Thermoplastic electrodes as a new electrochemical platform coupled to microfluidic devices for tryptamine determination.

This study reports a new electrochemical method for tryptamine determination using a paper-based microfluidic device and a thermoplastic electrode (TPE) as an amperometric detector. Tryptamine (Tryp) is a biogenic amine present in drinks and foods. Even though this compound has some beneficial effects on human health, the ingestion of foods with high concentrations of Tryp may be detrimental, which justifies the need for monitoring the Tryp levels. The TPEs were made from 50% carbon black and 50% polycaprolactone and characterized by cyclic voltammetry, demonstrating enhancement in the analytical response compared to other carbon composites. TPEs also showed a better antifouling effect for Tryp compared to conventional glassy carbon electrodes. Once characterized, the electrodes were incorporated into the microfluidic device to determine Tryp in water and cheese samples using amperometry. A linear range was achieved from 10 to 75 µmol L-1 with limits of detection and quantification of 3.2 and 10.5 µmol L-1, respectively. Therefore, this work shows promising findings of the electrochemical determination of Tryp, bringing valuable results regarding the electrochemical properties of thermoplastic composites.

Effects of putrescine injection in broiler breeder eggs.

The aim of this study was to evaluate the effects of increasing doses of putrescine injected in ovo on hatchability, intestinal morphology and pre-starter performance of broilers. For this purpose, 720 eggs from broiler breeders were separated into a negative control (no injection) and injection treatments with increasing doses of putrescine (0.05; 0.1; 0.15 and 0.2%), totalling five treatments of 144 eggs each. Eggs were distributed in a completely randomized design inside the setter and the injection of solutions occurred at 17 days of incubation. After hatch, 330 birds were housed in mixed lots following the original treatments, totalling 5 treatments of 6 replicates with 11 birds each. Six birds per treatment were weighed and euthanized by cervical dislocation to collect the liver, intestine and breast 24 hr after injection, at hatch and 24 hr after hatch. At 2 days of age, intestines were collected from 4 animals per treatment to analyse histomorphology. The effects of putrescine levels were evaluated by polynomial regression models, ANOVA and Tukey test at 5% probability. The hatchability decreased linearly in response to increased doses of putrescine. The percentage of residual yolk was lower in animals that received putrescine compared to the control. After injection, the percentage of breast increased linearly, and the percentage of intestine had a quadratic response to increased doses of putrescine. However, 24 hr after hatch, the percentage of intestine linearly decreased, and the percentage of liver linearly increased in response to increased doses of putrescine. Villus height increased quadratically, crypt depth decreased linearly, and goblet cells increased linearly in response to the putrescine dose. FI and BWG were not affected in the pre-starter phase; however, FCR increased in response to increased levels of putrescine. Due to putrescine effects on embryos, it is recommended that the doses injected in ovo not exceed 0.1%.

Exploring the Capability of Yeasts Isolated from Colombian Fermented Cocoa Beans to Form and Degrade Biogenic Amines in a Lab-Scale Model System for Cocoa Fermentation.

Yeast starters for cocoa fermentation are usually tested according to their enzymatic activities in terms of mucilage degradation and flavor improvement, disregarding their influence on the production or elimination of toxic compounds as biogenic amines (BAs), important for human health. In this work, we tested 145 strains belonging to 12 different yeast species and isolated from the Colombian fermented cocoa beans (CB) for their capability of producing BAs in vitro. Sixty-five strains were able to decarboxylate at least one of the amino acids tested. Pichia kudriavzevii ECA33 (Pk) and Saccharomyces cerevisiae 4 (Sc) were selected to evaluate their potential to modulate BAs, organic acids, and volatile organic compounds (VOCs) accumulation during a simulated cocoa fermentation. The growth of Sc or Pk in the presence of CB caused a significant reduction (p < 0.05) of 2-phenylethylamine (84% and 37%) and cadaverine (58% and 51%), and a significant increase of tryptamine and putrescine with a strong influence of temperature in BA formation and degradation. In addition, our findings pointed out that Pk induced a major production of fatty acid- and amino acid-derived VOCs, while Sc induced more VOCs derived from fatty acids metabolism. Our results suggest the importance of considering BA production in the choice of yeast starters for cocoa fermentation.

Short communication: Biogenic amine formation during fermentation in functional sheep milk yogurts.

The present study evaluated biogenic amine (BA) content during the fermentation period in functional sheep milk yogurts. Four treatments were prepared and assessed: natural (NSY), prebiotic (PreSY), probiotic (ProSY), and synbiotic (SynSY). Biogenic amines (putrescine, cadaverine, spermidine, spermine, and tyramine), proteolysis activity, and pH were measured during each hour of fermentation. Grumixama pulp was added to all formulations as a technological strategy and potential substrate for bacteria during fermentation. The yogurt and probiotic bacteria were viable (≥7 log cfu·mL-1) on d 0. The pH levels of the functional sheep milk yogurts had a more pronounced decrease than did the control of NSY. However, all yogurt samples underwent gradual decreases in pH until final fermentation. Proteolytic activity remained constant in all treatments during fermentation. The NSY, PreSY, ProSY, and SynSY presented the same behavior for all BA, with differences in concentration. Putrescine, cadaverine, and spermidine contents decreased, whereas spermine remained constant and tyramine increased. We conclude that fermentation of functional sheep milk yogurts can produce tyramine.

Effects of packaging, mineral oil coating, and storage time on biogenic amine levels and internal quality of eggs.

This study was carried out with the aim of evaluating the effects of mineral oil application on eggshells and the use of plastic packages with lids on the physical-chemical and microbiological quality and biogenic amine contents of eggs stored under refrigeration for up to 125 d. A total of 1,920 eggs from 46-wk-old Hyline W36 laying hens were randomly distributed into 4 groups soon after classification: (i) 480 eggs were stored in pulp carton tray packages; (ii) 480 eggs were stored in plastic packages with lids; (iii) 480 eggs were stored in carton packages after the application of mineral oil; and (iv) 480 eggs were stored in plastic packages with lids after the application of mineral oil. The internal quality was measured by Haugh units, by the counts of mesophilic and psychrotrophic microorganisms, by the most probable number of total and thermal-tolerant coliforms, by the counts of molds and yeasts, by the analysis of Salmonella spp. and Staphylococcus spp., and by the levels of biogenic amines in the egg yolk and albumen. The application of mineral oil to the eggshell resulted in higher Haugh unit values throughout storage, and the use of plastic packages altered the internal quality. The application of mineral oil and the use of packaging had no effects on the microbiological and biogenic amine results. Microbiological analyses showed the absence of Salmonella spp., Staphylococcus aureus, thermal-tolerant coliforms, and fungi. However, the highest counts of mesophilic (1.1 × 10(7) cfu/g) and psychrotrophic (6.7 × 10(7) cfu/g) microorganisms were recorded. The highest values of biogenic amines detected and quantified were putrescine (2.38 mg/kg) and cadaverine (7.27 mg/kg) in the egg yolk and putrescine (1.95 mg/kg), cadaverine (2.83 mg/kg), and phenylethylamine (2.57 mg/kg) in the albumen. Despite these results, the biogenic amine levels recorded were considered low and would not be harmful to consumer health.

Composition of amino acids and bioactive amines in common wines of Brazil / Composição de aminoácidos e aminas bioativas em vinhos comuns brasileiros

Since most consumed wines in Brazil are common wines and since their representativeness is not accounted for in scientific research, current study quantifies bioactive amines and their precursors in Brazilian sweet and dry common wines, correlates the formation of amines with physical and chemical parameters and clusters studied areas by their amine and amino acid contents. Forty-seven wine samples varying in type, color and origin were analyzed simultaneously for seventeen amino acids, ammonium ion and five bioactive amines by reversed-phase high performance liquid chromatography and ultraviolet detection after the derivation phase. Physical and chemical analyses comprised titratable acidity, pH, organic acids, sugar and alcohol contents. Sweet wines had lower concentrations of amino acids and bioactive amines. Dry white wines had higher amino acid contents when compared to those in dry red wines. Since multivariate data analysis confirmed similarities between the studied regions, their unity as potential viniculture area was reinforced. Amine levels in Brazilian common wines were reported for the first time and results reinforced the importance of bioactive amines quantification and the use of suitable vinification practices to reduce their formation.

Considerando que os vinhos mais consumidos no Brasil são vinhos comuns e que sua representatividade não é demonstrada na pesquisa científica, o presente estudo tem por objetivo quantificar as aminas bioativas e seus precursores em vinhos comuns brasileiros suaves e secos, correlacionar a formação das aminas com parâmetros físico-químicos e agrupar as áreas estudadas por meio do seu conteúdo em aminas e aminoácidos. Foram analisadas 47 amostras de vinhos que variam quanto ao tipo, cor e origem; foram analisados, simultaneamente, 17 aminoácidos, íon amônio e cinco aminas bioativas por cromatografia líquida de fase reversa depois de uma etapa de derivatização. Análises físico-químicas incluíram acidez total, pH, ácidos orgânicos, açúcar e teor alcoólico. Os vinhos doces tiveram menor concentração de aminoácidos e aminas bioativas. Os vinhos brancos secos apresentaram maior conteúdo em aminoácidos quando comparados com os apresentados nos vinhos tintos secos. Uma vez que a análise multivariada confirmou similaridades entre as regiões estudadas, sua unidade como uma área potencial para a vinicultura foi reforçada. Os níveis de aminas em vinhos comuns brasileiros foram reportados pela primeira vez e os resultados reforçam a importância da quantificação de aminas bioativas e o uso de práticas apropriadas de vinificação para reduzir a sua formação.

Aminas biógenas y bacterias en salchichón tipo milano: Efecto del tiempo de almacenamiento / Bacterial and Biogenic Amines in Milano Type Sausage: Storage Time Effect

La presencia de aminoácidos libres, bacterias descarboxilantes, temperatura y tiempo de almacenamiento son factores que favorecen la formación de aminas biógenas. El objetivo de este trabajo fue determinar el efecto del tiempo de almacenamiento sobre la presencia de aminas biógenas y bacterias en salchichones tipo milano. Se utilizaron 9 salchichones enteros de tres marcas comerciales (tres unidades por marca), con fecha de vencimiento de dos meses. Las muestras se analizaron 60, 30 y 0 días antes del vencimiento. Se determinaron aminas biógenas por cromatografía líquida de alta resolución (HPLC), recuento de bacterias ácido lácticas (BAL), enterococos (ENTC) y enterobacterias (ENTB) según ICMSF. En la marca 1 se observó una disminución significativa (P < 0,05) del número de BAL entre los muestreos, la marca 2 se mantuvo constante, mientras que la marca 3 aumentó significativamente (P < 0,05) entre el primer y segundo muestreo, para mantenerse constante hasta el vencimiento. No hubo diferencias significativas en los ENTC de las marcas 1 y 3, mientras que en la marca 2 se encontraron diferencias significativas (P < 0,05) entre la primera fecha y las dos últimas, en las que se incrementó el número de UFC. Los factores marca, tiempo de almacenamiento e interacción de ambos tuvieron un efecto significativo (P < 0,05) sobre el contenido de aminas biógenas, ENTC y BAL. Durante el almacenamiento BAL predominó sobre ENTC. No se encontraron ENTB. Se detectó la presencia de tiramina, histamina, cadaverina y putrescina; las concentraciones de tiramina e histamina encontradas podrían producir intoxicación alimentaria en individuos susceptibles.

Free aminoacids presence, decarboxilating bacteria, temperature and storage time may induce biogenic amine formation. The objective of this research was to determine storage time effect on biogenic amine and bacteria presence in milano type sausage. Nine (9) complete sausages of three brands (3 units per brand) were used, two months from expiration date. Samples were analyzed 60, 30 and 0 days before expiration. Biogenic amines were determined by means of liquid chromatography (HPLC), lactic acid bacteria (LAB), enterococci (ENTC) and enterobacteria (ENTB) according to ICMSF. In brand 1 a significant diminishment (P < 0.05) in LAB number, brand 2 remain stable, meanwhile brand 3 raised significantly (P < 0.05) between first and second sampling, and kept this values until expiration date. There were no significant differences in ENTC of brands 1 and 3, but in brand 2, the number raised, and significant differences (P < 0.05) between first and later dates were found. Brand and storage time and interaction between them had a significant effect (P < 0.05) on biogenic amine content, ENTC and LAB. LAB was higher than ENTC during storage. ENTB were not found. Tiramine, histamine, cadaverin and putrescine were detected; tiramine and histamine concentrations could produce a food poisoning in susceptible individuals.