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Gac (Momordica cochinchinensis Spreng.) seed proteins (GSPs) hydrolysate was investigated for angiotensin I-converting enzyme (ACE) inhibitory activities. GSPs were hydrolyzed under simulated gastrointestinal digestion using a combination of enzymes, including pepsin, trypsin, and chymotrypsin. The screening of ACE inhibitory peptides from GSPs hydrolysate was performed using two sequential bioassay-guided fractionations, namely hydrophilic interaction liquid chromatography (HILIC) and reversed-phase high-performance liquid chromatography (RP-HPLC). Then, the peptides in the fraction with the highest ACE inhibitory activity were identified by LC-MS/MS. The flow-through (FT) fraction showed the most potent ACE inhibitory activity when HILIC fractionation was performed. This fraction was further separated using RP-HPLC, and the result indicated that fraction 8 (RP-F8) showed the highest ACE inhibitory activity. In the HILIC-FT/RP-F8 fraction, 14 peptides were identified using LC-MS/MS analysis coupled with de novo sequencing. These amino acid chains had not been recorded previously and their ACE inhibitory activities were analyzed in silico using the BIOPEP database. One fragment with the amino acid sequence of ALVY showed a significant ACE inhibitory activity (7.03 ± 0.09 µM). The Lineweaver-Burk plot indicated that ALVY is a competitive inhibitor. The inhibition mechanism of ALVY against ACE was further rationalized through the molecular docking simulation, which revealed that the ACE inhibitory activities of ALVY is due to interaction with the S1 (Ala354, Tyr523) and the S2 (His353, His513) pockets of ACE. Bibliographic survey allowed the identification of similarities between peptides reported as in gac fruit and other proteins. These results suggest that gac seed proteins hydrolysate can be used as a potential nutraceutical with inhibitory activity against ACE.

Andrographolide (Andro) is the major active component of the traditional herbal bitter tea Andrographis paniculata. We tested the hypothesis that Andro exerted its antitumor activities through its effects on three key survival enzymes, glyoxalase 1 (GLO1), glutamate-cysteine ligase catalytic subunit (GCLC) and HMG-CoA reductase (HMGCR), leading to cancer cell apoptosis. In human leukemia HL-60 cells Andro could reduce cholesterol levels, accompanied with down-regulation of Ras translocation to the membrane and downstream phosphorylation of Akt and ERK. Based on results obtained using specific inhibitors, LY294002 (PI3K inhibitor), U0126 (MEK1/2 inhibitor), and JSH-23 (NF-κB activation inhibitor), we proposed that the apoptotic effects of Andro in HL-60 cells arose because of interactions with the Ras/Akt/NF-κB/GLO1 and Ras/Raf/ERK/NF-κB/GLO1 pathways. Andro has a potential to be used as a functional food ingredient to prevent and manage inflammatory diseases including cancers.

In recent years, biodegradable and alternative biodiesel has attracted increased attention worldwide. Producing biodiesel from biomass involves critical separation and purification technology. Conventional technologies such as gravitational settling, decantation, filtration, water washing, acid washing, organic solvent washing and absorbent applications are inefficient, less cost effective and environmentally less friendly. In this study supercritical carbon dioxide (SC-CO2) with few steps and a low environmental impact, was used for biodiesel fractionation from impure fatty acid methyl ester (FAME) solution mixes. The method is suitable for application in a variety of biodiesel production processes requiring subsequent stages of purification. The fractionation and purification was carried out using continuous SC-CO2 fractionation equipment, consisting of three columns filled with stainless steel fragments. A 41.85% FAME content solution mix was used as the raw material in this study. Variables were a temperature range of 40–70 °C, pressure range of 10–30 MPa, SC-CO2 flow rate range of 7–21 mL/min and a retention time range of 30–90 min. The Taguchi method was used to identify optimal operating conditions. The results show that a separated FAME content of 99.94% was verified by GC-FID under optimal fractionation conditions, which are a temperature of 40 °C of, a pressure level of 30MPa and a flow rate of 7 mL/min of SC-CO2 for a retention time of 90 min.

The effects of dry processing and maturity on antioxidant activity, total phenolic content, total procyanidins, and identity of phenolic compounds in coffee leaves were evaluated. Fresh coffee leaves were tray-dried at 40 °C for 8 h before total phenolic content, total procyanidins, and antioxidant activity were analyzed. The drying process significantly (p < 0.05) improved the release of total phenolic content and total procyanidins compared with the fresh leaves. The results showed that the young leaves exposed to drying processes had the highest total phenolic content, total procyanidins, and DPPH radical scavenging activity. Therefore, the effect of different drying temperatures (30, 40, and 50 °C) in the young leaves were further analyzed. The results indicated that DPPH radical scavenging activity, total phenolic content, and total procyanidins were increasingly generated when exposed to an increase in drying temperatures, whereby the highest bioactivity was evident at 50 °C. The DPPH radical scavenging activity of the coffee leaf teas was significantly correlated with total phenolic content and total procyanidins. Identification of Coffea arabica L. bioactive compounds by LC-MS showed the presence of catechin or epicatechin, mangiferin or isomangiferin, procyanidin B, caffeoylquinic acids (CQA), caffeine, quercetin-3-O-glucoside, procyanidin C, rutin, and 3,4-diCQA. Coffea arabica L. leaf tea was confirmed to be a potential functional food rich in phenolic compounds with strong antioxidant activity.

Very late antigen-4 (VLA-4)-mediated monocyte adhesion and transendothelial migration are important events during immune surveillance and in the pathogenesis of inflammatory diseases, such as atherosclerosis. Under physiological conditions, circulating monocytes that are in various states of maturation enter tissue microenvironments and participate in immune responses by interacting with other leukocytes. The effects and regulatory mechanisms of eriodictyol on VLA-4 expression, cell adhesion, and migration in U937 cells were investigated. Eriodictyol lowered VLA-4 expression in a dose- and time-dependent manner in U937 cells. Moreover, VLA-4- and vascular adhesion molecular-1 (VCAM-1)-mediated adhesion and migration were decreased by eriodictyol. Upon treatment with eriodictyol, NF-κB translocated to the nucleus; the NF-κB inhibitor JSH-23 inhibited this translocation and prevented the decrease of VLA-4 expression by eriodictyol. Thus, eriodictyol regulates immune responses by modulating VLA-4 expression, cellular migration, and VLA-4-mediated adhesion in monocytes – evidence that eriodictyol regulates adhesion molecules during immune responses.

Background: The calamondin (Citrus microcarpa Bunge) and the kumquat (Fortunella crassifolia Swingle) are two small-size citrus fruits that have traditionally been consumed in Taiwan; however, there has been a lack of scientific research regarding the active compounds and functionalities of these fruits. Methods: Analysis of volatile composition of essential oil and phytosterol was carried out using Gas Chromatography–Mass Spectrometry (GC-MS). Flavonoid and limonoid were analyzed by High Performance Liquid Chromatography (HPLC). Moreover, antioxidant capacity from their essential oils and extracts were assessed in vitro. Results: The compositions of the essential oils of both fruits were identified, with the results showing that the calamondin and kumquat contain identified 43 and 44 volatile compounds, respectively. In addition, oxygenated compounds of volatiles accounted for 4.25% and 2.04%, respectively, consistent with the fact that oxygenated compounds are generally found in high content in citrus fruits. In terms of flavonoids, the calamondin exhibited higher content than the kumquat, with disomin-based flavonoids being predominant; on the other hand, phytosterol content of kumquat was higher than that of calamondin, with amyrin being the dominant phytosterol. Both of them contain high amounts of limonoids. The ethanol extracts and essential oils of small-sized citrus fruits have been shown to have antioxidant effects, with those effects being closely related to the flavonoid content of the fruit in question. Conclusions: The present study also reviewed antioxidant activity in terms of specific bioactive compounds in order to find the underlying biological activity of both fruits. The calamondin and kumquat have antioxidant effects, which are in turn very important for the prevention of chronic diseases.

This research aimed to develop an electrolysis method to generate high-concentration chlorine dioxide (ClO2) for tilapia fillet disinfection. The designed generator produced up to 3500 ppm of ClO2 at up to 99% purity. Tilapia fillets were soaked in a 400 ppm ClO2 solution for 5, 10, and 25 min. Results show that total plate counts of tilapia, respectively, decreased by 5.72 to 3.23, 2.10, and 1.09 log CFU/g. In addition, a 200 ppm ClO2 solution eliminated coliform bacteria and Escherichia coli in 5 min with shaking treatment. Furthermore, ClO2 and trihalomethanes (THMs) residuals on tilapia fillets were analyzed by GC/MS and were nondetectable (GC-MS detection limit was 0.12 ppb). The results conform to Taiwan’s environmental protection regulations and act governing food sanitation.

Transesterification of oils and lipids in supercritical methanol is commonly carried out in the absence of a catalyst. In this work, supercritical methanol, carbon dioxide, and acetic acid were used to produce biodiesel from soybean oil. Supercritical carbon dioxide was added to reduce the reaction temperature and increase the fats dissolved in the reaction medium. Acetic acid was added to reduce the glycerol byproduct and increase the hydrolysis of fatty acids. The Taguchi method was used to identify optimal conditions in the biodiesel production process. With an optimal reaction temperature of 280°C, a methanol-to-oil ratio of 60, and an acetic acid-to-oil ratio of 3, a 97.83% yield of fatty acid methyl esters (FAMEs) was observed after 90 min at a reaction pressure of 20 MPa. While the common approach to biodiesel production results in a glycerol byproduct of about 10% of the yield, the practices reported in this research can reduce the glycerol byproduct by 30.2% and thereby meet international standards requiring a FAME content of >96%.

As local varieties of citrus fruit in Taiwan, Ponkan (Citrus reticulata Blanco), Tankan (C. tankan Hayata), and Murcott (C. reticulate × C. sinensis) face substantial competition on the market. In this study, we used carbon dioxide supercritical technology to extract oleoresin from the peels of the three citrus varieties, adding alcohol as a solvent assistant to enhance the extraction rate. The supercritical fluid extraction was fractionated with lower terpene compounds in order to improve the oxygenated amounts of the volatile resins. The contents of oleoresin from the three varieties of citrus peels were then analyzed with GC/MS in order to identify 33 volatile compounds. In addition, the analysis results indicated that the non-volatile oleoresin extracted from the samples contains polymethoxyflavones (86.2~259.5 mg/g), limonoids (111.7~406.2 mg/g), and phytosterols (686.1~1316.4 μg/g). The DPPH (1,1-Diphenyl-2-picrylhydrazyl), ABTS [2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] scavenging and inhibition of lipid oxidation, which test the oleoresin from the three kinds of citrus, exhibited significant antioxidant capacity. The component polymethoxyflavones contributed the greatest share of the overall antioxidant capacity, while the limonoid and phytosterol components effectively coordinated with its effects.

Teas can be classified according to their degree of fermentation, which has been reported to affect both the bioactive components in the teas and their antioxidative activity. In this study, four kinds of commercial Taiwanese tea at different degrees of fermentation, which include green (non-fermented), oolong (semi-fermented), black (fully fermented), and Pu-erh (post-fermented) tea, were profiled for catechin levels by using high performance liquid chromatography (HPLC). The result indicated that the gallic acid content in tea was directly proportional to the degree of fermentation in which the lowest and highest gallic acid content were 1.67 and 21.98 mg/g from green and Pu-erh tea, respectively. The antioxidative mechanism of the gallic acid was further determined by in vitro and in silico analyses. In vitro assays included the use of phorbol ester-induced macrophage RAW264.7 cell model for determining the inhibition of reactive oxygen species (ROS) production, and PKCδ and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit (p47) activations. The results showed that only at a concentration of 5.00 μM could gallic acid significantly (p < 0.05) reduce ROS levels in phorbol ester-activated macrophages. Moreover, protein immunoblotting expressed similar results in which activations of PKCδ and p47 were only significantly (p < 0.05) attenuated by 5.00 μM treatment. Lastly, in silico experiments further revealed that gallic acid could block PKCδ activation by occupying the phorbol ester binding sites of the protein.

An incident of foodborne poisoning causing illness in 67 victims due to ingestion of fried fish fillets occurred in June 2011, in southern Taiwan. Of the five suspected fish fillets, one fried sample contained 62.0 mg/100 g and one raw sample contained 89.6 mg/100 g histamine, levels which are greater than the potential hazard action level (50 mg/100 g) in most illness cases. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fish samples, this foodborne poisoning was strongly suspected to be caused by histamine intoxication. Five histamine-producing bacterial strains capable of producing 59 to 562 ppm of histamine in Trypticase soy broth supplemented with 1.0% L-histidine were identified as Enterobacter aerogenes (two strains), Raoultella ornithinolytica (two strains), and Morganella morganii (one strain). The degradation loss of histamine in suspected raw fillets was 28% after they were fried at 170°C for 5 min. [ABSTRACT FROM AUTHOR]

Dectin-1, a specific pattern recognition receptor for β-1,3/β-1,6-glucans, is expressed mainly on phagocytes. Human dectin-1 (hDectin-1) and mouse dectin-1 (mDectin-1) were separately expressed on HEK293 cell surfaces for examination of the binding abilities of a synthetic particulate β-glucan (pβG), a product extracted from Saccharomyces cerevisiae, in this study. The binding of zymosan-FITC to hDectin-1 and mDectin-1 was inhibited by pβG at similar concentrations for 50% inhibition of binding (IC50). However, the kinetics of the time course and dose response to zymosan stimulation observed for U937 and J774A.1 differed. Superoxide anion production was increased in U937 but reduced in J774A.1 when cells were treated with pβG, zymosan, or laminarin, whereas ovalbumin endocytosis was enhanced in U937 and J774A.1 treated either with pβG, zymosan, laminarin, or barley-glucan. These results indicate that the binding affinity of pβG to hDectin-1 is similar to the binding affinity to mDectin-1, and that stimulation by pβG as well as various forms of β-1,3-glucans on U937 and J774A.1 resulted in upregulation of cell activity and ovalbumin endocytosis. Additionally, other coreceptors on U937 and J774A.1 may be involved in directing different responses to superoxide anion production in these two types of cells. These results will likely contribute to further investigations on identifying the biological forms of β-glucans capable of binding its specific receptor as the effective immunomodulators. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [ABSTRACT FROM AUTHOR]

The process of applying salt-stressed baker’s yeast during southern style Chinese steamed bread dough preparation was examined. Baker’s yeast was stressed in 7% salt solution then mixed into dough, which was then evaluated for dough fermentation producing gas, dough expansion, texture profile analysis (TPA), colour, specific volume, spread ratio and sensory analysis. The results of this study pointed out salt-stressed baker’s yeast produced significant amount of gas and dough expansion, particularly after 40 min of salt stressing. The texture of steamed bread was softer (463.08 g) than control (541.35 g) ( P < 0.05), greater in specific volume (3.15 cm3 g−1) than control (2.89 cm3 g−1) ( P < 0.05), had a lower spread ratio (1.45) than control (1.74) ( P < 0.05) and a significantly improved sensory properties for taste (90.6) than control (81.6) ( P < 0.05) were obtained. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor binding protein-3 (IGFBP-3) is expressed in many different cell types and has a regulatory function in the insulin-like growth factor (IGF) system. To further understand the molecular mechanism, we cloned and sequenced the 5′-promoter region of zebrafish Danio rerio IGFBP-3 and characterized its activity using firefly luciferase transient transfection expression assays. Different fragments of the zebrafish IGFBP-3 5′-flanking region were transfected into HeLa and ZFL cells. In these cell lines, maximum promoter activity was located within 1218 bp of the zebrafish IGFBP-3 flanking region in the HeLa cell line and within 304 bp of the zebrafish IGFBP-3 flanking region in the ZFL cell line. Several putative transcription factors were revealed in the zebrafish IGFBP-3 promoter region, such as organic cation transporter-1, GATA-1 and yin and yang-1. Further study of the in vivo expression of the IGFBP-3 promoter during development was carried out in transgenic zebrafish expressing an IGFBP-3 promoter-driven green fluorescent protein (GFP) encoding the GFP cDNA transgene. The GFP transcripts appeared for the first time in the 32-cell stage. These results indicate that the IGFBP-3 promoter is active in a development-specific manner and suggest that the IGFBP-3 promoter plays an important role in teleost embryo growth. Finally, IGFBP-3 has important IGF-independent effects on cell growth and may involve nuclear localization. By transiently transfecting HeLa cells with various zebrafish IGFBP-3 segments, we identified one nuclear localization signal (NLS): a basic amino acid rich sequence (PSKGRKR) between amino acids 256 and 262 was able to direct enhanced green fluorescence protein predominantly into the nucleus, whereas a deletion of this motif abrogated this nuclear localization property. These data suggest that zebrafish IGFBP-3 contains a NLS around the second NLS sequence, whereas the putative NLS at the first NLS is non-functional. [ABSTRACT FROM AUTHOR]

Interferon plays important roles in confronting viral infections as the first line of defense. For the purpose of understanding the molecular mechanism which controls transcription of the interferon gene, we cloned and sequenced the interferon promoter region of the zebrafish interferon gene and characterized its activity using firefly luciferase transient transfection expression assays. Different fragments of the zebrafish interferon 5'-flanking region were transfected into ZFL cells. In these cell lines, maximum promoter activity was located in 2.2 kb of the zebrafish interferon 5' flanking region of the ZFL cell line. In this study, we investigated whether the viral replicative intermediate double-stranded RNA (herein we used synthetic polyinosinic-polycytidylic acid [poly(I):poly(C)] modifies the effects of interferon on gene expression. For this purpose, all zebrafish interferon promoter fragments were treated with either 1, 10, or 100 µg/ml poly(I):poly(C). The results showed that after treatment with 10 µg/ml poly(I):poly(C), high promoter activity was observed in the –2.2-kb interferon promoter fragment. Several putative transcription factors were shown in the promoter region, including IRF-1, C/EBP, NFκB, and GATA-1. Further study of the in vivo expression of the interferon promoter during development was carried out in transgenic zebrafish expressing an interferon promoter-driven green fluorescent protein (GFP) encoding the GFP cDNA transgene. Morphological studies of transgenic zebrafish indicated that the interferon promoter-driven GFP transcripts appeared in the yolk, head, and lymphoid organs. These results indicate that the interferon promoter is active in a tissue-specific manner, and suggest that the interferon promoter plays an important role in virus resistance during teleost growth. [ABSTRACT FROM AUTHOR]

Grey relational analysis (GRA), an approach totally different from traditional statistical analysis used to calculate the relational grade between two sequence data, was applied to classify dried roselle (Hibiscus sabdariffa L.). In this study, 49 groups of roselle calyces representing five treatments – (1) frozen at −20C; (2) cold-air-dried at 25C, or (3) hot-air-dried at 50C; (4) 75C; or (5) 85C – were investigated. Five calyces from each group of treated roselle calyces were selected at random as reference samples and were built into the database. The rest of the treated roselle calyces were selected as test calyces to validate the feasibility of the developed Grey identification system. A GRA calculation procedure is demonstrated step-by-step and results are compared with the results of principal component analysis (PCA). PCA exhibited no distinguishable cluster pattern on the PCA plot of roselle calyces hot-air-dried at 50C or 75C. The GRA grades identified and classified all undried and dried roselle calyces correctly. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor binding protein 2 (IGFBP-2) plays an important role in the regulation of IGF's actionand endocrinology in fish. To understand the molecular mechanism which controls transcription of theIGFBP-2 gene, we cloned and sequenced the IGFBP-2 proximal promoter region of the zebrafish IGFBP-2gene and characterized its activity by firefly luciferase transient transfection expression assays. Different fragmentsof the zebrafish IGFBP-2 5′-flanking region were transfected into Hela and ZFL cells. In these celllines, maximum promoter activity was located in the 900 base pairs (bp) of the zebrafish IGFBP-2 5′ flankingregion in the ZFL cell line and 318 bp of the zebrafish IGFBP-2 5′ flanking region in the Hela cell line.Theactions of the IGFBP-2 promoter on developmental stage expression were further investigated intransgenic zebrafish in which an IGFBP-2 (900-bp) promoter-driven green fluorescent protein encoding theGFP cDNA transgene was microinjected into zebrafish embryos. Morphological and RT-PCR studies of transgeniczebrafish indicated that the IGFBP-2 promoter-driven GFP transcripts appeared for the first time inthe 32-cell stage. These results indicate that the IGFBP-2 promoter is active in a development-specific manner.These results suggest that the IGFBP-2 promoter plays an important role in teleost embryo growth. [ABSTRACT FROM AUTHOR]

Mulberry wine stored for 1, 3, and 12 months was used to investigate the relationship between wine color, copigmentation, polymerization of anthocyanins, and the antioxidant capacity of the wine. Color density, patterns of anthocyanins (monomeric, copigmented and polymeric) and antioxidant capacity were measured. The results show that copigmented and polymeric anthocyanins in mulberry wine increased from 0% and 16.63% to 20.93% and 30.44%, respectively, while monomeric anthocyanins decreased from 83.37% to 48.63%. The 1,1,Diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging ability increased after storage and was highly correlated with the polymeric anthocyanin content (r = 0.98). The ferric reducing ability of plasma (FRAP) reducing power decreased on storage. Sephadex G25 was used to separate the pigments into three different molecular sizes. The largest molecules were in Fraction I, which contained the polymerized anthocyanins and was associated with the DPPH scavenging activity. Fraction II, intermediate in size, contained the copigmented anthocyanins. Fraction III, the smallest in size, was composed of the monomeric anthocyanins and was associated with the FRAP activity. [ABSTRACT FROM AUTHOR]

Antioxidant testing of natural products has attracted increasing interest in recent years, mainly due to the fact that an antioxidant-rich diet might provide health benefits. Activated macrophages are a major source of reactive oxygen species, reactive nitrogen species, and peroxynitrite generated through the so-called respiratory burst. Constitutively released proinflammatory cytokine, especially tumor necrosis factor-α, triggers nuclear factor-κB, and activator protein-1 translocation leading to the over production of reactive oxygen species and reactive nitrogen species in macrophages. Activation of transcription factors in the long-lived tissue-resident macrophages and/or monocyte-derived macrophages, trigger epigenetic modifications leading to the pathogenesis of chronic diseases. Nutraceuticals including lipid raft structure disruption agent, cholesterol depletion agent, farnesyltransferase inhibitor, nuclear factor-κB blocker (α,β-unsaturated carbonyl compounds), glucocorticoid receptor agonist, and peroxisome proliferator-activated receptor-g agonist have long been used to inactive macrophage. The inhibition effects on the formation of nitric oxide, superoxide, and nitrite peroxide may be responsible for the anti-inflammatory functionalities. Activated macrophage models could be used to identify the active components for functional diets development through a multiple targets strategy. [ABSTRACT FROM AUTHOR]

An incident of food-borne poisoning causing illness in 37 victims due to ingestion of fried fish sticks occurred in September 2014, in Tainan city, southern Taiwan. Leftovers of the victims' fried fish sticks and 16 other raw fish stick samples from retail stores were collected and tested to determine the occurrence of histamine and histamine-forming bacteria. Two suspected fried fish samples contained 86.6 mg/100 g and 235.0 mg/100 g histamine; levels that are greater than the potential hazard action level (50 mg/100 g) in most illness cases. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fried fish samples, this food-borne poisoning was strongly suspected to be caused by histamine intoxication. Moreover, the fish species of suspected samples was identified as milkfish (Chanos chanos), using polymerase chain reaction direct sequence analysis. In addition, four of the 16 commercial raw milkfish stick samples (25%) had histamine levels greater than the US Food & Drug Administration guideline of 5.0 mg/ 100 g for scombroid fish and/or products. Ten histamine-producing bacterial strains, capable of producing 373e1261 ppm of histamine in trypticase soy broth supplemented with 1.0% L-histidine, were identified as Enterobacter aerogenes (4 strains), Enterobacter cloacae (1 strain), Morganella morganii (2 strains), Serratia marcescens (1 strain), Hafnia alvei (1 strain), and Raoultella orithinolytica (1 strain), by 16S ribosomal DNA sequencing with polymerase chain reaction amplification. [ABSTRACT FROM AUTHOR]

Bacillus polymyxa D05-1, isolated from salted fish product and possessing amine degrading activity, was used as a starter culture in salted fish fermentation in this study. Fermentation was held at 35C for 120 days. The water activity in control samples (without starter culture) and inoculated samples (inoculated with B. polymyxa D05-1) remained constant throughout fermentation, whereas the pH value rose slightly during fermentation. Salt contents in both samples were constant in the range of 17.5e17.8% during the first 60 days of fermentation and thereafter increased slowly. The inoculated samples had considerably lower levels of total volatile basic nitrogen (p < 0.05) than control samples at each sampling time during 120 days of fermentation. Aerobic bacterial counts in inoculated samples were retarded during the first 60 days of fermentation and thereafter increased slowly, whereas those of control samples increased rapidly with increased fermentation time. However, the aerobic bacterial counts of control samples were significantly higher (p < 0.05) than those of inoculated samples after 40 days of fermentation. In general, overall biogenic amine contents (including histamine, putrescine, cadaverine, and tyramine) in the control samples were markedly higher (p < 0.05) than those of the inoculated samples throughout fermentation. After 120 days of fermentation, the histamine and overall biogenic amine contents in the inoculated samples were reduced by 34.0% and 30.0%, respectively, compared to control samples. These results emphasize that the application of starter culture with amines degrading activity in salted fish products was effective in reducing biogenic amine accumulation. [ABSTRACT FROM AUTHOR]

Histamine is the causative agent of scombroid poisoning, a foodborne chemical hazard. Histamine is degraded by the oxidative deamination activity of certain microorganisms. In this study, eight histamine-degrading bacteria isolated from salted fish products were identified as Rummeliibacillus stabekisii (1 isolate), Agrobacterium tumefaciens (1 isolate), Bacillus cereus (2 isolates), Bacillus polymyxa (1 isolate), Bacillus licheniformis (1 isolate), Bacillus amyloliquefaciens (1 isolate), and Bacillus subtilis (1 isolate). Among them, B. polymyxa exhibited the highest activity in degrading histamine than the other isolates. The ranges of temperature, pH, and salt concentration for growth and histamine degradation of B. poly- myxa were 25-37°C, pH 5-9, and 0.5-5% NaCl, respectively. B. polymyxa exhibited optimal growth and histamine-degrading activity at 30°C, pH 7, and 0.5% NaCl in histamine broth for 24 hours of incubation. The histamine-degrading isolate, B. polymyxa, might be used as a starter culture in inhibiting histamine accumulation during salted fish product fermentation. [ABSTRACT FROM AUTHOR]