Structure and Technofunctional Properties of Protein-Polysaccharide Complexes: A Review

Food proteins and polysaccharides are the two key structural entities in food materials. Generally, interactions between proteins and polysaccharides in aqueous media can lead to one- or two-phase systems, the latter being generally observed. In some cases of protein-polysaccharide net attraction, mainly mediated through electrostatic interactions, complex coac-ervation or associative phase separation occurs, giving rise to the formation of protein-polysac-charide complexes. Physicochemical factors such as pH, ionic strength, ratio of protein to polysaccharide, polysaccharide and protein charge, and molecular weight affect the formation and stability of such complexes. Additionally, the temperature and mechanical factors (pressure, shearing rate, and time) have an influence on phase separation and time stability of the system. The protein-polysacchaide complexes exhibit better functional properties than that of the proteins and polysaccharides alone. This improvement could be attributed to the simultaneous presence of the two biopolymers, as well as the structure of the complexes. Consequently, the interesting hydration (solubility, viscosity), structuration (aggregation, gelation) and surface (foaming, emulsifying) properties of these complexes can be used in a number of domains. Among others, these could be macromolecular purification, microencapsulation, food formulation (fat replacers, texturing agents), and synthesis of biomaterials (edible films, artificial grafts).     

Interpolymeric Complexes Formed Between Whey Proteins and Biopolymers: Delivery Systems of Bioactive Ingredients

Whey proteins are obtained from dairy industry waste. Studies involving the analysis of the bioactive compounds in whey show health benefits, as it is an excellent source of indispensable amino acids. Milk whey contains principally β‐lactoglobulin, α‐lactoglobulin, bovine serum albumin, and lactoferrin, proteins with innumerable functional and technological properties. One application of these proteins in food is the formation of interpolymer complexes, along with other proteins or anionic polysaccharides. The formation of complexes occurs mainly through electrostatic interactions between a negatively charged biopolymer and a positively charged biopolymer. This formation is influenced by factors such as pH, ionic strength, and biopolymer ratio. Because they do not use high temperatures and chemical reagents and have additional nutritional and functional value, these complexes have been used as encapsulating agents for bioactive ingredients. Recent studies on their training and applications are addressed in this review to boost new research and applications in the food industry, thus increasing opportunities for utilizing whey proteins.     

蛋白质-卵磷脂复合体系功能特性的研究进展

蛋白质与卵磷脂间发生的相互作用可以增强蛋白质功能特性,且二者形成的复合体系不仅能够作为递送系统传递生物活性物质、药物等以达到在胃肠道中的缓释效果,提高包埋物质的装载率及体外释放度,还能够实际应用于食品工业中提高我国传统蛋白基产品的质量及拓宽种类,如蛋白粉、婴儿配方乳以及运动营养食品等。本文综述了玉米醇溶蛋白、大豆蛋白、卵磷脂的理化性质和功能特性,蛋白-卵磷脂二者间的相互作用对蛋白的改善,蛋白-卵磷脂复合纳米颗粒、乳液及凝胶的特性,以及复合体系在食品工业、医药等领域作为递送系统和提高食品质量的应用,为改善单一蛋白体系的稳定性及提高其应用价值提供参考价值依据,对促进我国蛋白基食品产业高质量发展具有重要意义。     

Polysaccharide–protein interactions in dairy matrices,control and design of structures

Protein–polysaccharide interactions are of great importance in the design of dairy formulations, as they play a key role in the formation of structure and texture in dairy products. With a detailed understanding of the factors affecting the interactions, the ability of charged polysaccharides to associate with the milk proteins is continuously exploited to create functional complexes, novel ingredients and delivery systems. In addition, formulations containing non-interacting polysaccharides also need to be carefully controlled, as these biopolymers may give rise to segregative phase separation, with important consequences to the stability and quality of the final matrix. As casein micelles play a major role in imparting structure to dairy products, emphasis in this review will be given to the molecular details of the interactions between polysaccharides with these protein particles. Some of the most researched polysaccharides will be highlighted in this context, and the progress made in understanding their role during structure formation of dairy matrices will be discussed. The opportunity of creating novel microstructures provided by association or/and incompatibility of milk proteins and different polysaccharides will be assessed.     

Food‐Grade Covalent Complexes and Their Application as Nutraceutical Delivery Systems: A Review

Food proteins, polysaccharides, and polyphenols are 3 major food constituents with distinctly different functional attributes. Many proteins and polysaccharides are capable of stabilizing emulsions and foams, thickening solutions, and forming gels, although they differ considerably in their abilities to provide these functional attributes. Many plant polyphenols exhibit beneficial physiological functions, such as antitumor, antioxidant, antibacterial, and antiviral properties. Proteins, polysaccharides, and polyphenols can form complexes with each other, which leads to changes in the functional and nutritional properties of the combined systems. Recently, there has been considerable interest in understanding and utilizing covalent interactions between polyphenols and biopolymers (proteins and polysaccharides). The binary or tertiary conjugates formed may be designed to have physicochemical properties and functional attributes that cannot be achieved using the individual components. This article provides a review of the formation, characterization, and utilization of conjugates prepared using proteins, polysaccharides, and polyphenols. It also discusses the relationship between the structural properties and functionality of the conjugates, and it highlights the bioavailability of bioactive compounds loaded in conjugate‐based delivery systems. In addition, it highlights the main challenges to be considered when preparing and analyzing conjugates. This article provides an improved understanding of the chemical reactions that occur between major food ingredients and how they can be utilized to develop biopolymer‐based delivery systems with enhanced functional attributes.     

Starch–lipid and starch–lipid–protein complexes: A comprehensive review

Physical interactions often occur between major food components during food processing. These interactions may involve starch, lipids, and proteins forming V‐type starch–lipid complexes or ternary starch–lipid–protein complexes of larger molecular size and greater structural order. Complexes between starch and lipids have been the subject of intensive research for over half a century, whereas the study of starch–lipid–protein complexes is a relatively new field with only a limited amount of knowledge being gained so far. The formation of these complexes can significantly affect the functional and nutritional properties of finished food products in terms of flavor, texture, shelf life, and digestibility. This article provides a comprehensive review of starch–lipid and starch–lipid–protein complexes, including their classification, factors affecting their formation and structure, and preparative and analytical methods. The review also considers how complexes affect the physicochemical and functional properties of starch, including digestibility, and potential applications in the food industry.     

蛋白质与多糖类交互作用研究进展

对蛋白质与多糖类交互作用的研究概况作一阐述,蛋白质与多糖类在水溶液中表现出热力学相容性及不相容性,蛋白质具有许多功能性质,这些性质由于多糖与蛋白质的交互作用而得到改善,从而影响食品体系的性质,两种大分子的交互作用在食品工业中具有广泛的应用。     

Milk proteins: physicochemical and functional properties

Because of the growing trend toward widespread use of protein ingredients in food formulation and fabrication, an understanding of the relationships between the physical properties of proteins and their behavior in food systems is desirable. A range of milk-derived protein preparations, i.e., dry milk, milk proteins, caseins, whey proteins, and lactalbumin, are used in a range of food products for their specific functional attributes. In this paper some of the apparent relationships between the properties of the protein components and specific functional properties are discussed. Thus, the roles of milk proteins in determining some important physical characteristics (i.e. color, bulk density, sinkability, dispersibility) of milk powders and their involvement in a range of functional properties (water holding, solubility, rheological behavior, gelation, film formation, emulsification, and foaming) are reviewed. Because of the various methods and conditions used in determining functional properties and the variability in composition of preparations it is difficult to compare data and/or reconcile differences in published information. The desirability of developing standard methods is emphasized.     

On the protein functional properties and the methods of their control. Part 2. On the methods of control of functional properties of proteins and gel-forming systems

In the review the advantages of the physico-chemical methods of control of functional properties of proteins are shown. Examples of protein functional properties control through the production of protein complexes with acid polysaccharides, as well as of functional properties control in the gel-forming systems on the account of combinations of the gel-forming agents and the production of complex and mixed gels filled with proteins are presented.     

Aspects of milk-protein-stabilised emulsions

Milk proteins are widely used as ingredients in prepared foods, in which they perform a wide range of key functions, including emulsification, thickening, gelling and foaming. An important functionality of milk proteins in food colloids is their ability to facilitate the formation and stabilisation of oil droplets in emulsions. The ability of milk proteins to adsorb at the oil–water interface and to stabilise emulsions has been exploited by the food industry in the manufacture of nutritional products, specialised medical foods, dietary formulations, cream liqueurs and dairy desserts. This article provides an overview of the properties and functionalities of food emulsions formed with milk proteins, focusing on the structure and composition of adsorbed protein layers, competition between proteins and the physical and chemical stability of emulsion droplets. Of particular importance is the understanding of the behaviour of milk-protein-based emulsions under the conditions relevant to digestion in the human gastrointestinal tract. Recent relevant research in this area is reviewed and discussed.     

Protein deamidation to produce processable ingredients and engineered colloids for emerging food applications

With the ever-increasing demands for functional and sustainable foods from the general public, there is currently a paradigm shift in the food industry toward the production of novel protein-based diet. Food scientists are therefore motivated to search for natural protein sources and innovative technologies to modify their chemical structure for desirable functionality and thus utilization. Deamidation is a viable, efficient, and attractive approach for modifying proteins owing to its ease of operating, specificity, and cost-effective processes. Over the past three decades, the knowledge of protein deamidation for food applications has evolved drastically, including the development of novel approaches for deamidation, such as protein-glutaminase and ion exchange resin, and their practices in new protein substrate. Thanks to deamidation, enhanced functionalities of food proteins from cereals, legumes, milk, oil seeds and others, and thereby their processabilities as food ingredients have been achieved. Moreover, deamidated proteins have been used to fabricate engineered food colloids, including self-assembled protein particles, protein–metallic complexes, and protein–carbohydrate complexes, which have demonstrated tailored physicochemical properties to modulate oral perception, improve gastrointestinal digestion and bioavailability, and protect and/or deliver bioactive nutrients. Novel bioactivity, altered digestibility, and varied allergenicity of deamidated proteins are increasingly recognized. Therefore, deamidated proteins with novel techno-functional and biological properties hold both promise and challenges for future food applications, and a comprehensive review on this area is critically needed to update our knowledge and provide a better understanding on the protein deamidation and its emerging applications.     

Maximizing the value of milk through separation technologies.

Milk is the source of a wide range of proteins that deliver nutrition to the most promising new food products today. Isolated milk proteins are natural, trusted food ingredients with excellent functionality. Separation technologies provide the basis for adding value to milk through the production of proteins that provide the food industry with ingredients to meet specific needs, not possible with milk itself or with other ingredients. The major milk proteins, casein and whey protein, can be isolated by manipulating their compositional and physical properties and then by using various separation technologies to recover the proteins. Additionally, they can be processed in various ways to create a wide range of ingredients with diverse functional characteristics. These ingredients include milk protein concentrate, milk protein isolate, casein, caseinate, whey protein concentrate, whey protein isolate, hydrolysates, and various milk fractions. Within each of these ingredient categories, there is further differentiation according to the functional and nutritional requirements of the finished food. Adding value to milk by expanding from consumer products to ingredients often requires different technologies, marketing structure and distribution channels. The worldwide market for both consumer products and ingredients from milk continues to grow. Technology often precedes market demand. Methods for the commercial production of individual milk components now exist, and in the future as clinical evidence develops, the opportunity for adding value to dairy products as functional foods with health benefits may be achieved. The research and development of today will be the basis of those value-added milk products for tomorrow.     

食品级共价复合物在递送生物活性物质方面的研究进展

生物活性物质由于具有抗肿瘤、抗炎、抗氧化和降血脂活性,是功能性食品开发的良好原料,但在生产加工和储存的过程中大多容易分解。为解决这一问题,围绕蛋白质、多糖和多酚设计了食品级的递送系统,形成的复合物改变了食品的功能和营养特性。本文综述了利用蛋白质、多糖、多酚为原料制备不同功能性质的二元或三元食品级复合物的共轭方法、表征和功能性质的研究进展,总结了复合物作为载体的主要类型,以及在生物活性物质传递系统中的应用,并总结了递送体系与人体胃肠道之间的相互作用,强调了在制备和分析复合物作为递送体系时要注意的主要问题并展望了其应用前景。     

Functional Biopolymer Particles: Design,Fabrication, and Applications

Abstract: Biopolymer nano‐ and micro‐particles, fabricated from either proteins and/or polysaccharides, can be utilized as delivery systems or to modulate the physicochemical and sensory characteristics of food products. This article reviews the principles underlying the design, fabrication, and application of biopolymer particles fabricated from globular proteins, used either alone or in combination with polysaccharides, within the food industry. The properties of biopolymer particles and their impact on the physicochemical and functional properties of foods are described. The molecular characteristics and interactions of the building blocks (proteins and polysaccharides) used to assemble these particles are briefly reviewed. The major structural design principles that can be used to fabricate biopolymer particles from food‐grade proteins and polysaccharides are outlined. Finally, some of the potential applications of functional biopolymer particles within foods are highlighted.     

海藻多糖的提取、分离纯化及其在食品工业的应用

海藻多糖具有良好的保湿性、凝胶性、成膜性、增稠性和稳定性等物化性质,同时具有抗氧化、抑菌、免疫调节、抗肿瘤、抗炎、抗衰老和降血糖血脂等生物活性,在食品工业有着广泛应用。本文综述了海藻多糖的提取、分离、纯化方法,及其在饮品、食品包装、肉制品、糖果和烘焙食品等工业上的应用,以期对食品生产加工有一定作用。     

Carrageenans and their use in meat products

Carrageenans are sulfated linear polysaccharides of D‐galactose and 3,6‐anhydro‐D‐galactose extracted from red seaweeds. They have been used by the food industry for their gelling, thickening, and stabilizing properties, and more recently by the meat industry for reduced fat products. Meat is a complex system of muscle tissue, connective tissue, fat, and water; during processing, numerous interactions occur among all these components. These interactions are responsible for the functional properties of the meat system. In meat products, carrageenans contribute to gel formation and water retention. Their addition is of special interest in low‐fat meat products because fat reduction often leads to unacceptable, tough textures. When carrageenans are incorporated in these formulations, they improve the textural characteristics of the product by decreasing toughness and increasing juiciness. Although carrageenan interactions with milk proteins have been studied extensively, the mechanism by which carrageenans interact with meat proteins and the other meat components is not fully understood.     

Innovative Uses of Milk Protein Concentrates in Product Development

Milk protein concentrates (MPCs) are complete dairy proteins (containing both caseins and whey proteins) that are available in protein concentrations ranging from 42% to 85%. As the protein content of MPCs increases, the lactose levels decrease. MPCs are produced by ultrafiltration or by blending different dairy ingredients. Although ultrafiltration is the preferred method for producing MPCs, they also can be produced by precipitating the proteins out of milk or by dry‐blending the milk proteins with other milk components. MPCs are used for their nutritional and functional properties. For example, MPC is high in protein content and averages approximately 365 kcal/100 g. Higher‐protein MPCs provide protein enhancement and a clean dairy flavor without adding significant amounts of lactose to food and beverage formulations. MPCs also contribute valuable minerals, such as calcium, magnesium, and phosphorus, to formulations, which may reduce the need for additional sources of these minerals. MPCs are multifunctional ingredients and provide benefits, such as water binding, gelling, foaming, emulsification, and heat stability. This article will review the development of MPCs and milk protein isolates including their composition, production, development, functional benefits, and ongoing research. The nutritional and functional attributes of MPCs are discussed in some detail in relation to their application as ingredients in major food categories.     

多糖-蛋白质复合水凝胶研究进展

多糖和蛋白质是食品中最重要的2种功能大分子,可以通过相互作用形成复合水凝胶。与单一组分相比,多糖和蛋白质形成的复合水凝胶不仅具有优异的物理结构和化学性质,而且具有提高复合体系机械性能的潜在优势。该文对部分多糖-蛋白质复合水凝胶的研究进展进行总结,综述了形成复合水凝胶的多糖及蛋白质的类型和条件、二者主要相互作用及影响二者相互作用的内部和外部因素,阐述了多糖对其与蛋白质形成复合水凝胶机械性能的影响,并概述了多糖-蛋白质复合水凝胶在食品工业及生物医药等领域的应用现状。该文将为多糖-蛋白质基创新凝胶的设计、开发及应用提供理论参考依据。     

乳清蛋白及与其它乳成分的热聚合作用机制研究进展

乳蛋白决定奶类品质,而热加工会影响乳清蛋白尤其是β-乳球蛋白的稳定性。热处理时,乳清蛋白不仅自身发生不同程度的聚合,而且通过巯基-二硫键分别与酪蛋白胶束和乳脂球膜蛋白发生结合。乳清蛋白亦可与其它乳成分如乳糖、钙盐、乳脂发生热聚合作用。本文根据乳品受热温度的不同,针对乳清蛋白间及其与其它乳成分的相互作用途径进行分析,阐明热聚合作用过程及机理,对改善乳制品的热稳定性、凝胶性等功能性质具有重要的理论意义,拓宽乳清蛋白作为配料在相关食品体系中的应用。     

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.