RESUMO
Researchers are obligated to ensure food quality and provide laboratory animals with a palatable diet. Factors influencing the quality and palatability of very high-fat diet (VHFD), a widely used rodent diet, however, are understudied. We conducted experiments to establish best practices for ensuring the quality of VHFD and to improve mouse welfare. We found that VHFD in the food hopper was vulnerable first to dehydration and then oxidation within 7-days, leading to dramatic changes in food intake and food preference behavior in mice. Mitigating dehydration and oxidation of VHFD by replacing food daily, rather than weekly, stabilized feeding behavior without effect on overall cardio-metabolic health. Importantly, daily replacement of VHFD also reduced measures of anxiety-like behavior in the open field test. Refining husbandry practices to include daily replacement of VHFD can therefore ensure VHFD quality and improve animal welfare. Standardizing the practice of daily VHFD replacement may also prevent experimental confound and improve experimental reproducibility and replicability.
Assuntos
Desidratação , Dieta Hiperlipídica , Animais , Camundongos , Dieta Hiperlipídica/efeitos adversos , Reprodutibilidade dos Testes , Qualidade dos Alimentos , Ingestão de AlimentosRESUMO
This review is providing an overview of the actual and past research in the field of ground meat. The forces that are acting in the meat grinder are well understood. The higher the forces that are acting on the meat while grinding, the stronger the disintegration of the meat cells after the process. These forces can be calculated as energy transfer in meat grinders using specific mechanical energy (SME). The amount of non-intact cells (ANIC) can be used to describe the extent of disintegrated cells. Different methods are available to rate the quality of ground meat, which is mainly influenced by the raw material and processing. Over the past decades of industrialization, the landscape of ground meat production has changed. However, the effects of the process adjustments on the quality of ground meat are not yet sufficiently described in the literature.
Assuntos
Qualidade dos Alimentos , Carne , AnimaisRESUMO
The development of the green food industry can not only meet people's demand for high-quality food and promote the sustainable development of the ecological environment but also carry the additional expectation of realizing rural revitalization. Based on the data of Heilongjiang province from 2000-2021, we examined the dynamic effects of price fluctuations and Internet penetration on the green food industry using a system dynamics model. The empirical results showed that both price fluctuations and Internet penetration affect people's demand for green food, which in turn affects the development of the green food industry. The inhibitory effect of price fluctuation on green food industry is more obvious in the early stage of green food industry development, and Internet penetration always significantly promotes the development of green food industry. Moreover, the Internet penetration can effectively mitigate the negative impact of price fluctuation on the green food industry, and the impact becomes more significant with the increase of Internet penetration. The results of this study can help promote the sustainable development of the green food industry.
Assuntos
Meio Ambiente , Indústria Alimentícia , Humanos , Alimentos , Qualidade dos Alimentos , InternetRESUMO
Flour products played a vital role in the global diet structure. With the increasing demand for dietary health and food standardization, the staple food of flour products made from coarse grains due to its unique flavor and rich nutrition has become a trend and is favored by consumers. However, the lack of gluten protein in the raw materials prevented the formation of a stable gluten network structure, leading to the deterioration of the quality of flour products. Ultrasonic treatment, as an innovative food processing technology, generated energy during the action of ultrasonic waves that had a positive impact on the texture, organizational structure, or flavor characteristics of food. That was of great significance for improving food production efficiency, improving food processing quality, and extending food shelf life. This article applied ultrasonic technology to the processing of flour products from the perspective of promoting fermentation and improving production efficiency of flour products. The cavitation effect of ultrasound promoted the formation of gluten network structure, improved the rheology properties of dough and the quality of flour products by promoting protein cross-linking, improving the foaming and emulsifying stability of gluten protein, and promoting the growth and reproduction of yeast. All reviewed studies indicate that ultrasound would be a promising technology for producing high-quality surface products under appropriate conditions.
Assuntos
Pão , Farinha , Farinha/análise , Pão/análise , Glutens/química , Manipulação de Alimentos , Qualidade dos AlimentosRESUMO
In this study, rapid respirometric microbial testing was combined with 16S rRNA amplicon sequencing, to assess the composition of microbiota in a total of 64 samples of commercial beef, turkey, lamb and pork mince. The O2 sensor-based respirometry system, while producing the anticipated total aerobic viable counts (TVC) data and patterns for most samples, also revealed unusual (linear) respiration profiles for some samples, mostly lamb and pork mince. The TVC values for beef mince, produced by respirometry and calculated using the available calibration equation, correlated well with the conventional plate counting method, ISO 4833-1:2013, 2013, while for the other species the correlation was less good. These effects, not observed in previous studies employing various food matrices, require further investigation. Using the same samples (crude homogenates) as in respirometry, the whole microbiome was also analysed by 16S rRNA amplicon sequencing for each mince-type. The sequencing showed an overall decrease in alpha diversity over shelf-life, with lamb and pork mince maintaining a proportion of rare taxa. Some taxa exhibited significant changes in abundance over shelf-life and after the respirometric analysis, with beef mince exhibiting a decrease in aerobic bacteria and an increase in facultative anaerobes. Beta diversity was also seen to depend on mince-type. Thus, the combined use of respirometry and sequencing techniques shows promise as a useful and unique analytical approach for food quality and safety evaluation, However, more data points and in-depth analysis are required to back up the findings of this initial study.
Assuntos
Microbiota , Bovinos , Animais , Ovinos , RNA Ribossômico 16S/genética , Calibragem , Qualidade dos Alimentos , OxigênioRESUMO
The Huai pig is a well-known indigenous pig breed in China. The main advantages of Huai pigs over Western commercial pig breeds include a high intramuscular fat (IMF) content and good meat quality. There are significant differences in the meat quality traits of the same muscle part or different muscle parts of the same variety. To investigate the potential genetic mechanism underlying the meat quality differences in different pig breeds or muscle groups, longissimus dorsi (LD), psoas major (PM), and biceps femoris (BF) muscle tissues were collected from two pig breeds (Huai and Duroc). There were significant differences in meat quality traits and amino acid content. We assessed the muscle transcriptomic profiles using high-throughput RNA sequencing. The IMF content in the LD, PM, and BF muscles of Huai pigs was significantly higher than that in Duroc pigs (p < 0.05). Similarly, the content of flavor amino acids in the three muscle groups was significantly higher in Huai pigs than that in Duroc pigs (p < 0.05). We identified 175, 110, and 86 differentially expressed genes (DEGs) between the LD, PM, and BF muscles of the Huai and Duroc pigs, respectively. The DEGs of the different pig breeds and muscle regions were significantly enriched in the biological processes and signaling pathways related to muscle fiber type, IMF deposition, lipid metabolism, PPAR signaling, cAMP signaling, amino acid metabolism, and ECM-receptor interaction. Our findings might help improve pork yield by using the obtained DEGs for marker-assisted selection and providing a theoretical reference for evaluating and improving pork quality.
Assuntos
Qualidade dos Alimentos , Carne , Fibras Musculares Esqueléticas , Suínos , Transcriptoma , Animais , Aminoácidos/análise , Aminoácidos/biossíntese , Aminoácidos/genética , China , Carne/normas , Fibras Musculares Esqueléticas/química , Fibras Musculares Esqueléticas/metabolismo , Músculos Paraespinais/química , Músculos Paraespinais/metabolismo , Suínos/genética , Transcriptoma/genéticaRESUMO
Currently, growing concerns about sustainable development and health awareness have driven the development of plant-based meat substitutes. Soybean proteins (SPs) are eco-friendly and high-quality food sources with well-balanced amino acids to meet consumer demand. The functionality and physicochemical attributes of SPs can be improved by appropriate processing and modification. With the burgeoning advances of modern processing technologies in the food industry, a multitude of functional foods and ingredients can be manufactured based on SPs. This review mainly highlights the conformational changes of SPs under traditional and emerging processing technologies and the resultant functionality modifications. By elucidating the relationship between processing-induced structural and functional alterations, detailed and systematic insights are provided regarding the exploitation of these techniques to develop different nutritional and functional soybean products. Some popular methods to modify SPs properties are discussed in this paper, including thermal treatment, fermentation, enzyme catalysis, high hydrostatic pressure, high-intensity ultrasound, atmospheric cold plasma, high-moisture extrusion, glycosylation, pulsed ultraviolet light and interaction with polyphenols. Given these processing technologies, it is promising to expand the application market for SPs and boost the advancement of the soybean industry.
Assuntos
Manipulação de Alimentos , Proteínas de Soja , Manipulação de Alimentos/métodos , Soja , Qualidade dos Alimentos , Indústria de Processamento de AlimentosRESUMO
Biogenic amines (BAs), which naturally occur as chemicals in seafood, are indicators of food freshness and quality. High concentrations of BAs can cause an undesirable inflammatory response. However, traditional detection methods cannot meet the needs of rapid analysis nowadays. It is essential to explore a simple and valid method to monitor the food quality. Herein, we design and prepare a nanoclay-based turn on fluorescent material with BAs response, which could be used for the real-time and visual detection of raw fish freshness. As the concentration of BAs increase, the sensor of the fluorescence signal is significantly enhanced. The sensor demonstrated wonderful response and sensitivity which showed a detection limit of 0.935 mg/L for typical BAs histamine within a linear range of 2-14 mg/L in an aqueous solution. More importantly, we developed a responsive BAs device by doping the sensor into polyvinyl alcohol (PVA), which is well applied as a rapid-responsive fluorescent marker for visual monitoring the freshness of raw fish.
Assuntos
Aminas Biogênicas , Histamina , Animais , Histamina/análise , Fluorescência , Aminas Biogênicas/análise , Qualidade dos Alimentos , Peixes , Alimentos Marinhos/análiseRESUMO
Mineral nutrients spatiotemporally participate in the biosynthesis and accumulation of storage biopolymers, which directly determines the harvested grain yield and quality. Optimizing fertilizer nutrient availability improves the grain yield, but quality aspects are often underestimated. We hypothesize that extensive mineral nutrients have significant effects on the biosynthesis, content, and composition of storage proteins, ultimately determining physicochemical properties and food quality, particularly in the context of climate change. To investigate this, we hierarchized 16 plant mineral nutrients and developed a novel climate-nutrient-crop model to address the fundamental question of the roles of protein and starch in grain-based food quality. Finally, we recommend increasing the added value of mineral nutrients as a socioeconomic strategy to enhance agro-food profitability, promote environmental sustainability, and improve climate resilience.
Assuntos
Grão Comestível , Nutrientes , Grão Comestível/química , Qualidade dos Alimentos , Minerais/análiseRESUMO
Oven roasting (OR) could induce hierarchical structural changes in starch, which is fundamental for altering the pasting and hydration properties of cereal flour. OR makes proteins denatured and peptide chains unraveled or rearranged. OR could alter compositions of cereal lipids and minerals. Although OR may degrade phenolics, their release from bound forms is predominant when mild/moderate conditions are exerted. Hence, some OR-modified cereals even exhibit many physiological functions, such as anti-diabetic and anti-inflammatory activity. Furthermore, these minor components interplay with starch/protein via physical entrapment, non-covalent interactions, or cross-linking. The structural changes and interactions modulate functionalities of OR-modified cereal flour, its dough/batter property, and related staple food quality. Compared with hydrothermal or high-pressure thermal treatments, proper OR even induces greater enhancement in technological quality and bioactive compounds release. Given the simple operation and low cost, it is worth utilizing OR for the development of sensory-appealing healthy staple foods.
Assuntos
Grão Comestível , Farinha , Farinha/análise , Grão Comestível/química , Amido/química , Qualidade dos AlimentosRESUMO
BACKGROUND: Currently, meat cut traits are integrated in pig breeding objectives to gain extra profit. However, little is known about the heritability of meat cut proportions (MCP) and their correlations with other traits. The aims of this study were to assess the heritability and genetic correlation of MCP with carcass and meat quality traits using single nucleotide polymorphism chips and conduct a genome-wide association study (GWAS) to identify candidate genes for MCP. RESULTS: Seventeen MCP, 12 carcass, and seven meat quality traits were measured in 2012 pigs from four populations (Landrace; Yorkshire; Landrace and Yorkshire hybrid pigs; Duroc, and Landrace and Yorkshire hybrid pigs). Estimates of the heritability for MCP ranged from 0.10 to 0.55, with most estimates being moderate to high and highly consistent across populations. In the combined population, the heritability estimates for the proportions of scapula bone, loin, back fat, leg bones, and boneless picnic shoulder were 0.44 ± 0.04, 0.36 ± 0.04, 0.44 ± 0.04, 0.38 ± 0.04, and 0.39 ± 0.04, respectively. Proportion of middle cuts was genetically significantly positively correlated with intramuscular fat content and backfat depth. Proportion of ribs was genetically positively correlated with carcass oblique length and straight length (0.35 ± 0.08 to 0.45 ± 0.07) and negatively correlated with backfat depth (- 0.26 ± 0.10 to - 0.45 ± 0.10). However, weak or nonsignificant genetic correlations were observed between most MCP, indicating their independence. Twenty-eight quantitative trait loci (QTL) for MCP were detected by GWAS, and 24 new candidate genes related to MCP were identified, which are involved with growth, height, and skeletal development. Most importantly, we found that the development of the bones in different parts of the body may be regulated by different genes, among which HMGA1 may be the strongest candidate gene affecting forelimb bone development. Moreover, as previously shown, VRTN is a causal gene affecting vertebra number, and BMP2 may be the strongest candidate gene affecting hindlimb bone development. CONCLUSIONS: Our results indicate that breeding programs for MCP have the potential to enhance carcass composition by increasing the proportion of expensive cuts and decreasing the proportion of inexpensive cuts. Since MCP are post-slaughter traits, the QTL and candidate genes related to these traits can be used for marker-assisted and genomic selection.
Assuntos
Carne Vermelha , Suínos , Animais , Suínos/genética , Genótipo , Estudo de Associação Genômica Ampla , Qualidade dos Alimentos , Locos de Características QuantitativasRESUMO
Nitrite (NO2-) is a widely used food additive and long-term aging of cooked leftovers may also contribute to the formation of NO2-, excessive consumption of NO2- is harmful to human health. Developing an effective sensing strategy for on-site monitoring of NO2- has attracted considerable attention. Herein, a novel colorimetric and fluorometric probe ND-1 based on photoinduced electron transfer effect (PET) was designed for highly selective and sensitive detection of nitrite (NO2-) in foods. The probe ND-1 was strategically constructed by employing naphthalimide as the fluorophore and o-phenylendiamine as the specific recognition site for NO2-. The triazole derivative ND-1-NO2- could be produced exclusively by reacting with NO2-, leading to a visible colorimetric change from yellow to colorless accompanied by a significantly enhanced fluorescence intensity at 440 nm. The probe ND-1 exhibited promising sensing performances towards NO2- including high selectivity, rapid response time (within 7 min), low detection limit (47.15 nM) and wide quantitative detection range (0-35 µM). In addition, probe ND-1 was capable of quantitative detecting of NO2- in real food samples (including pickled vegetables and cured meat products) with satisfactory recovery rates (97.61%-103.08%). Moreover, the paper device loaded by probe ND-1 could be utilized for visual monitoring of NO2- levels variation of stir-fried greens. This study provided a feasible method for the accurate, traceable and rapid on-site monitoring NO2- in foods.
Assuntos
Corantes Fluorescentes , Nitritos , Humanos , Nitritos/análise , Naftalimidas , Dióxido de Nitrogênio , Qualidade dos AlimentosRESUMO
Phenol-protein interaction is considered an effective tool to improve the functional properties of vegan proteins. The present work aimed to evaluate the covalent interaction between kidney bean polyphenols with rice protein concentrate and studied their characteristics for quality improvement in vegan-based foods. The impact of interaction on the techno-functional properties of protein was evaluated and the nutritional composition revealed that kidney bean was rich in carbohydrates. Furthermore, a noticeable antioxidant activity (58.11 ± 1.075 %) due to the presence of phenols (5.5 mg GAE/g) was observed for the kidney bean extract. Moreover, caffeic acid and p-Coumaric acid were confirmed using ultra-pressure liquid chromatography and the amount was 194.43 and 0.9272 mg/kg, respectively. A range of rice protein- phenols complexes (PPC0.025, PPC0.050, PPC0.075, PPC0.1, PPC0.2, PPC 0.5, PPC1) were examined and PPC0.2 and PPC0.5 showed significantly (p < 0.05) higher binding efficiency with proteins via covalent interaction. The conjugation reveals changes in physicochemical properties of rice protein, including, reduced size (178.4 nm) and imparted negative charges (-19.5 mV) of the native protein. The presence of amide â , â ¡, â ¢, was confirmed in native protein and protein-phenol complex with vibration bands, particularly at 3784.92, 1631.07, and 1234 cm-1, respectively. The X-ray diffraction pattern depicted a slight decrease in crystallinity after the complexation and scanning electron microscopy revealed the alteration in morphology from less to improved smoothness and continuous surface characteristics for the complex. Thermo gravimetric analysis revealed high thermal stability of the complex with a maximum weight loss at a temperature range of 400-500 °C. Protein-phenol complex added fruit-based smoothie was developed and it was found to be acceptable in terms of various sensory attributes including color & appearance, textural consistency, and mouthfeel as compared to the control smoothie. Overall, this study provided novel insights to understand the phenol-protein interactions and the possible use of the phenol-rice protein complex in the development of vegan-based food products.
Assuntos
Fabaceae , Oryza , Humanos , Fenóis/análise , Fabaceae/química , Fenol/análise , Oryza/química , Frutas/química , Veganos , Verduras/química , Qualidade dos AlimentosRESUMO
Several of the existing food manufacturing processes are based on empirical knowledge, and not many are rationally designed and operated based on a sufficient understanding of the underlying phenomena. Drying and rehydration processes are one such example of this, and a new method for measuring the moisture distribution was developed, focusing on the fact that the brightness of food varies depending on its moisture content. Using this method, new mechanisms of water transfer inside food were proposed based on the rehydration process of noodles. In addition, as a new analysis method for understanding of extremely complex phenomena, we suggest the "artificial intelligence comprehensive and reverse analysis methods". As a future prospect, we discussed the possibility that this method could contribute to elucidating various unknown complex phenomena.
Assuntos
Inteligência Artificial , Manipulação de Alimentos , Manipulação de Alimentos/métodos , Dessecação , Água/química , Qualidade dos AlimentosRESUMO
In this work, we reported a chromogenic and near infrared (NIR) region fluorogenic dual-channel probe NRB, which could visually detect gaseous amines with high sensitivity (eg. 50 and 17 ppt for methylamine (MeNH2) via naked eyes and fluorescence spectrometer respectively). It exhibited a wide fluorescent emission band extending to the NIR region with a peak at 615 nm when stimulated by the MeNH2 solution. The plausible sensing mechanism was proved by mass spectrometry, where the reaction process was based on a nucleophilic substitution between the probe and amines rather than the ester group hydrolysis. Furthermore, NRB was successfully applied to monitor the food freshness (seafood and meat food), because of its low cytotoxicity and excellent photophysical properties. It was worth mentioning that real time monitoring for food quality can be realized visually by using a 365 nm UV lamp. In addition, the probe was stable during the quality guarantee period for perishable packaged food. It was believed that the applied experiments have demonstrated the value of this probe in the practical applications for food safety.
Assuntos
Aminas , Corantes Fluorescentes , Corantes Fluorescentes/química , Colorimetria/métodos , Qualidade dos Alimentos , CarneRESUMO
Intelligent labels provide customers with food freshness information. However, the existing label response is limited and can only detect a single kind of food. Here, an intelligent cellulose-based label with highly antibacterial activity for a multi-range sensing freshness was developed to overcome the limitation. Cellulose fibers were modified using oxalic acid to graft -COO- followed by binding chitosan quaternary ammonium salt (CQAS), the remaining charges of which attached methylene red and bromothymol blue to form response fibers and to further self-assemble into the intelligent label. CQAS electrostatically gathered the dispersed fibers, resulting in an increase in TS and EB of 282 % and 16.2 %, respectively. After that, the rest positive charges fixed the anionic dyes to broaden pH response range of 3-9 effectively. More significantly, the intelligent label exhibited highly antimicrobial activity, killing 100 % of staphylococcus aureus. The rapid acid-base response revealed the potential for practical application in which the label color from green to orange represented the milk or spinach from fresh to close to spoiled, and from green to yellow, and to light green indicated the pork fresh, acceptable, and close to spoiled. This study paves a way for the preparation of intelligent labels in large-scale and promote the commercial application to improve food safety.
Assuntos
Celulose , Quitosana , Celulose/química , Alimentos Marinhos/análise , Azul de Bromotimol , Qualidade dos Alimentos , Corantes , Quitosana/química , Embalagem de Alimentos/métodos , Concentração de Íons de Hidrogênio , Antocianinas/químicaRESUMO
Introducción: Los chocolates son procesados en fábricasde alta, mediana y pequeña escala, donde el cacao pasa pordiferentes operaciones unitarias que brindan el valor agregado esperado; sin embargo, es importante controlar los ingredientes de la formulación: azucares totales y grasa saturada, que afecta el sobrepeso del consumidor de chocolates. Objetivo: Evaluar aspectos de calidad de un chocolate oscuro al 70% de cacao a partir de una fórmula optimizada (CO-70) en cuanto a aspectos energéticos, componentes antioxidantes, de inocuidad y sensoriales. Materiales y métodos: Se analizó valores nutricionales, componentes antioxidantes y alcaloides, valores microbiológicos y toxicológicos, así como la aceptabilidad sensorial conconsumidores de 20 a 40 años, utilizando métodos analíticos. Resultados y discusiones: Los resultados muestran aun CO-70 reducido en calorías con 555,9 ± 0,1 kcal; un nivel de azúcar de 35,45 g; un nivel de grasa de 35,12 g; contenido de ácidos grasos insaturados de 13,05 ± 0,03 g; uncontenido de proteínas de 11,88 g; una cantidad importantede polifenoles de 2,20 ± 0,15 g EAG en 100 g chocolate; libre de microorganismos patógenos y compuestos tóxicos;con una aceptabilidad sensorial de 70,80 % en consumidores peruanos. Conclusiones: Con el adecuado diseño y desarrollo deproductos se pueden obtener chocolates con calidad sensoria nutricional cada vez mejores, en beneficio de la salud del consumidor.(AU)
Introduction: The chocolates are processed in factoriesof high, medium, and small scale, where the cacao beansgo through different unit operations that provide the exected added value; however, it is important to control theingredients of the formulation: total sugars and saturatedfatty acids, which affects the overweight of the chocolateconsumer. Aim: To evaluate quality aspects of a dark chocolate 70 %cacao made from an optimized formula (CO-70) in terms ofenergy aspects, antioxidants components, safety and sensory. Materials and methods: The following were analyses nutritional values, antioxidant, and alkaloid components, microiological and toxicological, as well as sensory acceptabilitywith 2040-year-old consumers, using analytical methods. Results and discussions: The CO-70 reduced in calorieswith 555.9 ± 0.1 kcal; a sugar level of 35.45 g; a fat level of35.12 g; unsaturated fatty acid content of 13.05 ± 0.03 g; aprotein content of 11.88 g; a significant number of polyphenols of 2.20 ± 0.15 g GAE in 100 g chocolate; free of pathogenic microorganisms and toxic compounds; with a sensoryacceptability of 70.80% in peruvian eaters. Conclusions: With the adequate design and developmentof products, chocolates with sensory and nutritional quality that are increasingly better for the health of the consumer canbe obtained.(AU)
Assuntos
Humanos , Chocolate/análise , Cacau , Qualidade dos Alimentos , Alcaloides , Antioxidantes , Valor Nutritivo , Gorduras InsaturadasRESUMO
Today, one of the world's biggest problems is the assurance of food integrity from farm to fork. Economically motivated food adulteration and food authenticity problems are increasing daily with considerable health and economic effects. Early detection and prevention of food integrity-related problems could be provided by the application of effective on-site food analysis technologies. FTIR spectroscopy coupled with chemometrics can be used for the rapid quality control of a wide variety of food products with fast, high-throughput, accurate and nondestructive analysis advantages. In particular, hand-held and portable FTIR instruments have the potential to surveil food quality and food safety in various critical segments of the food supply chain. In this review, we explore the abilities of hand-held and portable FTIR spectrometers combined with multivariate statistics to conduct a quality evaluation of various food products in terms of food adulteration and authenticity issues. An examination of the literature showed that comparable results were obtained based on detection limits, correlation coefficient (R2) values, standard error values and discrimination power by using both portable/hand-held FTIR spectrometers and benchtop FTIR spectrometers. In conclusion, this review highlights the potential usefulness of portable and hand-held FTIR spectrometers combined with chemometrics for maintaining the food quality through the presentation of various applications that may shed light for on-site food control at any point of the food supply chain.
Assuntos
Qualidade dos Alimentos , Inocuidade dos Alimentos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Fazendas , Contaminação de Alimentos/prevenção & controle , Contaminação de Alimentos/análise , Controle de QualidadeRESUMO
Histamine is a biogenic amine found in fish-derived and fermented food products with physiological relevance since its concentration is proportional to food spoilage and health risk for sensitive consumers. There are various analytical methods for histamine quantification from food samples; however, a simple and quick enzymatic detection and quantification method is highly desirable. Histamine dehydrogenase (HDH) is a candidate for enzymatic histamine detection; however, other biogenic amines can change its activity or produce false positive results with an observed substrate inhibition at higher concentrations. In this work, we studied the effect of site saturation mutagenesis in Rhizobium sp. Histamine Dehydrogenase (Rsp HDH) in nine amino acid positions selected through structural alignment analysis, substrate docking, and proximity to the proposed histamine-binding site. The resulting libraries were screened for histamine and agmatine activity. Variants from two libraries (positions 72 and 110) showed improved histamine/agmatine activity ratio, decreased substrate inhibition, and maintained thermal resistance. In addition, activity characterization of the identified Phe72Thr and Asn110Val HDH variants showed a clear substrate inhibition curve for histamine and modified kinetic parameters. The observed maximum velocity (Vmax) increased for variant Phe72Thr at the cost of an increased value for the Michaelis-Menten constant (Km) for histamine. The increased Km value, decreased substrate inhibition, and biogenic amine interference observed for variant Phe72Thr support a tradeoff between substrate affinity and substrate inhibition in the catalytic mechanism of HDHs. Considering this tradeoff for future enzyme engineering of HDH could lead to breakthroughs in performance increases and understanding of this enzyme class.
Assuntos
Agmatina , Rhizobium , Animais , Histamina/metabolismo , Especificidade por Substrato , Rhizobium/metabolismo , Agmatina/análise , Aminas Biogênicas/análise , Qualidade dos Alimentos , Engenharia de ProteínasRESUMO
Frequently occurrence of food safety incidents has induced global concern over food safety. To ensure food quality and safety, an increasing number of rapid and sensitive analytical methods have been developed for analysis of all kinds of food composition and contaminants. As one of the high-profile analytical techniques, Raman spectroscopy has been widely applied in food analysis with simple, rapid, sensitive, and nondestructive detection performance. Research on Raman techniques is a direction of great interest to many fields, especially in food safety. Hence, it is crucial to gain insight into recent advances on the use of Raman-based techniques in food safety applications. In this review, we introduce Raman techniques from normal Raman spectroscopy to developed ones (e.g., surface enhanced Raman scattering (SERS), spatially offset Raman spectroscopy (SORS), surface-enhanced spatially offset Raman spectroscopy (SESORS)), in view of their history and development, principles, design, and applications. In addition, future challenges and trends of these techniques are discussed regarding to food safety.