Abel Mariné-Font

Determination of water-soluble vitamins in infant milk by high-performance liquid chromatography

A rapid, simple and reliable liquid chromatographic method has been developed for the simultaneous determination of nicotinamide, thiamin, riboflavin, pyridoxine, pyridoxal, pyridoxamine, cyanocobalamine and folic acid in liquid and powdered infant milk. Ion-pair chromatography with a reversed-phase C18 column is used. Six vitamins were resolved in a single analysis; total analysis time never exceeded 55 min. A mobile phase of methanol-water (15:85), 5 mM octanesulfonic acid, with 0.5% triethylamine at pH 3.6 and a flow-rate of 1.0 ml/min gave the most satisfactory separation of these vitamins using a UV detector set at different wavelengths. Sample preparation involves acidification to precipitate proteins, and centrifugation followed by gravity filtration. Linearity, precision, recovery and sensitivity were always satisfactory. Detection limits ranged from 0.02 to 0.10 microgram/ml and determination limits ranged from 0.03 to 0.25 microgram/ml.

Ion-pair high-performance liquid chromatographic determination of biogenic amines and polyamines in wine and other alcoholic beverages.

An optimised ion-pair reversed-phase high-performance liquid chromatographic method with automatic o-phthalaldehyde post-column derivatization and spectrofluorometric detection for the same-run separation and quantification of 12 biogenic amines and polyamines in alcoholic beverages has been validated. The reliability of the method was satisfactory in terms of linearity (from 0.5 to 15 mg/l), precision (relative standard deviation below 5%), recovery (from 98.7 to 101.1%), and sensitivity (detection limit between 0.03 and 0.06 mg/l). The automatic accomplishment of the derivatization step reduces time and effort of analysis, especially thanks to the easy preparation of the sample.

Histamine and tyramine in spanish wines: Relationships with total sulfur dioxide level, volatile acidity and malo-lactic fermentation intensity

Abstract Histamine and tyramine contents in 226 and 186 Spanish wine samples, respectively, have been studied employing spectrofluorometric methods. The average content of histamine in red wines (4·07 mg/liter) proves to be higher than in white wines (0·81 mg/liter) and rose wines (0·86 mg/liter). The average content of tyramine was also higher in red wines (3·03 mg/liter) than in white (1·49 mg/liter) and rose ones (1·66 mg/liter). Relationships are studied between the contents of these amines and that of total sulfur dioxide and volatile acidity, as well as with the intensity of malo-lactic fermentation. Our results, in general, show that (a) the highest levels of both amines occur in red wines with low concentrations of total sulfur dioxide, (b) white and rose wines with high volatile acidity show higher levels of these amines than wines with low volatile acidity, and (c) in all wines highest levels of amines correspond to wines with a stronger malo-lactic fermentation.

Changes in Biogenic Amines during the Manufacture and Storage of Semipreserved Anchovies

Biogenic amines were determined by using high-pressure liquid chromatography during spoilage of raw Engraulis encrasicholus (anchovies), during ripening and shelf life. Histamine, cadaverine, tyramine, and putrescine were extensively formed at the beginning of spoilage, while β-phenylethylamine and tryptamine were formed only at advanced stages of spoiling. Serotonin, spermine, and spermidine levels were constant throughout spoilage. Seventeen lots of anchovies were evaluated through the typical ripening process. Each ripening process lasted 18 to 22 weeks, Only a slight formation of biogenic amines was observed during the first period of ripening (2 to 4 weeks). According to our results, ripening had little influence on the formation of amines, and therefore the amount of amines in the final products depends primarily on the levels of these substances in the raw material. During shelf-life studies, anchovies packed in brine were more stable, from the point of view of biogenic amine formation, than anchovies packed in oil. High formation of tryptamine and histamine was observed in both products when they were stored at room temperature. Refrigerated storage prevents amine formation.

Effect of tyrosine on tyramine formation during beer fermentation

Changes in tyramine, in its precursor amino acid tyrosine, and in Pediococcus spp. were followed during 54 beer fermentations. No statistical relationship between tyramine production and wort tyrosine levels was found, either between the amount of tyramine formed or the decrease in tyrosine through beer fermentation. However, tyramine formation significantly correlated with Pediococcus spp. contamination (r=0.876; P<0.001, n=54). Higher initial tyrosine levels did not induce greater tyramine formation when a similar degree of contamination by Pediococcus spp. occurred, either between tyrosine decrease and tyramine formation. Special attention is required in controlling the presence of lactic acid bacteria to minimise the formation of tyramine. However, the amount of tyrosine does not seem to be a critical factor in the tyramine formation during beer fermentation.

Biogenic amine index for freshness evaluation in iced mediterranean hake (Merluccius merluccius)

Biogenic amine accumulation was studied during the ice storage of Mediterranean hake. Sensory analysis and counts of Shewanella, Pseudomonas, enterobacteria, psychrotrophic, and mesophilic bacteria provided complementary information on hake spoilage. Putrescine and cadaverine were the main amines accumulated, whereas histamine and tyramine were minor amines but had qualitative interest from the hygienic point of view. Although all biogenic amines were less abundant than in pelagic fish, they may also be used as indicators of freshness and/or spoilage in hake. Cadaverine was the amine best correlated with Shewanella, which was the specific spoilage organism. Therefore, cadaverine may be regarded as the specific spoilage biogenic amine for hake stored at chilling temperatures. However, the biogenic amine index, which considers cadaverine, putrescine, histamine, and tyramine, has several advantages as an indicator of hake quality. Taking into account sensory data, an acceptability limit of the biogenic amine index could be established in 15 to 20 microg/g.

Volatile and biogenic amines, microbiological counts, and bacterial amino acid decarboxylase activity throughout the salt-ripening process of anchovies (Engraulis encrasicholus).

Chemical and microbiological parameters were studied during the industrial production of salt-ripened anchovies (Engraulis encrasicholus). Gradual acidification and increases in the proteolysis index and in total volatile basic nitrogen were observed. At the end of the maturing process, the values reached pH 5.55 +/- 0.03, 21.33 +/- 5.82%, and 44.06 +/- 12.47 mg/ 100 g, respectively. In the three studied anchovy batches, the biogenic amines tyramine, histamine, putrescine, cadaverine, and agmatine increased during ripening. The highest values were found in the batch where initial microbial load was highest (batch 1), especially for enterobacteria and enterococci. Tyramine was the most abundant amine, reaching values from nondetectable to 90 mg/kg, whereas histamine did not surpass 20 mg/kg. Among the microorganisms isolated, Enterobacter cloacae, Aerococcus viridans, Kocuria varians, and Staphylococcus chromogenes were able to decarboxylate amino acids and produce biogenic amines in vitro. Most (70.59%) of the microorganisms identified were able to produce histamine, 23.53% were able to produce the diamines putrescine and cadaverine, and only 11.76% were able to produce tyramine, although this substance was the major biogenic amine found in anchovy samples.

Tyramine formation by Pediococcus spp. during beer fermentation

The role of Pediococcus spp. in the production of tyramine was studied. Strains of these microorganisms were isolated from industrial beer fermentations where high tyramine formation occurred. It has been verified that Pediococcus spp. are able to form tyramine during beer fermentation, and the quantity of tyramine produced depends on the degree of contamination. Thus, CFU of Pediococcus spp. ranging from 4 ×103 to 1 × 104 CFU/ml led to low tyramine formation (<5 mg/liter). Tyramine production between 5 and 15 mg/liter was related to Pediococcus spp. counts from 1 × 104 to 5 × 104 CFU/ml, while counts of these microorganisms above 5 ×104 CFU/ml led to tyramine levels ranging from 15 to 20 mg/liter. Prolonged storage in culture media of the isolated strains of Pediococcus spp. as well as isolation of these microorganisms from beer and transfer to media caused them to lose their ability to produce tyramine. Determination of tyramine levels in beer was found to be a reliable indicator of the degree of contamination by Pediococcus spp. during beer fermentation.

Biogenic amines in Spanish beers: differences among breweries

Ten biogenic amines in Spanish beers were studied using HPLC. Agmatine, tyramine and putrescine were the prevailing amines, while histamine,β-phenylethylamine, tryptamine, cadaverine, spermine and spermidine were detected at relatively low levels (in general <2 mg/l). On the basis of the wide range of levels observed for tyramine (from 1.90 to 31.55 mg/l), the consumption of beer requires restriction in patients receiving monoamine oxidase inhibitor drugs. Biogenic amine levels in beers of the same type from the same company and from different companies were monitored every month over 1 year. Agmatine and putrescine levels showed minimal fluctuations in beers from the same company as well as from different breweries. Raw materials and brewing conditions would not affect the levels of those amines. However, tyramine levels were subject to wide fluctuations in beers produced by particular breweries irrespective of whether they were produced by the same company. Relatively high levels of tyramine were specific to some breweries.

Histamine and tyramine in beers. Changes during brewing of a Spanish beer

A preliminary study of the evolution of histamine and tyramine during a brewing process was carried out. A clear formation of tyramine was observed during the main fermentation (from 2·5 to 40·5 mg/litre), but histamine formation was negligible in this same period. Good correlations (p < 0·001) were found between formation of tyramine and alcoholic content, and between this amine and apparent extract during the main fermentation. In addition, a statistical comparison was done of the biogenic amine contents in 64 samples corresponding to the four types of beer established by the Spanish law on the basis of their extract of original wort and their alcoholic content. No significant statistical differences were found between the histamine and tyramine contents in the four types of beer (p = 0·05).