Some chemical investigations of Amoora rohituka seed proteins

The inadequate supply of protein food, especially in the context of increasing population, has been an important factor in malnutrition in third world countries. Proteins were extracted from de-oiled seeds of Amoora rohituka, a potential source of non-conventional seed, in aqueous solutions of various pHs or by different concentrations of NaCl, KCl, CaCl₂ and MgSO₄ at pH 7.0. The nitrogen content of seeds and de-oiled seeds showed good protein content. Fractionation of protein was done to separate albumin, globulin, prolamine and glutelin. Gel-permeation chromatography on Sephadex G-200 revealed the presence of six components. PAGE identified different polypeptide bands in the range of 15.5–67.6 kDa in the total protein isolate (TPI) as well as in protein fractions. Amino acid analysis of TPI and fractions isolated identified 16 amino acids, most of which are essential. Studies on surface topographies of proteins and seed flour by scanning electron microscope are also incorporated.     

Chemical investigation of Erythrina variegata Linn. seed proteins

Proteins were extracted from deoiled seeds of Erythrina variegata Linn., a potential source of non-conventional seed, in aqueous solutions of various pHs or by different concentrations of NaCl, KCl, CaCl₂ and MgSO₄ at pH 7.0. Nitrogen contents of the seeds and deoiled seeds showed good protein content. Fractionation of protein was done to separate albumin, globulin, prolamine and glutelin. Amino acid analysis of the total protein isolates (TPI) and the fractions isolated (except prolamine) identified 17 amino acids, most of which were essential. The molecular weights of TPI and the fractions were determined by SDS–PAGE electrophoresis. The results showed that TPI was composed of twelve bands, eight for globulin, nine for prolamine and six for glutelin. Studies on surface structure of the proteins and seed flour by scanning electron microscopy (SEM) are also included.     

Effect of grain hardness,fractionation and cultivars on protein,pasting and dough rheological properties of different wheat flours

Coarse flour fractions (CFFs) and fine flour fractions (FFFs) obtained from flour milled from twelve different wheat cultivars varying in grain hardness index (GHI) were evaluated for particle size distribution, pasting and protein characteristics. Cultivars with greater hardness produce flour with high protein content had more proportion of large size particles. FFF had higher unextractable polymeric protein, solvent retention capacity (SRC), sedimentation value (SV) and dough stability (DS) than their corresponding CFF. Both FFF and CFF from cultivars with lower hardness showed lower sodium SRC. CFF showed higher pasting viscosities than their corresponding FFF, and difference in these properties was greater amongst soft cultivars. DS increased with decrease in grain hardness, but medium hard cultivars showed exceptionally higher value. The concentration of HMW‐GS in the CFF was higher than FFF of hard wheat cultivars, whereas the concentration of LMW‐GS in the CFF and FFF was not influenced by the fractionation of flour.     

Water Uptake, Protein Solubility, and Protein Changes of Cod Mince Stored on Ice as Affected by Polyphosphates

Water uptake ability (WUA) and protein solubility of cod mince were higher with sodium hexametaphosphate (SHMP) than with sodium tripolyphosphate (STP) or untreated controls during ice storage. WUA increased significantly with SHMP concentration up to 0.7% SHMP but above that WUA decreased, although protein solubility continued to increase. The SDS-PAGE results showed that extraction of a specific amount of water-soluble protein, perhaps including some myosin heavy chain (MHC, 200 kd), correlated with high WUA. However, excess extraction of MHC may cause destruction of the structural matrix of the insoluble protein network, preventing it from holding water.     

Isolation and chemical evaluation of carob (Ceratonia siliqua L.) seed germ

The present investigation was undertaken in order to study the influence of the dehusking procedure on the germ meal composition of carob (Ceratonia siliqua L.) seeds and also to investigate its detailed composition and nutritive value. Meals of carob seed germ were obtained by acid treatment or boiling water treatment of the whole seeds. These procedures allowed to separation of the tight-fitting brown coat of the seed and the removal of the endosperm. Results indicated that the carob germ meal composition could be affected by the isolation procedures. Small reductions were observed in protein and lipid contents in germ meals from acid extraction. The analysis of the carob germ meal (containing fine fragments of husk and endosperm), which could be really obtained industrially, showed the following composition: moisture 8.3%, ash 6.5%, lipids (neutral and polar) 6.6% containing ∼21% of polar lipids, crude proteins 54.7% and energy value 17.5 kJ/g.     

Role of steaming and toasting on the odor, protein characteristics of chickpea (Cicer arietinum L.) flour, and product quality

Proteins play an important role in imparting functional attributes like texture and shape, which determine the sensory quality of the foods. Boondi, a deep fried product from chickpea (Cicer arietinum L.) flour dispersion, is a popular snack food in India. Chickpea dhal (splits) or flour was subjected to various processing conditions like steaming and toasting, to determine their effect on the chickpea flour protein characteristics and on the product quality. Dhal and flour subjected to different heat treatments showed differences in their odor profiles. The SDS-PAGE of sodium phosphate buffer extracts of steamed dhal or flour showed that the high molecular weight (HMW) proteins of 66 to 100 kDa that were present in the untreated dhal were found to be absent in steamed dhal extracts. However, SDS buffer extracts on SDS-PAGE of these steamed samples did not show any difference between untreated and thermally treated dhal samples. Phosphate buffer extracts of the thermally treated flours were subjected to gel filtration chromatography and the results indicated that the HMW protein fraction content decreased significantly in the treated dhal or flour samples compared to control. Boondi prepared from the thermally treated dhal samples resulted in the loss of spherical shape of boondi. Thus, the results indicate that thermal treatment of chickpea dhal and flour influence changes in protein characteristics, the sensory profile and quality of boondi.     

椰子分级蛋白组分制备及理化性质研究

目的 制备椰子分级蛋白组分并研究其理化性质。方法 对椰子蛋白进行分级并制备相应组分,测定椰子蛋白分级组分的氨基酸组成、疏水性、游离巯基含量、溶解度、乳化性和起泡性,以评估其功能特性。结果 椰子蛋白含有18种氨基酸, 富含精氨酸和谷氨酸,必需氨基酸含量丰富、比例合理,是营养良好的蛋白质来源。所有样品在蛋白质的等电点处溶解度最差、起泡性最差而泡沫稳定性却最好。随着pH增加,溶解度整体趋势先降低后增加,乳化能力总体呈现增加的趋势,而较高的pH下表现出更好的乳化稳定性。结论 椰子蛋白具有良好的营养价值及优良的溶解度、乳化性及起泡性,可为椰子蛋白在食品加工中的应用提供理论参考。     

Effect of the stage of growth,wilting and inoculation in field pea (Pisum sativum L.) silages,III. Changes in the herbage and silage protein profiles

BACKGROUND: The effects of stage of growth, field wilting and inoculation with lactic acid bacteria (LAB) on the protein profile of herbage and silage were studied on field peas (Pisum sativum L.) harvested at four progressive morphological stages (end of flowering, I; beginning of pod filling, II; advanced pod filling, III; beginning of ripening, IV). The herbage was field wilted to a dry matter (DM) content around 330 g kg^?1, for each stage of growth. The unwilted and wilted herbages were ensiled with (I) and without (C) a LAB inoculant. RESULTS: As a result of the advancing maturity of the crop, the main protein component was Rubisco in the early stages and seed storage proteins in the more advanced stages, due to the redistribution of organic nitrogen during seed filling. Extensive degradation of Rubisco occurred in all the silages, without any effect of inoculation or wilting. A good preservation of the proteins was observed in stage IV for both unwilted and wilted silages, without further protein preservation due to LAB inoculation. CONCLUSION: Protein protection observed in the more mature pea silage was due to the protein type and its localization and not to the level of DM at ensiling or to the inoculation. Copyright © 2007 Society of Chemical Industry     

Effects of roasting and boiling on the chemical composition,amino acids and oil stability of safflower seeds

The objective of this study was to determine the effects of roasting and boiling on compositional and oil stability of safflower seeds. The moisture, carbohydrate and fibre contents decreased because of roasting and boiling treatments while fat and protein contents increased. The fatty acid compositions of treated samples changed slightly compared with control. The total amount of amino acids in control sample was 151.29, and this amount increased to 158.8 and 186.9 mg g^?1 N by roasting and boiling, respectively. The peroxide value of the oil increased because of roasting and boiling, and it reaches above the accepted value to consumer. Concentrations of major elements such as Na, K and Cu in raw safflower seeds were significantly (P < 0.05) higher than roasted and boiled seeds. The effects of roasting and boiling with regard to loss and retention of the nutrients differed significantly (P > 0.05), with only the roasting retaining more of the nutrients than boiling. The peak intensities of control oil using FTIR spectroscopy were changed in comparison with treated oils.     

Chemical,amino acid and fatty acid composition of Sterculia urens L. seed

The chemical, amino acid and fatty acid compositions of Sterculia urens seeds are reported. The cotyledons were found to be rich in protein (30.88%) and lipids (39.2%). The major amino acids in defatted Sterculia urens cotyledon flour (DSCF) were determined as glutamic acid, arginine and aspartic acid. Cysteine, methionine, tyrosine and histidine were observed in minor quantities. The ratio of essential to non-essential amino acids was observed to be 0.45. Among the essential amino acids, isoleucine was found to be higher than the reported FAO/WHO requirements. The GC-FID and GC–MS analysis revealed that the major fatty acids of the total lipid were stearic acid (31.72%), linoleic acid (28.83%) and palmitic acid (26.79%). Eicosadienoic acid (4.98%) and eicosatrienoic acid (2.96%) were also found in the total lipid.     

Effects of gamma irradiation on edible seed protein,amino acids and genomic DNA during sterilization

This work describes radiation-induced effects on edible seed protein profiles, carbohydrates, amino acids and genomic DNA during gamma sterilization. The total protein and carbohydrate was decreased with increasing dose compared to control samples. Oryzasativa L. Cv-2233 exhibited a minimum effect in terms of its loss in total soluble protein content, compared to other seeds at 6 kGy, and the soluble protein fraction, containing 14–16 kDa albumins and 22 kDa globulin, was unchanged up to 6 kGy. In Cicer arietinum, the effect of gamma rays was more pronounced on albumin and prolamin with respect to glutelin and globulin. The easy-to-digest and difficult-to-digest proteins were not significantly affected up to 4 kGy. However, the soluble free amino acids of all the seeds increased with increasing dose. The total DNA content and band intensities both decreased with increasing absorbed dose; however, the band positions were unchanged for all seed types.     

Comparison of Lupinus angustifolius protein digestibility in dependence on protein,amino acids,trypsin inhibitors and polyphenolic compounds content

Lupine seeds are proposed as a source of valuable protein in human and animal nutrition. However, not only protein content but its bioavailability is important. Thus, the protein digestibility of twenty Lupinus angustifolius varieties seeds and the impact of some factors (protein and polyphenols content, trypsin inhibition and amino acids composition) on the protein digestion were discussed. Composition as well as the digestibility of these seeds was influenced by variety, weather conditions (precipitations) and place of cultivation (soil quality). The average digestibility of the seeds was 46%. The positive impact on the digestibility had the extractivity of the protein. Higher than it was expected activity of trypsin inhibitors (even up to ~32%) in some varieties influenced the protein availability, while the lysine and phenolic compounds content did not affect digestibility. The content of compounds influencing protein digestibility depends both on variety as well as on agronomical conditions.     

Effect of glycation on protein structure,amino acid composition and digestibility of silver carp mince

This study was to investigate the effects of glycation on the quality of silver carp mince (SCM) proteins. The browning index (BI), sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FTIR), total amino acid composition, chemical score, protein digestibility and reductive power of digested products were determined. The correlation between the degree of glycation, protein structure and protein nutritional quality was analysed. The results showed that the BI value of SCM-G increased with the increase in heating time. Myosin heavy chain (MHC), myosin light chain (MLC), tropomyosin and actin were the main protein reactants for glycation. Glycation led to the expansion of the secondary structure of SCM proteins. Glycation reduced lysine and cysteine content but did not change the first limiting amino acid (Val) in SCM. The essential amino acid content of glycated SCM remained consistent with the amino acid nutritional requirements for children and above recommended by FAO/WHO. In addition, glycation did not change protein digestibility but significantly increased the reducing power of digested products with increasing degree of glycation. These results provided a theoretical basis for the application of glycation in food processing industry and the development of aquatic products with high nutritional value.     

Effect of nitrogen fertilisation on protein content,total fatty acid content and composition of barley (Hordeum vulgare L.) grains

The impact of N-fertilisation level on protein content, total fatty acid (TFA) content and major fatty acid composition of barley grains (cv. Eldorado), grown in a replicated field trial, was investigated. Increasing amounts of N-fertiliser, applied at several stages during the growing season, resulted in a higher protein content and a very slightly lowered TFA content in the grains. Protein and TFA contents were negatively correlated (r=-0.4685). Minor changes of fatty acid composition were found in the decrease of the oleic acid (C18:1) proportion (r=-0.8376) and in the increase of the palmitic acid (C16:0) proportion (r=0.7273). The stearic acid (C18:0) and the linoleic acid (C18:2) proportions were also affected, however, no significant linear correlations with the total N-fertiliser level were obtained. The slow increase in the linolenic acid (C18:3) proportion (r=0.5674) was too small, compared to the residual variance, to be significant. TFA content was positively (P<0.001) correlated with the oleic acid proportion, and negatively (P<0.001) with the palmitic acid proportion. These data suggest that the application of higher amounts of N-fertiliser slightly decreases the total fatty acid content of barley grains, probably due to a decreased synthesis of oleic acid, precursor of the unsaturated C18 fatty acids. The result is a relative increase in palmitic acid.     

玉米株型对套作大豆氮素积累、转运和籽粒蛋白质产量的影响

以＂玉/豆＂套作模式为背景,三个不同株型的玉米和三个不同熟期的大豆材料,采用两因素裂区设计,研究了大豆地上部氮素积累和转运,以及籽粒蛋白质含量的差异。结果表明,各大豆品种中,以晚熟大豆在不同时期、不同器官的氮素积累量为最高,分别高出中、早熟品种121.09%和165.33%,其氮素积累速率、有效荚数、籽粒产量和蛋白质含量平均分别为3.78kg/hm2.d、60.27荚、3 840.22kg/hm2和48.71%,均显著高于中、早熟品种;大豆地上部氮素积累总量、积累速率、转运量和单株有效荚数均随着玉米株型的变化（从紧凑型到平展型）而减少,紧凑型玉米下的大豆籽粒产量和蛋白质产量分别为2 609.10kg/hm2和1 203.83kg/hm2,显著高于其他玉米株型处理;交互作用分析表明,玉米株型与大豆熟性在单株荚数、单荚粒数、籽粒产量和蛋白质产量上互作显著;相关性分析表明蛋白质产量与籽粒产量极显著相关。因此,选择紧凑型玉米与晚熟大豆品种搭配有利于提高套作大豆的产量,从而提高籽粒蛋白质产量。     

Neriifolin S, a dimeric serine protease from Euphorbia neriifolia Linn.: Purification and biochemical characterisation

A dimeric serine protease Neriifolin S of molecular mass 94 kDa with milk clotting activity has been purified from the latex of Euphorbia neriifolia by anion exchange and size-exclusion chromatography. It hydrolyses peptidyl substrates l-Ala-pNA with highest affinity (K_m of 0.195 mM) and physiological efficiency (K_cat/K_m of 144.5 mM s). Enzyme belongs to the class of neutral proteases with pI value of 6.8, optimal proteolytic activity displayed at pH 9.5 and temperature 45 °C. Its proteolytic activity is strongly stimulated in the presence of Ca⁺² ions and exclusively inhibited by serine protease inhibitors. Enzyme is fairly stable toward chemical denaturants, pH and temperature. The apparent T_m, was found to be 65 °C. Thermal inactivation follow first order kinetics with activation energy (Ea), activation enthalpy (ΔH∗), free energy change (ΔG∗) and entropy (ΔS∗) of 27.54 kJ mol⁻¹, 24.89 kJ mol⁻¹, −82.34 kJ mol⁻¹ and 337.20 J mol⁻¹ K⁻¹.     

Influence of whey protein concentrate, additives, their combinations on the quality and microstructure of vermicelli made from Indian T. Durum wheat variety

Effect of whey protein concentrate (5%, 7.5%, 10%) and additives on the quality of vermicelli made from Indian durum wheat was studied. The results revealed that with increase in whey protein concentrate (WPC) from 0% to 10%, cooked vermicelli weight increased from 82.5 to 88 g/25 g, cooking loss increased from 6.0 to 8.4%, L values indicating lightness increased (47.42–52.9); b values indicating yellowness decreased (7.0–3.80) and shear force decreased (66–45 g). Sensory evaluation of vermicelli with 5%, 7.5%, 10% WPC showed that addition of above 5% WPC resulted in whitish colour vermicelli with mashy strand quality and sticky mouthfeel. Studies on the effect of additives namely ascorbic acid (0.01% and 0.015%), gluten (1.5% and 3.0%) and glycerol monostearate (GMS) (0.25% and 0.5%) individually as well as in combination on the quality of vermicelli with 5% WPC indicated that combination of 0.01% ascorbic acid, 3% gluten and 0.5% GMS resulted in vermicelli having lower cooking loss, creamy yellow colour, firm, discrete strands and non-sticky mouthfeel. The protein content of vermicelli with 5% WPC and combination of additives was 16% as against 11.5% of control vermicelli. Scanning electron microscopy study of control vermicelli, vermicelli with 5% WPC and vermicelli with 5% WPC and combination of additives revealed that vermicelli with 5% WPC showed a rough surface with a prominent rupture while vermicelli with 5% WPC and combination of additives showed a continuous, rupture free structure.     

Influence of yeast strain,immobilisation and ageing time on the changes of free amino acids and amino acids in peptides in bottle‐fermented sparkling wines obtained from Vitis vinifera cv. Emir

This paper reports the influence of yeast strain, immobilisation and ageing time on the free amino acids and amino acids in peptides of sparkling wine made by the traditional method from the Emir grape variety over a period of 365 days in vintages 2004 and 2005. Four sparkling wines were obtained from the same base wine using yeast strains (both immobilised and free Saccharomyces bayanus and Saccharomyces oviformis). The analysis of variance and cluster revealed that there were significant differences between free amino acids and amino acids in peptides due to ageing time. However, the yeast strain affected most of the free amino acids and amino acids in peptides in only the 2004 vintage. The total amount of free amino acids was higher in the wine made with the S. oviformis compared to S. bayanus. Furthermore, there were no significant differences between the use of immobilised and free yeast in cases of free amino acids and amino acids in peptides.     

Influence of dietary oils and protein level on pork quality. 1. Effects on muscle fatty acid composition, carcass, meat and eating quality

This study evaluated the effects of three dietary oils - palm kernel (PKO), palm (PO) and soyabean (SBO) - and two protein levels - high (HP) and low (LP) in a 3×2 factorial design involving 60 pigs on growth performance, muscle fatty acid composition and content, carcass, meat and eating qualities. Oil type did not have a significant effect on growth and carcass quality. PKO significantly reduced the polyunsaturated (PUFA) to saturated (SFA) fatty acid (P:S) ratio in longissimus muscle (P<0.001). PKO increased the concentrations of lauric (12:0), myristic (14:0), palmitic (16:0) and stearic (18:0) fatty acids and decreased linoleic acid (18:2). The LP diet increased intramuscular fat (IMF) from 1.7g/100g muscle in HP to 2.9g/100g (P<0.001), increased tenderness by 0.6 units (P<0.01) and juiciness by 0.5 units (P<0.01) on the 1-8 scale, but at the expense of lower daily weight gain (P<0.01), lower feed conversion efficiency (P<0.01), reduced P:S ratio (P<0.001) and increased lipid oxidation (P<0.01). The results suggest that PKO and PO could be used in tropical developing countries as cheaper alternatives to SBO for the production of good quality and healthy pork, but their limits of inclusion need to be determined.