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Fractionation by Gel Exclusion HPLC of Proteins from Phaseolus Beans
BASE CATALYZED TRANSESTERIFICATION OF VEGETABLE OILS AND PHOSPHATIDYL CHOLINE. Casimir C. Akoh** and Barry G. Swanson, Department of Food Science and Human Nutrition, Washington State University, Pullman, Washington. Anhydrous methanolic sodium hydroxide catalyzed transesterification of vegetable oils and phosphatidyl choline yielded pure methyl esters within one minute at ambient temperature under nitrogen. Methanolic sodium hydroxide was stable and required no benzene or phenolphthalein. Neutralization to convert free fatty acids to methyl esters was not required. Tetramethylammonium hydroxide catalyzed transesterification yielded a mixture of methyl esters and free fatty acids, and required neutralization. Pentane and diethyl ether were excellent solvents for methanolic sodium hydroxide catalysis.
IN VITRO DIGESTIBILITY OF LEGUME PROTEINS. R. Bhatty*, Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. In vitro digestibility of pea, fababean and lentil meal proteins, and of albumin, globulin, GI or legumin (I IS) proteins isolated from the three meals was determined using pepsin, trypsin and pronase under optimum conditions of E to S ratios. In another experiment, the influence of heat, a-amylase treatment, reduction and oxidation of the disulfide bonds on protein digestibility was investigated. The meal proteins as well as the isolated proteins responded differently to the three enzymes, and to the treatments which reflected in their extent of hydrolysis by the enzymes. These differences in protein hydrolysis partly reflected differences in the molecular weight of the proteins, amino acid composition and the presence in them of carbohydrates.
COLOUR INTENSIFICATION OF SASKATOON BERRY EXTRACTS. R.C. Green**, Food Science Department, The University of Manitoba, Winnipeg, and G. Mazza, Agriculture Canada Research Station, P.O. Box 3001, Morden, Manitoba. The influence of acetaldehyde and catechin on colour intensification of saskatoon berry (Amelanchier alnifolia Nutt.) extracts was investigated. Presence of 0.05 and 0.5M acetaldehyde increased colour intensity of the fruit extract. After thirty days of storage at room temperature, in the dark, the absorbance at 530-535 nm. increased by 72flJo in extracts containing 0.05M acetaldehyde and by more than IOOflJo in samples containing 0.5M acetaldehyde. HPLC profiles of acetaldehyde treated samples revealed the appearance of new peaks and the decrease of two anthocyanin peaks. Addition of catechin had no significant effect on the colour of the berry extracts. Possible mechanisms of colour intensification are discussed.
INDICES OF DRY BEAN COOKING TIME: SODIUM CHLORIDE SOLUTIONS, STORAGE CONDITIONS, PHYTIC ACID AND CALCIUM CONCENTRATIONS. Losso Nzuzi* and Barry G. Swanson, Department of Food Science and Human Nutrition, Washington State University, Pullman, Washington. The effects of harvest time, phytic acid concentration, soaking in distilled water or in salt solutions, and storage conditions on bean cooking time were evaluated over three months. Soaking beans in distilled water did not decrease bean phytic acid concentration, but soaking in salt solutions decreased bean phytic acid concentration. Bean cooking time increased with storage time regardless of the treatments. Phytic acid concentration was not a reliable index of bean cooking time. Salt soaking of dry beans prior to storage was not a practical alternative to preserve an acceptable short cooking time for dry beans.
FRACTIONATION BY GEL EXCLUSION HPLC OF PROTEINS FROM PHASEOLUS BEANS. Jasmine Musakhanian** and Inteaz AlIi, Department of Food Science and Agricultural Chemistry, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec. Beans (Phaseolus vulgaris, P. lunatus) were extracted (a) with NaOH and (b) citric acid (CA) solutions. Proteins (isoelectric, crystalline), were recovered from the NaOH extracts (by adjustment to pH 4.5) and from CA extracts by refrigeration (5°C). Elution patterns from gel exclusion HPLC indicated the following: (i) the NaOH and CA extracts from a P. vulgaris bean contained three major fractions (MW 210,000, 115,000, & 8,000) and at least three minor fractions (ii) the NaOH and CA extracts from a P. lunatus bean contained four major fractions (MW 270,000, 150,000,60,000, & 9,000) and at least two minor fractions (iii) the fraction of MW 250,000 constituted more than 80flJo of the P. vulgaris isoelectric and crystalline proteins. CONVERSION OF LINOLEIC ACID HYDROPEROXIDE BY FRENCH BEAN HYDRO PEROXIDE ISOMERASE. S. Kermasha*, F.R. van de Voort and M. Metche, Department of Food Science and Agricultural Chemistry, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec. Hydroperoxide isomerase (HPI) was extracted from the cotolydon portion of sprouted French bean seeds after five days of incubation and purified by ammonium sulphate fractionation and ultracentrifugation. Linoleic acid hydroperoxides (LAHPO) were produced using commercial soybean Iipoxygenase and purified using a silicic acid column and identified by HPLC. The characterized LAHPOs were used as a substrate for the French bean HPI. The purified French bean extract showed a three fold increase in activity over the crude preparation and a pH optimum of 7.2. The primary endproducts of the enzyme reaction were separated into ketol and carbonyl compounds and then further purified by preparative TLC. Subsequent GC-MS analysis of the ketol fraction indicated that HPI converted the 13-hydroperoxyoctadec-9,1l-dienoic acid primarily into 1O,13-dihydroxyoctadec-I I-enoic acid (a-ketol) and to a lesser extent into l2,13-dihydroxyoctadec-9-enoic acid (,,-ketol). Trace amounts of 9, l2-dihydroxyoctadec-lO-enoic acid resulting from the isomerization of 9-hydroperoxyoctadec-lO, l2-dienoic acid were also found. Hexanal was revealed to be the principal carbonyl compound resulting from the decomposition of l3-hydroperoxyoctadec-9,11dienoic acid and it is believed that a lyase was also present in the French bean extract.
xxxviii / Affaires de l'Institut
IRON FORTIFICATION OF BARLEY SPROUTS. J. Craig Alexander* and Anna Cudjoe, Departmc;nt of Nutritional Sciences, University of Guelph, Guelph, Ontario. Iron deficiency anemia is a common nutritional problem on a global basis. In spite of this, addition of iron salts to foods is not accepted in a number of countries. To provide a natural source of the mineral, availability of iron in barley sprouts was studied. The seeds were germinated hydroponically in the dark at 22°C, using distilled water with various concentrations of FeS04' The sprouts were frozen, freeze-dried and ground. Iron levels in the flour were increased substantially relative to the supply, and the efficiency of iron utilization also was improved. Cereal fortification with iron was achieved by hydroponics. CHLORINATION OF WHEAT FLOUR PENTOSANS. N.L. Crowe* and V.F. Rasper, Department of Food Science, University of Guelph, Guelph, Ontario. The effect of cWorine compounds (gaseous chlorine, chlorine dioxide, sodium chlorite) on the water-soluble nonstarchy polysaccharides (WSNP; pentosans) of wheat flour was investigated in order to further elucidate the effect of chlorination of flour. WSNP were extracted from three flours and examined for the ability of the chlorine compounds to induce oxidative gelation in the WSNP as measured by capillary viscometry. Other oxidants (hydrogen peroxide/peroxidase, ferric chloride) were compared to the chlorine compounds. Sodium chlorite solutions exhibited oxidative gelation only in the presence of exogenous peroxidase which acted by increasing the level of reactive chlorine (CI 2 ,HOCl). THERMAL PROPERTIES OF PROTEIN AND STARCH FRACTIONS FROM BLACK BEANS (PHASEOLUS VULGARIS). Andres Hohlberg*, Michael J. Leszkowiat and David W. Stanley, Department of Food Science, University of Guelph, Guelph, Ontario. Differential scanning calorimetry (DSC) was used to monitor gelatinization and melting endotherms of bean starch at different heating rates and moisture levels. In addition, thermodynamic parameters for the denaturation of the main 7S protein in black beans were determined. Gelatinization and melting peak temperatures increased with moisture c
IN VITRO DIGESTIBILITY OF LEGUME PROTEINS. R. Bhatty*, Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. In vitro digestibility of pea, fababean and lentil meal proteins, and of albumin, globulin, GI or legumin (I IS) proteins isolated from the three meals was determined using pepsin, trypsin and pronase under optimum conditions of E to S ratios. In another experiment, the influence of heat, a-amylase treatment, reduction and oxidation of the disulfide bonds on protein digestibility was investigated. The meal proteins as well as the isolated proteins responded differently to the three enzymes, and to the treatments which reflected in their extent of hydrolysis by the enzymes. These differences in protein hydrolysis partly reflected differences in the molecular weight of the proteins, amino acid composition and the presence in them of carbohydrates.
COLOUR INTENSIFICATION OF SASKATOON BERRY EXTRACTS. R.C. Green**, Food Science Department, The University of Manitoba, Winnipeg, and G. Mazza, Agriculture Canada Research Station, P.O. Box 3001, Morden, Manitoba. The influence of acetaldehyde and catechin on colour intensification of saskatoon berry (Amelanchier alnifolia Nutt.) extracts was investigated. Presence of 0.05 and 0.5M acetaldehyde increased colour intensity of the fruit extract. After thirty days of storage at room temperature, in the dark, the absorbance at 530-535 nm. increased by 72flJo in extracts containing 0.05M acetaldehyde and by more than IOOflJo in samples containing 0.5M acetaldehyde. HPLC profiles of acetaldehyde treated samples revealed the appearance of new peaks and the decrease of two anthocyanin peaks. Addition of catechin had no significant effect on the colour of the berry extracts. Possible mechanisms of colour intensification are discussed.
INDICES OF DRY BEAN COOKING TIME: SODIUM CHLORIDE SOLUTIONS, STORAGE CONDITIONS, PHYTIC ACID AND CALCIUM CONCENTRATIONS. Losso Nzuzi* and Barry G. Swanson, Department of Food Science and Human Nutrition, Washington State University, Pullman, Washington. The effects of harvest time, phytic acid concentration, soaking in distilled water or in salt solutions, and storage conditions on bean cooking time were evaluated over three months. Soaking beans in distilled water did not decrease bean phytic acid concentration, but soaking in salt solutions decreased bean phytic acid concentration. Bean cooking time increased with storage time regardless of the treatments. Phytic acid concentration was not a reliable index of bean cooking time. Salt soaking of dry beans prior to storage was not a practical alternative to preserve an acceptable short cooking time for dry beans.
FRACTIONATION BY GEL EXCLUSION HPLC OF PROTEINS FROM PHASEOLUS BEANS. Jasmine Musakhanian** and Inteaz AlIi, Department of Food Science and Agricultural Chemistry, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec. Beans (Phaseolus vulgaris, P. lunatus) were extracted (a) with NaOH and (b) citric acid (CA) solutions. Proteins (isoelectric, crystalline), were recovered from the NaOH extracts (by adjustment to pH 4.5) and from CA extracts by refrigeration (5°C). Elution patterns from gel exclusion HPLC indicated the following: (i) the NaOH and CA extracts from a P. vulgaris bean contained three major fractions (MW 210,000, 115,000, & 8,000) and at least three minor fractions (ii) the NaOH and CA extracts from a P. lunatus bean contained four major fractions (MW 270,000, 150,000,60,000, & 9,000) and at least two minor fractions (iii) the fraction of MW 250,000 constituted more than 80flJo of the P. vulgaris isoelectric and crystalline proteins. CONVERSION OF LINOLEIC ACID HYDROPEROXIDE BY FRENCH BEAN HYDRO PEROXIDE ISOMERASE. S. Kermasha*, F.R. van de Voort and M. Metche, Department of Food Science and Agricultural Chemistry, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec. Hydroperoxide isomerase (HPI) was extracted from the cotolydon portion of sprouted French bean seeds after five days of incubation and purified by ammonium sulphate fractionation and ultracentrifugation. Linoleic acid hydroperoxides (LAHPO) were produced using commercial soybean Iipoxygenase and purified using a silicic acid column and identified by HPLC. The characterized LAHPOs were used as a substrate for the French bean HPI. The purified French bean extract showed a three fold increase in activity over the crude preparation and a pH optimum of 7.2. The primary endproducts of the enzyme reaction were separated into ketol and carbonyl compounds and then further purified by preparative TLC. Subsequent GC-MS analysis of the ketol fraction indicated that HPI converted the 13-hydroperoxyoctadec-9,1l-dienoic acid primarily into 1O,13-dihydroxyoctadec-I I-enoic acid (a-ketol) and to a lesser extent into l2,13-dihydroxyoctadec-9-enoic acid (,,-ketol). Trace amounts of 9, l2-dihydroxyoctadec-lO-enoic acid resulting from the isomerization of 9-hydroperoxyoctadec-lO, l2-dienoic acid were also found. Hexanal was revealed to be the principal carbonyl compound resulting from the decomposition of l3-hydroperoxyoctadec-9,11dienoic acid and it is believed that a lyase was also present in the French bean extract.
xxxviii / Affaires de l'Institut
IRON FORTIFICATION OF BARLEY SPROUTS. J. Craig Alexander* and Anna Cudjoe, Departmc;nt of Nutritional Sciences, University of Guelph, Guelph, Ontario. Iron deficiency anemia is a common nutritional problem on a global basis. In spite of this, addition of iron salts to foods is not accepted in a number of countries. To provide a natural source of the mineral, availability of iron in barley sprouts was studied. The seeds were germinated hydroponically in the dark at 22°C, using distilled water with various concentrations of FeS04' The sprouts were frozen, freeze-dried and ground. Iron levels in the flour were increased substantially relative to the supply, and the efficiency of iron utilization also was improved. Cereal fortification with iron was achieved by hydroponics. CHLORINATION OF WHEAT FLOUR PENTOSANS. N.L. Crowe* and V.F. Rasper, Department of Food Science, University of Guelph, Guelph, Ontario. The effect of cWorine compounds (gaseous chlorine, chlorine dioxide, sodium chlorite) on the water-soluble nonstarchy polysaccharides (WSNP; pentosans) of wheat flour was investigated in order to further elucidate the effect of chlorination of flour. WSNP were extracted from three flours and examined for the ability of the chlorine compounds to induce oxidative gelation in the WSNP as measured by capillary viscometry. Other oxidants (hydrogen peroxide/peroxidase, ferric chloride) were compared to the chlorine compounds. Sodium chlorite solutions exhibited oxidative gelation only in the presence of exogenous peroxidase which acted by increasing the level of reactive chlorine (CI 2 ,HOCl). THERMAL PROPERTIES OF PROTEIN AND STARCH FRACTIONS FROM BLACK BEANS (PHASEOLUS VULGARIS). Andres Hohlberg*, Michael J. Leszkowiat and David W. Stanley, Department of Food Science, University of Guelph, Guelph, Ontario. Differential scanning calorimetry (DSC) was used to monitor gelatinization and melting endotherms of bean starch at different heating rates and moisture levels. In addition, thermodynamic parameters for the denaturation of the main 7S protein in black beans were determined. Gelatinization and melting peak temperatures increased with moisture c