Technical problems and opportunities in using vegetable proteins in dairy products

The food processing industry is giving increased emphasis to the production and utilization of alternate protein isolate products as functional and nutritional ingredients in an expanding number of formulated food products. Alternate protein sources such as soy and other vegetable proteins offer additional flexibility in formulating foods due to their economics, availability, functionality and nutritional properties. This paper discusses needs for developing soy and vegetable protein isolates with improved flavor, color and functionality for producing simulated dairy foods. It also considers alternative technologies for incorporating soy and vegetable proteins into the formulation so that they may function properly for forming stable solutions, emulsions, foams and gels that resemble those in their natural dairy food counterparts.     

Study of the adsorption of proteins on stainless steel surfaces using QCM-D

Stainless steel is widely used in a number of industries, ranging from food and dairy to pharmaceuticals. However, fouling associated with protein adsorption constitutes a main issue in such industries, as it decreases the efficiency of stainless steel process equipment and leads to an increase in operational costs due to the need for regular cleaning. In this study, to understand the underlying adsorption phenomena and to identify the mechanisms associated with bio-fouling, adsorption of a set of proteins on 316 grade stainless steel surfaces was studied. Eleven proteins with varying physicochemical properties were tested. The proteins consisted of milk proteins, blood proteins and commercially available proteins. Adsorption experiments were carried out on stainless steel sensors using a quartz crystal microbalance with dissipation at a temperature of 22 °C. The adsorption characteristics of the test proteins were studied and an empirical correlation relating the amount of protein adsorbed to their physical properties is proposed.     

聚离子液体及其在天然产物分离中的应用

天然产物资源丰富,其高效利用离不开先进的分离技术。兼具离子液体高选择性及聚合物安全、易回收等特性的聚离子液体为天然产物的分离提供了新途径。在介绍聚阳离子型、聚阴离子型和聚两性型离子液体制备技术的基础上,综述了使用聚离子液体的固相萃取、固相微萃取、分子印迹固相萃取、液液萃取及毛细管电泳技术在黄酮类、生物碱类、酚类、蛋白质类等天然产物分离中的研究进展,分析了聚离子液体分离作用机理及其具有良好的分离效率、稳定性和回收再利用性能的原因,特别强调了刺激响应聚离子液体在天然产物分离中的优势,并从聚离子液体设计和定制出发对聚离子液体在分离领域所存在的挑战和潜在的应用进行了展望。     

Antifungal Peptides and Proteins to Control Toxigenic Fungi and Mycotoxin Biosynthesis

The global challenge to prevent fungal spoilage and mycotoxin contamination on food and feed requires the development of new antifungal strategies. Antimicrobial peptides and proteins (AMPs) with antifungal activity are gaining much interest as natural antifungal compounds due to their properties such as structure diversity and function, antifungal spectrum, mechanism of action, high stability and the availability of biotechnological production methods. Given their multistep mode of action, the development of fungal resistance to AMPs is presumed to be slow or delayed compared to conventional fungicides. Interestingly, AMPs also accomplish important biological functions other than antifungal activity, including anti-mycotoxin biosynthesis activity, which opens novel aspects for their future use in agriculture and food industry to fight mycotoxin contamination. AMPs can reach intracellular targets and exert their activity by mechanisms other than membrane permeabilization. The mechanisms through which AMPs affect mycotoxin production are varied and complex, ranging from oxidative stress to specific inhibition of enzymatic components of mycotoxin biosynthetic pathways. This review presents natural and synthetic antifungal AMPs from different origins which are effective against mycotoxin-producing fungi, and aims at summarizing current knowledge concerning their additional effects on mycotoxin biosynthesis. Antifungal AMPs properties and mechanisms of action are also discussed.     

In-situ poly(butylene adipate-co-terephthalate)/soy protein concentrate composites: Effects of compatibilization and composition on properties

In this study, soy protein concentrate (SPC) was blended as plastic with poly(butylene adipate-co-terephthalate) (PBAT). An extra amount of water was added to SPC prior to compounding to ensure that SPC behaved like a plastic during mixing. Because of the extensive crosslinking and agglomeration during compounding and the fact that most water was evaporated after drying the compounds, the SPC phase was not able to flow like a plastic in the subsequent processing. Therefore, the compounds became in-situ formed composites. The effects of SPC content and compatibilizer on the morphological, rheological, tensile and dynamic mechanical properties of PBAT/SPC blends were studied. Using maleic anhydride grafted PBAT as compatibilizer resulted in fine domain sizes and good dispersion of SPC and hence improved tensile and dynamic mechanical properties. In the presence of compatiblizer, the formation of percolated SPC network structure was observed at high SPC concentrations, subsequently, resulted in drastic changes in rheological properties, mechanical and dynamic mechanical properties of the blends.     

Hydrophilic antioxidants of virgin olive oil. Part 1: Hydrophilic phenols: A key factor for virgin olive oil quality

Virgin olive oil (VOO) consumption is increasing all over the world due to its excellent organoleptic and nutraceutical properties. These beneficial traits stand from a prominent and well‐balanced chemical composition, which is a blend of major (98% of total oil weight) and minor compounds including antioxidants. The main antioxidants are phenolic compounds, which can be divided into lipophilic and hydrophilic phenols. While lipophilic phenols such as tocopherols can be found in other vegetable oils, most hydrophilic phenols in olive oil are exclusive of the Olea europaea species endowing it with a chemotaxonomic interest. This review is focused on VOO antioxidant profile and, particularly, on hydrophilic phenols that are divided into different sub‐families such as phenolic acids and alcohols, hydroxy‐isochromans, flavonoids, secoiridoids, lignans and pigments. Analytical methods for qualitative and/or quantitative determination of these compounds are assessed. The implementation of efficient sample preparation protocols, separation techniques such as liquid chromatography, GC and capillary electrophoresis, as well as detection techniques such as ultraviolet absorption, fluorescence or MS are critical to succeed in the quality of the results. The effects of hydrophilic phenols on increasing VOO stability, its nutraceutical interest and organoleptic properties are also considered.     

Bioactive Compounds During Drying of Chili Peppers

Chili pepper (Capsicum annuum L.) is one of the most popular fresh vegetables or ingredients (condiments) that provide natural flavor and color. Its color is provided by carotenoids and its flavor is provided by capsaicinoids, which are considered bioactive compounds due to their beneficial effect on health. Moreover, the chili pepper also contains other bioactive compounds, such as phenols and vitamin C. The main process for its preservation and marketing is drying, during which bioactive compounds can be degraded. This review describes the effect of drying on the bioactive compounds of chili peppers using conventional and unconventional technologies.     

聚乙烯醇共混薄膜研究进展

从近年来聚乙烯醇（PVA）与天然高分子［淀粉、壳聚糖（CS）及蛋白质］、合成型生物降解高分子［聚乳酸（PLA）、聚己内酯（PCL）及聚乙二醇（PEG）］以及合成型不可生物降解高分子［聚苯胺（PANI）、低密度聚乙烯（PE⁃LD）及聚氨酯（PU）］进行共混研究角度进行分析,总结了共混薄膜的制备方法及结构性能,并介绍了PVA共混膜材料在医疗、分离、食品包装及农业领域的应用情况,最后对PVA共混薄膜未来的研究方向进行了展望。     

Stabilisation of edible oils with natural antioxidants

Natural antioxidants have recently gained increased interest because of the belief that natural food ingredients are better and safer than synthetic ones. The review presents the results on stabilisation of the main edible oils with different types of natural antioxidants. Sources of natural antioxidants are spices, herbs, teas, oils, seeds, cereals, cocoa shell, grains, fruits, vegetables, enzymes, proteins. Researchers concentrate on ascorbic acid, tocopherols and carotenoids as well as on plant extracts containing various individual antioxidants such as flavonoids (quercetin, kaemferol, myricetin), catechins or phenols (carnosol, rosmanol, rosamaridiphenol) and phenolic acids (carnosic acid, rosmarinic acid). Ascorbyl palmitate is regarded as a 'natural' antioxidant because it is hydrolysed in the body to ascorbic and palmitic acids. Among the herbs of the Lamiaceae family, rosemary has been more extensively studied and its extracts are the first marketed natural antioxidants. Oregano, which belongs to the same family, has gained the interest of many research groups as a potent antioxidant in lipid systems. The review concerns the following main topics: stabilisation of oil with individual natural antioxidants, interaction of antioxidants with synergists, stabilisation of oil with extracts or dry materials from different plant sources (e.g. herbs and spices), stabilisation at frying temperatures and in emulsions.     

An overview of the phenolics of canola and rapeseed: Chemical,sensory and nutritional significance

Utilization of rapeseed meal in human foods has been thwarted by the presence of antinutritional factors such as glucosinolates, phenolics, phytates and hulls. The content of phenolics in rapeseed flour is nearly 30 times higher than that of soybean. Phenolic compounds contribute to the dark color, bitter taste and astringency of rapeseed meals. They may also interact with amino acids, enzymes and other food components, thus influencing the nutritional value of rapeseed meal and its products. Therefore, phenolic compounds are important factors when considering rapeseed meal as a protein source in food formulations. Available literature data on phenolic compounds and tannins of rapeseed/canola are fragmentary and diverse. Furthermore, developing a standardized method for analysis and quantitation of these compounds is warranted. Interaction of rapeseed phenolics/tannins with proteins and their effects on enzymes and other food components remain to be studied.     

Inhibition of lipid peroxidation by anthocyanins,anthocyanidins and their phenolic degradation products

Food components that delay or prevent biomolecule oxidation may be relevant in shelf life extension as well as disease prevention. Anthocyanins are a potentially important group of compounds, but they are prone to degradation both in vitro and in vivo, producing simple phenols. In this study, eight structurally related (poly)phenols [anthocyan(id)ins and phenolic acids] were examined for their ability to inhibit lipid oxidation at physiologically relevant concentrations (100–1000 nM) using the Cu²⁺‐mediated low‐density lipoprotein oxidation model. Interaction between each (poly)phenol and Cu²⁺ ions was also investigated. (Poly)phenols with an ortho‐dihydroxy group arrangement, i.e. cyanidin‐3‐glucoside, cyanidin and protocatechuic acid, were the most effective within their class, extending the lag phase to oxidation by 137, 255 and 402%, respectively (at 1000 nM). At the same concentration, trihydroxy‐substituted compounds (delphinidin and gallic acid) were of intermediate efficacy, extending the lag phase by 175 and 38%, respectively. Compounds with the 4'‐hydroxy‐3',5'‐methoxy arrangement (i.e. malvidin‐3‐glucoside and malvidin) were the least effective (3 and 58% extension, respectively), while syringic acid (4‐hydroxy‐3,5‐dihydroxy benzoic acid) was pro‐oxidant (lag phase shortened by 31%). (Poly)phenols with the ortho‐dihydroxy arrangement chelated Cu²⁺ ions, which in part explains their greater efficacy over the other (poly)phenols in this model oxidation system. However, differences in their hydrogen‐donating properties and their partitioning between lipid and hydrophilic phases are also relevant in explaining these structure‐activity relationships.     

New protein structure-function technology and applications

Recent advances in protein structure technology such as affinity chromatography, high performance liquid chromatography (for protein and peptide isolation) and microsequencing have provided new opportunities for answering fundamental questions as well as providing new applications. For example, it has been recognized for many years that aging causes the accumulation of “abnormal” proteins in cells. The amount of these aged proteins in human cells is exceedingly small, and only through the use of microstructural analyses has it been possible to explore the properties of aged proteins. Such studies suggest that aged cells have a decreased ability to catabolize covalently modified proteins. High-sensitivity structural analyses also provide the opportunity to study the molecular basis of genetic diseases with small amounts of tissue or blood. Examples of the aplication of these new technologies include isolation of enzymes for therapeutic purposes such as digestion of herniated spinal discs and the debridement of burns and ulcers. The use of microencapsulated proteins and matrix-bound enzymes also has provided new application opportunities. For example, covalently bound lactase has been found to have bio-adhesive properties in the intestine and may be used for treatment of lactase insufficiency in persons who cannot tolerate milk or milk products.     

Phospholipids at the Interface: Current Trends and Challenges

Phospholipids are one of the major structural elements of biological membranes. Due to their amphiphilic character, they can adopt various molecular assemblies when dispersed in water, such as bilayer vesicles or micelles, which give them unique interfacial properties and render them very attractive in terms of foam or emulsion stabilization. This article aims at reviewing the properties of phospholipids at the air/water and oil/water interfaces, as well as the recent advances in using these natural components as stabilizers, alone or in combination with other compounds such as proteins. A discussion regarding the challenges and opportunities offered by phospholipids-stabilized structure concludes the review.     

Targeting Mammalian 5-Lipoxygenase by Dietary Phenolics as an Anti-Inflammatory Mechanism: A Systematic Review

5-Lipoxygenase (5-LOX) plays a key role in inflammation through the biosynthesis of leukotrienes and other lipid mediators. Current evidence suggests that dietary (poly)phenols exert a beneficial impact on human health through anti-inflammatory activities. Their mechanisms of action have mostly been associated with the modulation of pro-inflammatory cytokines (TNF-α, IL-1β), prostaglandins (PGE₂), and the interaction with NF-κB and cyclooxygenase 2 (COX-2) pathways. Much less is known about the 5-lipoxygenase (5-LOX) pathway as a target of dietary (poly)phenols. This systematic review aimed to summarize how dietary (poly)phenols target the 5-LOX pathway in preclinical and human studies. The number of studies identified is low (5, 24, and 127 human, animal, and cellular studies, respectively) compared to the thousands of studies focusing on the COX-2 pathway. Some (poly)phenolics such as caffeic acid, hydroxytyrosol, resveratrol, curcumin, nordihydroguaiaretic acid (NDGA), and quercetin have been reported to reduce the formation of 5-LOX eicosanoids in vitro. However, the in vivo evidence is inconclusive because of the low number of studies and the difficulty of attributing effects to (poly)phenols. Therefore, increasing the number of studies targeting the 5-LOX pathway would largely expand our knowledge on the anti-inflammatory mechanisms of (poly)phenols.     

Soy-based adhesives for wood-bonding – a review

Over recent years, the interest in bio-adhesives, including soy-based adhesives, has increased rapidly. Among natural renewable resources suitable for industrial use, soy is a reasonable choice due to its high production volume and the small use of soy meal-based products for human food consumption. Soy flour can be an ideal raw material for the manufacturing of wood adhesives due to its low cost, high protein content and easy processing. There are also more concentrated forms of soy proteins, i.e. concentrates and isolates, which are also suitable raw materials for adhesive production except that their prices are higher. Extensive research has been carried out on improving the cohesive properties, especially water resistance, of soy-based adhesives. However, there is insufficient experimental data available for understanding the influences of modification methods on the structure of soy proteins and therefore for understanding the influences of structural changes on the adhesion. In this paper, some experimental techniques are proposed to be used for analysing soy-based adhesives to enable better understanding of those factors and improve future development. This review of soy-based adhesives is made with the focus on soy proteins’ chemical composition, soy protein product types (raw materials for adhesive production), modification methods for improving the adhesive properties of soy-based adhesives, and commercial soy-based adhesives.     

Pluronic嵌段共聚物胶束化行为及其胶束增溶

两亲性质的Pluronic嵌段共聚物在合适条件下能自发形成内核很大的稳定胶束 ,其胶束化行为复杂 ,初步的研究深化了对两亲分子自组织机理的认识。实验发现这类胶束具有很强的增溶油溶性物质的能力 ,由于这些分子单体和胶束化行为的特点 ,可望利用这类嵌段共聚物实现在增溶应用场合中的突破。综述Pluronic嵌段共聚物的胶束化行为和胶束增溶规律的当前研究进展     

Hibiscus sabdariffa L: source of antioxidant dietary fiber

Dietary fiber and antioxidants are food constituents and functional ingredients that are generally addressed separately. Nowadays there is scientific evidence that primary characteristics of DF assigned to non starch polysaccharides and lignin (resistance to digestion and absorption in the small intestine and fermentation in the large intestine) can be extended to other indigestible food constituents that are resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine. The antioxidant dietary fiber concept was defined as a dietary fiber concentrate containing significant amounts of natural antioxidants associated with non digestible compounds. Hibiscus sabdariffa L flower shows in its composition an important percentage of dietary fiber and high antioxidant capacity. The infusion obtained by decoction of flowers, had been extensibility studied due to the healthy properties. In this work the principal nutritional aspects from Hibiscus sabdariffa L and its use as a possible antioxidant dietary fiber source had been considered.     

Rethinking Membrane Processes for Food: From Particle Behavior to Innovative Membrane Cascades

Within the food industry, membrane separation is commonplace due to its relatively low energy consumption. It allows fractionation of various feeds (e.g., milk) into starting materials for food design. We feel that considerable progress can still be made. For this, the specific properties of the components of interest would need to be taken into account, such as their mobility in flow, and their deformability in relation to the actual membrane structure. Furthermore, improvements are possible through cascaded use of membrane processes, and upgrading waste streams, which leads to new opportunities.     

Comparison between pea and soy protein-based bioplastics obtained by injection molding

The elaboration of bioplastics from renewable polymers (e.g., proteins) is a field with great potential for industrial applications such as food packaging and agriculture. This study evaluates the development of bioplastic systems by injection molding using two different raw materials: soy protein isolate (SPI) and pea protein isolate (PPI). Both proteins are by-products, which lowers the price of processed bioplastics. However, it is necessary to control their properties during the manufacture processing, in order to ensure that they can replace conventional plastics. Therefore, the main objective of this work was to compare the properties of SPI and PPI bioplastics processed at different injection times (150, 300, and 450 s) and different mold temperatures (70 and 130°C). Thus, mechanical properties, water uptake capacity, and transparency were evaluated. The results show the potential of these raw materials to produce bioplastics that can replace conventional plastics, and that the processing conditions can be modified to obtain the desired final properties.     

Standards for protein based foods in developing countries

Legal specifications in India are issued by the Central Committee for Food Standards and are limited in number. Specifications issued by the Indian Standards Institution (ISI), which are discussed in this paper, are optional but prestigious and much more numerous. Foods based on milk proteins emphasize minimal protein damage, estimated by solubility measurement, and high sanitary quality. The latter is common to all other ISI food specifications as well. Edible oilseed proteins for use as food ingredients are formulated in various types or grades and carry such criteria as protein level, fiber content, and appropriate antinutrient level. Proteins from various sources may enter products such as protein mixes, weaning and toddler foods, biscuits, “vegetable” milks, and offspring of the latter like yogurt, ice cream, and reconstitutable powders. In certain products, protein level may be varied inversely with protein quality. To define the latter, the protein efficiency ratio has been adopted and a working methodology for India evolved through collaborative experimentation. The level of any added vitamins and minerals in these protein foods is such that an expected daily consumption of the food would carry 1/3 the Indian recommended daily allowance. Concentrate protein foods stand in a class apart in their very high levels of the nutrients present. Enriched staples like wheat flours could carry proteins, vitamins, and minerals or omit proteins if found functionally disadvantageous. Codes of practice are being developed by ISI in related fields, such as food advertising, in which one clause enjoins that sound established foods or food practices should not be denigrated; food labeling, in which the problem is to ensure a label meaningful to consumers; and date marking, which could hinge on certain and expected shelf life of the food.