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Papers by Munkh-Erdene Baatar

Preparation, Composition and Functional Properties of Oat Protein Isolates

Canadian Institute of Food Science and Technology Journal, 1983

ABSTRACT

Influence of pH Shift on Functional Properties of Protein Isolated of Tilapia (Oreochromis niloticus) Muscles and of Soy Protein Isolate

Food and Bioprocess Technology, 2011

The physicofunctional and chemical properties of acid-aided protein isolate (AcPi), alkaline-aide... more The physicofunctional and chemical properties of acid-aided protein isolate (AcPi), alkaline-aided protein isolate (AlPi) and soy protein isolate (SPI) prepared from tilapia muscle and defatted soy flour as a function of pH and/or NaCl concentration were investigated. Both acid- and alkali-aided processes lead to significant recoveries (P < 0.05) of proteins with substantial reduction of lipids in AlPi (0.81%) and AcPi (0.96%), the lowest for SPI (0.336%) facilitated by the processing method and sample used. There is greater lipid reduction at alkali pH, effective removal of impurities such as bones and scales, indicated by percentage ash (AcPi, 4.53%; AlPi, 3.75% and SPI, 3.51%). No major difference noted in sodium dodecyl sulphate polyacrylamide gel electrophoresis protein bands (14.4–97.4 kDa) possibly representing partial hydrolysis of myosin. Solubility was the highest at pH 3.0 and 11.0 and the lowest at isoelectric point with foam capacity showing similarity at varying pH. The addition of NaCl improved foam stability, possibly due to the increased solubility and surface activity of the soluble protein. On the whole, AcPi, AlPi and SPI manifested lower solubility and foamability at pH 4.0 and 5.0. AlPi exhibited appreciable levels of solubility, emulsion capacity, oil-holding capacity, viscosity and whiteness, whereas SPI had appreciable water-holding capacity. AcPi, AlPi and SPI have excellent relevance for product development based on their functionality.

Plant Foods for Human Nutrition, 2005

Protein isolates from L. campestris and soybean seeds were prepared using isoelectric precipitati... more Protein isolates from L. campestris and soybean seeds were prepared using isoelectric precipitation (PI) and micellization (MI) procedures. The amount of protein recovered was considerably higher with the isoelectric precipitation than with the micellization procedure (60% and 30%, respectively). Protein contents were higher than 90% in protein isolates. Antinutritional factors content (alkaloids, lectins, and tannins) were reduced to innocuous levels after protein isolate preparation. Minimum protein solubility for the precipitated lupin protein isolate (LPI) was at pH 4.0, and between pH 4 and 6 for the micellized lupin protein isolate (LMI), increasing at both extremes of the pH scale. Water absorption for the LMI was 1.3 ml/g of protein and its oil absorption 2.2 ml/g of protein. The LPI had 1.7 ml/g of protein in both water and oil absorption. Foaming capacity and stability was pH-dependent. Foaming capacity was higher at pH 2 and lower near the protein isoelectric points. Minimum protein concentration for gelation in LMI was 8% w/v at pH 4, while for LPI was 6% at pH 4 and 6. Amino acid composition in L. campestris flour and protein isolates was high in lysine and low in methionine. Most of the essential amino acids in lupin protein isolates were at acceptable levels compared to a reference pattern for infants and adults. The electrophoretic pattern of both protein isolates showed three bands with different mobilities, suggesting that the protein fractions belong to α-conglutin (11S-like protein), β-conglutin (7S-like protein) and γ-conglutin. It is proven that some of the functional properties of L. campestris protein isolates are similar to those soybean protein isolates recovered under equal conditions.

Planta, 1988

When plasma-membrane vesicles isolated from oat (Arena sativa L.) root cells were incubated with ... more When plasma-membrane vesicles isolated from oat (Arena sativa L.) root cells were incubated with [7-32P]ATP, the H+-ATPase was found to be phosphorylated at serine and threonine residues. Phosphotyrosine was not detected. Endogenous ATPase kinase activity was also observed in plasma-membrane vesicles isolated from potato (Solanum tuberosum L.) root cells as well as from yeast (Saccharomyces cerevisiae). Identity of the phosphorylated oat root M r = 100000 polypeptide as the ATPase was confirmed using conventional glycerol density-gradient centrifugation to purify the native enzyme and by a new procedure for purifying the denatured polypeptide using reversephase high-performance liquid chromatography. Kinase-mediated phosphorylation of the oat root plasma-membrane H +-ATPase was stimulated by the addition of low concentrations of Ca 2+ and by a decrease in pH, from 7.2 to 6.2. These results demonstrate that kinase-mediated phosphorylation of the H+-ATPase is a plausible mechanism for regulating activity. They further indicate that changes in the cytoplasmic [Ca 2+] and pH are potentially important elements in modulating the kinase-mediated phosphorylation.

Pesticide Biochemistry and Physiology, 1998

The cellular localization of difenzoquat was investigated using suspension cell cultures derived ... more The cellular localization of difenzoquat was investigated using suspension cell cultures derived from inbred wild oat (Avena fatua L.) lines that were susceptible (S) or resistant (R) to the herbicide. Compartmental analysis of S cell cultures resolved [3-14 C]difenzoquat efflux from three cellular compartments which contained 75, 19, and 6%, respectively, of the total absorbed difenzoquat. Greater than 98% of the efflux from S cells occurred within 420 min. In contrast, compartmental analysis of R cell cultures differentiated only two cellular components, containing 73 and 27% of the absorbed difenzoquat. Further, difenzoquat efflux from R cell cultures occurred more slowly, requiring Ͼ2000 min for 98% efflux to be achieved. Washing cell cultures preloaded with [3-14 C]difenzoquat in methanol:chloroform indicated that difenzoquat was preferentially bound in cell wall material of R cell cultures. In whole plants, a greater proportion of total leaf-absorbed [3-14 C]difenzoquat was present in an insoluble residue in R plants than in S as determined by tissue homogenization and liquid scintillation counting. By 96 h after treatment with [3-14 C]difenzoquat, Ͼ90% of the absorbed radiolabel was extractable from S plants, whereas Ͻ10% was extractable from R tissues. The results indicate that tight binding of difenzoquat in R cell walls may be responsible for difenzoquat resistance in wild oats. ᭧1998 Academic Press

Plant Foods for Human Nutrition, 1997

Pea (Pisum sativum), faba bean (Vicia faba) and soybean (Glycine max) seeds were characterized, a... more Pea (Pisum sativum), faba bean (Vicia faba) and soybean (Glycine max) seeds were characterized, and protein isolates were prepared following an isoelectric point precipitation procedure. Soybean seeds showed the highest protein content (36.7%) and carbohydrate was the major constituent in the pea (59.4%) and the faba bean seeds (52.1%). Protein contents were higher than 80% in all the protein isolates.

The Journal of Nutritional Biochemistry, 2004

Cereals are an important part of diets for hypercholesterolemic patients. However, some of these ... more Cereals are an important part of diets for hypercholesterolemic patients. However, some of these patients are allergic to these natural products. The purpose of the current study was to compare oatmeal with equal in nutritional values two allergy-free amaranth meals to determine whether this pseudocereal can be a substitute for allergic to cereals individuals. The total phenols of the samples were determined with the Folin-Chocalteu reagent, anthocyanins, and flavonoids spectrophotometrically. The antioxidant activities were estimated with nitric oxide scavenging radical (NO) and by ␤-carotene bleaching (␤-carotene). It was found that the contents of different protein fractions, antioxidant compounds, and the antioxidant activities of oatmeal were significantly higher than those of the two amaranth samples. The results of kinetic reactions showed that samples differed in their capacities to quench these radicals, and oats have shown more antioxidant activity than amaranth. High correlation was observed between antioxidant activities and phenols (R 2 ϭ 0.99). In the in vivo part of the investigation, 60 male Wistar rats were divided into five diet groups of 12 animals each; these groups were designated as Control, Chol, Chol/Oat, Chol/AmarI, and Chol/AmarII. The rats of the Control group were fed basal diet (BD) only. To the BD of the four other groups were added the following: 1% of cholesterol (Chol), 10% of oat meal and 1% of cholesterol (Chol/Oat), 10% of amaranth I meal, and 1% of cholesterol (Chol/AmarI) and 10% of amaranth II meal and 1% of cholesterol (Chol/AmarII). After 32 days of different feeding, diets supplemented with oat meal and, to lesser degree, with amaranth I and amaranth II hindered the rise in the plasma lipids: a) TC: 3.14 vs.

Journal of Food Science, 1984

Protein extracted from defatted oat (Auena sativa L., variety Sentinel) was acylated with acetic ... more Protein extracted from defatted oat (Auena sativa L., variety Sentinel) was acylated with acetic or succinic anhydride at levels of 0.05 and 0.20 g/g protein. Acetic anhydride was more reactive than succinic anhydride in modifying lysine groups. Total essential amino acid content was slightly lowered by acetylation but unaffected by succinylation. Gel filtration chromatography showed some dissociation of oat polypeptides by succinylation. Solubility, emulsifying properties and fat finding capacity were all markedly improved by acylation, and the effect was more pronounced with succinylation. Emulsifying capacity of meat was enhanced by blending with acylated oat protein. Water hydration capacity and foam stability were adversely affected by acylation. Results suggest that acylated oat protein may be a valuable functional ingredient in meat and other emulsion food products.

Journal of Food Science, 1977

An alkaline ex traction process \vas developed to produce protein isolates and starch from defatt... more An alkaline ex traction process \vas developed to produce protein isolates and starch from defatted nour or defatted groats of high-protein oats. Optimum extraction was at pH 9.2 in 0.02N sodium hydroxide with a solid:solvent ratio of 1:6. The defatted nour was extracted with sodium hydroxide solution, and bran was removed by screening the alkaline dispersion. After centrifuging the slurry that passed through the screen. the alkaline supernatant was adjusted to pH 5.0 to yield a precipitate (protein isolate) and supernatant. The defatted groats were first extracted with water followed by two sodium hydroxide extractions. Bran was removed by screening the second alkaline dispersion, and protein isolate was precipitated from the first alkaline extract at pH 5.7. Protein content (nitrogen x 6.25) of the isolate varied between 94 and 103% and accounted for 53-67% of total protein from defatted nour or groats. The isolate contained from 3.4-4.0g lysine and 2.2-4.2g total sulfur amino acids l6g nitrogen. Minimum nitrogen solubility of the isolates was near pH 5.5, and solubility was 78-83;; near pH 2.2. All protein isolates had good hydration capacity (2.9-3.9) and two of the isolates had good emulsifying activity (around 50%) and good emulsion stability (near 50 r ;;).

Journal of Food Science, 1981

Succinylated cottonseed protein isolates (40% and 54% modification of amino groups ,f control iso... more Succinylated cottonseed protein isolates (40% and 54% modification of amino groups ,f control isolate) were prepared under pilot scale processing conditions. Partial succinylation of cottonseed flour increased the yield of protein isolate in isoelectric precipitation (pH 4.5). The succin!Iated isolates were more water soluble, less heat-coagulable in waler, and lighter in color as compared to conventional isolates. Th':y also showed improved functional properties including higher oil absorption, emulsion capacity, gel strength, water hydration, water retention, and viscosity. Bulk density was decreased and resulted in fluffy isolates.

Journal of Food Engineering, 2007

Protein concentrates were prepared from defatted rice brans and analyzed for their functional pro... more Protein concentrates were prepared from defatted rice brans and analyzed for their functional properties. Water-binding capacity was in the range of 3.87-5.60 (g/g) while oil absorption capacity ranged between 3.74 and 9.18 (g/g). Basmati 370 had highest bulk density (0.21 g/ml). Rice bran protein concentrates of Basmati 370 exhibited good foam stability with a half-life of 42.6 h at 15% sugar concentration. Emulsifying capacity of protein concentrates ranged between 24% and 74%. Emulsions were fairly stable under different pH, salt and sugar concentrations. Functional properties of rice bran protein concentrates are comparable with casein and have good potential in food industry.

Journal of Agricultural and Food Chemistry, 1997

Flaxseed protein isolates were prepared by sodium hexametaphosphate complexation and acylated wit... more Flaxseed protein isolates were prepared by sodium hexametaphosphate complexation and acylated with acetic or succinic anhydride to improve their functional properties. The degree of acylation of free amino groups was lower when succinic anhydride was used in place of acetic anhydride. The color of the acylated proteins became lighter as the degree of acylation was increased. Emulsification properties of protein preparations were improved due to acylation, particularly for succinylated products. While foaming properties of flax protein isolates were not improved by acylation, their solubility was markedly improved. Low degrees of acetylation improved fat binding capacity of flax protein isolates, but succinylation did not exhibit such an effect. Acylation also increased aromatic or surface hydrophobicity of the products, and the highest value was observed at the lowest degree of acetylation. The in-vitro enzymic hydrolysis of the isolated proteins was reduced due to the acylation process.

Limited Deamidation of Soybean Protein Isolates by Glutaminase and its Impacts on the Selected Properties

International Journal of Food Properties, 2012

Glutaminase (EC 3.2.1.5) was applied in the present work to deamidate soybean protein isolates wi... more Glutaminase (EC 3.2.1.5) was applied in the present work to deamidate soybean protein isolates with limited extent, and some reaction conditions were selected. Three deamidated soybean protein isolates products with degree of deamidation of 3.5, 5.6, and 6.6% were prepared with reaction conditions as follows: soybean protein isolates concentration of 5% (w/v), glutaminase addition level of 400 U/kg soybean protein isolates, reaction temperature of 37°C, and reaction times of 12, 24, and 36 h, respectively. SDS-PAGE and size exclusion chromatography analysis showed that glutaminase exhibited weak ability to catalyze the hydrolysis of the peptide bonds in soybean protein isolates. The results indicated that the deamidated soybean protein isolates prepared showed improved solubility in a pH range of 3 to 10, and had higher emulsion stability on the oil-in-water dispersions when compared to the original soybean protein isolates, but had poor emulsifying activity. Rheological assay revealed that the suspensions prepared by the deamidated soybean protein isolates products showed higher apparent viscosity, and the values of apparent viscosity depended on the degree of deamidation of the deamidated soybean protein isolates product and the addition level of Ca in the suspensions. The storage modulus G′ and viscous modulus G′′ of the prepared suspensions gave similar behaviors as apparent viscosity. Three deamidated soybean protein isolates products prepared contained better iron (II)-chelating activity than the original soybean protein isolates as the evaluated index showed an increase of 19 to 30%. Limited deamidation of soybean protein isolates by glutaminase showed beneficial impacts on the selected properties of deamidated soybean protein isolates totally, and might be served as a practical approach to prepare multifunctional ingredients for the food industry.

Histochemistry, 1989

P2 is described along with its application to determine levels of activity in embryos of Pisum sa... more P2 is described along with its application to determine levels of activity in embryos of Pisum sativum and Arena sativa. The activity of ATP-PFK has also been studied in parallel as have PFK activities during the switch from dormant to non-dormant embryos in Arena sativa. PPcPFK activity has been demonstrated in all tissues of Pisum sativum embryos and of Arena sativa embryos including the scutellum and the Neurone layers. The PP~-PFK activity was greater than that of ATP-PFK in both dormant and non-dormant seeds though with only marginally more activity in the dormant as opposed to the non-dormant state.

Food Research International, 1998

Commercial defatted soy meal was solubilized in an aqueous solution at pH 8.5 to prepare a soy pr... more Commercial defatted soy meal was solubilized in an aqueous solution at pH 8.5 to prepare a soy protein isolate (SPI) with 90.45% protein and 95% solubility. Soy protein hydrolysate (SPH) was obtained by enzymatic hydrolysis of the SPI using a neutral proteinase at dierent degrees of hydrolysis (DH=4, 6, 8 and 10). A previous heat treatment of native SPI at 80 C for 10 and 30 min caused a gradual dissociation and/or unfolding of some fractions of the soy protein leading to a decrease in high molecular weight fractions. Gel ®ltration chromatography of SPH with DH=8 indicated that the soluble fraction consisted mostly of low molecular weight peptides having a molecular weight less than 12.5 kDa. Combined hydrolysis and succinylation greatly increased protein solubility and caused marked changes in other functional properties depending on the degree of mod-i®cation.

Food Research International, 2009

Oat protein isolate (OPI) was extracted in 0.015 N NaOH and acetylated or succinylated. The therm... more Oat protein isolate (OPI) was extracted in 0.015 N NaOH and acetylated or succinylated. The thermal analysis of the isolate showed a glass transition (T g) at 43.4°C and DC p of 0.102 J/g/°C. The positive net charge of OPI and the positive or neutral charge of the modified OPI were apparent from the free capillary zone electrophoresis (FZCE) profiles. Acetylation significantly lowered foaming and emulsifying properties of OPI, while succinylation showed the highest foaming capacity, foam stability, and emulsion stability. Acetylated OPI showed the highest surface hydrophobicity compared to the other samples, while OPI was the most soluble of all. The water holding capacity of all samples analyzed was the same except for acetylated-crosslinked (ACXL). The surface tension test confirmed that unmodified and modified OPI possessed surface activity and the equilibrium surface tensions decreased sharply with increasing protein concentration and leveled off to a constant value. The elastic modulus, G 0 , for the acetylated OPI suspension exhibited the highest value, while the G 0 of the crosslinked (XLOPI) had the lowest. The plateau of G 0 ,

Food Research International, 2012

Rice bran protein isolate (RBPI) containing approximately 92.0% protein was prepared from unstabi... more Rice bran protein isolate (RBPI) containing approximately 92.0% protein was prepared from unstabilized and defatted rice bran using phytase and xylanase. The yield of RBPI increased from 34% to 74.6% through the use of the enzymatic treatment. Nitrogen solubilities of RBPI were 53, 8, 62, 78, 82, and 80% at pHs 2.0, 4.0, 6.0, 8.0, 10.0, and 12.0, respectively. Differential scanning calorimetry showed that RBPI had denaturation temperature of 83.4°C with low endotherm (0.96 J/g of protein). RBPI had similar foaming properties in comparison to egg white. But emulsifying properties of RBPI were significantly lower than those of bovine serum albumin. The result of amino acid analysis showed that RBPI had a similar profile of essential amino acid requirements for 2-5year-old children in comparison to that of casein and soy protein isolate.

Some functional properties of oat bran protein concentrate modified by trypsin

Food Chemistry, 2007

Oat bran protein concentrate (OBPC) was prepared from oat bran, and hydrolyzed using trypsin. Pro... more Oat bran protein concentrate (OBPC) was prepared from oat bran, and hydrolyzed using trypsin. Protein hydrolysates of three different degrees of hydrolysis (4.1%, 6.4% and 8.3% respectively) were obtained. SDS-PAGE analysis demonstrated that oat globulin was the major protein component in OBPC. After trypsin treatment, acidic polypeptides were partly degraded into large peptides (Mr=29,000–33,000) and small peptides (Mr&amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;20,000); however, basic

Food Chemistry, 2009

The effects of two different modification methods (deamidation and succinylation) on the function... more The effects of two different modification methods (deamidation and succinylation) on the functional properties (solubility, water-and oil-binding capacity, foaming capacity and stability, emulsion activity and stability) of oat protein isolates were evaluated. Protein isolates extracted from defatted oat flour at alkaline pH were acylated by 0.20 g/g of succinic anhydride. The protein isolate was also modified using a mild acidic treatment (HCl, 0.5 N). Succinylation and deamidation improved solubility and emulsifying activity of the native protein isolate. Foaming capacity of oat protein isolate increased after deamidation, whereas succinylation decreased it. The deamidated and succinylated proteins had lower foam and emulsion stabilities than had their native counterpart. Water-and oil-binding capacity, in both modified oat proteins, was higher than those of the native oat protein isolate.

Functional properties of protein isolates, globulin and albumin extracted from Ginkgo biloba seeds

Food Chemistry, 2011

In this study, the functional properties of Ginkgo seed protein isolate (GPI), Ginkgo seed globul... more In this study, the functional properties of Ginkgo seed protein isolate (GPI), Ginkgo seed globulin protein (GGP) and Ginkgo seed albumin protein (GAP) extracted from Ginkgo biloba seeds were investigated. The protein contents of GPI, GGP and GAP were 91.0%, 93.4% and 87.8%, respectively in the samples in which the sugar, polyphenol and crude fibre were removed by the preparation