Acceleration of Thai fish sauce fermentation using proteinases and bacterial starter cultures

ABSTRACT:  A means to accelerate fish sauce fermentation without adversely affecting fish sauce quality was investigated. Starter cultures prepared from Virgibacillus sp. SK33, Virgibacillus sp. SK37, and Staphylococcus sp. SK1-1-5 were added separately to anchovy that was hydrolyzed by 0.25% Alcalase at 60 °C for 2 h followed by 0.5% Flavourzyme at 50 °C for 4 h. The mixtures were then adjusted to contain 25% solar salt and incubated at 35 °C for 4 mo. α-Amino contents of all inoculated samples were higher than the control (without the addition of starter culture) during the course of fermentation. After 4-mo fermentation, the samples inoculated with Staphylococcus sp. SK1-1-5 contained the highest α-amino content of 733.37 ± 13.89 mM while that of the control was 682.67 ± 3.33 mM. Amino acid profiles of inoculated samples showed similar patterns to that of commercial product fermented for 12 mo, with glutamic, aspartic, and lysine being predominant amino acids. Virgibacillus sp. SK33 appeared to decrease histamine content of fish sauce by 50% when compared to the control. Volatile compounds analyzed by GC–MS of all inoculated samples fermented for 4 mo exhibited a similar pattern to those of the 12-mo-old commercial product. Samples inoculated with Staphylococcus sp. SK1-1-5 produced higher levels of volatile fatty acids and showed similar sensory characteristics to the commercial fish sauce fermented for 12 mo. Staphylococcus sp. SK1-1-5 is a potential strain that can be applied to produce fish sauce with overall sensory characteristics of traditional fish sauce in shorter time.     

Biochemical Properties and Consumer Acceptance of Pacific Whiting Fish Sauce

ABSTRACT Biochemical characteristics of fish sauce made from Pacific whiting whole fish and a mixture (1:1) of its byproducts were investigated at 0, 1, 3, and 9 mo. As fermentation time extended, the degree of hydrolysis, total nitrogen content, amino nitrogen content, and hypoxanthine content increased, while inosine content, moisture content, and pH decreased. Degree of hydrolysis was significantly different at 9 mo of fermentation. All cathepsin activities were negligible after 3 mo. Consumer tests showed a nonsignificant difference in overall acceptance between our samples and commercial anchovy fish sauce ( P > 0.05). This study demonstrated that surimi byproducts can be utilized as raw material for fish sauce.     

Biogenic Amines Formation in Fish Sauce Prepared from Fresh and Temperature-abused Indian Anchovy (Stolephorus indicus)

ABSTRACT: The formation of biogenic amines in fish sauce made from fresh and temperature-abused (left at 35°C for 8 and 16 h) Indian anchovy ( Stolephorus indicus ) was investigated. Histamine, cadaverine, putrescine, and tyramine were the predominant biogenic amines found in anchovy left at 35°C for 16 h and its fish sauce product. Changes of biogenic amines were subtle during the course of fermentation at room temperature (RT) and at 40°C, suggesting that the main source of biogenic amines was associated with raw material, rather than with the fermentation process. Soluble peptide and total nitrogen of fish sauce prepared from temperature-abused anchovy were higher at the initial stage of fermentation at RT and 40°C and became comparable to those prepared from fresh anchovy at the end of fermentation. Total free amino acid contents of samples fermented at RT for 52 wk (7208.3 to 8473.6 mg/100 mL) were higher than those fermented at 40°C for 13 wk (4560.9 to 5730.9 mg/100 mL). Fish sauce prepared from temperature-abused anchovy contained less free histidine and arginine. Fish sauce of a good quality was obtained using fresh anchovy fermented at RT. Besides total nitrogen content, biogenic amines should be considered as quality indicators of fish sauce.     

Seasonal effects on the physicochemical characteristics of fish sauce made from capelin (Mallotus villosus)

Fresh capelin (Mallotus villosus) was harvested from the North Atlantic during both summer and winter fishing seasons. Reaction conditions for fish sauce processing were optimized with respect to temperature, salt concentration and reaction time, using a response surface methodology (RSM) experimental design. Whole capelin was minced and samples were ground with increasing salt concentrations. RSM optimizations were conducted, ranging from 5% to 30% salt, and incubating at 5° intervals from 0 to 65 °C. Autolytic activity was estimated by extracting the liquid formed by the mixture with trichloroacetic acid and estimating protein content by the Lowry method. Samples for fish sauce production were then prepared under optimized conditions by mixing ground capelin with 10% salt and incubating at 50 °C for up to 270 days for the summer capelin and up to 360 days for the winter capelin. Samples were collected at regular intervals and analyzed for liquid yield, moisture, protein, soluble solids, specific gravity, pH, colour and amino acid content. Kjeldahl protein content in the fish sauce from summer capelin was 2.03% after 250 days of fermentation and twice as high as that in winter capelin fish sauce. Moisture content and pH were lower in the summer capelin fish sauce, but Brix and density were higher than those in fish sauce from winter capelin. Brown colour formation was very rapid in the summer capelin fish sauce but slow in the winter capelin fish sauce. Summer capelin may be successfully utilized for the production of fish sauce without added enzymes.     

秋刀鱼鱼露速酿加工工艺研究

为了研究鱼露快速发酵生产工艺,以秋刀鱼为原料,采用加曲适量保温的方式生产鱼露,通过单因素实验探讨不同因素(发酵周期、温度、固液比、加盐量、加曲量)对鱼露发酵生产的影响,并在此基础上进行正交实验工艺优化,结果表明,在发酵周期30 d时,鱼露发酵液中氨基酸态氮含量维持稳定,表明鱼肉组织基本分解完全,最佳发酵工艺条件为:温度30℃、固液比1∶0.6、加曲量5%、加盐量12%。在此条件下制得的鱼露氨基酸态氮含量(0.97±0.02)g/100 m L,可溶性固形物含量23%±0.51%,感官评分88分,鱼露颜色棕红至橙红,无异味,富有鱼露特殊香气,达到快速生产鱼露目的。      

Proteinase inhibition of fish muscle enzymes using legume seed extracts.

Seed extracts from indigenous and introduced legumes were prepared and used to search for inhibitors of fish muscle proteinases. Fish flesh extracts were prepared from samples of Merluccius productus (Pacific whiting or merluza) obtained off the Oregon coast and in the Gulf of California, respectively. The proteinase activity in the fish muscle for the Pacific whiting was the highest, followed by parasitized merluza. The lowest proteinase activity was for the nonparasitized merluza. Six out of 12 seed extracts reduced the proteinase activity from the fish flesh by more than 50%. The reduction of enzyme activity was higher for samples of fish flesh extracts from the Gulf of California than for the Oregon samples. Seed extracts also reduced the proteinase activity of commercial serine and cysteine proteinases such as trypsin, chymotrypsin, and papain. This inhibitory capacity was maintained even after heating the seed extracts to 90 degrees C for 15 min. Several seed extracts show promise for use as proteinase inhibitors during production of surimi, the intended commercial product of massive fisheries such as Pacific whiting or merluza.     

Effects of the addition of spleen of skipjack tuna (Katsuwonus pelamis) on the liquefaction and characteristics of fish sauce made from sardine (Sardinella gibbosa)

The effects of the addition of spleen of skipjack tuna (Katsuwonus pelamis), at levels of 0%, 10% and 20%, on the liquefaction and characteristics of fish sauce produced from the sardine (Sardinella gibbosa) with different salt concentrations (15%, 20% and 25%) were monitored during fermentation for 180 days. Fish sauces prepared from sardine with spleen supplementation contained greater total nitrogen, amino nitrogen, formaldehyde nitrogen and ammonia nitrogen than did those without spleen addition throughout the fermentation. The rate of liquefaction was dependent on the amount of spleen added. Reduction of salt content accelerated the hydrolysis of fish protein during fermentation. The liquefaction rate of the lower salt-treated samples was generally faster than were those treated with higher salt content. Among all treatments, sardine with 25% spleen and 15% salt added exhibited the greatest protein hydrolysis, particularly at the early stages, suggesting the combined effects of autolysis and spleen proteinase. The greater liquefaction was coincidental with the development of browning as well as the increase in redness of liquid formed. An acceptability test revealed that the samples were different in colour, aroma, taste and overall acceptance (p < 0.05). Fish sauce samples containing 20% salt, without and with 10% spleen addition had similar acceptabilities to commercial fish sauce. Therefore, the addition of spleen, as well as salt reduction, can accelerate the liquefaction of sardine for fish sauce production.     

Rheological Behavior and Potential Cross-Linking of Pacific Whiting (Merluccius productus) Surimi Gel

Gelation behavior and potential cross-linking of Pacific whiting (Merluccius productus) surimi were affected by setting temperatures and an enzyme inhibitor. Gels of Pacific whiting surimi with salt and beef plasma protein were compared with those containing guanidine hydrochloride, sodium dodecyl sulfate, and β-mercaptoethanol. The strongest gels were formed at 25°C setting followed by 90°C heating. Hydrogen and hydrophobic bonds appeared to strongly influence gel formation, while the influence of disulfide bonds was moderate. Viscosity scanning during setting at different temperatures was also useful to estimate effects of enzymes and inhibitors.     

Acceleration of autolysis during fish sauce fermentation by adding acid and reducing the salt content

Good quality fish sauce was produced from anchovies (Stolephorus spp.) that had been allowed to autolyse at pH 4 and low salt concentration. After an initial phase of rapid autolysis, the samples were neutralised, and salt was added to the normal level (250 g kg^?1) before the fish sauce was separated by suction. By this method fish sauce with acceptable flavour could be produced after 2 months, whereas the normal production time is more than 6 months. This rapidly-produced fish sauce had a lower level of volatile base and acid, and a better balanced composition of essential amino acids than a first grade commercial fish sauce.     

大黄鱼卵鱼露的发酵工艺

以大黄鱼鱼卵发酵鱼露为研究对象,分析其在发酵过程中接曲量、加盐量、温度等条件对鱼露pH、总酸、氨基酸态氮、挥发性盐基氮、脂肪、硫代巴比妥酸等理化指标的影响,并分析了发酵第30 d时氨基酸的含量.结果表明:在大黄鱼鱼卵鱼露发酵过程中,pH整体上呈波动现象,且总酸含量的变化与其一致;氨基酸态氮含量在发酵过程中呈上升趋势,且...     

EFFECT OF PACIFIC WHITING WASH WATER PROTEINS ON ALASKA POLLACK SURIMI GELS

The objective of this work was to evaluate the effect of adding insoluble proteins recovered from Pacific whiting surimi wash water (SWW) on the mechanical and functional properties of Alaska pollack surimi gels. Insoluble proteins from Pacific whiting SWW were added at 0 (control), 10, 30 or 50 g/kg into Alaska pollack grade FA surimi. Changes on mechanical properties, expressible water ( EW ) and color attributes were evaluated in pastes and gels. Results obtained showed that texture profile analysis, puncture test and EW parameters increased significantly by increasing the amount of insoluble proteins added. Although slight changes in color attributes were detected, all surimi gels remained in the same color zone. The results obtained suggest that insoluble proteins from Pacific whiting SWW could be used to improve the mechanical properties of Alaska pollack grade FA surimi gels with a minimum effect on color.

PRACTICAL APPLICATIONS

Insoluble proteins recovered from surimi wash water (SWW) of Pacific whiting added at 10–50 g/kg to Alaska pollack surimi showed no adverse effects on their textural properties (hardness, fracturability, springiness and chewiness) and slight changes on color attributes. The results obtained suggest that it is feasible the use of insoluble proteins recovered from SWW of Pacific whiting in Alaska pollack surimi. Therefore, a double target is obtained: the preservation of environment and an increase in the yield of surimi processing without negative effects on texture.     

Histamine Formation in Fish Sauce Production

ABSTRACT: The formation of histamine in fish sauce made from Stolephorus sp was studied. In the first experiment, fish were iced on board and mixed with salt at the factory, while in the second experiment fish were mixed with salt on board collection vessels. Eight batches were fermented for 12 mo. Histamine levels increased during fermentation to 22 to 159 and 589 to 686 ppm in the first and second experiments respectively. Good correlation between histamine levels in raw material and final products was found. It was concluded that histamine was formed both in the raw material and during fermentation. It was speculated that histidine decarboxylase enzymes formed prior to fermentation produced histamine during fermentation.     

Biochemical changes occurring during the manufacture of budu

The changes that occur during the commercial production of budu, a Malaysian fish sauce were examined. It was shown that the maximum volume of liquid was produced after 140 days and that proteolysis continued to occur until 200 days when 56% of the insoluble fish protein had been hydrolysed into soluble form. The colour was produced early during the fermentation. The aroma constituents, ammonia and trimethylamine, were produced early in the fermentation process, but the volatile fatty acids did not appear when fresh fish (Stolephorus) was used for the fermentation. In the commercial production, n-butanoic acid concentration remained constant during the fermentation but ethanoic acid did increase during the period. The salt concentration and the pH were approximately constant throughout, at 26% and 5.65, respectively.     

Use of exogenous enzymes to elaborate the Roman fish sauce ‘garum’

A fermented fish sauce, which tries to imitate the ancient Roman ‘garum’, was developed from tuna (Tunnus thynnus) liver and mackerel (Scomber scombrus). Exogenous proteolytic enzymes were used to accelerate the elaboration process, and various fermentation technological parameters (salt percentage, temperature, enzyme dose, continuous stirring) were assayed in order to optimise the process and obtain the best yield. Best conditions were 10% salt (5% added at the start of the process and the 5% after 24 h of fermentation), 35–37 °C and Neutrase (an endoprotease from Bacillus subtilis) at 0.125 Anson Units per 100 g. The fermentation process was carried out in 48 h. The obtained product (filtered and diluted with a guar gum solution) was a thick sauce with 21 mgNg^?1, 5.9% salt and 10% fat. The lipidic fraction showed a very interesting fatty acid profile, especially in relation to its ω‐3 fatty acids (PUFA/SFA ratio 0.98; 4.2 g eicosapentaenoic acid and 11.3 g docosahexaenoic acid per 100 g fat). The developed garum was rather different from fish sauces that are manufactured nowadays in South East Asian countries. © 2001 Society of Chemical Industry     

静磁场对发酵鱼露工艺的影响

为探究鱼露酿造的新工艺,以淡水鱼下脚料为原料,粉碎成鱼糜与80 g/L盐、沪酿3.042米曲霉制成的酱油曲混合后,在静磁场环境下培养发酵生产鱼露.在不同静磁场环境下40℃发酵30 d,通过测定鱼露发酵过程中氨基态氮、总氮、挥发性盐基氮、无盐固形物、总酸、pH值和非酶褐变的变化,分析静磁场环境对鱼露发酵工艺及其品质的影响...     

Electrodialysis Desalination of Fish Sauce: Electrodialysis Performance and Product Quality

ABSTRACT:  Fish sauce has a unique, pleasant flavor, but contains high levels of sodium chloride, which is nowadays not desirable for health-conscious consumers. Although many researchers have attempted to solve this problem by substituting sodium with potassium in fish sauce, potassium-based products are still unsuitable for patients with kidney disease. Thus, electrodialysis (ED) desalination of fish sauce was carried out. The rate of salt removal, evolution of total soluble solids, and electrical conductivity of the electrodialysis-treated fish sauce were investigated. Moreover, the system performance in terms of yield, energy consumption, and current efficiency were examined. Density, viscosity, ion concentrations (that is, Na⁺, K⁺), total nitrogen, amino nitrogen, and color were investigated at various values of input voltage (6, 7, and 8 V) and remaining salt concentration (22%, 18%, 14%, 10%, 6%, and 2%[w/w]). The results indicated that an increase in the input voltage led to an increase in the rates of salt removal, electrical conductivity, and total soluble solids. The energy consumption increased whereas current efficiency and yield decreased significantly with an increase in input voltage and the salt removal level. Physicochemical properties of the treated fish sauce, in terms of the total soluble solids, density, viscosity, ion concentrations (that is, Na⁺, K⁺), total nitrogen, and color were significantly affected by the input voltage and the salt-removal level.     

Bacteriological properties and health-related biochemical components of fermented fish sauce: An overview

Fish sauce is an amber-colored salty liquid in Southeast Asian cuisine used as an important condiment for improving the taste of foods. It is produced by fermenting the fish with salt in the ratios of 1:1 or 3:1 (fish:salt, wet wt) in underground concrete tanks or earthenware for 6–12 months at ambient conditions. Proteins of the raw materials are hydrolyzed into peptides and amino acids by microbial proteolytic enzymes during fermentation. This paper reviews fish sauce diversity and its bacteriological, biochemical, and biofunctional properties. Additionally, efforts to accelerate fish sauce production by employing halotolerant bacterial cultures and proteinases to reduce the fermentation period and also to improve the acceptability of the product are also reviewed. Further, the review provides an overview of bacterial proteinases that have been employed to enhance the sensory and microbiological quality of fish sauce. The review also outlines the effect of fermented fish sauces on health, especially in reference to several bioactive peptides and bacterial metabolites apart from discussing desalination technique to recover the metabolites from fish sauce.     

淡水鱼加工下脚料速酿低盐鱼露的工艺研究

对利用淡水鱼加工下脚料制备低盐鱼露的速酿工艺进行研究。结果表明低盐淡水鱼露发酵最适条件为：加盐量8%、加酶量0.25%、温度45℃、固液比为1:0.75。制得的鱼露产品固形物含量19.43%,游离态含基酸氮含量0.73g/100ml。鱼露呈橙红色;透明,无悬浮物和沉淀物;具固有香味,无异臭味;口感咸鲜,入口滑爽。研究表明,在外加酶和保温的情况下实现了淡水鱼加工下脚料速酿低盐鱼露的目的。     

Effect of Monascus Fermentation on the Characteristics of Mackerel Mince

ABSTRACT: To improve the characteristics of fish muscle, Monascus purpureus or Monascus species was inoculated in 2.1% rice powder broth containing 30% minced mackerel tissue to produce a fermented fish product. Enterbacteriaceae, Staphylococcus , and Pseudomonas were not present during the 7 d of fermentation at 25 °C. The activities of both amylase and acidic proteases were detected after 1 and 2 d of fermentation, respectively, and further increased during fermentation. The volatile base nitrogen of all Monascus fermented samples were lower than the limit of food regulation in Taiwan (< 25 mg/100 g) even after 7 d of fermentation. Hydrolysis of the muscle protein and accumulation of free amino acid were observed. The fermented fish products had good flavor and color that were highly likeable to the sensory panel.