471 MPs kg-1 with 71% identified as polyvinyl chloride (PVC) for salt, 20 MPs kg-1 with 67% polyethylene terephthalate (PET) for white sugar, 67 MPs kg-1 with 77% polypropylene (PP) for brown sugar, 3 MPs L-1 for fish sauce, and 5 MPs kg-1 with 100% PET for cooked rice. For sea salt, the highest MP contamination found was PVC that is likely from the processing of this product. This implies the need for careful use of PVC materials in their manufacture. For sugar, rice, and fish sauce, the likely contamination is from plastic packaging. The present findings provide estimation of human consumption of MPs from food items and insights on the use of plastic materials in the manufacturing processes. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05978-2.

Regulation of microbial metabolism on the formation of characteristic flavor and quality formation in the traditional fish sauce during fermentation: a review.

Fish sauce is a special flavored condiment formed by traditional fermentation of low-value fish in coastal areas, which are consumed and produced in many parts of the world, especially in Southeast Asia. In the process of fish sauce fermentation, the diversity of microbial flora and the complex metabolic reactions of microorganisms, especially lipid oxidation, carbohydrate fermentation and protein degradation, are accompanied by the formation of flavor substances. However, the precise reaction of microorganisms during the fersmentation process is difficult to accurately control in modern industrial production, which leads to the loss of traditional characteristic flavors in fermented fish sauces. This paper reviews the manufacturing processes, core microorganisms, metabolic characteristics and flavor formation mechanisms of fermented fish sauces at home and abroad. Various methods have been utilized to analyze and characterize the composition and function of microorganisms. Additionally, the potential safety issues of fermented fish sauces and their health benefits are also reviewed. Furthermore, some future directions and prospects of fermented fish sauces are also reviewed in this paper. By comprehensive understanding of this review, it is expected to address the challenges in the modern production of fish sauce thereby expanding its application in food or diet.

Removal of Histamine from Fish Sauce by Staphylococcus debuckii sp. Isolated from Fermented Fish.

Research background: One of the issues in the production of fish sauce is the legal constraints on the concentration of histamine produced by bacteria during fermentation because it causes allergic reactions in humans. The goal of this study is therefore to eliminate histamine from the final product after fermentation to enhance the quality of fish sauce for consumer safety, manufacturer exportability and domestic sales. Experimental approach: The bacteria that grow in the histamine medium were isolated from the salted fish. Their ability to degrade histamine in the media with high NaCl content was tested. The bacterium with the highest histamine-degrading ability was identified and the histamine-degrading conditions were optimized, including the incubation temperature and the amount of NaCl in the medium. The regression equation was generated and tested using the local fish sauce in which different concentrations of histamine were added. Results and conclusions: Among the five bacteria isolated from the salted fish, the isolate with the greatest ability to degrade histamine was identified as Staphylococcus debuckii sp. The study of the capacity of the isolated bacteria to degrade histamine using the synthetic histamine broth (pH=7.0, t=25 °C and NaCl 25 % (m/V)) indicated that they were able to degrade up to 56 % of histamine. The optimization analysis showed that increasing the pH of the medium to 7.5 and lowering the incubation temperature to 20 °C could improve the histamine removal from 56 to 73 %. The generated regression model, validated by the experimental results of histamine removal from fish sauce, showed an acceptable error (not more than 10 %). S. debuckii, the isolated histamine-degrading bacteria, could be used as an inoculum to reduce histamine accumulated in fish products. Novelty and scientific contribution: The microbiological technique developed here can decrease the histamine concentration in the final product, fish sauce, to improve its quality in terms of food safety and satisfy the histamine regulation requirement. The findings of this study can also be used to treat other liquid foods that contain high concentrations of histamine.

Dynamics of Bacterial Composition and Association with Quality Formation and Biogenic Amines Accumulation during Fish Sauce Spontaneous Fermentation.

High-throughput sequencing and high-pressure liquid chromatography (HPLC) methods were used to investigate the influences of microbial dynamics on the quality and biogenic amine (BA) content during fish sauce fermentation. The homogeneity of total viable bacteria and lactic acid bacteria in fish sauce becomes higher as fermentation progresses. Tetragenococcus was the key genus of fish sauce fermentation. Carnobacterium (38.43%) and Lentibacillus (41.01%) were the dominant genera in the samples fermented for 3 months and 18 months, respectively. These three bacterial genera were significantly related to the physicochemical characteristics and characteristic flavors of the sauces. Tetragenococcus was significantly positively correlated with nitrogen oxides, the main characteristic flavor components in fish sauce. The BA content in fish sauce fermentation increased from 106.88 to 376.03 mg/kg, and the content of histamine reached 115.30 mg/kg at the end of fermentation, indicating that fish sauce has health risks. About 66.67% of Lentibacillus isolates were able to produce a large amount of BA, suggesting that Lentibacillus was the key genus for BA accumulation in fish sauce fermentation. Research on reducing the content of BA in fish sauce by intervening with regard to the fermentation temperature showed that a safe fish sauce product could be obtained at the fermentation temperature of about 25°C. These results help us to understand the contribution of microbial community composition to fish sauce fermentation and provide a basis for improving the quality and safety of fermented fish sauce. IMPORTANCE Traditional fermentation of fish sauce is mainly carried out by complex microbial communities from raw anchovies and processing environments. However, it is still unclear how the environmental microbiota influences the quality and the safety of fish sauce products. Therefore, this study comprehensively explained the influence of microorganisms on the quality and safety of fish sauce during the fermentation process in terms of physicochemical characters, flavors, and BA. Additionally, the accumulation of BA in fish sauce fermentation was controlled by intervening in the fermentation temperature. This finding contributes to a deeper understanding of the role of environmental microbiota during fermentation and provides data support for improving the safety of fish sauce.

The functional starter and its genomic insight for histamine degradation in fish sauce.

Histamine is a biogenic amine significantly formed in fish sauce leading to a major concern in consumers. This study aimed to identify a halophilic bacterium for histamine degradation in fish sauce, and understand its genomic insight to enhance histamine degradation activity. We discovered the novel halophilic bacterium, Bacillus piscicola FBU1786, degrading histamine and other biogenic amines. Its histamine breakdown was growth-associated in a wide range of NaCl concentrations, pH, and temperature from 4% to 18%, 6.0 to 9.0, and 30 to 45 °C, respectively. Genome sequencing revealed the presence of Cu2+-binding oxidase-encoding genes and their heterologous expression with Cu2+ supplementation triggered histamine degradation in E. coli. The degree of histamine breakdown in B. piscicola FBU1786 could be enhanced by Cu2+ addition. Histamine degradation of the culture was evaluated in raw fish sauce mixtures to partially mimic the condition during fish sauce fermentation. Histamine degradation was suppressed to the extent of raw fish sauce, but could be restored by Cu2+ supplementation. Together, this study disclosed B. piscicola FBU1786 with the potent histamine degradation activity, identified Cu2+-binding oxidases responsible for histamine breakdown, and enhanced histamine degradation of the culture using Cu2+ supplementation.

Physicochemical characteristics and flavor profiles of fermented fish sauce (budu) during fermentation in commercial manufacturing plant.

This study was done by dynamically monitoring the changes in bacterial composition, physicochemical characteristics, and volatile substances during fermentation of fermented fish sauce (budu). The degree of hydrolysis, TCA-soluble peptides, and nitrogen contents increased as the fermentation time progressed. A continuous decrease in peroxide value and thiobarbituric acid reactive substances was noted over 60 days of fermentation. A total of 44 volatile compounds were detected, and increases in volatile compounds, such as 2-methylbutanal, 3-methylbutanal, benzaldehyde, and 2-ethyl furan, with low odor thresholds values, might contribute to budu's flavor of the final product. Additionally, the relationship between evolving microbiota and the formation of flavor compounds was analyzed, and halophilic lactic acid bacteria was identified to be the most important bacterial contributing to flavor and aroma development. This finding will provide important information for improving the quality of budu in terms of flavor characteristics.

[Effect of Soy Sauce, Fish Sauce for Nitrite Determination in Meat Products].

The diazotization method is used for nitrite determination in meat products. In this method, it is known that the presence of reducing substances such as ascorbic acid and cysteine in the sample interferes with nitrite determination. We speculated that soy sauce, fish sauce and mirin, which are used in meat products, might be the reducing substances, so investigated meat products which contain soy sauce and other ingredients. The results showed that quantitative disturbance was observed in soy sauce and fish sauce, and the recovery in spiked samples of these products decreased in proportion to the increase in soy sauce and fish sauce content. However the antioxidant of soy sauce and fish sauce depending on manufacturing methods, so quantitative disturbance dose not be observed each time, so nitrite determination in meat products, and to conduct simultaneous determination using different sample amounts to confirm whether there is any difference in the quantitative values.

Volatile compounds, physicochemical and sensory characteristics of Colatura di Alici, a traditional Italian fish sauce.

BACKGROUND: The present study reports for the first time the physical, chemical and sensory characterization of a traditional fish sauce from Italy, called 'Colatura di Alici', which is considered to be the direct descendant of the ancient roman sauce 'Garum'. RESULTS: Among the volatile compounds, carboxylic acids, aldehydes, sulphuric compounds and pyrazines were identified. The most abundant compounds identified were 3-methyl-butanoic acid, nonanal and 3-methyl-butanal. The sample A had the highest amount of volatile fatty acids (>250 µg kg-1 ) and sample B had the highest concentration of aldehydes (>80 µg kg-1 ). These volatile compounds arise from the long fermentation activity and oxidation of fatty acids of the fish flesh and are responsible for the strong cheesy and fishy aroma. The protein content ranged from 90 to 130 g kg-1 , and the soluble solids ranged from 30 to 38 °Brix, as a result of the high amount of NaCl used during processing. The sensory analysis showed a great intensity for the cheesy, fishy and umami attributes, and a medium intensity for the roasted and meaty attributes. CONCLUSION: For the first time, the volatile compounds and sensory characteristics of this traditional fish sauce are reported. The samples differ in terms of sensory and aromatic profiles. These differences are probably linked to the poorly standardized methods used in the production process. Overall, the results of the present study could be used by local fish sauce producers to monitor the quality of the product and to improve the production process. © 2020 Society of Chemical Industry.

Household Consumption of Thiamin-Fortified Fish Sauce Increases Erythrocyte Thiamin Concentrations among Rural Cambodian Women and Their Children Younger Than 5 Years of Age: A Randomized Controlled Efficacy Trial.

OBJECTIVES: To assess whether ad libitum consumption of thiamin-fortified fish sauce over 6 months yields higher erythrocyte thiamin diphosphate concentrations (eTDP) among women of childbearing age and their children aged 12-59 months compared with control sauce containing no thiamin. STUDY DESIGN: In this double-blind, randomized controlled efficacy trial, 276 nonpregnant, nonlactating women (18-45 years of age) and their families in Prey Veng, Cambodia, were randomized to receive 1 of 3 fish sauce formulations: low thiamin concentration (low, 2 g/L), high thiamin concentration (high, 8 g/L), or a control (no thiamin) fish sauce. Baseline (t = 0) and endline (t = 6 months) eTDP were measured with the use of high-performance liquid chromatography with a fluorescence detector. RESULTS: Fish sauce consumption did not differ between treatment groups (P = .19). In intent-to-treat analysis, women's baseline-adjusted endline eTDP (mean; 95% CI) was higher among women in the low (259; 245-274 nmol/L) and high (257; 237-276 nmol/L) groups compared with control (184; 169-198 nmol/L; P < .001); low and high groups did not differ (P = .83). Similarly, children's baseline-adjusted eTDP was higher in the low (259; 246-271 nmol/L) and high (257; 243-270 nmol/L) groups compared with control (213; 202-224 nmol/L; P < .001). CONCLUSION: Fortified fish sauce appears to be an efficacious means of improving biochemical thiamin status in nonpregnant, nonlactating women and their children (1-5 years of age) living in rural Cambodia. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02221063.

Quality improvement on half-fin anchovy (Setipinna taty) fish sauce by Psychrobacter sp. SP-1 fermentation.

BACKGROUND: A method of improving fish sauce quality during fermentation was investigated. Psychrobacter sp. SP-1, a halophilic protease-producing bacterium, was isolated from fish sauce with flavor-enhancing properties and non-biogenic amine-producing activity. The performance of Psychrobacter sp. SP-1 in Setipinna taty fish sauce fermentation was investigated further. RESULTS: The inoculation of Psychrobacter sp. SP-1 did not significantly affect pH or NaCl concentration changes (P > 0.05), although it significantly increased total moderately halophilic microbial count, protease activity, total soluble nitrogen content and amino acid nitrogen content, and also promoted the umami taste and meaty aroma (P < 0.05). Furthermore, the inoculation of Psychrobacter sp. SP-1 significantly decreased total volatile basic nitrogen content and biogenic amines content (P < 0.05), which were regarded as harmful compounds in foods. CONCLUSION: The results of the present study demonstrate that Psychrobacter sp. SP-1 can be used as a potential starter culture for improving fish sauce quality by fermentation. © 2017 Society of Chemical Industry.

Reduction of salt content of fish sauce by ethanol treatment.

Fish sauce is a traditional condiment in Southeast Asia, normally containing high concentration of salt. The solubility of salt is lower in ethanol than in water. In the present study, fish sauce was desalted by ethanol treatment (including the processes of ethanol addition, mixing, standing and rotary evaporation). The salt concentration of fish sauce decreased significantly from 29.72 to 19.72 g/100 mL when the treated ethanol concentration was 21% (v/v). The addition of more than 12% (v/v) of ethanol significantly reduced dry weight, total soluble nitrogen content and amino acids nitrogen content. Besides, the quality of fish sauce remained first grade if no more than 21% (v/v) of ethanol was used. Furthermore, sensory analyses showed that ethanol treatment significantly reduced the taste of salty and the odor of ammonia. This study demonstrates that ethanol treatment is a potential way to decrease salt content in fish sauce, which meanwhile limits the losses of nutritional and sensorial values within an acceptable range.

Quantification of viable bacterial starter cultures of Virgibacillus sp. and Tetragenococcus halophilus in fish sauce fermentation by real-time quantitative PCR.

Real-time quantitative polymerase chain reaction (qPCR) methods were developed for the quantification of Virgibacillus sp. SK37 and Tetragenococcus halophilus MS33, which were added as starter cultures in fish sauce fermentation. The PCR assays were coupled with propidium monoazide (PMA) treatment of samples to selectively quantify viable cells and integrated with exogenous recombinant Escherichia coli cells to control variabilities in analysis procedures. The qPCR methods showed species-specificity for both Virgibacillus halodenitrificans and T. halophilus as evaluated using 6 reference strains and 28 strains of bacteria isolated from fish sauce fermentation. The qPCR efficiencies were 101.1% for V. halodenitrificans and 90.2% for T. halophilus. The quantification limits of the assays were 10(3) CFU/mL and 10(2) CFU/mL in fish sauce samples with linear correlations over 4 Logs for V. halodenitrificans and T. halophilus, respectively. The matrix effect was not observed when evaluated using fish sauce samples fermented for 1-6 months. The developed PMA-qPCR methods were successfully applied to monitor changes of Virgibacillus sp. SK37 and T. halophilus MS33 in a mackerel fish sauce fermentation model where culture-dependent techniques failed to quantify the starter cultures. The results demonstrated the usability of the methods as practical tools for monitoring the starter cultures in fish sauce fermentation.

Proteolysis of Sardine (Sardina pilchardus) and Anchovy (Stolephorus commersonii) by Commercial Enzymes inSaline Solutions.

Fish sauce production is a very long process and there is a great interest in shortening it. Among the different strategies to speed up this process, the addition of external proteases could be a solution. This study focuses on the effect of two commercial enzymes (Protamex and Protex 51FP) on the proteolysis of two fish species traditionally converted into fish sauce: sardine and anchovy, by comparison with classical autolysis. Hydrolysis reactions were conducted with fresh fish at a temperature of 30 °C and under different saline conditions (from 0 to 30% NaCl). Hydrolysis degree and liquefaction of the raw material were used to follow the process. As expected, the proteolysis decreased with increasing amount of salt. Regarding the fish species, higher rate of liquefaction and higher hydrolysis degree were obtained with anchovy. Between the two proteases, Protex 51FP gave better results with both fish types. This study demonstrates that the addition of commercial proteases could be helpful for the liquefaction of fish and cleavage of peptide bonds that occur during fish sauce production and thus speed up the production process.

Statistical Optimization of the Production of NaCl-Tolerant Proteases by a Moderate Halophile, Virgibacillus sp. SK37.

The objectives of this study are to optimize the conditions for providing high yield of NaCl-tolerant extracellular protease from Virgibacillus sp. SK37 based on a fish-based medium and to investigate the effects of the key factors (mass per volume ratios of dried anchovy, yeast extract and NaCl, and initial pH of the medium) on the secretion pattern of proteases. Based on the predicted response model, the optimized medium contained 1.81% of dried anchovy, 0.33% of yeast extract and 1.25% of NaCl at pH=7.8. Under these conditions, a 5.3-fold increase in protease production was achieved, compared with the broth containing only 1.2% of dried anchovy (5% of NaCl at pH=7). The cubic regression adequately described the protease production. Protease activity was determined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) on the synthetic substrate (Suc-Ala-Ala-Pro-Phe-AMC). Proteases of molecular masses of 19, 34, 35 and 44 kDa were secreted in the presence of NaCl, whereas those of 22 and 42 kDa were the main proteases detected in the absence of NaCl. In addition, no secreted proteases were detected when initial pH of the medium was pH=6. The peptide mass fingerprint of the medium cultured with 10% NaCl showed a higher abundance of peptides with lower mass of 500-1000 m/z compared with the medium containing 0% NaCl, indicating the higher proteolytic activity of the high-salt medium. The Virgibacillus sp. SK37 proteases showed a marked preference towards Lys, Arg and Tyr in the presence of NaCl and towards Lys and Arg in the absence of NaCl.

Microbial and chemical properties of Cambodian traditional fermented fish products.

BACKGROUND: Fermented fish products, commonly consumed in south-east Asia, are used as condiments that contribute to people's nutritional sources and as seasonings to improve food taste and flavour. Among these, the Cambodian products prahok (fish paste), kapi (shrimp paste) and toeuk trey (fish sauce) have not been examined in detail. This is the first study to investigate their chemical and microbial properties. RESULTS: Acetic acid was the most common organic acid with the highest concentration in 10/13 samples (1.9-26.6 g kg(-1)). Lactic acid was also found at high concentrations (0.4-12.9 g kg(-1)). 16S ribosomal RNA gene-dependent phylogenetic analyses indicated that Gram-positive cocci and rods, such as Bacillus, Clostridium, Staphylococcus and Tetragenococcus, were the major microbial populations. High sodium chloride concentrations detected in these products (170-270 g kg(-1)) could be responsible for inhibition of the growth of Gram-negative putrefactive microorganisms. CONCLUSION: This study established a relationship between the chemical and microbial compositions of Cambodian fermented fish products, which provides a basis for preservation and maturation. These data could be beneficial in the manufacturing of these products in terms of microbial control and quality stabilisation.

Novel Archaeal Histamine Oxidase from Natronobeatus ordinarius: Insights into Histamine Degradation for Enhancing Food Safety.

Histamine, found abundantly in salt-fermented foods, poses a risk of food poisoning. Natronobeatus ordinarius, a halophilic archaeon isolated from a salt lake, displayed a strong histamine degradation ability. Its histamine oxidase (HOD) gene was identified (hodNbs). This is the first report of an archaeal HOD. The HODNbs protein was determined to be a tetramer with a molecular weight of 307 kDa. HODNbs displayed optimum activity at 60-65 °C, 1.5-2.0 M NaCl, and pH 6.5. Notably, within the broad NaCl range between 0.5 and 2.5 M, HODNbs retained above 50% of its maximum activity. HODNbs exhibited good thermal stability, pH stability, and salinity tolerance. HODNbs was able to degrade various biogenic amines. The Vmax of HODNbs for histamine was 0.29 µmol/min/mg, and the Km was 0.56 mM. HODNbs exhibited high efficiency in histamine removal from fish sauce, namely, 100 µg of HODNbs degraded 5.63 mg of histamine (37.9%) in 10 g of fish sauce within 24 h at 50 °C. This study showed that HODNbs with excellent enzymatic properties has promising application potentials to degrade histamine in high-salt foods.

The principal component analysis of key and significant features of the safety and nutritional value of Mahyaveh sauce.

The objective of present research is to evaluate the changes in the chemical, microbial, and biogenic amines in Persian fish sauce (Mahyaveh) during 40 days of fermentation. In the current survey, the parameters of salt percentage, pH, total nitrogen concentration, amino nitrogen concentration, Brix, color features, cadaverine, and histamine concentration were measured in the fish sauce. The amino nitrogen content, total protein, Brix, and salt were increased along with the progression of fermentation process. The microbial population of Mahyaveh sauce demonstrated that lactic acid bacteria (LAB), total bacterial count, and Enterobacteriaceae decreased during fermentation. The population of lactic acid bacteria and the total count of bacteria were around one logarithmic cycle lower in the presence of 10% salt than under low salt conditions. Histamine and cadaverine concentrations increased to 43.49 and 42.76 mg/kg during the fermentation period, respectively. As a result, the population density of histamine-producing bacteria rose from 3.00 log CFU/mL at the beginning to 4.58 log CFU/mL at the end of process. The population density of cadaverine-producing bacteria was 3.43 and 5.24 log CFU/mL on the 20th and 40th days of fermentation, respectively. Sensory evaluation results indicated that our sample of fish sauce had an overall acceptability score of 5.1 (good). On the other hand, Principal Component Analysis (PCA) demonstrated a positive correlation between the most of chemical parameters and the fermentation period. The concentration of cadaverine and histamine has a positive association with the pH and type of bacteria producing the biogenic amines.

Changes in the chemical properties and metabolite profiling of fish sauce prepared from underutilized large yellow croaker roes during fermentation at different temperatures.

Fish sauce is a popular aquatic condiment with unique flavor. In this study, the changes in the chemical properties and metabolite profiling of fish sauce from large yellow croaker roes during fermentation at different temperatures were revealed. The results found that the contents of total acid, amino acid nitrogen, total soluble nitrogen and soluble salt-free solids of fish sauce fermented at 40 °C were higher than those in other temperatures groups (25 °C and 32 °C), while the contents of total volatile basic nitrogen were lower than other temperatures. Therefore, 40 °C was the ideal fermentation temperature for fish sauce. The metabolomics analysis showed that organic acids, amino acids, nucleotide, and lipid compounds were found to participate in the biosynthesis pathway. Compared to 25 °C and 32 °C, fermented at 40 °C could increase the abundance of metabolic substances in the fish sauce, such as sugar alcohols, L-Citrulline, L-Aspartic acid, L-Cysteine, Glutathione, and L-Arginine. These results provide a theoretical basis for the production of high-quality fish sauce and the high-value utilization of fish roes.