Determination of biogenic amines in processed and unprocessed mushrooms from the Polish market

Mushrooms and mushroom products are very popular in many countries around the world. However, these food products can be a source of biogenic amines, due to the content of precursors of these compounds and the high susceptibility to microbiological spoilage. Biogenic amines have a significant impact on food quality and may pose a threat to human health. The presence of spermidine, putrescine, tyramine, cadaverine, histamine, spermine, and agmatine was determined for the first time in 53 processed and unprocessed mushroom products available on the Polish market. The results showed a high variation in the content of biogenic amines in the individual products, depending on the producer. Spermidine and putrescine were the main biogenic amines, as they were found in 47 and 39 types of mushroom products, respectively. Tyramine and cadaverine were found in 15 samples of processed mushrooms. Histamine was present in only eight samples of dried Polish forest mushrooms; nevertheless, it was regarded a real threat to consumer health due to its very large quantities. It should be noted that dried mushrooms are intermediate products used after hydration as ingredients of various dishes, e.g. soups, sauces, stuffing; hence, the amount of histamine in the final product is substantially lower.     

Composition of fatty acids and triglycerides in goat cheeses and study of the triglyceride composition of goat milk and cow milk blends

The composition of fatty acids and triglycerides in the fat of Uruguayan goat cheeses was determined. Additionally, in the present study, triglyceride composition was determined in terms of partition number (PN) for fats from pure goat milk, pure cow milk and blends thereof (90:10, 80:20, and 50:50 blends of goat milk:cow milk). All Uruguayan goat cheeses showed high levels of conjugated linoleic acid and trans-vaccenic acid, well above those reported in cheeses from other countries. This is advantage in terms of nutritional quality. In fats from goat milk in Uruguayan cheeses, the highest average percentages of triglycerides correspond to PN = 36 (13.2%) and PN = 42 (13.6%). The results demonstrate that the triglyceride profile changes when cow milk is added to goat milk. When the amount of cow milk added to goat milk increases, triglycerides with PN values of 38, 40, and 42 tend to decrease, while triglycerides with PN values of 46, 48, and 50 tend to increase. These results suggest that the triglyceride profile could be used to determine whether a given goat cheese was adulterated with cow milk, which is cheaper. This was detected in the case of three Uruguayan goat cheeses that were analysed.     

Composition of goat and cow milk produced under similar conditions and analyzed by identical methodology

The aim of this study was to identify, under the best possible conditions, the interspecific differences between the proteins, fat and minerals in goat and cow milk. The protein fractions presented evident differences, especially concerning the amount of α_S1-casein, which was lower in the goat milk (62.8%; P < 0.05). The amino acid profile of the two proteins revealed certain differences, although the total quantity of essential amino acids did not vary (P > 0.05). The composition of fats was well-differentiated, mainly as concerns the content of medium-chain fatty acids (C6–14), which were higher in the goat milk (28.8%; P < 0.05). The same was true for n-6 polyunsaturated fatty acids (10.0%; P < 0.05) and n-3 polyunsaturated fatty acids (51.0%; P < 0.05), and also the total level of conjugated linoleic acid (33.8%; P < 0.05). The quantities of Ca, P, Mg and Cu were greater in the ash derived from goat milk (17.4, 15.6, 16.3 and 66.6%, respectively; P < 0.05). Due to the greater quantity of total solids present in goat milk (16.3%; P < 0.05), all of the above-mentioned differences would be considerably increased by the fact that they refer to the amounts present in a given volume. The differences detected between cow and goat milk mean that the latter constitutes a food of particular interest, in terms of both health and nutrition.     

A comparative study of fatty acid composition and CLA concentration in commercial cheeses

A total of 52 Italian and French commercial cheeses were analysed for fatty acid composition and conjugated linoleic acid (CLA) concentration. The cheeses were first grouped according to the ruminant species of the milk used in manufacturing, then according to the following criteria: (1) cheeses obtained from milk of the same ruminant species but using different production technologies; (2) cheeses produced from milk of different ruminant species but through similar cheesemaking processes. Comparative studies of fatty acid composition and CLA levels in the different cheese classes were carried out. In our study, the arrangement of the ruminant species according to the increasing CLA concentration in cheese was: goat = cow < sheep. Sheep cheeses had the highest levels of CLA (9.86 mg/g fat), α-linolenic acid (0.75%) and trans-vaccenic acid (1.63%), and the lowest contents of linoleic acid (1.80%) and oleic acid (16.83%). The comparison of cheeses obtained from milk of the same ruminant species but through different production technologies reported statistically significant differences in the fatty acid profiles that could be due to a different degree of lipolysis in the cheeses compared. Nevertheless, statistically significant differences in CLA concentration were not found; this suggests that the factors involved in the cheesemaking process generally do not affect the CLA content in milk fat.     

Chemometric analysis on free amino acids and proximate compositional data for selecting cowpea (Vigna unguiculata L.) diversity

Biodiversity of cowpea, along with the interesting agricultural and nutritional properties, has encouraged research with local landraces of Portugal. This work deals with the composition of dry beans of cowpea from 28 different Portuguese cultivars concerning dry matter (DM), crude proteins (CP), fat content (FC), ash, and concentration of free essential and non-essential amino acids. Data obtained on these traits showed contents of DM, FC, ash, and CP in the ranges of 95.7–98.9%, 1.0–1.6%, 2.7–4.7%, and 18.6–26.9%, respectively. The content in free amino acids was evaluated as an indicator of germinating potential of the diverse cultivars assessed. The amino acids content was the highest in the varieties ‘Vg50’ and ‘Vg58’. Cluster and principal component analyses of the data allowed the identification of the most promising Portuguese landraces of cowpea to be used for breeding new varieties with improved germination potential and nutritional traits.     

Heterocyclic aromatic amines in grilled beef: The influence of free amino acids,nitrogenous bases,nucleosides, protein and glucose on HAAs content

The aim of the study was to determine the content and profile of heterocyclic aromatic amines (HAAs) formed during the process of grilling beef under various conditions and involving different cuts of beef meat. 4,8-DiMeIQx was the most prevalent (4.50–7.55 ng g⁻¹) the next were: MeIQx (1.10–7.20 ng g⁻¹), MeIQ (1.70–5.30 ng g⁻¹), and IQ (0.38 2.00 ng g⁻¹). Changes in HAAs content, depending on the chemical composition of beef meat, were investigated; the compounds under analysis included free amino acids, glucose and protein as well as free nitrogenous bases and their nucleosides. It was demonstrated that HAAs formation strongly correlates with the presence of various amino acids in raw beef as well as that of glucose and protein (correlation coefficient 0.84–0.93). It was also demonstrated that free purine bases, pyrimidine bases and their nucleosides, which had never previously been studied in terms of their role as substrates for HAAs synthesis, correlate very strongly with HAA formation in grilled beef (correlation coefficient 0.78–0.99). The influence of thermal processing at high temperatures on the thermal decomposition of aminoimidazoazaarenes has not been corroborated by the present study.     

Determination of urocanic acid,a compound implicated in histamine toxicity,and assessment of biogenic amines relative to urocanic acid content in selected fish and fish products

The contents of trans- and cis-urocanic acid (cis-UCA), NaCl and moisture, and pH of sixty-seven fish and shrimp products, including salted anchovy, different types of salted fish, salted shrimp and shrimp paste collected in Malaysia, were examined. Included in the analysis was determination of the contents of nine biogenic amines. The average levels of trans- and cis-UCA in salted anchovy, salted fish, salted shrimp and shrimp paste were 9.67 and 7.25, 14.2 and 11.0, 36.6 and 22.5, 6.96 and 18.7 mg/kg, respectively. In general, the average levels of trans- and cis-UCA were much lower than the histamine levels in fish products. Results showed no strong correlation of pH, salt and moisture contents with trans- and cis-UCA, nor with histamine. Biogenic amines were also detected in processed fish and shrimp products where the most abundant biogenic amine was putrescine with an average level of 227 mg/kg in shrimp paste. Thus, the high rates of cancers in consumers who consume dried salted fish could be indicative of the synergistic effects of biogenic amines and cis-UCA.     

Determination of 10-hydroxy-2-decenoic acid and free amino acids in royal jelly supplements with purpose-made capillary electrophoresis coupled with contactless conductivity detection

This study reported a simple and inexpensive method for determination of 10-hydroxy-2-decenoic acid (10-HDA) and free amino acids in different royal jelly based dietary supplement samples using a purpose-made dual-channeled capillary electrophoresis (CE) system with capacitively coupled contactless conductivity detection (C⁴D). The objective of the work is to propose a tool for food / quality control activities that can be realizable even with a modest infrastructure. 10-HDA and free amino acids were analyzed using the background electrolyte (BGE) solutions composed of 20 mM Tris(hydroxymethyl)aminomethane adjusted to pH8.5 with acetic acid and of 2 M lactic acid, respectively. The best achieved detection limit for 10-HDA was 0.039 mg/g and those for free amino acids were in ranged of 0.039–0.090 mg/g using the developed CE-C⁴D methods. Good agreement between results obtained from CE-C⁴D and those with the standard confirmation methods (HPLC-PDA) was achieved, with the result deviation for the two pairs of data being less than 5 % for 10-HDA and 16 % for free amino acids.     

Optimization of cheese sample preparation methodology for free amino acid analysis by capillary isotachophoresis

The objective of this work was the evaluation of different conditions for the selected free amino acids extraction from cheese samples, followed by capillary isotachophoresis analysis. Parameters of the extraction: concentration and type of extraction reagents (solvents: methanol, ethanol and mineral acids: perchloric acid, trichloroacetic acid, sulphuric acid and hydrochloric acid), time and temperature, and isotachophoretic separation conditions (voltage, time) were studied. Repeatability, reproducibility and stability of this method at different conditions are discussed. The best yield of free amino acids was obtained after triple extraction (30 min each process) with 0.1 M hydrochloric acid at 50 °C. Histidine, lysine, arginine, ornithine, tyrosine, and phenylalanine were determined using calibration curves and the standard additions method in different types of cheeses. The highest level of amino acids was determined in semi-hard cheese (2626.3 mg 100 g⁻¹ – calibration curve, and 2679.2 mg 100 g⁻¹ – standard additions method), whereas the lowest were found in sheep cheese (426.3 mg 100 g⁻¹ and 455.7 mg 100 g⁻¹, respectively), and Gouda type cheese samples (441.5 mg 100 g⁻¹ and 472.8 mg 100 g⁻¹, respectively).     

Variability in the fermentation index,polyphenols and amino acids of seeds of rambutan (Nephelium lappaceum L.) during fermentation

The variability in the fermentation index, polyphenols, and amino acids of rambutan seeds was investigated during fermentation. Results revealed that fermentation index (FI) value ≥1 was achieved on the 4th day of fermentation. While fermentation significantly reduced the levels of total polyphenols (59%), tannin (60%), and saponins (33%), it seems to have a moderate effect on geraniin, corilagin, and a much stronger effect on ellagic, and gallic acids. During fermentation, variability in gallic acid, geraniin, corilagin, and ellagic acid did not show a consistent trend. In contrast, amino acids significantly decreased up to the second day of fermentation. Importantly, amino acids (phenylalanine, tyrosine and leucine) with characteristic bitter taste showed reductions of 20%, 30%, and 40%, respectively after 10 days of fermentation. Sucrose, which was the only sugar present in significant concentrations in unfermented seed, was significantly reduced by fermentation.     

Evaluation of fatty acids and biogenic amines profiles in mullet and tuna roe during six months of storage at 4 °C

The aim of this study was to monitor the fatty acids and biogenic amines (BAs) profiles in mullet (Mugil Cephalus) and tuna (Thunnus thynnus) roe (bottarga) during storage (0–180 days) at 4 °C. Fatty acids were analyzed by gas chromatography (GC) as methyl ester derivatives while BAs were investigated using reverse-phase liquid chromatography (RP-LC) as dansyl derivatives. The content of total fatty acids decreased with time in mullet bottarga (BM) while in tuna bottarga (BT) the PUFA value showed a slight decrease up to 30 days followed by an intense reduction after 90 and 180 days. An increasing content of BAs was observed with time in all investigated samples without reaching hazardous concentrations. In general, the BAs concentrations were in decreasing order: tyramine, putrescine, cadaverine and histamine. In BM, phenylethylamine was always present, representing a possible discriminating compound as it was absent in tuna bottarga at any time of storage. A Pearson correlation matrix showed that lipid and protein degradation products were strongly and significantly correlated over the considered storage time implying that lipid oxidation processes are in some way linked to the chemical production of BAs.     

Biogenic amine profiles and antioxidant properties of Italian red wines from different price categories

The most significant and beneficial health properties of wine consumption are related to compounds with high antioxidant capacity like polyphenols, including trans-resveratrol. Red wines are also a source of biogenic amines and sulphites that are detrimental to health. The main aim of this study was to assess whether a direct relationship between potential differences in the health-promoting and health-harmful properties can be found reflected in the commercial value of Italian red wines. Sixty Italian red wines, representative of three retail price categories, were analyzed by chromatographic and spectrophotometric techniques and the results evaluated by Principal Component Analysis. Wines in the category with a higher commercial value were clearly separated from those in the lower price category. In particular, the higher-priced wines showed higher values for trans-resveratrol (3.31 mg/L) and antioxidant capacity (p < 0.05), but also of total biogenic amines content, in particular putrescine (10.71 mg/L) and cadaverine (3.23 mg/L) (p < 0.05). The lower-priced wines showed a lower polyphenol content (1.35 g/L GAE) and a higher histamine content (1.02 mg/L) (p < 0.05). The oenological procedures that lead to wines of higher antioxidant quality cause the natural formation of only putrescine and cadaverine, which are not harmful to human health.     

Fatty acid composition, cholesterol and α-tocopherol of Barrosã-PDO veal produced in farms located in lowlands, ridges and mountains

Forty-five Barrosã calves produced according to Protected Denomination of Origin (PDO) guidelines were used to characterise intramuscular fat composition (neutral and polar lipid fractions), cholesterol and α-tocopherol contents in Barrosã-PDO meat obtained from lowlands (<400 m), ridges (400–700 m) and mountains (>700 m). In addition, meat fatty acids were used as chemical markers to differentiate veal from farms located at distinct grazing altitudes through a canonical discriminant analysis. Although the altitude of farm location seems to slightly affect the fat composition of Barrosã-PDO veal, still it depends on the muscle considered. The fatty acid composition of the polar fraction from biceps femoris muscle was the most influenced by the altitude of farm location (14:0, 16:1c, 18:1c9, 18:2n-6, 20:4n-6, odd chain saturated fatty acids, branched chain fatty acids, cis-monounsaturated fatty acids, n-6 and total polyunsaturated fatty acids; P < 0.05), followed by the polar fraction of supraspinatus muscle (18:0, conjugated linoleic acids, 20:4n-6 and even-chain saturated fatty acids; P < 0.05). Furthermore, the results herein suggest that intramuscular fatty acid profile has little relevance to discriminate Barrosã-PDO meat from lowlands, ridges and mountains.