SIMULTANEOUS DETERMINATION OF FREE AMINO ACIDS, L-CARNOSINE, PURINE, PYRIMIDINE, AND NUCLEOSIDES IN MEAT BY LIQUID CHROMATOGRAPHY/SINGLE QUADRUPOLE MASS SPECTROMETRY

Rapid and sensitive approaches for detecting food fraud: A review on prospects and challenges

Precise and reliable analytical techniques are required to guarantee food quality in light of the expanding concerns regarding food safety and quality. Because traditional procedures are expensive and time-consuming, quick food control techniques are required to ensure product quality. Various analytical techniques are used to identify and detect food fraud, including spectroscopy, chromatography, DNA barcoding, and inotrope ratio mass spectrometry (IRMS). Due to its quick findings, simplicity of use, high throughput, affordability, and non-destructive evaluations of numerous food matrices, NI spectroscopy and hyperspectral imaging are financially preferred in the food business. The applicability of this technology has increased with the development of chemometric techniques and near-infrared spectroscopy-based instruments. The current research also discusses the use of several multivariate analytical techniques in identifying food fraud, such as principal component analysis, partial least squares, cluster analysis, multivariate curve resolutions, and artificial intelligence.

Study on the Correlations between Quality Indicators of Dry-Aged Beef and Microbial Succession during Fermentation

Dry-aged beef has been long favored by people due to its unique flavor and taste. However, the inner relationship between its overall quality formation and microbial changes during dry aging has not yet received much attention and research. To deeply reveal the forming mechanism of the unique flavor and taste of dry-aged beef, correlations between its three main quality indicators, i.e., texture, free amino acids (FAAs), volatile flavor compounds (VFCs), and microbial succession were analyzed in this study. The results showed that Staphylococcus spp. and Macrococcus spp. were key strains that influenced the total quality of dry-aged beef and strongly correlated with chewiness, hardness, and sweet FAAs (Ala), providing beef with unique palatability and taste. Additionally, among VFCs, Staphylococcus spp. and Macrococcus spp. showed a strong correlation with octanal and heptanal, and meanwhile, those highly correlated with nonanal, pentanol, and oct-1-en-3-ol were Debaryomyces spp., Psychrobacter spp., and Brochothrix spp., respectively, providing beef with a unique flavor. Staphylococcus spp. was proposed to be the dominant genus for dry-aged beef. This study provides valuable reference for the understanding of the role of microorganisms involved in dry aging.

Carnosine, Small but Mighty-Prospect of Use as Functional Ingredient for Functional Food Formulation

Carnosine is a dipeptide synthesized in the body from β-alanine and L-histidine. It is found in high concentrations in the brain, muscle, and gastrointestinal tissues of humans and is present in all vertebrates. Carnosine has a number of beneficial antioxidant properties. For example, carnosine scavenges reactive oxygen species (ROS) as well as alpha-beta unsaturated aldehydes created by peroxidation of fatty acid cell membranes during oxidative stress. Carnosine can oppose glycation, and it can chelate divalent metal ions. Carnosine alleviates diabetic nephropathy by protecting podocyte and mesangial cells, and can slow down aging. Its component, the amino acid beta-alanine, is particularly interesting as a dietary supplement for athletes because it increases muscle carnosine, and improves effectiveness of exercise and stimulation and contraction in muscles. Carnosine is widely used among athletes in the form of supplements, but rarely in the population of cardiovascular or diabetic patients. Much less is known, if any, about its potential use in enriched food. In the present review, we aimed to provide recent knowledge on carnosine properties and distribution, its metabolism (synthesis and degradation), and analytical methods for carnosine determination, since one of the difficulties is the measurement of carnosine concentration in human samples. Furthermore, the potential mechanisms of carnosine's biological effects in musculature, metabolism and on immunomodulation are discussed. Finally, this review provides a section on carnosine supplementation in the form of functional food and potential health benefits and up to the present, neglected clinical use of carnosine.

Impact of Nisin-Producing Strains of Lactococcus lactis on the Contents of Bioactive Dipeptides, Free Amino Acids, and Biogenic Amines in Dutch-Type Cheese Models

The goal of this study was to determine changes in contents of free amino acids, biogenic amines, and bioactive dipeptides (anserine and L-carnosine) in cheese models produced with the addition of nisin-producing strains of Lactococcus lactis over their ripening period. After 5 weeks of ripening, contents of total biogenic amines in the cheese models with the addition of L. lactis strains were lower than in the control cheese model. The cheese models examined differed significantly in contents of free amino acids through the ripening period. Individual free amino acids, such as ornithine, were found in some of the cheese models, which is indicative of their specific microbial activities. Both anserine and L-carnosine were detected in all variants of the cheese models. After 5-week ripening, the highest total content of bioactive dipeptides was determined in the cheese models produced with the nisin-producing culture of L. lactis 11454 (142.15 mg∙kg⁻¹).

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

Taurine (a sulfur-containing β-amino acid), creatine (a metabolite of arginine, glycine and methionine), carnosine (a dipeptide; β-alanyl-L-histidine), and 4-hydroxyproline (an imino acid; also often referred to as an amino acid) were discovered in cattle, and the discovery of anserine (a methylated product of carnosine; β-alanyl-1-methyl-L-histidine) also originated with cattle. These five nutrients are highly abundant in beef, and have important physiological roles in anti-oxidative and anti-inflammatory reactions, as well as neurological, muscular, retinal, immunological and cardiovascular function. Of particular note, taurine, carnosine, anserine, and creatine are absent from plants, and hydroxyproline is negligible in many plant-source foods. Consumption of 30 g dry beef can fully meet daily physiological needs of the healthy 70-kg adult human for taurine and carnosine, and can also provide large amounts of creatine, anserine and 4-hydroxyproline to improve human nutrition and health, including metabolic, retinal, immunological, muscular, cartilage, neurological, and cardiovascular health. The present review provides the public with the much-needed knowledge of nutritionally and physiologically significant amino acids, dipeptides and creatine in animal-source foods (including beef). Dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline are beneficial for preventing and treating obesity, cardiovascular dysfunction, and ageing-related disorders, as well as inhibiting tumorigenesis, improving skin and bone health, ameliorating neurological abnormalities, and promoting well being in infants, children and adults. Furthermore, these nutrients may promote the immunological defense of humans against infections by bacteria, fungi, parasites, and viruses (including coronavirus) through enhancing the metabolism and functions of monocytes, macrophages, and other cells of the immune system. Red meat (including beef) is a functional food for optimizing human growth, development and health.

Inhibitory profiles of spices against free and protein-bound heterocyclic amines of roast beef patties as revealed by ultra-performance liquid chromatography-tandem mass spectrometry and principal component analysis

The effects of various levels of chili pepper, Sichuan pepper, and black pepper on the amounts of 17 heterocyclic amines (HAs) from seven categories of both free and protein-bound states in roast beef patties were assessed by ultra-performance liquid chromatography-tandem mass spectrometry combined with principal component analysis. Three groups of HA, including imidazopyridines (DMIP), imidazoquinoxalines (MeIQx and 4,8-MeIQx), and β-carbolines (norharman and harman), were detected and quantified in both their free and protein-bound states, whereas PhIP was detected only in its free state, and imidazoquinolines (IQ, IQ[4,5-b], and MeIQ), α-carbolines (AαC and MeAαC), and phenylpyridines (Phe-P-1) were detected only in their protein-bound states. The results demonstrate that the peppers at all three levels had significant inhibitory effects on free PhIP, DMIP, MeIQx, and 4,8-DiMeIQx and could promote free norharman. Harman was significantly suppressed by chili pepper and black pepper, but enhanced by Sichuan pepper. All 11 protein-bound HAs, with the exception of IQ, IQ[4,5-b], and MeIQx with added chili pepper, were significantly reduced by the three peppers. The total amounts of the free and protein-bound states of all 11 HAs (1692.4 ± 78.9 ng g^-1), imidazopyridines (5.5 ± 0.2 ng g^-1), imidazoquinolines (7.2 ± 0.2 ng g^-1), imidazoquinoxalines (6.9 ± 0.2 ng g^-1), α-carbolines (20.1 ± 0.4 ng g^-1), and β-carbolines (1651.7 ± 79.5 ng g^-1) were suppressed by each level of all of the three peppers except for 0.5% and 1.0% chili pepper. Our findings may facilitate the inhibition of HA formation in the processing of meat products.

Liquid Chromatography-Single-Quadrupole Mass Spectrometry as a Responsive Tool for Determination of Biogenic Amines in Ready-to-Eat Baby Foods

Baby food has never been the object of biogenic amine profiling. The aim of this study was to develop a highly sensitive method for analysis of biogenic amines in ready-to-eat baby foods. The principle of the developed method involves high-performance liquid chromatography coupled to single-quadrupole mass spectrometry (HPLC-APCI-MS) of dansyl derivatives, presented also in comparison with common diode array and fluorescence detection systems. The confirmation of correct identification of derivatives was performed by in-source fragmentation of the product ion at 170 m/z, performed only in one MS analyzer. The method was used to identify the amine profile and quantify the putrescine, cadaverine, histamine, tyramine, spermidine, and spermine content in 68 ready-to-eat baby foods. The limits of detection and quantification were in the range of 0.07-1.67 and 0.2-5.0 ng mL^- 1. The method enabled quantification of amines at ng/g level in almost all analyzed samples, without any preconcentration step. Amine recoveries of 86.0-105.2% were obtained with RSD ≤ 9.7%. The developed method could be used for quantification of the most frequently occurring BAs in foods including vegetables, fish, meat, or fruit at previously undetectable concentration levels, making the method multimatrix applicable and highly-sensitive.

The effects of different spices and fat types on the formation of heterocyclic aromatic amines in barbecued sucuk

BACKGROUND

Sucuk is one of the popular traditional Turkish meat products. The aim of this research was to evaluate the effects of different spices (clove, 0.2%; cinnamon, 0.5%) and animal fat types (beef fat, tallow, subcutaneous and tail fat) on the formation of heterocyclic aromatic amine (HCA) in barbecued sucuk.

RESULTS

Although 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAαC) could not be detected in the any of the samples, 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx) (up to 0.54 ng g^-1 ), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (up to 5.96 ng g^-1 ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (up to 0.21 ng g^-1 ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) (up to 0.34 ng g^-1 ), 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx) (up to 0.32 ng g^-1 ), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (up to 0.19 ng g^-1 ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (up to 1.94 ng g^-1 ) and 2-amino-9H-pyrido[2,3-b]indole (AαC) (up to 0.98 ng g^-1 ) were found in the barbecued sucuk samples.

CONCLUSION

The results of the current study have shown that HCAs could be formed in barbecued sucuk. Total HCA can be affected by adding different fat types; however, adding clove and cinnamon decreased the total HCA content in the subcutaneous fat group of sucuk samples. © 2017 Society of Chemical Industry.

Contents variation analysis of free amino acids, nucleosides and nucleobases in semen sojae praeparatum fermentation using UFLC-QTRAP MS

UFLC-QTRAP MS was used to develop a sensitive and rapid method of evaluating content variation during Semen sojae praeparatum (SSP) fermentation. It did this through the simultaneous quantification of 22 free amino acids and 16 nucleosides and nucleobases in the raw materials and processed products of SSP. The method was shown to be reproducible and accurate. The limits of detection and quantity values were 0.09-168.75 and 0.31-562.50 ng/mL for the 38 analytes, respectively. The data were examined through principal components analysis to compare the content variations. The quantitative results showed that the ingredients were properly determined in most of the samples and were converted regularly throughout the SSP fermentation process. These results correspond to the morphologic changes and principal components analysis results.

Recent trends in analytical methods for the determination of amino acids in biological samples

Amino acids are widely distributed in biological fluids and involved in many biological processes, such as the synthesis of proteins, fatty acids, and ketone bodies. The altered levels of amino acids in biological fluids have been found to be closely related to several diseases, such as type 2 diabetes, kidney disease, liver disease, and cancer. Therefore, the development of analytical methods to measure amino acid concentrations in biological samples can contribute to research on the physiological actions of amino acids and the prediction, diagnosis and understanding of diseases. This review describes the analytical methods reported in 2012-2016 that utilized liquid chromatography and capillary electrophoresis coupled with ultraviolet, fluorescence, mass spectrometry, and electrochemical detection. Additionally, the relationship between amino acid concentrations and several diseases is also summarized.

Formation of Free and Protein-Bound Heterocyclic Amines in Roast Beef Patties Assessed by UPLC-MS/MS

The effect of different roasting temperatures on the amounts of 17 heterocyclic amines (HAs) from seven categories of both free and protein-bound states in roast beef patties was assessed using an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. There were increased amounts and more types of HAs detected at higher roasting temperatures. Nine free HAs were detected at 250 °C, including PhIP (14.34 ± 0.36 ng/g), DMIP (1.02 ± 0.07 ng/g), 1,5,6-TMIP (1.70 ± 0.08 ng/g), MeIQ (0.36 ± 0.01 ng/g), IQx (0.37 ± 0.04 ng/g), MeIQx (9.94 ± 0.61 ng/g), 4,8-DiMeIQx (0.90 ± 0.05 ng/g), norharman (6.03 ± 0.30 ng/g), and harman (2.60 ± 0.09 ng/g). Also, 37.32 ng/g of total free HAs was generated. Twelve protein-bound HAs were detected in roast beef patties at 250 °C, including PhIP (1.70 ± 0.13 ng/g), DMIP (2.33 ± 0.25 ng/g), 1,5,6-TMIP (3.62 ± 0.49 ng/g), MeIQ (5.47 ± 0.18 ng/g), IQ[4,5-b] (0.70 ± 0.03 ng/g) MeIQx (4.03 ± 0.41 ng/g), 4,8-DiMeIQx (0.67 ± 0.09 ng/g), MeAαC (19.51 ± 1.12 ng/g), AαC (2.91 ± 0.45 ng/g), norharman (1304.96 ± 110.73 ng/g), harman (400.85 ± 25.29 ng/g), and Phe-P-1 (0.81 ± 0.06 ng/g). The highest amount of protein-bound HAs was 2913.31 ng/g at 175 °C. PhIP tended to exist in a free state, whereas MeIQ, harman, and norharman tended to exist in a protein-bound state. Furthermore, Phe-P-1, MeAαC, and AαC were detected only in a protein-bound state. These results could be useful for evaluating the exposure to HAs in a daily diet.

Composition of free and peptide-bound amino acids in beef chuck, loin, and round cuts

Meat is a food for humans. However, beef consumption in the United States has steadily declined by >14% over the past decade due to a variety of factors, including insufficient knowledge of animal protein. This study quantified all proteinogenic AA as well as nutritionally and physiologically significant nonproteinogenic AA and small peptides in beef cuts from 3 subprimals (chuck, round, and loin). Beef carcasses ( = 10) were selected at 3 commercial packing plants in the United States. Retail-cut samples were analyzed for the nitrogenous substances after acid, alkaline, or enzymatic hydrolysis and after deproteinization. In these chuck, round, and loin cuts, total amounts of glutamate (free plus peptide bound) were the highest (69-75 mg/g dry weight) followed by lysine, leucine, arginine, and glutamine in descending order. This is the first study to determine aspartate, asparagine, glutamate, and glutamine in meat proteins of any animal species. In all the beef samples evaluated, glutamine was the most abundant free AA (4.0-5.7 mg/g dry weight) followed by taurine, alanine, glutamate, and β-alanine. Additionally, samples from all beef cuts had high concentrations of anserine, carnosine, and glutathione, which were 2.8 to 3.7, 15.2 to 24.2, and 0.68 to 0.79 mg/g dry weight, respectively. Beef top loin steaks appear to provide higher protein nutrition values than top round steaks and under blade roasts, but all are excellent sources of proteinogenic AA as well as antioxidant AA and peptides to improve human growth, development, and health. Our findings may help guide future decisions regarding human and animal nutrition.

Simultaneous Quantitation of Free Amino Acids, Nucleosides and Nucleobases in Sipunculus nudus by Ultra-High Performance Liquid Chromatography with Triple Quadrupole Mass Spectrometry

To evaluate the nutritional and functional value of Sipunculus nudus, a rapid, simple and sensitive analytical method was developed using ultra-high performance liquid chromatography coupled with a triple quadrupole mass detection in multiple-reaction monitoring mode for the simultaneous quantitative determination of 25 free amino acids and 16 nucleosides and nucleobases in S. nudus within 20 min, which was confirmed to be reproducible and accurate. The limits of detection (LODs) and quantification (LOQs) were between 0.003–0.229 μg/mL and 0.008–0.763 μg/mL for the 41 analytes, respectively. The established method was applied to analyze 19 batches of S. nudus samples from four habitats with two different processing methods. The results showed that S. nudus contained a variety of free amino acids, nucleosides and nucleobases in sufficient quantity and reasonable proportion. They also demonstrated that the contents of these compounds in different parts of S. nudus were significantly discriminating, which were in the order: (highest) coelomic fluid > body wall > intestine (lowest). The method is simple and accurate, and could serve as a technical support for establishing quality control of S. nudus and other functional seafoods. Moreover, the research results also laid foundation for further exploitation and development of S. nudus.

Bioaccessibility of the Bioactive Peptide Carnosine during in Vitro Digestion of Cured Beef Meat

A bioactive compound is a food component that may have an impact on health. Its bioaccessibility, defined as the fraction released from the food matrix into the gastrointestinal tract during digestion, depends on compound stability, interactions with other food components, and supramolecular organization of food. In this study, the effect of pH on the bioaccessibility of the bioactive dipeptide carnosine was evaluated in two commercial samples of the Italian cured beef meat bresaola at two key points of digestion: before the gastric and after the duodenal phases. The digestion process was simulated using an in vitro static system, whereas capillary zone electrophoresis (CZE) and (1)H nuclear magnetic resonance (NMR) were used for quantitative analysis. The gap between the total carnosine content, measured by CZE, and its free diffusible fraction observable by NMR spectroscopy, was 11 and 19% for two independent bresaola products, where such percentages represent the fraction of carnosine not accessible for intestinal absorption because it was adsorbed to the food matrix dispersed in the digestion fluid.