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A series of biodegradable PEG-containing polyanhydrides composed of sebacic acid, 1, 6-bis( p-carboxyphenoxy) hexane, and poly (ethylene glycol) (PEG) were used as matrix material for BSA-loaded microspheres. The effects of polymer composition on the microsphere size, entrapment efficiency, in vitro degradation, and in vitro protein release were studied. Microspheres in the size range of 0.8-10 μm were fabricated via a modified double emulsion method and were characterized using scanning electron microscopy. As the content or the molecular weight of PEG was increased in the copolymer, a proportional increase was found in the particle size and the efficiency of BSA entrapment. The in vitro degradation rate of particles could be controlled by varying the polymer composition, increasing as the PEG proportion increased. In vitro release studies of BSA from polyanhydride microspheres revealed that the increased amounts of PEG within microspheres could accelerate the release rate of protein. These studies indicate that the PEG-containing polyanhydrides hold potential for protein delivery applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Dabing Zhang
(Corresponding author) As the worldwide commercialization of genetically modified organisms (GMOs) increases and consumers concern the safety of GMOs, many countries and regions are issuing labeling regulations on GMOs and their products. Analytical methods and their standardization for GM ingredients in foods and feed are essential for the implementation of labeling regulations. To date, the GMO testing methods are mainly based on the inserted DNA sequences and newly produced proteins in GMOs. This paper presents an overview of GMO testing methods as well as their standardization. [ABSTRACT FROM AUTHOR]

The F and F progenies of eight-parent diallel crosses were used to investigate the mode of inheritance of fatty acids, oil, and protein in safflower ( Carthamus tinctorius L.) seeds. The results indicated significant differences among the parents for general (GCA) and specific combining ability (SCA). Relatively high narrow-sense heritability was estimated for fatty acids including linoleic (0.84), oleic (0.77), palmitic (0.61), and stearic (0.6) acids. The high narrow-sense heritability and the high ratio of GCA/SCA mean squares for all the fatty acids investigated indicate the important role of additive gene action in controlling these traits. In our experiment, however, low narrow-sense heritability was obtained for oil (0.37) and protein (0.28) contents. Furthermore, the estimates of genetic variance components proposed the importance of non-additive genetic effects that contribute to variation in oil and protein content. The overall results indicated that K × Mex.22-191 cross could be employed for the production of high oil yielding and high oleic acid safflower lines in breeding programs. [ABSTRACT FROM AUTHOR]

queous extraction processing technologies, having advanced in recent years, may be a viable alternative to hexane extraction to separate oil and protein from soybeans. Different extraction strategies incorporating various modes of comminution, extraction buffers, and enzymes allow production of a range of oil and protein products, but also create different processing challenges. Processes capable of achieving high free oil yields often result in a soluble protein fraction difficult to isolate and dilute oil emulsions difficult to break. Other processes can achieve high yields and purities of native soy protein, but with reduced free oil yield or require a high osmotic and ionic strength extraction buffer. This review article discusses these various advanced processes and their relative advantages and disadvantages. In addition, the current understanding of the underlying fundamental concepts of aqueous extraction is discussed in order to help direct future investigations to improve these technologies. [ABSTRACT FROM AUTHOR]

As the current starch based ethanol market increases at its rapid pace, finding new markets for the primary coproduct, distiller's grains, has gained considerable interest. One possibility is to isolate the protein-rich fraction for use as precursors to biochemicals and bioplastics, further decreasing fossil fuel consumption. This research focuses on enzymatic extraction of protein peptides from wheat heavy stillage using commercially available proteases. The energy saved due to this process ranged from ∼1.5 to 3.0 GJ/ton wheat stillage compared to fossil fuel-based chemicals. Using Protex 6L (Genencor), ∼57% of the protein in the stillage was soluble 24 h after protease addition at 0.1% w/w loading. Of these proteins, ∼32% were already soluble, indicating the importance of using wet heavy stillage as the feedstock rather than dried distiller's grains. Peptide size was less than 6 kDa. Further improvements in protein removal may be obtained through a fed batch addition of protease and improved protease cocktails. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011 [ABSTRACT FROM AUTHOR]

In the last two decades, efforts focused in the field of drug delivery have made it possible to reach important goals, especially with proteins and peptides. The story of the evolution of this matter is vast and it is difficult to summarize its various aspects in a single review. On the other hand, it could be really interesting to look at the inside story of a typical academic research lab that has dedicated almost all its resources to drug delivery. In our case, an initial interest in the issue of protein conformation stability soon paved the way for a new area of study: the modification of proteins with synthetic polymers. We have seen this technique transformed from a crude and inhomogeneous procedure into a well-recognized and successful approach. This great advance has been possible thanks to the development of dedicated chemical coupling methods and to the better understanding of the behavior of polymers in vivo. In particular, among the several polymers investigated, PEG has became the best polymer for protein modification. Exploiting the unique properties of this polymer, we have conducted several investigations in the field of protein PEGylation and then transferred the acquired know-how to the development of conjugates with low molecular weight drug. This last aspect still presents several unmet needs that are awaiting proper solutions. [ABSTRACT FROM AUTHOR]

The small-amplitude conformational changes in macromolecules can be described by the changes in bond lengths and bond angles. The descriptors of large scale changes are torsions. We present a recursive algorithm, in which a bond vector is explicitly written in terms of these internal, or polyspherical coordinates, in a local frame defined by two other bond vectors and their cross product. Conformations of linear and branched molecules, as well as molecules containing rings can be described in this way. The orientation of the molecule is described by the orientation of a body frame. It is parametrized by the instantaneous rotation angle, and the two angles that parametrize the orientation of the instantaneous rotation axis. The reason not to use more conventional Euler angles is due to the fact that Euler angles are not well-defined in gimbal lock (i.e., when a body axis becomes aligned with its space fixed counter part). The position of the molecule is parametrized by its center of mass. Original and calculated positions are compared for several proteins, containing up to about 100,000 atoms. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 [ABSTRACT FROM AUTHOR]

1. Low pH inhibits microbial conditioning of leaf-litter, which forms the principal energy input to many headwater streams. This reduces food quality and availability for the shredder assemblage, thereby creating a potential bottleneck in the flux of energy and biomass through acidified food webs. 2. We explored the consequences of acidity on the well-characterised community of Broadstone Stream in southeast England, by quantifying the physiological condition (protein and lipid content) of three dominant shredder species ( Leuctra nigra, L. hippopus and Nemurella pictetii) and relating this to changes in the numerical abundance and biomass of invertebrates across a longitudinal pH gradient (5.3–6.5). 3. Total taxon richness increased with pH, as did shredder diversity. The acid-tolerant stonefly, L. nigra, exhibited a positive correlation between pH and protein content, but its abundance was suppressed in the less acid reaches. These results suggest that the impacts of environmental stressors might be manifested differently at the population (i.e. numerical and biomass abundance) versus the physiological (i.e. protein content of individuals) levels of organisation. Body composition of L. hippopus and N. pictetii did not exhibit any significant relationship with stream pH in the field. 4. The survey data were corroborated with a laboratory rearing experiment using N. pictetii, in which survival rate, growth rate, and protein and lipid content of individuals were measured in stream water of differing pH and acid versus circumneutral microbial conditioning regimes. Acid-conditioned leaves were associated with increased mortality and reduced protein content in consumers’ tissues, with acid water also having the latter effect. 5. Our results suggest that biochemical constraints within key taxa might create energy flux bottlenecks in detrital-based food webs, and that this could ultimately determine the productivity of the entire system. Hence assays of the body composition of macroinvertebrates could be an effective new tool that complements population level studies of the impacts of stressors in fresh waters. [ABSTRACT FROM AUTHOR]

Using the geometric framework for the first time in a field study of ant nutritional biology, we show that Ectatomma ruidum colonies actively regulate protein–carbohydrate intake, self-selecting a carbohydrate-biased diet. These data, combined with quantitative recruitment data, provide a more comprehensive understanding of colony-level nutritional requirements of ants. Abstract in Spanish is available at [ABSTRACT FROM AUTHOR]

The growth rate hypothesis (GRH) asserts, from known biochemistry, that maintaining high growth rates requires high concentrations of ribosomes. Since ribosomes are rich in phosphorus (P), the GRH predicts a positive correlation between growth rate and P content; this correlation is observed in some organisms. We consider the application of the GRH to phytoplankton and identify several key problems that require further research before the hypothesis can be accepted for these organisms. There are severe methodological problems that confound interpretation of data for testing the GRH. These problems include the measurement of protein and nucleic acids (such that ratio of these components carries a high level of uncertainty), studies of steady-state versus dynamic systems, and the presentation of data per cell (especially as cell size varies with growth rate limitations) and the calculation of growth rates. In addition, because of the short generation times and rapid responses of these organisms to perturbations, ribosome and RNA content is expected to vary in response to (de)repression of various systems; content may increase on application of growth-limiting stress. Finally, that most phytoplankton accumulate P when not P stressed conflicts with the GRH. In consequence, the value of the GRH for any sort of predictive role in nature appears to be severely limited. We conclude that the GRH cannot be assumed to apply to phytoplankton taxa without first performing experimental tests under transient conditions. [ABSTRACT FROM AUTHOR]

Diogenes is a Pan-European, randomized, controlled dietary intervention study investigating the effects of dietary protein and glycaemic index on weight (re)gain, metabolic and cardiovascular risk factors in obese and overweight families in eight European centres. The article is methodological in character, and the presentation of ‘results’ will be limited to baseline characteristics of the study populations included. A total of 891 families with at least one overweight/obese parent underwent screening. The parents started an initial 8-week low-calorie diet and families with minimum one parent attaining a weight loss of ≥8%, were randomized to one of five energy ad libitum, low-fat (25–30 E%) diets for 6 or 12 months: low protein/low glycaemic index, low protein/high glycaemic index, high protein/low glycaemic index, high protein/high glycaemic index or control (national dietary guidelines). At two centres the families were provided dietary instruction plus free foods for 6 months followed by 6-month dietary instruction only. At the remaining six centres the families received dietary instruction only for 6 months. The median weight loss during the low-calorie diet was 10.3 kg (inter-quartile range: 8.7–12.8 kg, n = 775). A total of 773 adults and 784 children were randomized to the 6-month weight (re)gain prevention phase. Despite major cultural and dietary regional differences in Europe, interventions addressing effects of dietary factors are feasible with a reasonable attrition. [ABSTRACT FROM AUTHOR]

The aim of this study was to describe the development and implementation of a multifaceted, low-fat, weight-loss strategy for a Pan-European randomized controlled dietary intervention study, Diogenes. There were 891 families with at least one overweight/obese parent who underwent screening. Eligible, overweight/obese adults followed an 8-week weight-loss phase with a fixed low-energy diet (800 kcal). On attaining weight loss of ≥8%, families were randomized to a 6- or 12-month low-fat (25–30%E) diet either based on national dietary guidelines or one of four interventions: low protein (LP)/low glycaemic index (LGI), LP/high GI (HGI), high protein (HP)/LGI and HP/HGI. The impact of each diet in preventing weight (re)gain was tested. A points-based system was used to manipulate dietary protein and carbohydrate. Manipulating carbohydrate composition involved substituting foods with a relatively high or low GI. A questionnaire was designed and completed by study investigators, providing feedback on the dietary intervention methods used to inform future interventions. The points system allowed macronutrient manipulations without compromising dietary flexibility or enforcing energy restrictions. Reported centre/participant differences in the ease of implementing the intervention may reflect dietary diversity and personal preferences for specific weight-management strategies. The points system provides a useful starting point for designing improved experimental paradigms for the manipulation of dietary intake in future trials. [ABSTRACT FROM AUTHOR]

Abstract: The correlation between mRNA and protein abundances in the cell has been reported to be notoriously poor. Recent technological advances in the quantitative analysis of mRNA and protein species in complex samples allow the detailed analysis of this pathway at the center of biological systems. We give an overview of available methods for the identification and quantification of free and ribosome-bound mRNA, protein abundances and individual protein turnover rates. We review available literature on the correlation of mRNA and protein abundances and discuss biological and technical parameters influencing the correlation of these central biological molecules. [Copyright &y& Elsevier]

The aim of this study was to analyse the effects of industrial processing on the composition of proteins, free amino acids and phenolics in Castanea sativa Mill. fruits of 2 years. The Portuguese cultivars were Judia, Longal, Martaínha and Lada, and the European cultivars were ‘Spanish’ (Puga do Bolo) and ‘Italian’ (Viterbes). At all processing stages the fruits contained low contents of protein (4.1–5.4 g 100 g−1 d.m.). The essential amino acid Thr had the highest values (3.6–10.0 mg 100 g−1 f.w.), while the highest non-essential amino acid was Asn (14.9–36.4 g 100 g−1 f.w.). Total phenolics (6.6–18.3 mg g−1 f.w.) were more significantly affected by the processing stage factor. In 2007 the gallic acid contents were more affected by the processing stage and interaction factors (cultivar × processing stage), whereas the cultivar factor had more of an effect on ellagic acid. Industrial processing has some negative effects, specifically reducing the contents of some amino acids. [ABSTRACT FROM AUTHOR]

Tyrosine sulfation is a post-translational modification of many secreted and membrane-bound proteins. It governs protein-protein interactions that are involved in leukocyte adhesion, hemostasis, and chemokine signaling. However, the intrinsic feature of sulfated protein remains elusive and remains to be delineated. This investigation presents SulfoSite, which is a computational method based on a support vector machine (SVM) for predicting protein sulfotyrosine sites. The approach was developed to consider structural information such as concerning the secondary structure and solvent accessibility of amino acids that surround the sulfotyrosine sites. One hundred sixty-two experimentally verified tyrosine sulfation sites were identified using UniProtKB/SwissProt release 53.0. The results of a five-fold cross-validation evaluation suggest that the accessibility of the solvent around the sulfotyrosine sites contributes substantially to predictive accuracy. The SVM classifier can achieve an accuracy of 94.2% in five-fold cross validation when sequence positional weighted matrix (PWM) is coupled with values of the accessible surface area (ASA). The proposed method significantly outperforms previous methods for accurately predicting the location of tyrosine sulfation sites. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009 [ABSTRACT FROM AUTHOR]

Use of hydrolyzed proteins is known to delay hardening of high-protein nutrition bars. Bars were formulated using ratios of 0%, 25%, 50%, 75%, or 100% partially hydrolyzed whey protein isolate (HWPI) to nonhydrolyzed whey protein isolate (WPI) in one experiment, and either WPI or HWPI combined with high-fructose corn syrup (HFCS) or sorbitol syrup (SS) in a 2nd experiment along with vegetable shortening such that initial aw was 0.59 for HWPI bars and 0.64 for WPI bars. After mixing, the dough was extruded into bars and stored at 32 °C for accelerated shelf-life testing. Hardness, color, and microstructure were measured during 42 d of storage. Bars initially had similar hardness of approximately 3.4 N that increased during storage. Bars with HWPI were softest with hardness at 37 d of 10 to 15 N compared to almost 100 N for bars with WPI. Water activity increased for WPI bars to 0.69 by 34 d. Bars became darker during storage depending on amount of Maillard browning reactants, that is, HWPI/HFCS bars ≫ HWPI/SS > WPI/HFCS bars > WPI/SS bars. Bar microstructure at day 2 showed protein and fat dispersed in particulate form throughout the carbohydrate syrup within the bar matrix. During storage, a single nonlipid phase developed in HWPI bars while in WPI bars a phase separation occurred between protein and carbohydrate. We propose that such phase separation initiates bar hardening and promotes subsequent protein aggregation. Successful formulation of HPN bars depends on cosolvent properties of the polyol/sugar toward the proteins and their preferential exclusion from the solvation layer surrounding the proteins. PRACTICAL APPLICATION: High-protein nutrition bars can be formulated so they remain soft during storage by selecting proteins and sugars that are compatible with each other. Otherwise, the protein and sugar will separate from each other which can then lead to hardening. [ABSTRACT FROM AUTHOR]

Barley contains several valuable nutrients including beta-glucan (BG), protein, and starch. Each has additional value when concentrated. Dehulled and hulless barleys were sequentially pearled for 1 to 6 cycles, each with 8% removal. The 6 pearled kernels and the initial kernel were subjected to impact or abrasive milling, followed by sieving with a series of U.S. standard sieves. Results of pearling fines show that protein was most concentrated in the outer area, and decreased all the way toward the core area (near 100% surface removal). Starch showed an opposite trend. BG followed the starch trend, but reached a peak at about 60% surface removal. Upon milling and sieving of kernel samples, genotype and particle size had significant effects on nutrient contents in sieved fractions. The pearling cycle had significant effects on protein and starch contents but little effect on BG content, while the milling method had significant effects on protein and BG contents but little on starch content. Abrasive milling produced sieved fractions with much higher variation in protein content than impact milling, but the opposite effect was observed for shifting BG content. Mass frequency influenced more on recovery rates of nutrients than their concentrations in individual fractions. When the recovery rate was also taken into consideration, pearling alone was found to be the most effective way to enrich protein in barley kernels. However, a combination of pearling with the method of milling and sieving was needed for maximally shifting BG and starch contents. PRACTICAL APPLICATIONS: Although dry fractionation is the method of choice for separating barley into fractions with varying levels of protein, BG, and/or starch, selection of a specific single or combined method is needed for achieving maximum shifts of a particular nutrient. Such information is significant to those who use dry fractionation methods to enrich protein, BG, and/or starch. [ABSTRACT FROM AUTHOR]

Postprandial oxidation of dietary free amino acids or egg white protein was studied using the [13CO2] breath test in rats, as well as in humans. Thirty-eight male rats were assigned to four dietary test groups. Two diets only differed in their protein fraction. Diet I contained 21% egg white protein. For the breath test egg white protein, intrinsically labelled with [1-13C]-leucine, was used as a substrate. Diet II contained the same amino acids as diet I, though not as egg white protein but in free form. Free [1-13C]-leucine was used to label this diet. In addition, two 1:1 mixtures of both diets were used. During the breath test either the free amino acid or the protein fraction was labelled as in diets I or II. The animals were breath-tested following short-term (day 5) and long-term adaptation (day 20) to their experimental diet. For all diets, including the mixed diets, postprandial oxidative losses on day 5 were significantly higher for the free leucine compared with the protein-derived leucine. Differences between free and protein-derived leucine oxidation had, however, largely disappeared on day 20. The human subjects were breath-tested without any adaptation period to the diets. The oxidative losses of free leucine were also higher than those of protein-derived leucine. None of the studies showed any indication for an interaction between the oxidation of protein-derived amino acids and free amino acids. It is concluded that free and protein-derived amino acids in the diet are mainly metabolized independently. [ABSTRACT FROM AUTHOR]

The article presents a study which determines the possible causes of size differences in American Crow nestlings by comparing their urban and rural habitats. The study quantified the land use in known crow territories and identified three distinct environments including the suburban-residential, suburban-managed, and rural. It measured the near fledging age of nestlings in each environment and used for determination of unbound plasma calcium, total protein, and cortisone. The results revealed that rural nestlings are larger compared to suburban-residential crows and had higher total serum protein.

Wheat protein is one of the most important specifications used in domestic and import purchase contracts and is used partly as a proxy for functional quality. The purpose of this article is to analyse the demand for wheat delineated by protein class. A choice-based econometric model is specified and estimated using a novel dataset of pooled wheat shipments to individual importing countries. Buyers are importing countries that make purchase decisions among different protein levels. The model frames the choice in terms of attributes of the choice and of the importing countries. Results indicate that there have been shifts over time, and purchase probabilities are highly price elastic and vary across importing regions. Functional characteristics including wet gluten content and extraction rates have significant impacts on purchase probabilities. These results have implications for breeders as it clearly illustrates the role of protein and functional characteristics on demand. The results also have implications for analysts modelling wheat trade in that there are many factors impacting market segments that would not be captured in conventional demand specifications. [ABSTRACT FROM AUTHOR]

The diffuse spread of glioma tumors leads to the inability to image and properly treat this disease. The optical spectral signature of targeted fluorescent probes provides molecular signals from the diffuse morphologies of glioma tumors, which can be a more effective diagnostic probe than standard morphology-based magnetic resonance imaging (MRI) sequences. Three orthotopic xenograft glioma models were used to examine the potential for transmitted optical fluorescence signal detection in vivo, using endogenously produced protoporphyrin IX (PpIX) and exogenously administered fluorescently labeled epidermal growth factor (EGF). Accurate quantification of the fluorescent signals required spectral filtering and signal normalization, and when optimized, it was possible to improve detection of sparse diffuse glioma tumor morphologies. The signal of endogenously produced PpIX provided similar sensitivity and specificity to MRI, while detection with fluorescently labeled EGF provided maximal specificity for tumors with high EGF receptor activity. Optical transmitted fluorescent signal may add significant benefit for clinical cases of diffuse infiltrative growth pattern glioma tumors given sufficient optimization of the signal acquisition for each patient. [ABSTRACT FROM AUTHOR]

Dialdehyde starch (DAS) was added to pork ham batter. The effects of DAS on the meat protein gel during heating were investigated using thermal and rheological analyses. In this study, the degree of DAS oxidation was controlled by the reaction time. The DSC thermogram showed that increasing the degree of oxidation resulted in DAS having a higher gelatinization temperature and lower heat absorption. In dialdehyde starch/meat (DAS/M) composites, meat protein reduced the availability of water to starch and raised the gelatinization temperature and heat absorbed by the composites. The G′max of the composites was greater than the linear combination of their components. The rheological properties of DAS were a major factor affecting the properties of its composites. Scanning electron microscopy and light microscopy with the aid of histologic technique revealed the network and distribution of DAS and DAS/M composites. The protein matrix formed the backbone of the network and gelatinized starch was trapped in the protein structure. [ABSTRACT FROM AUTHOR]

The objective of the research was to characterize the quality of damaged and undamaged jojoba seeds. The study was performed on jojoba seeds grown in La Rioja, Argentina. Proximal composition, fatty acid composition, acid value, peroxide value, conjugated dienes and trienes and protein electrophoresis profiles were determined in undamaged (JS) and damaged jojoba seeds (DJS). The fat content (wax) was lower in DJS (39.11%) than in JS (50.82%). The values of acid, peroxide, conjugated dienes and trienes were higher in DJS than in JS. No difference in fatty acid composition was observed between DJS and JS. The protein content was not significantly different between JS and DJS. However, DJS had lower soluble protein values. In the electrophoresis profiles, the band located at 50 kDa disappeared in DJS and the intensity of the band located at 25 kDa decreased. The deterioration process in jojoba kernels significantly affects the chemical quality of their proteins and waxes. [ABSTRACT FROM AUTHOR]

The article discusses a study on the levels of transaminases, alkaline phosphatase and protein in tissues of Clarias gariepienus fingerlings exposed to sublethal concentrations of cadmium chloride in Tamil Nadu, India. An overview of the effect of cadmium chloride on enzyme activities and protein levels in the gill of Clarias gariepienus fingerlings is offered. Findings revealed that exposure to xenobiotic contamination in aquatic ecosystems can have effects on inhabiting organisms. It cites the role of aminotransaminases in the utilization of amino acids for the oxidation and/or for gluconeogenesis. The authors conclude that cadmium had deleterious impact in Clarias gariepienus, particularly at high sublethal concentration.

Background/purpose: Tape stripping is commonly used to investigate the stratum corneum (SC). This study assesses if protein quantitative tape stripping method was suitable for human nails. Method: We used a colorimetric method to quantify proteins removed by the tape. Water barrier functions as a result of tape stripping were also observed by changes in transonychial water loss (TOWL) from the baseline. Results: Using tape stripping, we observed no difference between nails in the protein quantity removed by tape stripping ( P=0.39). The mean TOWL before and after tape stripping were 6.9 and 9.3 g/m2/h, respectively; this was significantly increased in tape stripped nails ( P<0.0001). Conclusion: Tape stripping seems to be an effective method to extract proteins from human nail plate and may aid the study of nail structure and function. Further studies are needed to extend our results in terms of age, gender, ethnicity and disease. [ABSTRACT FROM AUTHOR]

The effects of two commercial endoproteases (Protex 6L and Protex 7L, Genencor Division of Danisco, Rochester, NY, USA) on the oil and protein extraction yields from extruded soybean flakes during enzyme-assisted aqueous extraction processing (EAEP) were evaluated. Oil and protein were distributed in three fractions generated by the EAEP: cream + free oil, skim and insolubles. Protex 6L was more effective for extracting free oil, protein and total solids than Protex 7L. Oil and protein extraction yields of 96 and 85%, respectively, were obtained using 0.5% Protex 6L. Enzymatic and pH treatments were evaluated to de-emulsify the oil-rich cream. Cream de-emulsification generated three fractions: free oil, an intermediate residual cream layer and an oil-lean second skim. Total cream de-emulsification was obtained when using 2.5% Protex 6L and pH 4.5. The extrusion treatment was particularly important for reducing trypsin inhibitor activity (TIA) in the protein-rich skim fraction. TIA reductions of 69 and 45% were obtained for EAEP skim (the predominant protein fraction) from extruded flakes and ground flakes, respectively. Protex 6L gave higher degrees of protein hydrolysis (most of the polypeptides being between 1,000 and 10,000 Da) than Protex 7L. Raffinose was not detected in the skim, while stachyose was eliminated by α-galactosidase treatment. [ABSTRACT FROM AUTHOR]

A morpheein is a homo-oligomeric protein that can exist as an ensemble of physiologically significant and functionally distinct alternate quaternary assemblies. Morpheeins exist in nature and use conformational equilibria between different tertiary structures to form distinct oligomers as a means of regulating their function. Notably, alternate morpheein forms are not misfolded forms of a protein; they are differently assembled native states that contain alternate subunit conformations. Transitions between alternate morpheein assemblies involve oligomer dissociation, conformational change in the dissociated state, and reassembly to a different oligomer. These transitions occur in response to the protein's environment, for example, effector molecules, and represent a new model of allosteric regulation. The unique features of morpheeins are being revealed through detailed characterization of the prototype enzyme, porphobilinogen synthase, which exists in a dynamic equilibrium of a high activity octamer, a low activity hexamer, and two dimer conformations. Morpheeins are likely far more common than previously appreciated. There are, however, both intellectual and experimental barriers to recognizing proteins as morpheeins. These barriers derive from the way we were taught and continue to teach about protein folding, protein purification, protein structure-function relationships, and enzyme kinetics. This article explores some of these limitations and encourages incorporation of morpheeins into both introductory and advanced biochemistry classes. [ABSTRACT FROM AUTHOR]

There is an emerging interest in the impact of food structure on digestion behaviour and its relationship to human nutrition. The interactions between individual macronutrients (protein, fat and carbohydrate) in many cases control the rate of digestive processes such as proteolysis and lipolysis. Macronutrient interactions can also control the material properties of ingested foods which can influence post-prandial metabolic responses. This review summarises the current research into how the structure of individual macronutrients impacts digestion and how this relates to appetite. [ABSTRACT FROM AUTHOR]

Dietary protein induces greater satiety compared with carbohydrate in lean subjects, which may involve appetite-regulatory gut hormones. Little is known about the duration of effect, influence of protein and carbohydrate source and relevance to non-lean individuals. We compared the effect of various dietary proteins and carbohydrates on post-prandial appetite ratings, ad libitum energy intake (EI) and appetite hormones in lean and overweight men. Three randomised double-blinded cross-over studies examined appetite response (appetite ratings, ghrelin, glucagon-like peptide-1 (GLP-1) and cholecystokinin) to liquid preloads over three to four hours followed by a buffet meal to assess ad libitum EI. The 1-MJ preloads contained ∼55 g of protein (whey, casein, soy and gluten), carbohydrate (glucose, lactose and fructose) or combined whey/fructose. EI was 10% higher following glucose preloads compared with protein preloads, observed at three hours but not four hours. Protein ingestion was followed by prolonged elevation of cholecystokinin and GLP-1 (two hours) and suppression of ghrelin (three to four hours) compared with glucose and independent of protein type. Replacing some whey with fructose attenuated the effect of protein on these hormones. Treatment effects on EI and appetite hormones were independent of bodyweight status, despite higher GLP-1 and lower ghrelin in overweight subjects. Protein-rich liquid preloads reduce EI over three hours in overweight men compared with glucose. These findings suggest a potential application for protein-rich drinks and/or foods to facilitate reduced EI. Future studies should explore additional dietary manipulations that may enhance this relationship, and confirm these effects within the context of energy-restricted dietary patterns. [ABSTRACT FROM AUTHOR]

Ageing is associated with an increased incidence of diabetes, impaired immunity and numerous physiological, social and economic changes. Another under-recognised change to significantly impact on health outcomes and quality of life is the drastic loss of lean body mass. New concepts have recently emerged which indicate that different types of protein sources supply constituents differentially according to digestion rate, and that amino acids have roles additional to muscle synthesis. This review explores the benefits of higher protein intakes in older people and how the protein source may provide differential benefits. In particular, whey protein is more quickly digested than either casein or soy, and provides a faster and potentially greater net source of available nutrients and essential amino acids essential for maintaining better health. [ABSTRACT FROM AUTHOR]

S-(2-succinyl)cysteine (2SC) is a chemical modification of proteins formed by a Michael addition reaction between the Krebs cycle intermediate, fumarate, and thiol groups in protein—a process known as succination of protein. Succination causes irreversible inactivation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in vitro. GAPDH was immunoprecipitated from muscle of diabetic rats, then analyzed by ultra-performance liquid chromatography–electrospray ionization–mass spectroscopy. Succination of GAPDH was increased in muscle of diabetic rats, and the extent of succination correlated strongly with the decrease in specific activity of the enzyme. We propose that 2SC is a biomarker of mitochondrial and oxidative stress in diabetes and that succination of GAPDH and other thiol proteins may provide the chemical link between glucotoxicity and the pathogenesis of diabetic complications. [ABSTRACT FROM AUTHOR]

An important flavor component of citrus oils is limonene. Since limonene is lipid soluble, it is often added to foods as an oil-in-water emulsion. However, limonene-containing oil-in-water emulsions are susceptible to both physical instability and oxidative degradation, leading to loss of aroma and formation of off-flavors. Proteins have been found to produce both oxidatively and physically stable emulsions containing triacylglycerols. The objective of this research was to determine if whey protein isolate (WPI) could protect limonene in oil-in-water emulsion droplets more effectively than gum arabic (GA). Limonene degradation and formation of the limonene oxidation products, limonene oxide and carvone, were less in the WPI- than GA-stabilized emulsions at both pHs 3.0 and 7.0. These data suggest that WPI was able to inhibit the oxidative deterioration of limonene in oil-in-water emulsions. The ability of WPI to decrease oxidative reactions could be due to the formation of a cationic emulsion droplet interface at pH 3.0, which can repel prooxidative metals, and/or the ability of amino acids in WPI to scavenge free radical and chelate prooxidative metals. [ABSTRACT FROM AUTHOR]

To evaluate a practical method of determining more accurately conversion factors for calculating the protein contents of foods from the total nitrogen content, 19 cereal products found in Japan were analyzed for total nitrogen, amino acid nitrogen, and amide nitrogen, and then the nitrogen-to-protein conversion factors were calculated. The average conversion factors were 5.75 for rice, 5.81 for wheat, and 5.95 for others. These values, corresponding to the proportion of the amino acid residue to amino acid nitrogen recovered from 20 amino acids, were lower than the currently applied factors to these foods, except for wheat flour and amaranth. The use of this factor for estimating the protein content results in a considerable difference from the estimate based on amino acid residue concentrations, due to the wide variations in amino acid composition and to the presence of a significant level of nonprotein nitrogen. The distribution of the protein nitrogen recovered from the amino acids to total nitrogen averaged 93%. Adjusted conversion factors corresponding to the proportion of the amino acid residue to total nitrogen averaged 5.26 for rice, 5.47 for wheat, and 5.54 for other cereal products. Protein contents estimated using these factors are in good agreement with the contents defined as amino acid residues. [ABSTRACT FROM AUTHOR]

Low-molecular-weight S-nitrosothiols (RSNOs) are well known for their capability to transnitrosate cysteine residues of enzymes thereby altering their catalytic activity. It is unknown, however, whether N-nitrosomelatonin (NOMela) which is highly effective in transnitrosating low-molecular-weight thiols (RSHs) can also alter protein function. In the present study, we report on such a capability with glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as a target enzyme. Reaction of NOMela with GAPDH resulted in an increase of RSNOs at the expense of RSHs. Somewhat surprisingly, NOMela was about 10-fold more effective than S-nitrosocysteine in inhibiting GAPDH. Vitamin C and glutathione increased the NOMela-dependent inhibition of the enzyme by accelerating the intermediacy of nitroxyl which is also highly effective in nitrosating RSHs. The occurrence of this intermediate during the NOMela–vitamin C reaction was verified by using Mn(III)-tetrakis(1-methyl-4-pyridyl)porphorin pentachloride as nitroxyl scavenger. The NOMela-dependent inactivation of GAPDH was so effective that this reaction can be used to quantify NOMela with high sensitivity. [ABSTRACT FROM AUTHOR]

Increasing interest in high-quality food products with increased shelf life and reduced environmental impact has encouraged the study and development of edible and/or biodegradable polymer films and coatings. Edible films provide the opportunity to effectively control mass transfer among different components in a food or between the food and its surrounding environment. The diversity of proteins that results from an almost limitless number of side-chain amino-acid sequential arrangements allows for a wide range of interactions and chemical reactions to take place as proteins denature and cross-link during heat processing. Proteins such as wheat gluten, corn zein, soy protein, myofibrillar proteins, and whey proteins have been successfully formed into films using thermoplastic processes such as compression molding and extrusion. Thermoplastic processing can result in a highly efficient manufacturing method with commercial potential for large-scale production of edible films due to the low moisture levels, high temperatures, and short times used. Addition of water, glycerol, sorbitol, sucrose, and other plasticizers allows the proteins to undergo the glass transition and facilitates deformation and processability without thermal degradation. Target film variables, important in predicting biopackage performance under various conditions, include mechanical, thermal, barrier, and microstructural properties. Comparisons of film properties should be made with care since results depend on parameters such as film-forming materials, film formulation, fabrication method, operating conditions, testing equipment, and testing conditions. Film applications include their use as wraps, pouches, bags, casings, and sachets to protect foods, reduce waste, and improve package recyclability. [ABSTRACT FROM AUTHOR]

The main objective of this research was to test the hypothesis that bioavailable protein and, more specifically, the sulfur-containing amino acids within the protein, can' be degraded by proteolytic enzymes to produce odor-causing compounds--mainly volatile sulfur compounds (VSCs)--during biosolids storage. To achieve these objectives, samples of digester effluent and cake solids were collected at 11 different wastewater treatment plants in North America, and the samples were analyzed for protein and amino acid content and general protein-degrading enzyme activity. At the same time, cake samples were stored using headspace bottles, the concentration of VSCs were measured using gas chromatography, and olfactometry measurements were made by a trained odor panel. The results showed that the bound cake protein content and methionine content was well-correlated with VSC production and the detection threshold measured by the odor panel. Water Environ. Res., 80, 127 (2008). [ABSTRACT FROM AUTHOR]

Protein content and content of some antinutrients were determined in four Vigna unguiculata (L) Walp and three Vicia faba cultivars frequently consumed in Brazil. The V. faba cultivars showed higher protein contents [26.8%–27.2% (w/w)] than the V. unguiculata cultivars [20.5%–22.5% (w/w)]. The difference was, however, not statistically significant ( P ≥ 0.05). Compared with the V. unguiculata cultivars, the V. faba cultivars exhibited a significantly higher content of all antinutritional factors analysed. In V. faba, condensed tannins ranged from 1.95 to 2.87 g eq. catechin (CE) kg−1, polyphenols from 4.81 to 7.21 g kg−1, phytate from 12.7 to 14.3 mmol kg−1, trypsin inhibitor activity from 4.12–4.38 TIU mg−1 and haemagglutinating activity from 51.3 to 57.2 HU kg−1; whereas in V. unguiculata, the corresponding values were determined to be 0.97–1.81 g eq. CE kg−1 for condensed tannins, 5.87–6.62 g kg−1 for polyphenols, 8.7–12.6 mmol kg−1 for phytate, 3.09–3.56 TIU mg−1 for trypsin inhibitor activity and 0.5–0.6 HU kg−1 for haemagglutinating activity. [ABSTRACT FROM AUTHOR]

The blood-brain barrier (BBB) prevents the entrance of circulating molecules and immune cells into the central nervous system. The barrier is formed by specialized brain endothelial cells that are interconnected by tight junctions (TJ). A defective function of the BBB has been described for a variety of neuroinflanunatory diseases, indicating that proper regulation is essential for maintaining brain homeostasis. Under pathological conditions, reactive oxygen species (ROS) significantly contribute to BBB dysfunction and inflammation in the brain by enhancing cellular migration. However, a detailed study about the molecular mechanism by which ROS alter BBB integrity has been lacking. Here we demonstrate that ROS alter BBB integrity, which is paralleled by cytoskeleton rearrangements and redistribution and disappearance of TJ proteins daudin-5 and occludin. Specific signaling pathways, including RhoA and PI3 kinase, mediated observed processes and specific inhibitors of these pathways prevented ROS-induced monocyte migration across an in vitro model of the BBB. Interestingly, these processes were also mediated by protein kinase B (PKB/ Akt), a previously unknown player in cytoskeleton and TJ dynamics that acted downstream of RhoA and PI3 kinase. Our study reveals new insights into molecular mechanisms underlying BBB regulation and provides novel opportunities for the treatment of neuroinflammatory diseases. [ABSTRACT FROM AUTHOR]

Objective: Compared with whole saliva, residual saliva comprising the oral mucosal film shows a high protein concentration. The purpose of this study was to compare the composition of residual saliva with unstimulated and stimulated whole saliva in normosalivators. Materials and methods: The composition of oral mucosal residual saliva in 30 healthy individuals was investigated and compared with that of whole saliva. The concentrations of total protein, secretory immunoglobin A (sIgA), lactoferrin, total carbohydrate, and sialic acid were examined. The activities of peroxidase, lysozyme and α-amylase were determined. Results: Residual saliva had higher levels of total protein and carbohydrate than whole saliva, with a higher carbohydrate to protein ratio in the residual saliva suggesting that salivary glycoproteins are concentrated on the oral mucosal surface. sIgA, lactoferrin and sialic acid were present as highly concentrated forms in residual saliva. The enzymatic activity of peroxidase in residual saliva was higher than that of whole saliva. Conclusions: These concentrated carbohydrate and antimicrobials on the oral mucosal surface work for mucosal defence and could be used for targeting sites for the delivery of therapeutic agents. [ABSTRACT FROM AUTHOR]

Partition coefficients that are used to predict concentrations of hydrophobic organic chemicals in biota (e.g., the bioconcentration factor) often assume that the sorptive capacity of an organism or tissue is adequately represented by its lipid content. In lean organisms and tissues, however, theory suggests that partitioning may be strongly influenced by the sorptive capacity of nonlipid materials, such as protein. Little is known about the sorptive capacity of proteins for hydrophobic organic chemicals, and methods to include proteins in bioaccumulation models do not exist. Here, we present a compilation and meta-analysis of published data to estimate the relative sorptive capacities of animal proteins and lipids for neutral organic chemicals. We found that the estimated sorptive capacity of protein in solid animal tissues ranged from around 1 to 10% that of lipid for compounds with a log octanol/water partition coefficient (KOW) of greater than two. The sorptive capacity of blood protein (albumin) appeared to be substantially higher than this, especially for low-KOW chemicals. For modeling purposes, we recommend estimating the sorptive capacity of animal protein as 5% that of lipid. According to this estimate, the sorptive capacity of an animal or tissue will be dominated by the contribution from protein if the lipid content makes up less than 5% of the dry-weight organic content. In such situations, a consideration of the sorptive capacity of nonlipid constituents, such as protein, will permit more accurate predictions of chemical accumulation and distribution. [ABSTRACT FROM AUTHOR]

This study assessed the film-forming abilities of six types of proteins, as well as six types of polysaccharides at various concentrations (proteins: 0–16%; polysaccharides: 0–4%) and heating temperatures (60–80 °C). Biopolymer films evaluated included: sodium caseinate (SC), whey protein isolate (WPI), gelatine (G); caboxymethyl cellulose (CMC), sodium alginate (SA) and potato starch (PS). Screening trials showed that optimal film-forming conditions were achieved using SC and G (4% and 8%), WPI (8% and 12%), PS, CMC (2% and 3%) or SA (1% and 1.5%) solutions heated to 80 °C in combination with 50% (w/w) glycerol. Films manufactured from 1.5% SA, 8% G and 3% CMC had the highest tensile strength (24.88 MPa); flexibility (89.69%)/tear strength (0.30 N) and puncture resistance (22.66 N), respectively. SC, WPI and G-based films were more resistant to solvent than SA, CMC and PS. Film permeability to water vapour and oxygen decreased in the order: 12% WPI to 1% SA and 12% WPI to 1% SA. All films tested were impermeable to oil. [ABSTRACT FROM AUTHOR]

Quality of soybeans and soybean meals (SBM) from non-US and US origins were compared. The US SBM was more consistent with higher digestibility (by KOH solubility), lower fiber and better quality of protein (by essential amino acid levels) than SBM of other major export origins (Argentina, Brazil and India). Protein quality carried through from whole soybeans to SBM, for a given origin. While the protein content was higher for the SBM from Brazil, the percentage of total digestible amino acids was highest for the SBM from the US and China. The US SBM had the highest content (total) of five essential amino acids for both poultry and swine feed uses, which when coupled with higher digestibility, would give US meal an advantage in rations balanced on amino acids. The mean particle size for all SBM from all origins was within the desirable range specified by nutritionists. The US soybeans were lower in protein than Brazilian soybeans, but higher than Argentine soybeans. The crude protein disadvantage of US soybeans was offset by higher concentrations of the essential amino acids in the lower protein soybeans. The US soybeans were lower in oil content than soybeans from either of the South American origins. Average protein and oil contents of US soybeans were consistent with the 2003 and 2004 annual soybean quality surveys. The US SBM held an advantage in digestibility and concentration of key amino acids in all three studies. [ABSTRACT FROM AUTHOR]

Extrusion cooking, as a multi-step, multi-functional and thermal/mechanical process, has permitted a large number of food applications. Effects of extrusion cooking on nutritional quality are ambiguous. Beneficial effects include destruction of antinutritional factors, gelatinisation of starch, increased soluble dietary fibre and reduction of lipid oxidation. On the other hand, Maillard reactions between protein and sugars reduce the nutritional value of the protein, depending on the raw material types, their composition and process conditions. Heat-labile vitamins may be lost to varying extents. Changes in proteins and amino acid profile, carbohydrates, dietary fibre, vitamins, mineral content and some non-nutrient healthful components of food may be either beneficial or deleterious. The present paper reviews the mechanisms underlying these changes, as well as the influence of process variables and feed characteristics. Mild extrusion conditions (high moisture content, low residence time, low temperature) improve the nutritional quality, while high extrusion temperatures (⩾200 °C), low moisture contents (<15%) and/or improper formulation (e.g. presence of high-reactive sugars) can impair nutritional quality adversely. To obtain a nutritionally balanced extruded product, careful control of process parameters is essential. [ABSTRACT FROM AUTHOR]

The three-body energy expansion in the fragment molecular orbital method (FMO) was applied to the 2nd order Møller–Plesset theory (MP2). The accuracy of both the two and three-body expansions was determined for water clusters, alanine n-mers (α-helices and β-strands) and one synthetic protein, using the 6-31G* and 6-311G* basis sets. At the best level of theory (three-body, two molecules/residues per fragment), the absolute errors in energy relative to ab initio MP2 were at most 1.2 and 5.0 mhartree, for the 6-31G* and 6-311G* basis sets, respectively. The relative accuracy was at worst 99.996% and 99.96%, for 6-31G* and 6-311G*, respectively. A three-body approximation was introduced and the optimum threshold value was determined. The protein calculation (6-31G*) at the production level (FMO2/2) took 3 h on 36 3.2-GHz Pentium 4 nodes and had the absolute error in the MP2 correlation energy of only 2 kcal/mol. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007 [ABSTRACT FROM AUTHOR]

Abstract: Proteomics has provided a wealth of data related to the nature of the proteome, including subcellular location, copy number, interaction partners and protein complexes. This raises the question of whether it is feasible to combine these data, together with other data related to overall cellular structure, to construct a static picture of the cell. In this minireview, we discuss these data, and the issues of turning them into whole cell models. [Copyright &y& Elsevier]

We investigated the whole-body crude nutrient (fat, protein, ash) and mineral (Ca, P, Mg, Na, K) composition of mustached bats of three different groups: animals from the wild ( n = 6), and animals from captivity on an unsupplemented feeding regime of mealworms ( n = 7), and on a feeding regime in which the mealworms were kept on a mineral substrate prior to feeding ( n = 6). It was shown that mealworms from the mineral substrate had higher Ca contents than mealworms from the conventional substrates. In an earlier study, differences in bone mineral density had been found between the groups. These differences, however, were not reflected in differences in whole-body composition. Captive animals showed a larger variation in body weight and fat content, indicating potential shortcomings of the dietary and husbandry regime. [ABSTRACT FROM AUTHOR]

We developed a new parallel density-functional canonical molecular-orbital program for large molecules based on the resolution of the identity method. In this study, all huge matrices were decomposed and saved to the distributed local memory. The routines of the analytical molecular integrals and numerical integrals of the exchange-correlation terms were parallelized using the single program multiple data method. A conventional linear algebra matrix library, ScaLAPACK, was used for matrix operations, such as diagonalization, multiplication, and inversion. Anderson's mixing method was adopted to accelerate the self-consistent field (SCF) convergence. Using this program, we calculated the canonical wavefunctions of a 306-residue protein, insulin hexamer (26,790 orbitals), and a 133-residue protein, interleukin (11,909 orbitals) by the direct-SCF method. In regard to insulin hexamer, the total parallelization efficiency of the first SCF iteration was estimated to be 82% using 64 Itanium 2 processors connected at 3.2 GB/s (SGI Altix3700), and the calculation successfully converged at the 17-th SCF iteration. By adopting the update method, the computational time of the first and the final SCF loops was 229 min and 156 min, respectively. The whole computational time including the calculation before the SCF loop was 2 days and 17 h. This study put the calculations of the canonical wavefunction of 30,000 orbitals to practical use. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007 [ABSTRACT FROM AUTHOR]

The use of dry whole milk, skimmed milk, caseinate, regular and modified whey, at 2% level (w/w) and with 2% additional protein level was studied in a chicken breast meat system with 51% water addition. At the 2% (w/w) level, all dairy proteins significantly reduced cooking loss compared with the control, with caseinate showing the best results. When compared on an equal protein level (2% total protein), the best performing ingredients were the whole milk and modified whey. A similar observation was made in their effect on the products’ hardness and fracturability. A cost analysis revealed that modified whey provided the most economical ingredient even when used in quantities three times greater than that of as caseinate. Microscopy results showed the formation of larger fine-protein-matrix regions in the treatments that provided higher fracturability values. [ABSTRACT FROM AUTHOR]

The acquired enamel pellicle (AEP) is a protein film with unique composition and properties, which is formed by the selective adsorption of a variety of oral fluid–derived proteins onto tooth enamel surfaces. Since events leading to caries and periodontal disease occur in close proximity to the tooth surface, pellicle constituents are likely to contain biomarkers valuable for diagnostic applications. Despite the importance of this oral structure, progress in understanding its formation and composition has been slow because of difficulties in efficient pellicle collection methods and limitations of biochemical techniques for the characterization of microgram amounts of proteins/peptides. Recent developments in both pellicle collection methods and nanoscale sensing technologies have brought the exploitation of pellicle analysis into the realm of point-of-care oral diagnostics. [ABSTRACT FROM AUTHOR]

A new soybean line, known as high-sucrose/ low-stachyose (HS/LS) soybeans, has been developed having elevated sucrose content and reduced content of flatus-causing oligosaccharides, especially stachyose. There is also increased interest in understanding the health benefits, functional properties and potential applications for the two major storage proteins of soybeans, glycinin and β-conglycinin. We evaluated the protein fractionation behavior of a HS/LS soybean line and compared it to normal soybeans when using the three-step Wu procedure, which employs SO2, NaCl and precipitations at pH 6.4 and 4.8 and a new two-step Deak procedure, which employs SO2, CaCl2 and precipitations at pH 6.4 and 4.8. Both soybean variety and fractionation procedure significantly affected fraction yields, purities and functional properties. The Wu procedure gave glycinin- and b-conglycinin-rich fractions with 100% purities and high yields of solids (15.4%) and protein (31.7%) from HS/LS soy flour, which were significantly higher than the purities and yields achieved with normal soybeans. The Deak procedure was less efficient in fractionating proteins from HS/LS soybeans than from normal soybeans, producing protein fractions from HS/LS soybeans with purities ranging from 71 to 80%. The Deak procedures yielded products with unique solubilities, surface hydrophobicities, and emulsification and foaming properties. [ABSTRACT FROM AUTHOR]