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1.
The influences of lactic acid bacteria (LAB) on biogenic amines formation by foodborne pathogens (FBP) were investigated. Biogenic amines production by single and mix cultures was tested in histidine decarboxylase broth. All of the mix cultures (LAB with FBP) inhibited significantly (P < 0.05) the ammonia accumulation except for Escherichia coli with Lactococcus lactic subsp. lactic and Lactobacillus plantarum. Although LAB with most of the pathogen showed considerably stimulation effects on putrescine, cadaverine, spermine, 2‐phenylethylamine, histamine (HIS), tyramine, trimethylamine, dopamine and agmatine (AGM), some of the LAB with pathogens showed poor inhibition effect on different amines formation. HIS production by Klebiella pneumonia was 0.16 mg L?1, whereas HIS value in presence of Lb. plantarum increased to 30.92 mg L?1. Consequently, LAB inhibition of the ammonium production by FBP is favourable, while the stimulation effects of LAB on biogenic amines formation by FBPs are not desirable for food industry.  相似文献   

2.
The aim of this study was to investigate the production of biogenic amines (BA), histamine and tyramine by some probiotic lactic acid bacteria (LAB). Fifteen strains representing six LAB species were screened qualitatively by growing them in a decarboxylase medium. Quantitative analysis was carried out by HPLC analysis with direct derivatization of acid extracts. Lactobacillus casei (TISTR 389) and Lactobacillus delbrueckii subsp. bulgaricus (TISTR 895) were found to produce BA. The highest levels of histamine (1820.9 ± 3.5 mg L?1) and tyramine (5486.99 ± 47.6 mg L?1) formation were observed for the TISTR 389 strain, while TISTR 895 produced only histamine (459.1 ± 0.63 mg L?1) in the decarboxylase broth. Biogenic amine potential was not observed for the Lactobacillus acidophilus, Lactobacillus lactis subsp. lactis, Lactococcus lactis subsp. lactis, and Lactobacillus plantarum strains studied. This study confirmed that BA formation is strain dependent and not related to the species. Therefore, careful screening for amino acid decarboxylase activity is recommended before selecting LAB as appropriate starter or probiotic strains in food and dairy industry.  相似文献   

3.
Natural antimicrobials and antioxidants from rosemary (Rosmarinus officinalis) and sage tea (Salvia officinalis) were produced using solvent extraction method. The effect of two extracts on ammonia (AMN) and biogenic amines (BAs) formation in vacuum packed sardine (Sardina pilchardus) fillets stored at 3 ± 1 °C was investigated for 20 days. Although the effect of extracts was dependent on specific amine and storage time, phenolic compounds from rosemary and sage tea generally resulted in lower AMN and BAs accumulation in sardine muscle. Putrescine (PUT) and cadaverine (CAD) were the most abundant amines, while histamine (HIS) concentration ranged from 2.05 to 28.77 mg 100g?1. Rosemary and sage tea extracts significantly reduced HIS, PUT, CAD and trimethylamine accumulation in the fish muscle (P < 0.05) while stimulating effect of extracts was observed on serotonin and agmatine formation. At the end of the storage period, PUT and CAD contents of control were 100‐fold higher than those of treated groups.  相似文献   

4.
The ability of typical probiotic culture of Bifidobacterium to produce biogenic amines could be considered a contrastive feature to the beneficial dietary effect on human health. The aim of this pilot study was to evaluate the decarboxylase activity of Bifidobacterium animalis subsp. lactis CCDM 239 influenced by selected factors (pH 4.5 and 5.0; the contents of NaCl 0–20.0 g L?1, glucose and lactose 0–10.0 g L?1) at in vitro conditions. The kinetics of the biogenic amine production under the above‐mentioned conditions was also monitored. The biogenic amine content detection was carried out in the supernatants of inoculated broth [MRS enriched with amino acids: arginine, ornithine, lysine, tyrosine; 3 g L?1 after the cultivation (48 h, 37 ± 1 °C)]. RP‐HPLC after the precolumn derivatisation with dansyl chloride was used. In most cases, the low concentrations of tyramine were monitored (<15 mg L?1). Simultaneously, it was found out that the addition of certain fermentable saccharide concentrations and NaCl in their mutual combination seemed to have supporting effect on the decarboxylase activity of the tested Bifidobacterium.  相似文献   

5.
This study examined the effect of co‐inoculation of yeast and lactic acid bacteria (LAB) on the chemical and sensory characteristics of cherry wines, in comparison with a traditional sequential culture. Three LABs were investigated, including two O. oeni (SG26 and Viniflora) and one L. plantarum (PL18). All co‐inoculations significantly shortened the fermentation time (average 8 days earlier) to reach a stable level of residual sugar (<2 g L?1) and L‐malic acid (<0.5 g L?1), and no inhibitory effect on the yeast proliferation was observed. For volatiles determined, co‐culture with SG26 produced the greatest amount of volatile components (138.5 mg L?1), whereas sequential inoculation with PL18 had the lowest level (119.6 mg L?1). PCA result revealed that different LABs had diverse influences on the volatile profile of cherry wines, and sensory analysis confirmed that these samples presented distinct sensory profiles, and particularly, a stronger note of fruity was perceived when co‐culture was used.  相似文献   

6.
The aim was to monitor production of eight biogenic amines (BAs) (histamine, tyramine (TYR), tryptamine, putrescine, cadaverine (CAD), phenylethylamine, spermine and spermidine) by selected 81 lactic acid bacteria (LAB) strains: Lactobacillus, Lactococcus, Leuconostoc, Enterococcus, Pediococcus, Tetragenococcus and Bifidobacterium. The tested LAB and bifidobacteria were isolated from dairy products and beer. The decarboxylase activity of the micro‐organisms was studied in growth medium after cultivation. The activity was monitored by HPLC after the pre‐column derivatisation with dansylchloride. Fifty LAB showed decarboxylase activity. Thirty‐one strains produced low concentrations of CAD (≤10 mg L?1). Almost 70% of beer isolates generated higher amounts of TYR (≤3000 mg L?1). Most of the tested LAB demonstrated decarboxylase activity. The above micro‐organisms can contribute to the increase of content of BAs in dairy products or beer and thereby threaten food safety and health of consumers. Production of BAs even by the representatives of some probiotic strains (Bifidobacterium and Lactobacillus rhamnosus) was detected in this research. This study has also proved that contaminating LAB can act as sources of higher amounts of CAD and TYR in beer.  相似文献   

7.
Alcohol acetyltransferase (AATase), which is mainly encoded by ATF1, is one of the most important enzymes for acetate ester synthesis. On the other hand, isoamyl acetate is degraded into a higher alcohol under the catalysis of IAH1‐encoded esterase. In this study, Chinese Saccharomyces cerevisiae was used as the parent strain to construct an ATF1 overexpression and IAH1 disruption mutant. The results show that after 5 days of pre‐fermentation, the concentrations of ethyl acetate, isoamyl acetate and isobutyl acetate in the yellow rice wines fermented with EY1 (pUC‐PIAK) increased to 468.94 mg L?1 (which is approximately 22‐fold higher than that of the parent cell RY1), 99.86 and 7.69 mg L?1 respectively. Meanwhile, isoamyl alcohol production was reduced to 56.37 mg L?1 (which is approximately 50% of that produced by the parent strain RY1). Therefore, ATF1 overexpression and IAH1 disruption can significantly increase acetate esters contents and reduce isoamyl alcohol content in Chinese yellow rice wine, thereby paving the way for breeding an excellent yeast strain for high‐quality Chinese yellow rice wine production.  相似文献   

8.
The aim of this study was to evaluate the bioconversion efficiency of rich in cellulose agro‐industrial by‐products such as wheat bran (WB), spent distiller's grain with solids (DGS), brewer's spent grain (BSG) and lupin (Lupinus angustifolius L.) wholemeal fraction (LF) to lactic acid (LA) using acid tolerant lactic acid bacteria (LAB) strains Lactobacillus sakei KTU05‐06, Pediococcus acidilactici KTU05‐7 and P. pentosaceus KTU05‐9. Carbohydrase preparation Depol? 692L was used for the hydrolysis of non‐starch polysaccharides. Analysed raw materials were suitable substrates for LAB propagation and L‐lactic acid production. The lowest pH (3.6) was found in LF medium after 48 h fermentation with P. acidilactici and P. pentosaceus strains. The lowest pH (3.86) was measured in WB fermented with L. sakei, and in DGS and BSG (pH 3.8 and 3.9 respectively) fermented with P. acidilactici. The highest endoxylanase activity was excreted by the P. acidilactici and P. pentosaceus (84 and 69 XU g?1 respectively), and the highest α‐amylase activity was of L. sakei (255.6 AU g?1) after 24 h incubation in WB medium. The L‐lactic acid concentration of 86.11 g kg?1 was reached after the bioconversion of hydrolysed WB in combination with 48 h fermentation by P. pentosaceus KTU05‐9 strain. LA contents between 222 and 282 mg kg?1 was produced from lupin processing residues via fermentation using P. acidilactici and P. pentosaceus KTU05‐9 strains. The major challenge within the presented study is the viability of tested LAB in cereal waste media and effective LA production at a low pH (3.63.8).  相似文献   

9.
The effect of lactic acid bacteria (LAB) strains on tyramine (TYR) and also other biogenic amines (BA) production by eight common food-borne pathogen (FBP) in tyrosine decarboxylase broth (TDB) was investigated by using a rapid HPLC method. Significant differences were observed among the FBP strains in ammonia (AMN) and BA production apart from tryptamine, histamine (HIS) and spermine formation (p < 0.05). Salmonella paratyphi A was characterised as the main amine producer. LAB had an important synergetic role in some BA production by food-borne pathogenic bacteria, although the effect of some LAB strains on BA production was strain-dependent. Lactococcus spp. and Streptococcus spp. resulted in significantly higher TYR accumulation by Aeromonas hydrophila and Enterococcus faecalis in TDB. The presence of Lactococcus and/or Lactobacillus in TDB significantly increased HIS production by A. hydrophila, Escherichia coli, Ent. faecalis, Klebsiella pneumoniae and Pseudomonas aeruginosa, whereas HIS accumulation was significantly reduced by Staphylococcus aureus, S. paratyphi A and Listeria monocytogenes.  相似文献   

10.
This study was carried out to examine the proteolytic and angiotensin‐converting enzyme (ACE‐I) activities of probiotic lactic acid bacteria (LAB) as influenced by the type of media, fermentation time, strain type and media supplementation with a proteolytic enzyme (Flavourzyme®). Lactobacillus casei (Lc210), Bifidobacterium animalis ssp12 (Bb12), Lactobacillus delbrueckii subsp. bulgaricus (Lb11842) and Lactobacillus acidophilus (La2410) were grown in 12% of reconstituted skim milk (RSM) or 4% of whey protein concentrates (WPC‐35) with or without combination (0.14%) of Flavourzyme® for 12 h at 37 °C. All the strains were able to grow in both media depending on type of strains used and fermentation time. All the strains showed higher proteolytic activity and produced more antihypersensitive peptides when grown in RSM medium at 12 h, when compared to WPC. Combination with Flavourzyme® also increased LAB growth and proteolytic and ACE‐I activities. Of the four strains used, Bb12 and La2410 outperformed Lc210 and Lb11842. The highest ACE‐I activity and proteolytic activity were found in B. animalis ssp12 combined with Flavourzyme®. Flavourzyme® led to an increase in the production of bioactive peptides with ACE‐I activity during 12 h at 37 °C.  相似文献   

11.
Gluten‐free (GF) sourdough was prepared from wheat sourdough and analysed both in fresh (GFS) and dried forms (DGFS). The gluten content in each GF sourdough sample was <20 mg kg?1. The dough leavening capacity and the properties of the bread samples were investigated and compared to those of bread prepared using bakery yeast (Saccharomyces cerevisiae). Two commercial rice‐based mixtures (different for the presence/absence of buckwheat flour) were used to prepare bread samples. In GFS, lactic acid bacteria (LAB) and yeasts were found in amounts corresponding to 108 and 107 CFU g?1, respectively, whereas both LAB and yeasts were detected in lower amounts (about 106 CFU g?1) in DGFS. When used in bread‐making, both GFS types produced significant dough acidification and exhibited good dough development during proofing, resulting in loaves with specific volume values between 3.00 and 4.12 mL g?1, values similar to those obtained for reference bread (3.05÷4.15 mL g?1). The use of GFS was effective in lowering the bread staling rate during storage for up to 7 days.  相似文献   

12.
The development of free fatty acids (FFA) and volatile flavour compounds in the Turkish white‐brined cheese Beyaz peynir made by using three wild strains of Lactococcus lactis subsp. lactis was investigated over 90 days. Results showed that production of both FFA and flavour compounds in the control (PK1) and experimental cheeses (MBLL9, MBLL23 and MBL27) was strain dependent. The hydrolysis of milk fat was more evident in the cheese made using Lc. lactis subsp. lactis MBL27. Considering the production of fat breakdown compounds and acidification activities of the strains MBLL23 and MBL27, the combination of these strains could be proposed for the production of white‐brined cheese.  相似文献   

13.
The aim of this study was to enhance β‐galactosidase production by Kluyveromyces lactis CICC1773. Firstly, the optimum culture conditions were obtained by response surface methodology, and the maximum β‐galactosidase activity reached 20.6 U mL?1, about two‐fold increase than that of the initial conditions (initial fermentation medium and conditions). To further improve β‐galactosidase production, a new fed‐batch strategy based on pH feedback control was developed successfully in a 7‐L fermenter, using 400 g L?1 lactose as feeding medium. As a result, the β‐galactosidase activity and productivity reached up to 111.61 U mL?1 and 5.31 U/(mL·h), enhanced by 15.3‐fold and 17.6‐fold superior than the results of initial conditions, respectively. To our knowledge, β‐galactosidase activity obtained was the highest value among the results reported by nonrecombinant strains. These results demonstrated that the new fed‐batch strategy based on optimum culture conditions could be automatic control easily and be conductive to further scale up for industrial fermentation.  相似文献   

14.
BACKGROUND: Yan‐jiang (fermented ginger) is a popular traditional fermented food in Taiwan. The lactic acid bacteria (LAB) microflora in yan‐jiang has not been studied in detail. In this study, LAB from yan‐jiang were isolated, characterised and identified. RESULTS: A total of 176 LAB were isolated; 160 cultures were isolated from yan‐jiang samples and 16 cultures were isolated from raw ginger. These isolates were characterised phenotypically and then divided into nine groups (A to I) by restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Lactobacillus sakei and Lactococcus lactis subsp. lactis were the major LAB found in the initial 2 days of fermentation without pickled plums; these species were mostly replaced by Weissella cibaria and L. plantarum after 3 days of fermentation. In the fermentation bucket with added pickled plums, W. cibaria was the most abundant LAB found during fermentation. The antibacterial activities of the isolates were determined. Twenty‐four Lc. lactis subsp. lactis and 19 W. cibaria strains showed inhibitory activity against the indicator strain L. sakei JCM 1157T. CONCLUSION: Results demonstrate that various LAB species were more numerous when fermentation was carried out without pickled plums. LAB also had effects on the aroma and flavour of yan‐jiang. Copyright © 2011 Society of Chemical Industry  相似文献   

15.
This study compared the efficacy of Lactobacillus casei strain Shirota (LAB13) and a probiotic cocktail for their anti‐obesity and other lipid profile modulating effects. Diet‐induced obese rats were supplemented with two different probiotics which are LAB13 (1 × 109 CFU day?1 per rat) and cocktail of five bacterial strains (1 × 109 CFU day?1 per rat) for 12 weeks. Comparative data on weight gain, energy intake, liver weight, subcutaneous fat, total fat weights, total cholesterol and leptin levels in both treatment groups showed significant reduction in probiotic‐treated groups compared to the obese control group. Both probiotics have the anti‐obesity and hypocholesterolaemic effects and are able to reduce body weight and fats via reduction in energy intake. Only LAB13 was able to reduce the level of triglyceride significantly. Therefore, the LAB13 is equally effective compared to the probiotic cocktail in weight reduction. LAB13 is more effective in improving lipid profile which is a common medical complication of obesity.  相似文献   

16.
Citreoviridin (CIT), one of the mycotoxins produced by Penicillium citreoviridin (PCV), is a common contaminant in a wide range of agricultural products and is detrimental to human and animal health. There is potential threat that terrorists can extract CIT from mouldy cereals, such as rice which forms the major source of starch intake in Asia–Pacific diets and corns which are readily available. The objective of this study was to develop a rapid method for detection of citreoviridin and evaluate its performance on luminescent bacterium Vibrio qinghaiensis sp.‐Q67 (Q67). A good correlation (R2 > 0.98) between concentrations of CIT and the relative luminosity unit of Q67 was obtained with a linear range from 0.0005 to 0.01 mg L?1. The precision expressed as relative standard deviation (RSD) was 3.2% for eleven replicate determinations of 0.005 mg L?1 CIT, and the recoveries of spiked samples were 88%–93%. The luminescence inhibition ratio of CIT increased from 0.0005 to 0.5 mg L?1, and the luminescence inhibition ratio remained stable at approximately 85% in the range of 0.5–10 mg L?1. The system detected low traces (≤0.0005 mg L?1) of CIT, and it has potential to be used as rapid detection method for mycotoxins. The effect of pure CIT on Q67 was time dependent and, it was the strongest (EC50 = 0.0066) at 20 min which indicated the high effect of CIT on Q67. Results obtained in this study suggest that Q67 is a promising method for rapid evaluation of the toxicity of CIT. Therefore, the luminescent bacteria assay can potentially be used as a system in monitoring sudden pollution in drinking water.  相似文献   

17.
The present research focused on the biogenic amines (BAs) formation in skipjack tuna (Katsuwonus pelamis) throughout the whole canning process. In agreement with its wide employment on this species, on‐board brine immersion freezing (BIF) was tested as post‐mortem processing. The study included fish samples corresponding to different stages of the canning process such as frozen, thawed, cooked and canned; after cooking, two kinds of tuna muscles were considered, that is, whole fillets (main product) and grated muscle (off‐product arising from small pieces). For the BAs (tryptamine, putrescine, cadaverine, histamine, spermidine and spermine) assessment, an HPLC‐DAD method was developed and validated in skipjack tuna samples, in agreement with different parameters such as suitability, linearity, limits of detection and quantification, precision, accuracy and robustness. Tuna submitted on‐board to BIF procedure provided low levels of spermine and spermidine (up to 27.6 mg kg?1), while contents on the remaining BAs maintained below the limit of detection. Throughout the different stages of the canning process, skipjack tuna showed a low formation of most BAs; interestingly, histamine content was found below 10.6 mg kg?1 level. The highest values were obtained for spermidine, these related to cooked grated tuna (from 22.6 to 66.7 mg kg?1) and canned grated tuna (from 70.6 to 104.4 mg kg?1). Values for pH assessment in all kinds of tuna samples corroborated the results obtained for BAs determination. BIF procedure proved to be an amenable post‐mortem processing to guarantee the quality of canned skipjack tuna.  相似文献   

18.
BACKGROUND: Plum has a very short storage life. The role of pre‐ or post‐harvest applications of putrescine (PUT) and low temperature storage on fruit ripening and quality was investigated in plum fruit (Prunus salicina Lindl. cv. Angelino). RESULTS: Pre‐ or post‐harvest PUT treatments [(0.1, 1.0 or 2.0 mmol L?1) + 0.01% Tween‐20 as a surfactant] delayed and suppressed the climacteric ethylene production and respiration rate irrespective of the method used to apply PUT. PUT‐treated fruit following low temperature storage (0 ± 1 °C; 90 ± 5% RH), at the ripe stage exhibited higher fruit firmness and titratable acidity (TA), while soluble solids content (SSC), levels of ascorbic acid, total carotenoids and total antioxidants were lower than in untreated fruit. Fruit both sprayed with PUT and stored in low temperature for 6 weeks, at the ripe stage showed reduced respiration rate, delayed changes in the SSC:TA ratio and levels of total carotenoids compared to post‐harvest PUT application. CONCLUSION: Pre‐harvest application of 2.0 mmol L?1 PUT 1 week before the anticipated commercial harvest was more effective in delaying plum fruit ripening and can be used to extend the storage (0 ± 1 °C) life of plums for up to 6 weeks with minimum losses in fruit quality. Copyright © 2008 Society of Chemical Industry  相似文献   

19.
Wine is a fermented beverage that could be affected by high concentrations of biogenic amines, thus altering organoleptic and health properties. In this work, the capacity of different selected yeast strains regarding to affect the content of tyramine, histamine, 2-phenylethylamine, tryptamine and their precursor amino acids (pAA) during fermentation has been described. Overall, biogenic amines (BAs) and pAA contents appeared significantly related both to the strain and to the nutrient supplementation applied. Among BAs, without and (with) nitrogen source addition, the concentrations covered a range between 0.1 and 9.5 (0.1–10.3) mg L−1 for tyramine; 0.1 and 4.4 (0.1–4.6) mg L−1 for histamine; 0.4 and 1.1 (0.4–1.4) mg L−1 for 2-phenylethylamine; and 0.02 and 0.14 (0.01–0.12) mg L−1 for tryptamine, respectively. Considering that also wine yeast species are responsible for BAs formation, the evidence from fermentation trials underlined the relevance of a careful choice of ADY strains and nitrogen sources in the management of alcoholic fermentation in wine.  相似文献   

20.
The potential of various concentrations of 24‐epibrassinolide (EBR) treatments on the control of grey mould in artificial Botrytis cinerea inoculation test and on the maintenance of postharvest quality of table grapes without inoculation in cold storage were researched. In the cold storage, clusters of grapes with exogenous EBR application (EBR1, 0.1 mg L?1 EBR; EBR2, 0.4 mg L?1 EBR; EBR3, 0.8 mg L?1 EBR) were stored at 0 ± 1 °C. Fruits’ quality attributes including berry firmness, weight loss, berry drop, decay berry percentages, total sugar and titratable acidity were measured at 15, 30 and 60 days. The results showed that EBR treatments exhibited a higher berry firmness and a lower percentage of weight loss, berry drop and decay berry. In the artificial inoculation trial, single berries were immersed in EBR1, EBR2 and EBR3, then inoculated by spraying with a B. cinerea spore suspension and stored at 25 ± 2 °C and 95% relative humidity. Disease severity (DS), lipid peroxidation and defence‐related enzymes of these berries were analysed every 2 days. EBR‐treated berries resulted in an increase in activities of defence‐related enzymes including superoxide dismutase, peroxidase, catalase and phenylalanine ammonia‐lyase compared with control berries inoculated by B. cinerea. Simultaneously, significant decreases in DS and production of superoxide anion radical and malondialdehyde were observed. These results suggested that exogenous application of EBR could play a protective role in controlling the grey mould of postharvest grapes and maintaining the postharvest quality during cold storage.  相似文献   

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