Formation of β-phenylethylamine as a consequence of lipid oxidation

Varietal Influence on the Formation of Bioactive Amines during the Processing of Fermented Cocoa with Different Pulp Contents

During cocoa processing, there can be the formation of bioactive amines, which are compounds that play relevant roles not only in plant development but also in human health. Thus, we aimed to investigate the presence and levels of bioactive amines during the processing of two important varieties of cocoa (PS 1319 and Parazinho). The seeds were fermented using five different pulp proportions: 100% (E1), 80% (E2), 60% (E3), and 0% (total pulp removal) (E4). The beans were fermented and dried on a farm following traditional procedures. Soon after, they were roasted and processed into chocolates with 60% cocoa in the laboratory. Bioactive amine contents were determined by ion-pair reversed-phase HPLC and fluorometric detection in the samples before, during, and after fermentation, after drying and roasting (nibs), and in the liquor and chocolate. The only amines found before processing in PS 1319 and Parazinho, respectively, in dry weight basis (dwb), were putrescine (pulp, 13.77 and 12.31; seed, 5.88 and 4.58) and serotonin (seed, 2.70 and 2.54). Fermentation was shorter for Parazinho (156 h) compared to PS 1319 (180 h). The changes in amines were affected by the cocoa variety. During drying, the presence of cadaverine stood out, appearing in all treatments of the PS 1319 variety, reaching 17.96 mg/kg dwb, and in two treatments of the Parazinho variety (100 and 60% pulp). During roasting, most of the amines decreased, except for phenylethylamine, which increased up to 2.47 mg/kg dwb for Parazinho and 1.73 mg/kg dwb for PS 1319. Most of the amines formed and built up (e.g., tyramine, putrescine, and cadaverine) during fermentation were not available or were at low levels in the nibs. Most of the amines found during processing did not reach the final product (chocolate), except for cadaverine in PS 1319 without pulp (7.54 mg/kg dwb). Finally, we confirmed how pulp content, processing, and variety influence the content of bioactive amines in cocoa and chocolate. These changes can be better demonstrated through a heatmap and principal component analysis.

Reducing biogenic amine in seriflux and huangjiu by recycling of seriflux inoculated with Lactobacillus plantarum JN01

High content of biogenic amine (BA) in huangjiu could pose serious quality concerns. More than 71% of BA in huangjiu were carried over from seriflux (rice soaking wastewater), which were produced by some BA producing bacteria during rice soaking process. A BA non-producing strain, Lactobacillus plantarum JN01, was introduced to rice soaking process, which decreased BA content in seriflux by 93.8% by niche competition at bench scale. Recycling of seriflux inoculated with L. plantarum JN01 at pilot run scale for ten batches demonstrated that BA in seriflux and huangjiu were reduced by 78.4% and 87.7%, respectively. The safety of huangjiu was enormously improved without affecting on the profiles of flavor compounds. Our results demostrated that seriflux recycling technology could reduce 50% of water consumption and achieve "zero effluents" in rice soaking process, which might potentially be a "green technology" not only for huangjiu brewing industry, but also for other related traditional fermented food industries.

Effects of Various Pre-Treatment and Cooking on the Levels of Biogenic Amines in Korean and Norwegian Mackerel

This study analyses the biogenic amines (BAs) formed in mackerel cooked by various methods and conditions. Five BAs, including tryptamine, β-phenylethylamine, putrescine, histamine, and spermidine, were analysed by high-performance liquid chromatography with UV detection. The level of total BAs was higher in the mackerel fillet (108.14 µg/g) than the headed and gutted fish (91.58 µg/g). Roasted, fried, and stewed mackerel recorded total BA concentrations of 54.28, 82.25, and 163.05 µg/g, respectively. Stewed mackerel contained about 3-fold more BAs than roasted mackerel. The level of total BAs in mackerel increased significantly up to 190%, 236% and 152% as the roasting temperature increased, upon frying, and as stewing temperature increased, respectively (p < 0.05).

Effect of Fermentation, Drying and Roasting on Biogenic Amines and Other Biocompounds in Colombian Criollo Cocoa Beans and Shells

The composition of microbiota and the content and pattern of bioactive compounds (biogenic amines, polyphenols, anthocyanins and flavanols), as well as pH, color, antioxidant and reducing properties were investigated in fermented Criollo cocoa beans and shells. The analyses were conducted after fermentation and drying (T1) and after two thermal roasting processes (T2, 120 °C for 22 min; T3, 135 °C for 15 min). The fermentation and drying practices affected the microbiota of beans and shells, explaining the great variability of biogenic amines (BAs) content. Enterobacteriaceae were counted in a few samples with average values of 10³ colony forming units per gram (CFU g⁻¹), mainly in the shell, while Lactobacillus spp. was observed in almost all the samples, with the highest count in the shell with average values of 10⁴ CFU g⁻¹. After T1, the total BAs content was found to be in a range of 4.9÷127.1 mg kg⁻¹_DFW; what was remarkable was the presence of cadaverine and histamine, which have not been reported previously in fermented cocoa beans. The total BAs content increased 60% after thermal treatment T2, and of 21% after processing at T3, with a strong correlation (p < 0.05) for histamine (ß = 0.75) and weakly correlated for spermidine (ß = 0.58), spermine (ß = 0.50), cadaverine (ß = 0.47) and serotonine (ß = 0.40). The roasting treatment of T3 caused serotonin degradation (average decrease of 93%) with respect to unroasted samples. However, BAs were detected in a non-alarming concentration (e.g., histamine: n.d ÷ 59.8 mg kg⁻¹_DFW; tyramine: n.d. ÷ 26.5 mg kg⁻¹_DFW). Change in BAs level was evaluated by principal component analysis. PC1 and PC2 explained 84.9% and 4.5% of data variance, respectively. Antioxidant and reducing properties, polyphenol content and BAs negatively influenced PC1 with both polyphenols and BA increasing during roasting, whereas PC1 was positively influenced by anthocyanins, catechin and epicatechin.

Formation of phenylacetic acid and benzaldehyde by degradation of phenylalanine in the presence of lipid hydroperoxides: New routes in the amino acid degradation pathways initiated by lipid oxidation products

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Degradation of phenylalanine into phenylacetic acid and benzaldehyde is described.

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Amino acid degradation by lipid hydroperoxides takes place in two steps.

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First step: phenylpyruvic acid and phenylacetaldehyde are formed by lipid carbonyls.

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Second step: phenylpyruvic acid and phenylacetaldehyde are broken by lipid radicals.

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Concerted action of both carbonyl-amine and free radical reactions is required.

Lipid oxidation is a main source of reactive carbonyls, and these compounds have been shown both to degrade amino acids by carbonyl-amine reactions and to produce important food flavors. However, reactive carbonyls are not the only products of the lipid oxidation pathway. Lipid oxidation also produces free radicals. Nevertheless, the contribution of these lipid radicals to the production of food flavors by degradation of amino acid derivatives is mostly unknown. In an attempt to investigate new routes of flavor formation, this study describes the degradation of phenylalanine, phenylpyruvic acid, phenylacetaldehyde, and β-phenylethylamine in the presence of the 13-hydroperoxide of linoleic acid, 4-oxononenal (a reactive carbonyl derived from this hydroperoxide), and the mixture of both of them. The obtained results show the formation of phenylacetic acid and benzaldehyde in these reactions as a consequence of the combined action of carbonyl-amine and free radical reactions for amino acid degradation.

Biogenic amines profile and concentration in commercial milks for infants and young children

Commercial milks for infants and young children (CMIYC) received much attention during last years for their impact on the nutritional status, health and development of the new-born and babies. Among possible contaminants contained in these foods, biogenic amines (BAs) have rarely been determined although they can exert toxic effects in humans if ingested at high concentrations. Spermine, spermidine, putrescine, histamine, tyramine, β-phenylethylamine and cadaverine have been quantified in CMIYC samples by LC-UV after derivatisation with dansyl-chloride. Once optimised in terms of linearity (R² ≥ 0.989), recovery percentages (92.9-97.3), LOD (0.2-0.4 μg g^-1 or 0.03-0.05 μg mL^-1 depending on the samples), LOQ (0.5-1.0 μg g^-1 and 0.08-0.13 μg mL^-1 depending on the samples) and repeatability (0.1-0.2 intra-day; 0.2-0.4 inter-day), the method has been applied to real samples. Very low total BAs concentrations have been found in reconstituted (1.18-3.12 mg L^-1) and liquid milks (0.33-2.30 mg L^-1), with different biogenic amine profiles and distributions. A risk assessment based on the available information regarding Acute Reference Doses of histamine and tyramine, as well as the application of common Biogenic Amine Indexes, showed that none of the analysed samples represented a possible risk for babies, also considering a worst case evaluation. These findings confirmed the strict safety and quality protocols adopted during the production of CMIYC. Chemical compounds studied in this article: Ammonium chloride (PubChem CID: 25517); Cadaverine hydrochloride (PubChem CID: 5351467); Hydrochloridric acid (PubChem CID: 313); Histamine dihydrochloride (PubChem CID: 5818); Phenylethylamine hydrochloride (PubChem CID: 9075); Putrescine dihydrochloride (PubChem CID: 9532); Sodium hydroxide (PubChem CID: 14798); Spermine tetrahydrochloride (PubChem CID: 1103); Spermidine trihydrochloride (PubChem CID: 1102); Tyramine hydrochloride (PubChem CID: 66449).

Structure-Activity Relationship (SAR) of Phenolics for the Inhibition of 2-Phenylethylamine Formation in Model Systems Involving Phenylalanine and the 13-Hydroperoxide of Linoleic Acid

Lipid hydroperoxides have been shown to produce amino acid decarboxylations. Because thermal decomposition of lipid hydroperoxides produces free radicals and reactive carbonyls, and phenolic compounds have been shown to scavenger both of them, phenolics are expected to inhibit these reactions and this protection should depend on the structures of the involved phenolics. In this study, the effect of a wide array of phenolics and their mixtures on 2-phenylethylamine formation by phenylalanine degradation in the presence of the 13-hydroperoxide of linoleic acid (LOOH) was studied. LOOH increased considerably the formation of the amine, and phenolics mostly exhibiting an inhibitory role that depended on their structure. Thus, 1,3-diphenols decreased the formation of 2-phenylethylamine because of their carbonyl trapping abilities. In contrast, the inhibition of 1,2- and 1,4-diphenols was lower because they could not trap the reactive carbonyls produced by LOOH decomposition. In addition, their free radical scavenging was likely accompanied by the formation of quinones, which acted as reactive carbonyls. The function of all other phenolics could be calculated by adding the individual functions of the different diphenols present in their structures. In fact, experimental values obtained for both mixtures of phenolics and complex phenolics correlated well with the calculated values obtained from their constituting diphenols. All of these results suggest that, when the reaction mechanisms are known, it is possible to predict the behavior of complex phenolics on the basis of their structure.

Extraction Efficiency of Different Solvents and LC-UV Determination of Biogenic Amines in Tea Leaves and Infusions

Biogenic amines (BAs), that is, spermine, spermidine, putrescine, histamine, tyramine, β-phenylethylamine, cadaverine, and serotonin, have been determined in several samples of tea leaves, tea infusions, and tea drinks by LC-UV method after derivatization with dansyl chloride. Different extraction solvents have been tested and TCA 5% showed better analytical performances in terms of linearity, recovery percentages, LOD, LOQ, and repeatability than HCl 0.1 M and HClO4 0.1 M and was finally exploited for the quantitative determination of BAs in all samples. In tea leaves total BAs concentration ranged from 2.23 μg g(-1) to 11.24 μg g(-1) and PUT (1.05-2.25 μg g(-1)) and SPD (1.01-1.95 μg g(-1)) were always present, while SER (nd-1.56 μg g(-1)), HIS (nd-2.44 μg g(-1)), and SPM (nd-1.64 μg g(-1)) were detected more rarely. CAD and PHE were determined in few samples at much lower concentrations while none of the samples contained TYR. Tea infusions showed the same trend with total BAs concentrations never exceeding 80.7 μg L(-1). Black teas showed higher amounts of BAs than green teas and organic and decaffeinated samples always contained much lower BAs levels than their conventional counterparts.

Oxidative versus Non-oxidative Decarboxylation of Amino Acids: Conditions for the Preferential Formation of Either Strecker Aldehydes or Amines in Amino Acid/Lipid-Derived Reactive Carbonyl Model Systems

Comparative formation of both 2-phenylethylamine and phenylacetaldehyde as a consequence of phenylalanine degradation by carbonyl compounds was studied in an attempt to understand if the amine/aldehyde ratio can be changed as a function of reaction conditions. The assayed carbonyl compounds were selected because of the presence in the chain of both electron-donating and electron-withdrawing groups and included alkenals, alkadienals, epoxyalkenals, oxoalkenals, and hydroxyalkenals as well as lipid hydroperoxides. The obtained results showed that the 2-phenylethylamine/phenylacetaldehyde ratio depended upon both the carbonyls and the reaction conditions. Thus, it can be increased using electron-donating groups in the chain of the carbonyl compound, small amounts of carbonyl compound, low oxygen content, increasing the pH, or increasing the temperature at pH 6. Opposed conditions (use of electron-withdrawing groups in the chain of the carbonyl compound, large amounts of carbonyl compound, high oxygen contents, low pH values, and increasing temperatures at low pH values) would decrease the 2-phenylethylamine/phenylacetaldehyde ratio, and the formation of aldehydes over amines in amino acid degradations would be favored.

Strecker-type degradation of phenylalanine initiated by 4-oxo-2-alkenals in comparison to that initiated by 2,4-alkadienals, 4,5-epoxy-2-alkenals, or 4-hydroxy-2-nonenal

The conversion of phenylalanine to phenylacetaldehyde as a consequence of its reaction with 4-oxo-2-alkenals was studied both to characterize the reaction pathway and to compare the reactivities and kinetic constants of oxoalkenals with those of other lipid oxidation products: 2,4-alkadienals, 4,5-epoxy-2-alkenals, and 4-hydroxy-2-nonenal. Oxoalkenals produced the Strecker aldehyde through imine formation, which was then decarboxylated and hydrolyzed. In the course of the reaction the lipid was converted into an unsaturated hydroxylamine that eventually cycled to 2-alkylpyrrole. The Ea of phenylacetaldehyde formation in the presence of oxoalkenals was 55-64 kJ/mol. This Ea was similar to the Ea determined for the other tertiary lipid oxidation products assayed (58-67 kJ/mol), but higher than the Ea determined for alkadienals (28-38 kJ/mol). However, this difference in Ea only correlated with the amount of phenylacetaldehyde produced at 37 °C. At higher temperatures, 4-oxo-2-nonenal was the lipid-derived carbonyl compound that produced the highest amount of the Strecker aldehyde, therefore pointing to this oxoalkenal as the most efficient Strecker aldehyde forming compound derived from lipids. For this reason, oxoalkenals should be expected to play a significant role in reactions in which Strecker aldehydes are recognized intermediates, as occurs in the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP).

Chemical conversion of phenylethylamine into phenylacetaldehyde by carbonyl-amine reactions in model systems

The chemical conversion of phenylethylamine into phenylacetaldehyde in the presence of lipid oxidation products (LOPs) was studied to investigate the possibility that biogenic amines can be converted into Strecker aldehydes upon processing. Model systems of phenylethylamine and methyl 13-hydroperoxyoctadeca-9,11-dienoate (HP), 2,4-decadienal (DD), 4,5-epoxy-2-heptenal (EH), 4,5-epoxy-2-decenal (ED), 4-oxo-2-hexenal (OH), 4-oxo-2-nonenal (ON), or 4-hydroxy-2-nonenal (HN) were heated for 1 h at 180 °C and pH 3. Although HN and EH did not produce more phenylacetaldehyde than when phenylethylamine was heated alone, all other lipid oxidation products assayed increased the amount of phenylacetaldehyde produced by 300-900%, with ON being the most reactive compound for this reaction. The reaction was mainly produced at acidic pH values (<6) and was dependent upon the concentration of the LOPs involved, and the phenylacetaldehyde produced increased linearly as a function of the time and temperature. The E(a) values for the reactions between phenylethylamine and DD and ON were 54.8 and 53.8 kJ/mol, respectively. The reaction is proposed to take place by the formation of an imine between the phenylethylamine and the LOPs, which is later converted into another imine by an electronic rearrangement. This new imine is the origin of phenylacetaldehyde by hydrolysis. These results show a new pathway for Strecker aldehyde formation. This route provides a potential way to reduce biogenic amine content in foods when they can be thermally processed before consumption.