美拉德反应研究进展

美拉德反应(Maillard Reaction)是指氨基化合物和羰基化合物之间的一类化学反应,此类反应常存在于食品加工、烟草研制、中药炮制、疾病生理以及饲料制备和酒业酿造等过程中。近年来,Maillard反应的研究主要集中在中药现代化和疾病生理等方面,尤其关注抗氧化产物以及甲基糠醛和丙烯酰胺等与人类健康密切相关方面的研究。拟对Maillard反应研究进展做一简要综述,并在此基础上对Maillard反应在各领域中的前景作一展望,为Maillard反应各类研究及应用提供一定的参考。     

食源蛋白水解物/多肽与糖类物质美拉德反应产物在食品应用中的研究进展

食源蛋白水解物/多肽和糖类物质是极具开发利用价值的食物资源，两者经美拉德反应得到的共价复合物结构和营养功能优势突出，美拉德反应被广泛用于改善蛋白水解物功能特性，已成为当前食品科学研究领域关注的热点。本文综述了食源蛋白水解物/多肽与糖类物质美拉德反应产物的原料来源、反应机制、制备方法、结构表征、功能性质、营养生物活性以及在食品医药领域应用的最新研究进展和展望，可为推动食源蛋白水解物/多肽与糖类物质美拉德反应产物功能产品开发提供新思路，也为其健康效应的深入研究提供理论参考。     

Creating proteins with novel functionality via the Maillard reaction: a review

Proteins are widely utilized to add functional properties, such as gelling and emulsification to foods. These attributes depend on a number of factors such as molecular structure of the protein, the pH, and the composition of its chemical environment. There is substantial evidence to suggest that the functional properties of food proteins can be further improved by derivatization. Covalent bonding of proteins to polysaccharides and smaller reducing sugars via the Maillard reaction has been shown to alter the functionality of proteins without requiring the addition of chemical reagents. Establishment of a technologically feasible method for preparing the conjugates and optimization of the processing conditions, however, is needed to promote their development as functional food ingredients. This paper provides a state-of-the-art contribution to the impact of the Maillard reaction on protein functionality. It presents a deeper understanding of the influence of processing conditions and reactant formulation on improving desirable properties of proteins. In particular attention is given to how potential improvements could be achieved in the emulsifying, textural, and solubility properties of proteins to add value to commodity food ingredients. Elements that are considered to be critical to the design of functional Maillard conjugates are highlighted and suggestions proposed to facilitate progress in this area.     

Forty years of furosine - forty years of using Maillard reaction products as indicators of the nutritional quality of foods

The Maillard reaction products (MRPs) most widely used as markers of the nutritional quality of foods are furosine, N(epsilon)-carboxymethyllysine (CML), hydroxymethylfurfural, pyrraline, pentosidine and pronyl-lysine. One of the MRPs identified first was furosine, which was quantified in foods 40 years ago as a chemical indicator of the Amadori compound N(epsilon)-fructoselysine. Since then, furosine has gained broad attention by food chemists and biomedical researchers, as its formation upon heat treatment is well characterised. Moreover, it represents the Amadori products from early Maillard reactions in which amino acids react with reducing carbohydrates, resulting in a loss of their availability. This is of importance for the essential amino acid lysine, which is also the limiting amino acid in many proteins. In order to evaluate the nutritional quality of a protein, the concomitant analysis of free - and nutritionally available - lysine and the amount of lysine reacted to form the respective MRP is essential, even for mildly processed foods. The other chemical markers of heat treatment such as CML, pyrraline, pentosidine or pronyl-lysine seem to be useful markers of the advanced stages of Maillard reactions. Compared to the conditions in which furosine is formed, these compounds are generated under more severe conditions of heat treatment. However, the concentrations analysed are significantly lower than those of furosine. Therefore, the nutritional evaluation of a food protein should include not only furosine, but also other chemical markers of heat treatment such as, for example, CML, pyrraline and pentosidine.     

Techno-functional properties of dry-fractionated plant-based proteins and application in food product development: a review

Dry-fractionated protein concentrates are gaining attention because they are produced using a versatile and sustainable technology, which can be applied to a wide range of plant material. To facilitate their utilization in new product development, it is crucial to obtain a comprehensive overview of their techno-functional properties. The present review aims to examine the techno-functional properties of dry-fractionated protein concentrates and describe their primary applications in food products, considering the published works in the last decade. The techno-functional properties of proteins, including water absorption capacity, emulsifying and foaming properties, gelling ability or protein solubility, are relevant factors to consider during food formulation. However, these properties are significantly influenced by the extraction technology, the type of protein and its characteristics. Overall, dry-fractionated proteins are characterized by high protein solubility, high foaming ability and foam stability, and high gelling ability. Such properties have been exploited in the development of food, such as bakery products and pasta, with the aim of increasing the protein content and enhancing the nutritional value. Additionally, innovative foods with distinctive textural and nutritional characteristics, such as meat and dairy analogues, have been developed by using dry-fractionated proteins. The results indicate that the study of these ingredients still needs to be improved, including their application with a broader range of plant materials. Nevertheless, this review could represent an initial step to obtaining an overview of the techno-functional properties of dry-fractionated proteins, facilitating their use in foods. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Determination of Nε-carboxymethyllysine in heated milk products by immunochemical methods

  N ^ε-Carboxymethyllysine (CML) is an important Maillard product which is formed in vivo and during food processing and heating, and which can therefore be used as a marker for heat damage of foodstuffs. A competitive enzyme-linked immunosorbent assay (ELISA) was developed to detect CML modifications on proteins. CML protein was synthesized and anti-CML antiserum was prepared, which recognized CML modifications specifically on CML proteins and proteins which were incubated with various carbohydrates. Heated milk and milk powder samples could be directly tested by ELISA without further clean-up procedures and the CML contents were determined in relation to reaction time and heating conditions. Positive results were confirmed by SDS-PAGE/immunoblotting using the same antiserum. ELISA proved to be a fast, specific, and easy-to-handle method to evaluate CML formation in heated milk products. Additionally, SDS-PAGE/immunoblotting can be helpful to detect CML also in insoluble food proteins. Received: 10 September 1998     

食品中丙烯酰胺形成机理的研究进展

综述了当前研究富含淀粉的食品在油炸、煎炸和焙烤等高温加工工艺形成丙烯酰胺的几种可能的反应机理.目前获得的公认研究结果是:天冬酰胺酸与还原糖发生美拉德反应,是大量的丙烯酰胺形成的主要途径;另外食品中的油脂、蛋白质和碳水化合物等成分在高温下条件下反应,生成丙烯醛,进而形成丙烯酰胺,是其在食物中存在的另一原因.本文希望通过揭示高温食品中丙烯酰胺形成的机理,能促进关于食品中有效地抑制/消除丙烯酰胺形成研究的进一步开展.     

Effect of cold plasma on the techno-functional properties of animal protein food ingredients

Proteins, as food ingredients, are employed in the food industry, not only for their high nutritional value, but also because of their techno-functional properties. Modifications of their native structure due to the action of external factors such as pH, temperature or processing by emerging technologies, can lead to changes in their functionality; and consequently, their applicability. The present study investigates the effects of cold atmospheric air plasma on the techno-functional properties of two common food ingredients (haemoglobin and gelatine from pork), and a novel source of functional proteins extracted from a meat co-product (bovine lung protein). Significant effects were found for their functional, rheological and gelling properties. However, the effects were found to depend on the native structure and nature of the protein. The findings point to the specific nature of plasma-protein interactions and the need for individual proteins to be studied as a function of plasma conditions.Industrial relevance textCold plasma is increasingly being investigated as a non-thermal technology for food and other biological applications such as primary agriculture and medicine. In addition to microbial and pest decontamination, it can be also be used to modify the functionality of food ingredients to achieve the desired properties of a specific food product.     

The dual effects of Maillard reaction and enzymatic hydrolysis on the antioxidant activity of milk proteins

The objective of this study was to determine the enhanced effects on the biological characteristics and antioxidant activity of milk proteins by the combination of the Maillard reaction and enzymatic hydrolysis. Maillard reaction products were obtained from milk protein preparations, such as whey protein concentrates and sodium caseinate with lactose, by heating at 55°C for 7 d in sodium phosphate buffer (pH 7.4). The Maillard reaction products, along with untreated milk proteins as controls, were hydrolyzed for 0 to 3 h with commercial proteases Alcalase, Neutrase, Protamex, and Flavorzyme (Novozymes, Bagsværd, Denmark). The antioxidant activity of hydrolyzed Maillard reaction products was determined by reaction with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, their 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, and the ability to reduce ferric ions. Further characteristics were evaluated by the o-phthaldialdehyde method and sodium dodecyl sulfate-PAGE. The degree of hydrolysis gradually increased in a time-dependent manner, with the Alcalase-treated Maillard reaction products being the most highly hydrolyzed. Radical scavenging activities and reducing ability of hydrolyzed Maillard reaction products increased with increasing hydrolysis time. The combined products of enzymatic hydrolysis and Maillard reaction showed significantly greater antioxidant activity than did hydrolysates or Maillard reaction products alone. The hydrolyzed Maillard reaction products generated by Alcalase showed significantly higher antioxidant activity when compared with the other protease products and the antioxidant activity was higher for the whey protein concentrate groups than for the sodium caseinate groups. These findings indicate that Maillard reaction products, coupled with enzymatic hydrolysis, could act as potential antioxidants in the pharmaceutical, food, and dairy industries.     

美拉德反应调节食物过敏反应的研究进展

近年来食物过敏发生率急剧增加,已是全球关注的公共卫生问题。美拉德反应作为食品加工和储存过程中最重要的化学反应之一,过敏原蛋白被修饰后由于结构发生了变化,必然引起致敏性改变,进而可能引发机体对于不同处理条件的抗原免疫耐受不一致,导致过敏反应。本文首先介绍了美拉德反应修饰蛋白质的过程及机理,进而解析不同影响因素调节美拉德反应终产物对致敏性的影响,最后阐述影响肠道菌群及其免疫应答机制的相关研究进行综述,并对美拉德反应作为一种尚未被完全开发和应用的加工方式进行展望。     

News on the Maillard reaction of oligomeric carbohydrates: a survey.

The reaction behaviour of monosaccharides in the Maillard reaction is well investigated. Amadori compounds, for instance, form deoxyhexosuloses which are responsible for the formation of volatile flavour substances and melanoidins. These intermediates can be quantified by a trapping reaction with o-phenylendiamine as stable quinoxalines. However the reaction behaviour of oligo and polymeric carbohydrates in non-enzymatic browning reactions are hardly known. Therefore maltooligosaccharides and in some cases starch were used together with glycine as model substances to investigate the Maillard reaction mechanism of oligo and polysaccharides. In quasi waterfree reaction systems oligosaccharides form alpha-dicarbonyl compounds via a "peeling off" mechanism. The Maillard reaction with the amino compound starts at the reducing end of an alpha-glucane residue and results in the formation of 1,4-dideoxyhexosulose. This is the main alpha-dicarbonyl compound found by trapping reaction with o-phenylendiamine during thermally induced degradation of maltooligosaccharides. The thermal reaction of maltooligosaccharides is accompanied by transglycosylations leading to formation of branched carbohydrate structures and by dehydrations forming anhydrosugars. The reaction mechanism which is responsible for degradation of oligomeric carbohydrates in aqueous model systems differs significantly from pathways mentioned above for water free reaction conditions. As the main alpha-dicarbonyl compound 3-deoxypentosulose is formed which can be proved also by trapping reactions. Under aqueous reaction conditions the formation of other alpha-dicarbonyls plays only a marginal role in the Maillard reaction of oligomeric carbohydrates. In an aqueous system transglycosylation and dehydration of maltooligosaccharides are not important.     

EFFECT OF MAILLARD REACTION PRODUCTS ON PROTEASES ACTIVITY IN VITRO

A complex chemical transformation known as the Maillard reaction may occur in foods containing reducing sugars and compounds with free amino groups. This reaction is accelerated by heating but occurs also at room temperature. Some food flavors, colors and texture characteristics depend on this reaction, but reduced nutritive values of proteins are also reported. To evaluate the contribution of digestive enzymes inhibition to this effect, activities of some proteases (pepsin, trypsin and chymotrypsin) were tested in the presence of glucose-glycine solutions heated at 90C for different times. Pepsin was partially inhibited by glycine itself but Maillard reaction products (MRP) did not produce additional effect. MRP showed a limited inhibition on trypsin and chymotrypsin. Unfractionated MRP solution showed an inhibiting effect on trypsin of the same order as already reported by Oeste (1989) for the low molecular weight (LMW) fraction of glucose-lysine MRP. High molecular weight (HMW) MRP presented an additional inhibiting effect, beside that reported for LMW on chymotrypsin. This however only occurred in particular conditions.     

Emulsifying Properties of Food Proteins Conjugated with Glucose or Lactose by Two Methods (Spray-Drying Or Freeze-Drying)

Emulsifying properties of two commercial food proteins (plasma protein or egg albumen) conjugated with two sugars (glucose or lactose) by spray-drying or lyophylization were studied. Changes in protein structure were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, sulfhydryl group, Fourier transform infrared spectroscopy and differential scanning calorimetry, emulsion properties (emulsion capacity and stability, emulsion work, and emulsifying activity index). Protein conjugation increased proteins molecular weight and decreased sulfhydryl groups, coinciding with lower denaturation enthalpies, corroborating structural changes by conjugation with glucose or lactose by either spray-drying or freeze-drying. Glucose conjugation of the proteins employed at the experimental conditions resulted in structural changes that emulsify more oil with no detrimental effect on emulsion superficial area formation. Although freeze-drying conjugation improved emulsifying properties, spray-drying also enhanced these properties, as compared to non-conjugated proteins. Spray-drying was a faster way to conjugate food proteins via Maillard reaction with improved emulsifying properties.     

美拉德反应产物的生物学活性和潜在健康风险

富含碳水化合物、蛋白质和油脂的食品在热加工过程中会发生剧烈的美拉德反应,生成大量的美拉德反应产物。美拉德反应产物中存在的低分子质量化合物和类黑精等物质具有多种生物学活性,但是其中的晚期糖基化终末产物、丙烯酰胺等潜在风险因子会加速人体的衰老或导致慢性退行性疾病的发生。本文综述了美拉德反应产物的抗氧化、抗菌和抗炎等生物学活性,同时也探讨了美拉德反应产生的晚期糖基化终末产物和丙烯酰胺等有害化合物的损伤机制和预防措施,以期为美拉德反应的深入研究提供科学参考。     

Legume byproducts as ingredients for food applications: Preparation,nutrition, bioactivity,and techno-functional properties

The demand for high-quality alternative food proteins has increased over the last few decades due to nutritional and environmental concerns, leading to the growing consumption of legumes such as common bean, chickpea, lentil, lupin, and pea. However, this has also increased the quantity of non-utilized byproducts (such as seed coats, pods, broken seeds, and wastewaters) that could be exploited as sources of ingredients and bioactive compounds in a circular economy. This review focuses on the incorporation of legume byproducts into foods when they are formulated as flours, protein/fiber or solid/liquid fractions, or biological extracts and uses an analytical approach to identify their nutritional, health-promoting, and techno-functional properties. Correlation-based network analysis of nutritional, technological, and sensory characteristics was used to explore the potential of legume byproducts in food products in a systematic manner. Flour is the most widely used legume-based food ingredient and is present at levels of 2%–30% in bakery products, but purified fractions and extracts should be investigated in more detail. Health beverages and vegan dressings with an extended shelf-life are promising applications thanks to the techno-functional features of legume byproducts (e.g., foaming and emulsifying behaviors) and the presence of polyphenols. A deeper exploration of eco-friendly processing techniques (e.g., fermentation and ohmic treatment) is necessary to improve the techno-functional properties of ingredients and the sensory characteristics of foods in a sustainable manner. The processing of legume byproducts combined with improved legume genetic resources could enhance the nutritional, functional, and technological properties of ingredients to ensure that legume-based foods achieve wider industrial and consumer acceptance.     

大豆分离蛋白美拉德反应研究进展

本文首先综述了美拉德反应对大豆分离蛋白的溶解性、乳化性以及凝胶性等一系列功能特性的影响,进而阐述了美拉德反应对大豆分离蛋白生物活性的影响,如抗氧化性和抗菌性。最后对大豆分离蛋白的美拉德反应在食品领域的研究进行了展望,以期对大豆分离蛋白的美拉德反应在食品领域的研究提供参考。     

Tailoring structure and technological properties of plant proteins using high hydrostatic pressure

The demand for proteins is rising and alternatives to meat proteins are necessary since animal husbandry is expensive and intensive to the environment. Plant proteins appear as an alternative; however, their techno-functional properties need improvement. High-pressure processing (HPP) is a non-thermal technology that has several applications including the modification of proteins. The application of pressure allows modifying proteins' structure hence allowing to change several of their properties, such as hydration, hydrophobicity, and hydrophilicity. These properties may influence the solubility of proteins and their ability to stabilize emulsions or foams, create aggregates or gels, and their general role in stability and texture of food commodities. Commonly HPP decreases the proteins' solubility yet increasing their surface hydrophobicity exposing sulfhydryl groups, which promotes aggregation or gelation or enhance their ability to stabilize emulsions/foams. However, these effects are not verifiable for all the proteins and are immensely dependent on the type and concentration of the protein, environmental conditions (pH, ionic strength, and co-solutes), and HPP conditions. This review collects and critically discusses the available information on how HPP affects the structure of plant proteins and how their techno-functional properties can be tailored using this approach.     

Free radical-scavenging activity of nonenzymatically-browned phospholipids produced in the reaction between phosphatidylethanolamine and ribose in hydrophobic media

The reaction of phosphatidylethanolamine (PE) and ribose (RI) in olive oil was studied in an attempt to both explore the possibilities of producing Maillard reaction in hydrophobic media and analyse the antioxidant properties of the formed compounds. When oil samples containing PE/RI mixtures were heated at a temperature higher than 90 °C, the oil rapidly developed browning, fluorescence, and free radical-scavenging activity, which was higher than the developed by the oil in the absence of added compounds or in the presence of only either PE or RI. These changes were a consequence of the formation of Maillard reaction products in the oil by reaction between PE and RI. Among them, the N-alkylpyrrole derivatives produced in this reaction could be determined by GC–MS after transpyrrolisation. Differently to Maillard products formed between carbohydrates and amino acids, the products of the reaction with aminophospholipids are more hydrophobic and, therefore, better candidates to be employed as lipophilic antioxidants in food products. Because of the different polarity of Maillard products between carbohydrates and either amino acids or aminophospholipids, Maillard reaction can be a useful procedure to obtain a wide range of antioxidants with different polarities to be employed in different food systems.     

Insight into the glycation of milk proteins: an ESI- and MALDI-MS perspective (review)

Protein-reducing sugar conjugates are formed by the naturally occurring Maillard reaction, otherwise known as glycation. The Maillard reaction products (MRP) formed can provide novel and/or improved functionality compared to the unmodified protein. Understanding the chemistry of the Maillard reaction, the physicochemical properties of its products, and, more importantly, the inter-relationships between these properties and the specific functionality of a given MRP will help to define the potential of MRP as food ingredients in their own right. Recently, electrospray ionization-mass spectrometry (ESI-MS) and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) have acquired a leading role in the structural characterization of proteins. The ability of these techniques to provide detail about the nature and extent of protein modifications at a molecular level as well as conformational information provides new insight into the glycation process. This article reviews the role that ESI- and MALDI-MS have played in advancing our understanding of the glycation of milk proteins.     

Modification of functional properties of egg-white proteins

Egg-white proteins are extensively utilised as food ingredients due to their unique functional properties. Several attempts have been made in order to improve the functional properties of egg-white proteins and to identify the optimal formulations for unique food products. Experimental data proves that controlled denaturation of egg-white proteins can have a beneficial impact on various functional applications in the food industry such as emulsifying ability, heat stability, and gelation. This review describes the effect of heat-induced denaturation on protein structure and functionality. Studies on the impact of Maillard reaction, which aim to elucidate the structure-function relationship of egg-white proteins, are presented. A novel approach which could be the basis for the development of new methods aiming to improve the functional properties of egg-white proteins is also discussed.