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The shift from animal-based towards more sustainable plant-based food systems has increased the interest in leguminous protein such as that from the pseudo-cereal quinoa. In spite of the importance of foaming agents in a wide variety of food systems, the foaming properties of quinoa protein are still poorly understood. In this research paper, the air-water (A-W) interfacial and foaming properties of aqueous extracts from defatted quinoa wholemeal were investigated. Foams contained both albumins and 11S globulins, but no 7S globulins, despite the presence of the latter proteins in the extracts. At pH 7.0, both albumins and 11S globulins were soluble and jointly adsorbed at the A-W interface. Closer to the 11S globulin isoelectric point (pH 5.0), only albumins adsorbed at the A-W interface. Cultivar-dependent differences in protein composition and functionality allowed to hypothesize that 11S globulins foam better when present as dissociated acidic and basic subunits rather than as monomers. Heat-induced aggregation of 11S globulins led to enrichment of albumins at the A-W interface. This was associated with an increased surface tension and a decreased surface dilatational modulus. Presumably, quinoa albumins have low tendency to interact at the A-W interface resulting in a weakly elastic interfacial network. At the same time, globulin aggregates formed during heating at pH 5.0 and 7.0 lead to unstable and stable foams, respectively. As protein functional properties are important for the quality of many food products, these insights are valuable when developing novel quinoa-based food products requiring interfacial stability. [Display omitted] • Foams of aqueous quinoa extracts (AQE) contain albumins and 11S globulins. • At pH 7.0, albumins and globulins jointly adsorb at the air-water (A-W) interface. • At pH 5.0, only albumins adsorb at the A-W interface. • 11S Globulin acidic and basic subunits foam better than intact globulin monomers. • Globulin aggregates formed during heating at pH 7.0 provide stability to foam. [ABSTRACT FROM AUTHOR]

The paper describes the fundamentals of the application of high-resolution ultrasonic spectroscopy for precision, real-time, non-destructive monitoring of enzymatic hydrolysis of proteins in aqueous mixtures and the incorporation of characteristics of ionisation processes accompanying the hydrolysis into the algorithms of calculations of the concentration of peptide bonds hydrolysed, degree of hydrolysis, the average degree of polymerisation, and molar mass. The real-time ultrasonic profiles of protein hydrolysis, adjusted for the ionisation effects, agree well with those obtained with complementary techniques. The limiting resolution of the technique in the concentration of peptide bonds hydrolysed is on the level of 1.5 × 10−6 mol kg−1. Overall, our results demonstrate the versatility of high-resolution ultrasonic spectroscopy in monitoring enzyme hydrolysis of proteins in a broad range of environmental conditions. [Display omitted] • Enzymatic protein hydrolysis can be monitored ultrasonically in a broad range of pH. • 1.5 μmol/kg limiting precision for HR-US monitoring of peptide bond hydrolysis. • Ionisation effects are incorporated into algorithms of ultrasonic monitoring of DH. • HR-US titration provides ionisation characteristics of protein hydrolysates. • pH shift accompanying enzymatic protein hydrolysis can be assessed ultrasonically. [ABSTRACT FROM AUTHOR]

Abstract: This paper summarizes the current status of research into the structure, texture and perception of food gels based on proteins and polysaccharides. The first part of this paper deals with mechanisms of biopolymer gelation. In the second part the effects of post-gelation phenomena are covered, demonstrating that it is of importance for the quality of food to realise that gels are metastable systems that continue to evolve after the initial gelation process has taken place. Phase separated networks are presented in the context of the huge interest from the industrial perspective and a short overview of physical mechanisms is given in a third part. In the final part examples from the dairy industry and flavour perception are presented. [Copyright &y& Elsevier]

Plant protein-based diets (e.g., egg or meat alternatives) have emerged as a promising approach for developing healthy and sustainable food systems. Mayonnaise, a formulated sauce prepared by mixing vegetable oil, egg yolk, vinegar and salt, is probably one of the most widely used condiments in the world today. In this paper, wheat gluten (WG) as an available and low-cost plant protein ingredient was used to prepare and stabilize oil-in-water high internal phase emulsions (HIPEs) as mayonnaise replacers via emulsification–evaporation method. Firstly, WG was dissolved into aqueous acetic acid/ethanol (55/45, v/v, pH 3.0) solution to form phase-separated WG particles, and then HIPEs were prepared through homogenization of high sunflower oil fraction (75 wt%) with WG particles suspension at 80 °C after evaporating ethanol completely. Compared with egg-based mayonnaise, HIPEs (especially for 1.0 wt% WG) exhibited very similar droplet size distribution, rheological behavior, near-perfect thixotropic recovery, and tribological property. These results demonstrated that HIPEs and mayonnaise might have similar sensory property and perceived texture such as creaminess, smoothness, and sliminess. The confocal laser scanning microscopy (CLSM) indicated that close-packed oil droplets could allow them to form homogeneous oil-in-protein network microstructure in HIPEs and mayonnaise, which might contribute to high viscoelasticity, consistency, and correct texture. In addition, thermal stability of HIPEs was much better than that of the mayonnaise. Design and construction of WG-stabilized oil-in-water HIPEs may provide a potential strategy for preparing mayonnaise replacers. [ABSTRACT FROM AUTHOR]

Foaming behavior strongly depends on the structural characteristics of protein colloidal particles. These characteristics may be modified by means of changes in pH value or temperature. In this paper, the foaming and surface properties of gliadin nanoparticles (GNPs) treated by different pH values (3.0–5.8) and heat temperatures (25–70 °C) were investigated. First, decreasing of the pH value (from 5.8 to 3.0) is a process that pHs stay away from isoelectric point (pI∼6.5) of gliadin. Accordingly, zeta potential of GNPs, as indicator of surface charge, rose from +16.3 to +22.0 mV with decreasing the pH from 5.8 to 3.0. But the particle size of GNPs decreased slightly. Meanwhile, the foamability (FA) and foam stability (FS) of GNPs significantly decreased, evidenced by the slow initial adsorption rate and low viscoelastic modulus at the air/water interface. Heating induced a growth of GNPs particle size, however, the zeta potential remained unchanged. The FA and FS of GNPs after heat treated at different temperature values (25–70 °C) kept at the high values and the bubble size maintained the same level. FA and FS of heated GNPs were good enough to board the application of GNPs in the food processing. To compare the effect of pH and temperature on GNPs surface behavior, our results found that the zeta potential played leading role on the adsorption rate of GNPs onto the air/water interface instead of particle size and morphology. Besides, for the foaming properties of GNPs, sensitivity of pH and non-sensitivity of heating give an instructor for further applications. [ABSTRACT FROM AUTHOR]

Egg white proteins (EWPs), in addition to their nutritional values, possess excellent functional properties that facilitate their use in the food industry. This review collates the published information concerning the major functional properties of EWPs such as gelling, foaming, and emulsifying. Gelation of EWPs has several applications in various food products such as puddings and desserts. Foaming is an important element in the manufacture of the foods such as cakes, bread, meringues, and cookies. However, the application of EWPs as an emulsifier in food products is limited, and thus, various techniques and methods for improving the emulsifying ability of these proteins have been investigated. The effect of various parameters on the functional properties of EWPs and possible correlations between structure and function, with a focus on practical performance in food systems, are discussed in this paper. These findings can lead to enriching the research systems on the functional properties of EWPs and providing information for the development of new EWPs -derived/enriched food products. [Display omitted] • Environmental conditions change hydrophilic/hydrophobic ratio of egg white proteins. • Heat treatments potentially denature egg white proteins (EWPs) and change their structure. • Emulsifying stability of egg white proteins under neutral and alkaline conditions is poor. • Electrostatic and hydrophobic interactions are important during gel formation of EWPs. • EWPs have considerable applications in foods such as meringues and cake batters. [ABSTRACT FROM AUTHOR]

In this paper, we investigate whether the rheology of plant proteins is following similar scaling rules, as recently found for maltodextrins. The aim is to construct master curves of the rheology measurements, such that in combination with the scaling rules, the rheology can also be extrapolated to relevant practical conditions, that are not accessible with rheometers. We have analysed 4 different plant proteins, which are currently used in the manufacturing of meat analogs, on which we have performed frequency and amplitude sweeps for a wide range of temperatures and moisture contents. The frequency sweeps show that for all investigated temperatures and moisture contents the protein doughs show elastic behaviour for small strains and low frequencies, which maps on to a single master curve. Yet, the linear elastic modulus is governed by the ratio of the (moisture-dependent) glass transition temperature and the actual processing temperature (T g / T). Furthermore, we have constructed master curves for the strain sweeps, characterized by a critical strain that is independent of moisture content and temperature. Beyond the critical strain, the protein dough is showing strain thinning behaviour. Also with the use of literature data, we have found for pea a similar scaling exponent for shear thinning, strain thinning, and the moduli in the transition zone. This seems to confirm that plant protein doughs adhere to the Cox-Merz and Rutgers-Delaware rule, allowing translation to practical steady flow conditions as occurring during manufacturing. [Display omitted] • For small strains all protein doughs show elastic behaviour for all investigated temperatures and moisture contents. • The linear elastic modulus is a function of T g /T. • Beyond a critical strain, which is temperature and moisture independent, doughs exhibit strain thinning. • An identical scaling exponent is found for transition zone, strain and shear thinning. [ABSTRACT FROM AUTHOR]

This paper studied the effects of inulin addition (0–20 mg mL−1) on the properties of chicken myofibrillar protein (MP) heat-induced gel. The molecular forces to maintain the gel structure, gelling formation process and gel microstructure were studied to explore the influencing mechanism of inulin on gel properties of MP. The results showed that the springiness and hardness of MP-inulin gel significantly increased when inulin was added at 5–20 mg mL−1, while the water holding capacity (WHC) significantly enhanced at 5–10 mg mL−1 inulin addition (P < 0.05). The most appropriate inulin addition to improve the properties of MP mixed gel was 10 mg mL−1. The addition of 20 mg mL−1 inulin decreased the cooking loss of mixed gel. Inulin promoted the exposure of more hydrophobic groups and the formation of disulfide bonds. Inulin addition significantly decreased the I850/I830 in Raman spectrometry, indicating an increase in the formation of hydrogen bonds with MP molecules. However, inulin had little effect on electrostatic interaction between MP molecules. During the heating process, the highest storage modulus (G′) value was observed in MP samples added with 15 mg·mL−1 inulin at gel forming and strengthening stage. The denaturation enthalpy (ΔH) value of myosin decreased when inulin exceeded 10 mg mL−1. The microstructure showed that MP composite gel with 10 mg mL−1 inulin had a dense and well-aggregated network structure. These results indicated that inulin addition could make MP denaturation easier during heating, strengthen the molecular forces of MP and the gel network structure, thus improving the MP gel properties. [Display omitted] • Inulin addition improved the gel properties and microstructure of myofibrillar protein. • Inulin strengthened the molecular forces of myofibrillar protein in gels. • Inulin addition made myofibrillar protein more prone to thermal denaturation. • Mechanisms of inulin addition affecting properties of myofibrillar protein gel was revealed. [ABSTRACT FROM AUTHOR]

In this paper, the synergistic effect of myofibrillar protein enrichment and homogenization on the quality of cod protein gel (CP-gel) was investigated. CP-gel properties were characterized through measuring the gel strength, rheological properties, water retention and the protein network structure. The results showed that myofibrillar protein was enriched after washing the steamed cod for more than three times. With the synergistic effects of homogenization and myofibrillar protein enrichment, CP-gel with 1:3 of solid: water ratio was produced, which had similar texture properties with the regular CP-gel (with 1:1 of solid: water ratio), and had better gel strength, storage modulus, and water holding capacity than the control (i.e., with no enrichment/homogenization treatments). Clearly, the combined protein enrichment and homogenization treatments pointed to a new CP-gel production method which would significantly increase the production yield and reduce the production costs without negatively impact the product quality. In addition, the CP-gel with thixotropy and shear-thinning behavior was suitable for extrusion-based 3-D printing, which could be utilized to develop custom-made designer specialty food with further enhanced nutritional and flavor/textual properties. [Display omitted] • Myofibrillar protein was enriched after washing the steamed cod more than 3 times. • Combined enrichment & homogenization treatments increased production yield. • The cod protein gel was suitable for extrusion-based 3-D printing. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the effect of the initial and advanced steps of glycosylation by Maillard reaction (MR) (glycation) of β-lactoglobulin (β-Lg) with galactose on the interfacial and foaming (foamability and foam stability) properties of this protein has been studied at both pH 7 and pH 5. Hardly any effect of glycation was observed at pH 7. However, a pH 5, due to its increased solubility, β-Lg glycated at 50 °C during 48 h (advanced steps of MR) presented the best dynamic of adsorption which lead to an increase of the surface dilatational modulus of adsorbed film. This resulted in a better foaming capacity, as well as higher stability of foams of β-Lg glycoconjugates with respect to native and control heated protein. These results could extend the applicability of β-Lg as a foaming agent, particularly in acid foods. [Copyright &y& Elsevier]

Abstract: Different kinds of plasticizers were chosen to study the effects of plasticizer composition, size and shape on the mechanical properties and water vapor permeability (WVP) of gelatin films in this paper. Firstly, oligosaccharides – sucrose, and some organic acids such as oleic acid, citric acid, tartaric acid, malic acid (MA) were added to gelatin. It was found that only MA could improve the ductility of gelatin film, and the visual appearance of MA modified gelatin film was better. Secondly, polyethylene glycols (PEG) with different molecular weights (300, 400, 600, 800, 1500, 4000, 10 000, 20 000) were used to plasticize gelatin films. This showed that PEG of lower molecular weights exhibited better plasticizing effect for gelatin films, and such films had better visual properties. This shows that mannitol (Man) and sorbitol (Sor) could make gelatin films flexible, whereas Man could crystallize from gelatin film. Following this, the plasticization of ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG) series and ethanolamine (EA), diethanolamine (DEA), triethanolamine (TEA) series was studied. At last, suitable plasticizers (MA, PEG300, sorbitol, EG, DEG, TEG, EA, DEA, TEA) for gelatin were selected to investigate the WVP and water content of these plasticized gelatin films. The mechanical properties of these films were also compared. [Copyright &y& Elsevier]

Abstract: This paper examines the potential of high hydrostatic pressure to produce whey protein hydrolysates that combine low immunoglobulin (Ig)G- and IgE-binding with acceptable functional properties, with the aim to produce milk-based ingredients with reduced potential allergenicity that could be used in hypoallergenic foods. Treatment with pepsin and chymotrypsin under high pressure produced, in minutes, hydrolysates in which α-lactalbumin and β-lactoglobulin were totally proteolysed, giving rise to large and hydrophobic peptides. Such hydrolysates presented reduced antigenicity and human IgE-binding properties. The hydrolysates obtained with pepsin at 400MPa showed improved heat stability, particularly at a pH, close to the isoelectric point of the whey proteins, and their emulsion activity indexes at pH 7.0 were superior to those of the untreated whey proteins. These results suggest that the peptides present retained low antigenicity together with sufficient capacity to form emulsions. [Copyright &y& Elsevier]

Abstract: This paper describes the relation between crumbliness of whey proteins/polysaccharide mixed gels and their physical properties. Crumbly sensation relates strongly to the breakdown behaviour of the gels, which is primarily determined by their viscoelastic properties. These properties result from the balance between elastically stored energy and energy dissipation during deformation. The stored energy is determined as the percentage of the recoverable energy in a compression–decompression test. Gels breaking readily via a free-running crack (i.e. high recoverable energy) were perceived as the most crumbly ones. Gels showing slow, yielding-like breakdown (i.e. high energy dissipation) were sensed as the least crumbly by assessors during quantitative descriptive analysis (QDA). Serum release from the gels contributed to a large extent to the energy dissipation and thus decreased crumbliness. Microstructure affects serum release and therefore indirectly microstructure affected the crumbly sensation. The relations between crumbly sensation and physical and structural properties of the gels are, to our knowledge, reported here for the first time and can be applied to control and engineer crumbliness of semi-solid foods. [Copyright &y& Elsevier]

Abstract: The stability of oil–water or oil–air emulsions as well as egg white foams is one of the main food-technological problems. On the other hand, proteins are good natural stabilizers and emulsifiers which are widely employed in the technological processing. In this paper we have studied the localization of hydrophobic-polar (HP)-copolymers (which can be viewed as a simplified model for proteins) at a selective solvent–solvent interface. The sequences of the H- and P-species range from regular multiblocks to random and correlated structures. Our approach is based on simple scaling arguments and describes the dependence of the components of the gyration radius of the copolymer chain, perpendicular and parallel to the interface, on the chain length N, the block size M or the “chemical correlation” length , as well as the selectivity parameter . The scaling relations differ for the case of weak and strong localization. We implemented a dynamic off-lattice Monte-Carlo model to verify these scaling predictions and for a wide range of chain lengths () we find a really good agreement between the simulation results and the theoretical predictions. Some further perspectives and applications are shortly discussed. [Copyright &y& Elsevier]

Abstract: This review paper analyses the impact of the weak non-specific physical interactions of the food biopolymers (proteins, polysaccharides) both with each other and with the major low-molecular-weight ingredients of the multicomponent food colloids (sugars, mineral salts, small-molecule surfactants) on such key functional properties of the biopolymers as their capacities for the structure formation in a bulk of the aqueous phases and at the interfaces of colloidal systems. The thermodynamic approach, based on the application of a combination of the thermodynamic methods (light scattering, mixing calorimetry, differential scanning calorimetry, tensiometry), is central in this analysis. The contribution from the biopolymer–biopolymer interactions to the structure formation and stability of the aqueous solutions and colloidal systems is divisible into the contributions from the biopolymer self-assembly and from the interactions between different by nature biopolymers. It is shown that both of these types of the biopolymer–biopolymer interactions are crucial to the features of gelation, formation of the adsorbed layers at the surface of the colloidal particles, phase separation, and to the interactions between the colloidal particles in the biopolymer-based colloids. In addition, the impact of the distinct character (complexation or segregation) of the interactions between unlike biopolymers is demonstrated and discussed. [Copyright &y& Elsevier]

Abstract: A process is described which enables the molecular structure of a wide range of food hydrocolloids to be modified in a controlled manner. It involves treating the hydrocolloid in the solid state with ionising radiation in the presence of a mediating gas. The molecular weight can be increased to the point where it ceases to be completely water soluble, and thereafter, with further dose increases, a hydrogel state results. The paper describes the changes which have been introduced into globular structures such as arabinogalactan proteins, branched chain polysaccharides such as pullulan and dextran, chemically modified structures such as carboxymethyl cellulose and gelling plysaccharides such as xanthan, pectin and carrageenan. Proteins can also be similarly modified and gelatin is used as an example. The change in physical properties and functionality, reflect the molecular changes, particularly emulsification, water binding, viscosity and viscoelasticity. Interactive blends can be produced when solid state mixtures of these materials are co-processed. [Copyright &y& Elsevier]

Abstract: The objective of this paper was to study the effect of plasticizers and their concentrations on the thermal and functional properties of gelatin-based films. Four polyols (glycerol—GLY, propylene glycol—PPG, di- DTG and ethylene glycol—ETG) were tested in five concentrations: 10, 15, 20, 25, and 30g plasticizer/100g of gelatin. For thermal analysis, the films were conditioned in desiccators with silica gel and for functional properties (mechanical properties, water vapor permeability, color and opacity) characterizations, the films were conditioned at 25°C and 58% relative humidity. The results were discussed in terms of ‘plasticizer efficiency’ meaning plasticizer content effect and also in terms of ‘plasticizer effect’ meaning the plasticizer type effect on the properties. In a general manner, the higher plasticizing effect on thermal properties was observed with the DTG, followed by PPG, GLY and ETG, principally with low plasticizer content. However, also in terms of thermal properties, the ETG presented the higher plasticizer efficiency followed by the GLY, DTG and PPG. Concerning the mechanical properties, the GLY showed the greater plasticizing effect and efficiency, but the plasticizing efficiency of DTG on the puncture deformation was also considerable. The mechanical resistance could be related with the glass transition temperature of films. It was not possible to observe the plasticizer effect on the water vapor permeability (WVP), but the DTG had shown greater plasticizer efficiency, followed by GLY and ETG, while a counter effect was observed with PPG. The effect of the type and concentration of plasticizer on the color and opacity of films could be considered as negligible. In conclusion, the more important plasticizer effect and efficiency were observed with DTG and ETG on the thermal properties, and with the GLY in terms of functional properties. The behavior of the mechanical properties of films could be explained by its glass transition temperature. [Copyright &y& Elsevier]

In beer, the main amphiphilic components are protein and iso-humulone. Two major populations of protein are identified as lipid transfer protein (LTP) (9.7 kDa) and protein Z (43 kDa). In this paper, protein and iso-humulone are extracted from barley malt and hop, respectively, based on the brewing process. Mixtures of protein and iso-humulone are mixed at different concentrations and centrifuged. Supernatants are analyzed by asymmetric flow field-flow fractionation (AF4) coupled to UV with multi-angle light scattering (MALS) detection as well as by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). The presence of aggregates and their structures are investigated by light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that protein and iso-humulone can form aggregates from molecular level by AF4-UV-MALS and SDS-PAGE. The interaction is shown as solution depletion which is analyzed by AF4-UV-MALS. With 300 mg/L iso-humulone and 3 g/L protein in bulk, the decrease of protein peak levels off. The peak of protein Z is preferentially decreased as an effect of iso-humulone being present, suggesting that interaction between these populations is favored. The iso-humulone/protein aggregates consist of both undefined irregular aggregates as well as spherical aggregates. The spherical aggregates are observed in light microscopy, SEM and TEM. From SEM, it is clear that there are two types of spherical aggregates: rough and smooth. With TEM it can be observed that the smooth aggregates consist of a thin layer of the aggregated proteins and iso-humulone enclosing a liquid domain. This structure can best be described as an iso-humulone/protein vesicle. The rough vesicles are formed by further precipitation at the surface of the smooth vesicles. Image 1 • Iso-humulone aggregates mainly with protein Z, and less with LTP. • Aggregates are large uncharacteristic floccs, but also vesicules • Vesicular aggregates are spontaneously formed in 1–20 μm. [ABSTRACT FROM AUTHOR]

Oilseeds represent a sustainable source of oils and proteins that can replace those of animal origin. However, the extraction of oil and proteins from oilseeds currently requires multiple steps and is plagued by undesired reactions occurring during the extraction, which limits valorization. In this paper, we describe a successful method for the simple simultaneous extraction of proteins and oil (as intact oleosomes). Non-defatted dehulled rapeseeds served as oilseed model. First, an aqueous extraction step at pH 9.0 was performed resulting in a protein-oleosome extract, with extraction yields of 78.8 ±0.2 wt% and 82.8 ±0.4 wt% of proteins and oleosomes respectively. Further separation resulted in a protein-rich and an oleosome-rich mixture. The oleosomes were recovered as high oil volume oil-in-water emulsion, while simple filtration of the protein-rich mixture led to a highly soluble (81.4 ±1.9 wt%) protein concentrate. Following this extraction method, complexation between proteins and phenolic compounds was prevented, a clear advantage over the existing methods. These findings emphasize the importance of designing new processes for the extraction of oilseed proteins and oleosomes that could initiate their use in food systems. Image 10526 • Rapeseed proteins and oleosomes were simultaneously extracted. • Rapeseed proteins and oleosomes were obtained separately in high yields. • Efficient removal of phenolic compounds was achieved. • Oleosomes were recovered as a dispersed oil phase (natural emulsion). [ABSTRACT FROM AUTHOR]

Abstract: Effects of deproteinization on the degree of oxidation of ozonated starch (corn, sago, and tapioca) were investigated. Starch in dry powder form was exposed to ozone for 10min at different ozone generation times (OGTs: 1, 3, 5, 10min), and then native starches (NS) and deproteinized starches (DPS) were analyzed for protein content. Deproteinization caused a significant reduction in protein content for corn (∼21%) and sago (∼16%) starches relative to NS. Carbonyl and carboxyl contents increased significantly in all ozonated deproteinized starches (ODPS) with increasing OGT. Carbonyl and carboxyl contents of ODPS ranged from 0.03 to 0.13% and 0.14 to 0.28%, respectively. The carboxyl content for all ODPS was significantly higher than that of ozonated native starches (ONS). A Rapid Visco Analyser was used to analyze pasting properties of all starches. Deproteinization increased the pasting viscosities of corn and sago starches compared to their native forms. Generally, pasting viscosity of all ODPS decreased drastically as OGT increased. At the highest oxidation level (10min OGT), all ODPS exhibited the lowest pasting viscosities compared to their ozonated native form, except for peak viscosity, breakdown viscosity, and setback viscosity for ozonated deproteinized corn starch. In conclusion, deproteinization as a pretreatment prior to starch ozonation successfully increased the degree of oxidation in the three types of starch studied. However, the extent of starch oxidation varied among the different starches, possibly due to differences in rates of degradation on amorphous and crystalline lamellae and in rates of oxidation of carbonyl and carboxyl groups. [Copyright &y& Elsevier]

Abstract: The physicochemical, functional and structural properties of vicilin-rich protein isolates from kidney, red and mung beans (KPI, RPI and MPI) were investigated, and the influences of heating (at 95 °C for 30 min) were also evaluated and compared. In the untreated samples, the thermal stability, free SH contents and surface hydrophobicity were different. The differences seemed to be closely related to the differences in extent of aggregation and/or tertiary and secondary conformational structures among proteins. The heating resulted in extensive denaturation of the protein, significant decreases in free SH groups and increases in surface hydrophobicity, but to a varying extent, depending on the type of protein isolates. The protein solubility and emulsifying activities were significantly improved by the heating. The tertiary and secondary structures of these proteins were also to a various extent affected. The conformational structures of proteins in RPI were most flexible, and susceptible to the heating, while the proteins in KPI were most heat-stable in structures. The results clearly indicated close relationships between functional properties of these vicilin-rich protein isolates and their conformational structures. [Copyright &y& Elsevier]