Changes of free amino acids and biogenic amines during extended ageing of Italian dry-cured ham

Sixty-two fresh hams were sub-grouped to undergo different processing times (15, 19 and 23 months), and corresponding dry-cured hams were analysed for changes in moisture, protein, NaCl, pH, proteolysis, free amino acids (FAAs) and biogenic amines (BAs) as related to the extended ageing. Dry-cured hams were influenced by ageing time, showing a decrease in moisture and water activity and an increase in pH, nonprotein nitrogen (NPN) and FAAs in more aged samples. The increase in FAAs and BAs progressively observed until the last sampling time might be enhanced by the moderate salt content (≈5 g NaCl/100 g muscle) and relatively high a_w (>0.90) of dried hams even at 23 months of processing. Among FAAs, arginine did not increase with ageing, which might be due to arginine hydrolysis to ammonia and ornithine, followed by decarboxylation to putrescine, i.e. molecules largely present in the more aged hams. Tyramine, the most abundant among BAs, putrescine and cadaverine showed a dependence on time and proteolysis indices (NPN and FAAs). In this respect, the practice of extending the standard ageing time of typical italian dry-cured ham (13-15 months), regarded as a tool for improving sensory property of this product, should be supported by further studies, mainly at the manufacturing level, to minimize FAA and BA generation.     

Effect of intensity of smoking treatment on the free amino acids and biogenic amines occurrence in dry cured ham

The aim of this study was to investigate the effect of the intensity of smoking treatment on the evolution of free amino acids (FAAs) of dry cured ham during processing. The correlation between FAAs and biogenic amines (BAs) content was also investigated as well as its effect on the perception of some sensory characteristics of ripened hams.     

Presence of biogenic amines in a traditional salted Italian cheese

Asino cheese is a traditional Italian cheese ripened in a special dilute brine (salmuerie), mixed with whey, milk and milk cream. The aim of this work was to ascertain whether this processing technology can influence amine production. The study demonstrated that biogenic amine content increased gradually in the Asino cheese during the soaking phase in brine. Moreover, the biogenic amine content of the salmuerie was very high and the salmuerie and the Asino cheese had a similar relative profile in amine content. These results suggested that the biogenic amines migrate from the brine into the cheese as a result of the concentration differential existing between the two systems.     

Evolution of amino acids and biogenic amines throughout storage in sausages made of horse,beef and turkey meats

The changes in concentration of free amino acids and biogenic amines, along 28 d of storage at 4 °C, were monitored in a wide range of European ripened sausages manufactured from horse, beef and turkey meats. Generally speaking, both chemical families became more concentrated with elapsing time – but rather distinct patterns were followed in each meat type: total free amino acids increased by 13-fold in the case of horse sausages, and 5-fold in the case of beef sausages, but decreased to one third in the case of turkey sausages; and total biogenic amines attained 730 mg/kg in turkey sausages, 500 mg/kg in beef sausages and 130 mg/kg in horse sausages by 28 d of refrigerated storage. For putrescine, maximum levels of 285 mg/kg were attained in turkey and 278 mg/kg in beef sausages; for cadaverine, maximum levels of 6 mg/kg in turkey and 9 mg/kg in beef; and for histamine, maximum levels of 263 mg/kg in turkey and 26 mg/kg in beef. Hence, public safety concerns may be raised in the case of turkey sausages.     

Free amino acids and biogenic amines in Alicante Monastrell wines

The simultaneous determination of 17 free amino acids and 8 biogenic amines in Alicante Monastrell wines was investigated for the first time. The quantification was carried out by using a RP-HPLC method, based on a pre-column derivatization with o-phthaldialdehyde (OPA) and fluorescence detection. From the results obtained it may be concluded that the most abundant free amino acids were Glu, Arg, Ala Asp, and Lys. None of the wine samples analysed had histamine (HIM) or Tyramine (TYM) levels above the limits considered as a possible toxic risk for healthy individuals. No measurable amounts of cadaverine (CAD) or methylamine (MEA) were found, showing no spoilage symptoms of sensory properties of the wines. Tryptamine (TRM) content was significantly higher in aged wines compared to young wines. However ethanolamine (ETA) content was lower. These data were used to make a preliminary classification of the samples using cluster analysis.     

Effect of grape storage time on biogenic amines content in must

The presence of amines in wine can produce a negative impact on the aroma of the product and, in some cases, detrimental health effects. Several factors affect the content of amines in wine, among those, the presence of biogenic amines in must.     

龙眼干白葡萄酒发酵过程中生物胺和氨基酸含量的变化

本研究利用高效液相色谱技术分析了龙眼干白葡萄酒酒精发酵和苹乳发酵过程中8种生物胺和22种氨基酸含量的变化。结果表明,在酒精发酵过程中8种生物胺含量均很低,而在苹乳发酵过程中迅速增加。发酵结束时干白葡萄酒中亚精胺和乙醇胺含量最高,其次为组胺和羟色胺。这4种生物胺的前体氨基酸在苹乳发酵阶段含量没有明显变化,而其它大部分氨基酸在酒精发酵过程中含量下降,在苹乳发酵过程中含量呈现不同程度升高。因此,我们认为：葡萄酒发酵过程中氨基酸含量变化与其对应生物胺的变化之间没有相关性,葡萄酒中生物胺的组成比例可能主要取决于乳酸菌中氨基酸脱羧酶的种类和活性。     

Changes of yolk biogenic amine concentrations during storage of shell hen eggs

The RP-HPLC/UV method, using dabsyl derivatization, optimised for the determination of biogenic amines in egg yolk, was appropriate for quantification of putrescine, cadaverine, histamine, ethylamine, propylamine, ethanolamine, tyramine, tryptamine, spermine, spermidine, phenylethylamine. Detection limits ranged between 0.05 and 0.06 mg of biogenic amine/kg of egg yolk. Two experiments using, respectively, farm and avian eggs were conducted to evaluate yolk biogenic amine concentrations of fresh and stored eggs, and to explain the effect of temperature and time of storage in the levels of biogenic amines during egg shelf-life. Only five of the 11 biogenic amines under study were detected: putrescine, cadaverine, propylamine, ethylamine and ethanolamine. Storage time during shelf-life presented a significant effect on the levels of the five amines (p < 0.01). On the contrary, storage temperature did not presented a significant effect on the levels of the mentioned amines, p > 0.01. The significant reduction of biogenic amine concentration during the shelf-life justified the application of a multiple linear regression using stepwise method to estimate the storage time. The regression equation was applied with success to confirm the storage time of farm eggs and avian eggs that were stored at two different temperatures.     

Prevalence of biogenic amines during ripening of a traditional dry fermented pork sausage and its relation to the amount of sodium chloride added

The presence of biogenic amines (BA) along the processing stages and storage period of "Painho de Portalegre" and its relationship with the NaCl concentration on their levels were evaluated. Total BA concentration of current "Painho de Portalegre" dry fermented sausage increased (P<0.001) with drying/smoking processing time, attaining 655mgkg(-1) dry matter (DM) at day 6, a level about six times higher than that obtained in seasoned raw material mixtures before casing stuffing (115mgkg(-1)DM). Between day 30 and 40 in the drying/smoking house, that amount increased 20-fold (2500mgkg(-1) DM) over the initial concentration. After one month of storage under vacuum at room temperature, the concentration decreased by almost half to 1561mgkg(-1)DM. Excluding tyramine, the other BA were already present in the minced raw materials. However the sum of cadaverine, putrescine, histamine and tyramine, was well below 5mgkg(-1) proposed as BA limit for meat of high hygienic quality. Cadaverine was the most concentrated BA at the last stage of the drying/smoking (1430-1254mgkg(-1)DM, after 30 and 40 days, respectively), almost double the concentration of putrescine (882-779mgkg(-1)DM), followed by tyramine, β-phenylethylamine and spermine (376-311, 24 and 27-23mgkg(-1)DM, respectively). Variation was detected among production batches, possibly due to poor control of the processing conditions in traditional manufactures and the effects of the prevailing weather conditions. A higher salt concentration in the final product, 6% compared to 3%, led to a significant reduction in the BA level (P<0.001). This difference was particularly relevant in the early stage of the drying/smoking phase, during which the greatest microbial development mainly occurred in relation to cadaverine, β-phenylethylamine, putrescine and tyramine levels.     

Effect of processing on proteolysis and biogenic amines formation in a Portuguese traditional dry-fermented ripened sausage “Chouriço Grosso de Estremoz e Borba PGI”

The influence of alternative drying environmental conditions on the proteolysis of a traditional Portuguese fermented sausage was evaluated, in relation to different ripening periods. Traditional sausages (batch T) had lower pH than counterparts (batch M), with differences (P < 0.05) focused at the fermentation stage. A remarkable accumulation of free amino acids (FAA) was detected in both batches along the ripening process, with batch T having higher mean levels than batch M (1795.2 mg 100 g⁻¹ DM vs. 1742 mg 100 g⁻¹ DM in S7, respectively), but with differences being significant for long ripened products. In both batches, glutamic acid became the most concentrated FAA in end products currently consumed (101.6 mg 100 g⁻¹ DM and 111.0 mg 100 g⁻¹ DM – S6; 233.8 mg 100 g⁻¹ DM and 220.9 mg 100 g⁻¹ DM – S7 from batches T and M, respectively) followed by leucine > alanine > taurine > serine > valine and taurine > alanine > leucine > serine > valine sequences in the former product from batches T and M, respectively, and, coincidently, the same sequence for both batches in the later (serine > leucine > alanine > proline > valine). Such effect on FAA concentrations led to a distinct (P < 0.05) expression of sweet, bitter, acidic and aged sensorial attributes between batches, in S8 and S9 products.BA typical quantitative sequences varied between batches according to the ripening stage, with differences in S6 and S7 end products also reflecting the distinct microbial development rates and profiles observed. Overall, the total BA mean concentration was higher (P < 0.05) in products from batch T.     

Dry fermented sausages of Southern Italy: a comparison of free amino acids and biogenic amines between industrial and homemade products

This paper compares some important parameters and the free amino acid and biogenic amine contents of cured industrial and homemade meat products. To this aim, industrial and homemade "soppressata" and "salsiccia", typical dry fermented sausages produced in Southern Italy, were analyzed. The homemade sausages showed a higher level of free biogenic amines than that manufactured industrially, most likely because biogenic amine formation in industrial products is limited by the use of starter cultures. The industrial sausages are characterized by a higher total free amino acid content than the homemade products. Overall, free amino acid and biogenic amine contents demonstrated that appreciable differences exist between homemade and industrial sausages.     

Influence of selected lab cultures on the evolution of free amino acids, free fatty acids and Fiore Sardo cheese microflora during the ripening

Fiore Sardo Protected Denomination of Origin is a traditional Sardinian (Italy) hard cheese produced exclusively from whole raw ovine milk and coagulated with lamb rennet paste. Currently, Fiore Sardo is still produced by shepherds at the farmhouse level without the addition of any starter culture and the cheese-making process is characterized by significant waste. The first objective of the present work was to investigate the autochthonous microflora present in milk and Fiore Sardo cheese in order to select lactic acid bacterial (LAB) cultures with suitable cheese-making attributes and, possibly reduce the production waste. Secondly, the ability of selected cultures to guarantee cheese healthiness and quality was tested in experimental cheese-making trials. In this study, we show that the typical lactic microflora of raw ewe's milk and Fiore Sardo cheese is mostly composed of mesophilic LAB such as Lactococcus lactis subsp. lactis, Lactobacillus plantarum and Lactobacillus casei subsp. casei. Moreover, strains belonging to the species were selected for cheese-making attributes and used in experimental cheese-making trials carried out in different farms producing Fiore Sardo. The evolution of the cheese microflora, free amino acids and free fatty acids during the ripening showed that the experimental cheeses were characterized by a balanced ratio of the chemical constituents, by a reduced number of spoilage microorganisms and, remarkably, by the absence of production waste that were significant for the control cheeses.     

Changes of biogenic amines in Chinese low‐salt fermented fish pieces (Suan yu) inoculated with mixed starter cultures

In this study, two groups of mixed starter cultures (S1, S2), which were isolated from Suan yu, were inoculated for this experimental product, and a batch without starters was used as the control. The effect of the mixed starter cultures on the suppression of biogenic amine (BA) produced during the ripening of Suan yu was investigated. Changes in BA, pH, total volatile base nitrogen (TVB‐N), microbial counts and free amino acids (FAA) contents were detected during ripening. The results show that the mixed starter cultures rapidly decreased pH, inhibited the growth of contaminant microorganisms emerged in the sample and drastically reduced the accumulations of tyramine, putrescine and cadaverine. However, histamine and spermine were not produced in any batch. Besides, pH, FAA and BA production were not directly correlated. The study suggests that inoculation with S1 and S2 inhibited BA, thereby improving the product safety.     

Novel starter cultures to inhibit biogenic amines accumulation during fish sauce fermentation

Bacteria with amine oxidase activity have become a particular interest to reduce biogenic amines concentration in food products such as meat and fish sausages. However, little information is available regarding the application of these bacteria in fish sauce. Hence, our study was aimed to investigate the effect of such starter cultures in reducing biogenic amines accumulation during fish sauce fermentation. Staphylococcus carnosus FS19 and Bacillus amyloliquefaciens FS05 isolated from fish sauce which possess amine oxidase activity were used as starter cultures in this study. Fermentation was held for 120 days at 35 °C. The pH value increased in all samples, while salt concentration remained constant throughout fermentation. Aerobic bacteria count was significantly lower (p < 0.05) in the control than in inoculated samples as a result of starter cultures addition. However, it decreased during fermentation due to the growth inhibition by high salt concentration. Proteolytic bacterial count decreased during fermentation with no significant difference (p > 0.05) among samples. These bacteria hydrolyzed protein in anchovy to produce free amino acid precursors for amines formation by decarboxylase bacteria. The presence of biogenic amines producing bacteria in this study was considered to be indigenous from raw material or contamination during fermentation, since our cultures were negative histamine producers. Amino acid histidine, arginine, lysine and tyrosine concentration decreased at different rates during fermentation as they were converted into their respective amines. In general, biogenic amines concentration namely histamine, putrescine, cadaverine and tyramine increased throughout fermentation. However, their concentrations were markedly higher (p < 0.05) in the control (without starter cultures) as compared to the samples treated with starter cultures. Histamine concentration was reduced by 27.7% and 15.4% by Staphylococcus carnosus FS19 and Bacillus amyloliquefaciens FS05, respectively. Both cultures could also reduce other amines during fermentation. After 120 days of fermentation, the overall biogenic amines concentration was 15.9% and 12.5% less in samples inoculated with Staphylococcus carnosus FS19 and Bacillus amyloliquefaciens FS05, respectively, as compared to control samples. These findings emphasized that application of starter cultures with amines oxidase activity in fish sauce fermentation was found to be effective in reducing biogenic amines accumulation.     

The effect of elevated temperature on ripening of Dutch type cheese

The aim of this study was to explore the effect of elevated temperature (16 °C) on ripening of Dutch-type cheese. Three slices of each cheese block were further divided into three layers. The processes in the control samples of cheese ripening at 10 °C were also monitored. The contents of free amino acids in accelerated cheese were two times higher than were those in control samples. The highest contents of free amino acids were observed in the cores of all slices of cheeses ripening at both temperatures. The contents of tyramine, in layers of the studied slices, reached almost 500 mg kg⁻¹ during 56 days of the experiment. The contents of biogenic amines in the edges grew even higher. Accelerated cheese showed faster equalisation of hardness than did control samples. The increase of temperature by 6 °C can reduce the ripening time in cellars by approximately one half.     

Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

The aim of the work was to evaluate the profile of free amino acids (FAA) as the possible precursors of biogenic amines (BAs) in different varieties and hybrid lines of Lupinus luteus and Lupinus angustifolius and its changes during fermentation. Lupins have high amounts of FAA, and therefore, significant contents of BAs by the action of bacterial amino acid decarboxylases can be formed. In view of this, the effect of three Pediococcus pentosaceus strains KTU05‐8, KTU05‐9 and KTU05‐10 on BA formation during lupin fermentation was studied. The formation of BAs was monitored during 48‐h fermentation at solid‐state conditions and compared with that in samples after submerged fermentation and in the control nonfermented samples. The lupin variety, fermentation conditions and the Pediococcus strain were found to have the significant effect on the FAA profile and BA contents in fermented lupin; the interaction between analysed factors was F(5.989) = 1755.321 (P < 0.0001) and F(5.660) = 130.736 (P < 0.0001), respectively. A weak correlation was found between amino acid His and histamine (r = 0.3709; P = 0.0005) and between Phe and phenylethylamine (r = 0.3914, P = 0.0002) in lupin samples, but the significant correlations between amino acid Tyr and tyramine and between Lys and cadaverine were not found. By optimising the fermentation technology, it is possible to increase the nutritional value and functionality of lupin.     

Estimation of biogenic amines in foods

Biogenic amines in foods have been proposed as initiators of dietary-induced migraine. Studies of levels of 2-phenylethylamine, p-tyramine and the diamines histamine, putrescine and cadaverine in a number of Australian and other foods were made by ion exchange and high pressure liquid chromatographic methods. In the latter method the amines were chromatographed as their fluorescamine derivatives. The use of such derivatives also enabled confirmation of the identity of the amine by field desorption-mass spectrometry. Extraction procedures were devised to give satisfactory recoveries of amines in foods and to overcome problems associated with the binding of amines to other food constituents.     

Changes in biogenic amines during iced and ambient temperature storage of tilapia

BACKGROUND: Changes in the biogenic amine content of tilapia (Oreochromis mossambicus) with time during iced and ambient temperature (28 °C) storage were quantified by high‐performance liquid chromatography in a gradient elution system using acetonitrile and water as solvents. RESULTS: The levels of amines in tilapia were significantly low even after a long storage period (18 h under ambient temperature storage and 15 days under iced storage). All amines except spermidine and spermine increased with time during both iced and ambient temperature storage. Spermidine and spermine showed a decrease with increasing storage time. CONCLUSION: Being euryhaline (tolerant of a wide range of salinity) in nature, tilapia shows significantly low quantities of biogenic amines even after a long period of ambient temperature or iced storage, unlike most other marine fish. Copyright © 2008 Society of Chemical Industry     

A survey on the presence of free glutamic acid in foodstuffs,with and without added monosodium glutamate

A survey on free glutamic acid (Glu) content in a variety of foods (broths, soups, sauces and salad dressings), with and without added monosodium glutamate (MSG), was carried out. A simple procedure, involving a dilution step for liquid samples or homogenization with 0.1 N HCl for solid and slurry samples, followed by derivatization with o-phthaldialdehyde, HPLC separation on C18 column and spectrofluorometric detection, was employed to quantify Glu, as well as a number of other free amino acids and biogenic amines. Broths and soups with added MSG had Glu contents of 92.7–341 mg/100 g. The highest amounts of Glu in foods with no added MSG were found in products containing hydrolyzed proteins (up to 129 mg/100 g). None of the products ready for consumption exceeded the limit of 10 g/kg of food, established by the European Directive, 95/2/CE [European Parliament and Council Directive (1995). No. 95/2/EC of 20 February 1995 on food additives other than colours and sweeteners. Official Journal, L061, 1–40].     

Kinetics of free protein amino acids, free non-protein amino acids and trigonelline in soybean (Glycine max L.) and lupin (Lupinus angustifolius L.) sprouts

A contribution for a better nutritional knowledge of lupin (Lupinus angustifolius L. var. zapaton) and soybean (Glycine max L. var. merit and var. jutro) sprouts about free protein amino acids (FPAA), free non-protein amino acids (FNPAA such as β-N-oxalyl-l-α,β-diaminopropionic acid (β-ODAP), α-aminoadipic acid, γ-aminobutyric acid (GABA) and β-alanine) and trigonelline content has been carried out. Seeds were germinated at 20 °C and darkness during several days in order to obtain good appearance sprouts. The content of FPAA and FNPAA varied among species and varieties. FPAA increased dramatically during germination and the lowest concentrations were found for G. max L. var. jutro. Cys was not detected as FPAA in seeds and seedlings of both legumes. Asn was present in the highest amounts in soybean and lupin seedlings. The α-aminoadipic acid gliotoxin, which was not present in raw soybean seeds, appeared in low amounts during germination. Later stages of germination caused significant increases of β-alanine and GABA, amino acids with beneficial properties. Germination also affected the content of the multifunctional plant hormone trigonelline and slight changes were observed. Highest levels of FPAA, beneficial FNPAA and trigonelline were found at 4, 6 and 9 days of germination for G. max L. var. jutro, G. max L. var. merit and L. angustifolius L. var. zapaton, respectively. Furthermore, these selected germination conditions showed low levels of the gliotoxic α-aminoadipic acid ensuring nutritional safety of the studied seedlings.