Interactions of vegetable proteins with other polymers: Structure-function relationships and applications in the food industry

peer-reviewedBackground In recent years, there has been increasing interest in vegetable proteins, due to their various health beneficial functions and wide applications in the food industry. Vegetable proteins combined with other edible polymers can be used to improve the quality and nutritional value of food products. In these complex food systems, interactions between different components are inevitable, and these interactions have a significant influence on the structure and functions of food products. Scope and approach This study reviews the current status of knowledge of interactions between vegetable proteins and other polymers (proteins or polysaccharides) in food systems and the structure of complexes formed by these interactions. The study also provides a comprehensive review of the applications of the complexes. Key findings and conclusions Vegetable proteins display different types of interactions with other polymers (e.g., polysaccharides, or animal proteins) under different conditions, thus forming a variety of complexes with different structures (e.g., double networks, mosaic textures and cross-linked structures), which showed different impact on properties of the final food products and their applications (e.g., substitution for fat, or encapsulation for bioactive ingredients) in the food industry. However, previous studies mainly focused on leguminous proteins and vegetable-protein-based mixtures of two polymers, further studies on other vegetable proteins and more complex food systems containing vegetable proteins and other polymers are required

Comparative study of the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours as affected by pH

Acknowledgments This work is part of the Strategic Research 2011–2016 and is funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS).Peer reviewedPublisher PD

Marine Glycomics

Marine creatures are rich sources of glycoconjugate-containing glycans and have diversified structures. The advance of genomics has provided a valuable clue for their production and developments. This information will encourage breeding and engineering functional polysaccharides with slime ingredients in algae. These glycans will have the potential for applications to antioxidant, anticancer, and antimicrobial drugs in addition to health supplements and cosmetics. The combination of both biochemical and transcriptome approaches of marine creatures will lead to the opportunity to discover new activities of proteins such as glycan-relating enzymes and lectins. These proteins will also be used for experimental and medical purposes, such as diagnostics and trial studies. The topic of marine glycomics is also focusing on understanding the physiological properties of marine creatures, such as body defense against pathogens and cancers. In the competitions for natural selection, living creatures have evolved both their glycans and their recognition. They have primitive systems of immunity, and few of their mechanisms are closely related to glycans. If we are able to describe the accumulation of data of glycans of creatures living in the seashore and the oceans, we may be able to anticipate a time when we can talk about the ecosystem with glycans. That knowledge will be useful for the development of drugs that cure our diseases and for an understanding of living systems in addition to the preservation of living environments

Plant extracts as additives in biodegradable films and coatings in active food packaging: effects and applications

Background: Petroleum-based polymers are widely used and known that they cause serious environmental problems due to their non-biodegradability. To this end, researchers have been focusing on the development of ecological packaging materials from natural resources. However, the films produced from natural biopolymers have fewer desirable properties than synthetic polymers; Subsequently, active packaging has arrived. Research has been conducted to develop biodegradable films/coatings based on wide range of ingredients, which may affect the properties of those materials. Scope and approach: Plant extracts represent an interesting ingredient for biodegradable food packaging. The scope of this review is to present the latest ideas on how plant extracts impact properties like physical, mechanical, barrier, functional, structural, antioxidant, antimicrobial and the biodegradability of the films. Moreover, it has been introduced the interaction of plant extracts with the food product, which may prevent or reduce deterioration and improve the quality of the packaged product during its lifetime. Key findings and conclusion: Recent studies focus on the identification of extracts from various plant sources such as leaves, fruits, pomace, seeds, etc. for use in biodegradable polymer. Generally, most of the plant extracts increase the thickness of the biopolymer, reduce the transparency, decrease water vapour and oxygen permeability, enhance water moisture and solubility, and have adverse effects on the mechanical properties. Additionally, in most cases natural extracts can boost the antioxidant and antimicrobial properties and alters the biodegradation rate, contact angle (θ), and viscosity of the films and coatings. Furthermore, improvement of shelf life of packaged food, like meat, and meat products, fruits, and vegetables with the incorporation of plant extracts has been observed. Results are promising further research on the effect of plant extracts on sensorial properties and application to many other food products may encourage practical application.Contexto: Polímeros à base de petróleo são usados em grande escala e sabe-se que causam problemas ambientais sérios devido a não serem biodegradáveis. Com base nisto, investigadores têm-se focado no desenvolvimento de materiais para embalagens ecológicas a partir de recursos naturais. Contudo, as películas produzidas de biopolímeros naturais possuem normalmente propriedades desejáveis menores quando comparadas com as obtidas de polímeros sintéticos; mais recentemente apareceram as embalagens ativas. Diferentes estudos têm sido conduzidos para desenvolver películas/revestimentos biodegradáveis, com base numa ampla variedade de ingredientes, que podem influenciar as propriedades destes materiais. Âmbito e abordagem: Extratos vegetais representam ingredientes interessantes para embalagens biodegradaveis usadas em alimentos ou em produtos alimentares. O Âmbito desta monografia é apresentar as mais recentes ideias do modo como os extratos de plantas afetam diferentes propriedades das películas, tais como físicas, mecânicas, de barreira, funcionais, estruturais, antioxidantes, antimicrobianas e ainda a sua biodegradabilidade. Além disso, foi introduzida a interação entre os extratos de plantas com o produto alimentar, que pode prevenir ou reduzir a deterioração e melhorar a qualidade do produto embalado aumentando o seutempo de vida. Principais conclusões: Estudos recentes focam-se na identificação de extratos vegetais de diferentes fontes como, folhas, frutas, sementes, bagaço, etc. para serem usados em polímeros biodegradáveis. Geralmente, a maioria dos extratos vegetais aumentam a espessura do biopolímero, reduzem a transparência, reduzir a permeabilidade ao vapor de água e ao oxigénio, elevam a humidade e a solubilidade, e têm diversos efeitos nas propriedades mecânicas. Adicionalmente, na maioria dos casos os extratos naturais podem aumentar as propriedades antioxidante e antimicrobiana e alterar a taxa de biodegradabilidade, ângulo de contato (θ), e viscosidade das películas e revestimentos. Com a incorporação dos extratos vegetais, verifica-se ainda, um aumento do tempo de prateleira, do alimento embalado, como carne, e produtos derivados de carne, frutas e legumes. Os resultados são promissores e o estudo do efeito dos extratos de plantas nas propriedades sensoriais e sua aplicação em muitos outros produtos alimentares, poderá estimular num futuro próximo a sua aplicação prátic

Preparation of modified whey protein isolate with gum acacia by ultrasound maillard reaction

peer-reviewedEffect of ultrasound treatment on whey protein isolate (WPI)-gum Acacia (GA) conjugation via Maillard reaction was investigated. And the physicochemical properties of the conjugates obtained by ultrasound treatment were compared with those obtained by classical heating. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, high-performance size exclusion chromatography and fourier transform infrared spectroscopy provided evidence on the formation of the Maillard type conjugation. Compared with classical heating, ultrasound treatment could accelerate the glycation reaction between WPI and GA. A degree of graft of 11.20% was reached by classical heating for 48 h, whereas only 20 min was required by ultrasound treatment. Structural analyses suggested that the conjugates obtained by ultrasound treatment had less α-helix content, higher surface hydrophobicity and fluorescence intensity than those obtained by classical heating. Significantly lower level of browning intensity and significantly higher (p < 0.05) level of solubility (under alkaline conditions), thermal stability, emulsifying activity and emulsifying stability were observed for the conjugates obtained by ultrasound treatment as compared with those obtained by classical heating

A comprehensive review on natural bioactive compounds and probiotics as potential therapeutics in food allergy treatment

Food allergy is rising at an alarming rate and is a major public health concern. Globally, food allergy affects over 500 million people, often starting in early childhood and increasingly reported in adults. Commercially, only one approved oral immunotherapy-based treatment is currently available and other allergen-based immunotherapeutic are being investigated in clinical studies. As an alternative approach, a substantial amount of research has been conducted on natural compounds and probiotics, focusing on the immune modes of action, and therapeutic uses of such sources to tackle various immune-related diseases. Food allergy is primarily mediated by IgE antibodies and the suppression of allergic symptoms seems to be mostly modulated through a reduction of allergen-specific IgE antibodies, upregulation of blocking IgG, and downregulation of effector cell activation (e.g., mast cells) or expression of T-helper 2 (Th-2) cytokines. A wide variety of investigations conducted in small animal models or cell-based systems have reported on the efficacy of natural bioactive compounds and probiotics as potential anti-allergic therapeutics. However, very few lead compounds, unlike anti-cancer and anti-microbial applications, have been selected for clinical trials in the treatment of food allergies. Natural products or probiotic-based approaches appear to reduce the symptoms and/or target specific pathways independent of the implicated food allergen. This broad range therapeutic approach essentially provides a major advantage as several different types of food allergens can be targeted with one approach and potentially associated with a lower cost of development. This review provides a brief overview of the immune mechanisms underlying food allergy and allergen-specific immunotherapy, followed by a comprehensive collection of current studies conducted to investigate the therapeutic applications of natural compounds and probiotics, including discussions of their mode of action and immunological aspects of their disease-modifying capabilities

Effect of glycerol, peanut oil and soybean lecithin contents on the properties of biodegradable film of improved cassava starches from Côte d’Ivoire

— Edible films have been successfully used in the food packaging industry for several decades. Today natural polysaccharides, including cassava starch,are increasingly being used in the production of such biodegradable edible films and food packaging. In Côte d'Ivoire, there are improved cassava varieties whose starches have not yet been tested in the production of biodegradable films. In thisstudy, the optical and mechanical properties and the water solubility of starch-based composite films of four improved cassava varieties withadded glycerol, peanut oil and soy lecithin were determined. Starchwas obtained by cold water extraction from native cassava from the varieties Bocou 1, Bocou 2, Yavo and TMS. Films preparation was made bycasting methodwithcassava, glycerol (25-30 %), peanutoil (5-10 %) and soybean lecithin (0-5 %). Increasing the glycerol content, increased L*color valueand elongationat break and decreased a*, b*, colourdifference (ΔE*ab) and tensilestrength of the composite films. Also, increasing the oil content from 5 to 10%, increased the opacity, b*, ΔE*ab, water solubility, elongationat break but decreased L*, a* and tensilestrength. Similarly, increasing the soy lecithin content from 0 to 5%, increased the opacity, L*, b* and ΔE*ab, but decreased a*, of the starch-based composite films. The results suggest an ideal formulation of 4% starch/25% glycerol/5% oil/5% soy lecithinfor a film with optimum mechanical properties with low solubility

Covalently cross-linked proteins & polysaccharides: Formation, characterisation and potential applications

This review presents recent research conducted on the development of various protein-polysaccharide conjugates, their functional properties and industrial applications. These conjugates are formed by the glycosylation of food proteins with carbohydrates via the Maillard reaction and are capable of improving the functional properties of proteins. The Maillard reaction facilitates covalent bonding between a reducing group of a carbohydrate and an amino group of a protein under controlled conditions of temperature, time, pH, and relative humidity. There is a great deal of interest in modifying the functional properties of proteins and in the use of novel conjugates for various industrial applications. This review discusses various methods and their implications for preparing and characterising these conjugates. Furthermore, the physicochemical properties of conjugates such as solubility, thermal stability, emulsifying activity, emulsion stabilising properties, gelling and foaming properties are also analysed. A novel processing technology, spinning disc reactor, could be an alternative process for the production of protein-polysaccharide conjugates, with desirable functionality in different food systems

Polysaccharides from Wastes of Vegetable Industrial Processing: New Opportunities for Their Eco-Friendly Re-Use

Natural polysaccharides constitute a major group of biopolymers widespread in the whole vegetable kingdom. Plant polysaccharides comprise highly heterogeneous biopolymers that play diverse biological roles as structural elements, energy reserve and biological signalling. Polysaccharides from natural sources have attracted significant interest as biotechnological products, due to their commercial uses in a wide range of industrial applications. Some of them, for example, possess strong antigenic and antipathogenic activities and are successfully employed by the pharmaceutical industry for the formulation of vaccines or as a matrix for drug-delivery applications; others are utilised as food additives taking advantage of their physical-chemical properties (emulsifying power, viscoelasticity, polyelectrolyte, adherence, bio-compatibility, stabilizer, etc). Production of these biopolymers for industrial applications has both economic and environmental costs, depending on the starting materials used as feedstocks and on the chemical/thermal treatments required for their extraction. Recently, wastes from industrial processing of vegetables for food production have been proposed as potential sources of useful polysaccharides. Indeed, transformation and packaging of fruits and vegetables generates huge amounts of wastes, since only a fraction of the incoming biomass is effectively used. The management of such waste biomasses is a problem worldwide, from both economic and environmental standpoints, and therefore research is encouraged to implement new strategies for their re-use. An advantageous option is the extraction of value added chemicals, including different kinds of polysaccharides, besides chemically different species such as polyunsaturated fatty acids, natural pigments, tannins, carotenoids, antioxidants etc. Treatment of vegetable residues by means of newly and environmentally sustainable extraction techniques represents at the moment a fascinating challenge for the valorisation of agro-industrial wastes. Remarkable examples in this framework are represented by polysaccharides isolated from wastes of tomato industrial processing and of tropical fruit juices production based on granadilla, a fruit species of Passiflora, distributed mainly in the warm temperate and tropical regions of America and Africa. These polysaccharides resulted to possess useful biotechnological properties and interesting biological activities. An accurate chemical characterization demonstrated that the main biopolymer obtained from tomato wastes was an heteropolymer with a molecular weight higher than 1 ×106 Da constituted by glucose/ xylose/ galactose/ galactosamine/ glucosamine/ fucose in a relative molar ratio of 1: 0.9: 0.5: 0.4: 0.2: trace, whereas the polysaccharide isolated from waste peels of granadilla (Passiflora liguralis) fruits (with a molecular weight higher than 1 ×106 Da as well) was characterised by the presence of six different sugar residues: xylose/ glucose/ galactose/ galactosamine/ unknown component/ fucose in the relative ratios of 1:0.5:0.2:0.06:0.05:trace. The study of rheological properties showed for both biopolymers an high thermal resistance and an high viscosity, depending, in particular for granadilla waste polysaccharide, on concentration and pH, with a maximum value of 1.4  at a concentration of 3% in distilled water and a maximum value of 7.0  in citrate buffer solution. The main point of interest was represented by their suitability to produce elastic and biodegradable films potentially useful in agriculture for mulching applications in fields protection. Further studies were performed to evaluate the biological activity of these biopolymers. Tomato waste polysaccharides resulted to inhibit NF-κB activation and iNOS gene expression in J774 macrophages by preventing the reactive species production, thus suggesting a key role of these compounds in controlling oxidative stress and/or inflammation. Biological activity of polysaccharides from granadilla peels was assessed by means of brine shrimp bioassay: the isolated compound was able to strongly inhibit the cytotoxic effects produced by avarol, whose LD50 was increased of about 10-fold with respect to the control in the absence of polysaccharide. More recent studies have been focused on lemon wastes. Citrus processing produces a considerable amount of waste biomass called “lemon pomace” consisting of peels (flavedo and albedo), pulp and seeds, mainly composed by water, soluble sugars and fibres, together with other compounds such as oils, flavonoids and vitamins. Lemon wastes, generated in huge amounts by Italian industries for “Limoncello” liquor production, have been treated in order to separate useful polysaccharides. A major polysaccharide fraction was isolated and purified: analysis by means of gel filtration allowed to determine a molecular weight higher than 1 ×106 Da. The sugar components were identified after acid hydrolysis, by means of TLC and HPAE-PAD chromatography: the main components resulted to be galactose, galacturonic acid and arabinose. Further studies are now being implemented to study both rheological properties and biological activity of lemon polysaccharides. In conclusion, polysaccharides are among the most interesting biopolymers that can be recovered from vegetables: the use of wastes from industrial processing of different vegetables together with eco-friendly extraction techniques allowed the isolation of remarkable polysaccharides. Some of them showed to possess interesting rheological properties, potential biotechnological applications and finally promising bioactivities as potential anti-inflammatory agents, as tested in different biological model systems