Purification of diamine oxidase and its properties in germinated fava bean (Vicia faba L.)

Background: γ‐Aminobutyric acid (GABA) is a non‐protein amino acid with bioactive functions for human health. Diamine oxidase (DAO, EC 1.4.3.6) is one of the key enzymes for GABA formation. In the present study, this enzyme was purified from 5 day germinated fava bean and its properties were investigated in vitro. Results: The molecular mass of the enzyme estimated by Sephadex G‐100 gel filtration was 121 kDa. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) displayed a single band at a molecular mass of 52 kDa. The enzyme had optimal activity at 40 °C and retained its activity after being incubated at 30 °C for 30 min. It showed higher activity at pH 6.5 than at other pH values. The enzyme was significantly inhibited by Mg²⁺, Cu²⁺, Fe³⁺, aminoguanidine, ethylene glycol tetraacetic acid (EGTA), ethylene diamine tetraacetic acid disodium salt (EDTA‐Na₂), L ‐cysteine and β‐mercaptoethanol. The K_m value of DAO was 0.23 mmol L^?1 for putrescine and 0.96 mmol L^?1 for spermidine. However, the enzyme did not degrade spermine. Conclusion: DAO from germinated fava bean was purified. The optimal reaction temperature and pH of the enzyme were mild. The enzyme had higher affinity to putrescine than to spermidine and spermine. Copyright © 2011 Society of Chemical Industry     

Structural studies of an acidic polysaccharide of Mesona blumes gum

Mesona blumes gum can be isolated into a neutral polysaccharide (NMBG) and an acidic polysaccharide (AMBG). The yield of AMBG can be up to 90% (w/w). AMBG with a molecular weight of 6566 Da is composed of galactose, glucose, mannose, xylose, arabinose, rhamnose and galacturonic acid in the molar ratio 2.66:1:0.37:2.29:12.5:5.99:23.5. Structural features of the purified AMBG were investigated by a combination of chemical and instrumental analysis, such as periodate oxidation, Smith degradation, methylation, and ¹³C and ¹H NMR. It was found that AMBG possessed a (1 → 4)‐α‐galacturonan backbone with some insertions of (1 → 2)‐α‐L ‐Rhap residues. The branches of arabinogalactan, arabinan, galactan and xylan were all attached to the backbone via O‐4 of α‐L ‐Rhap residues. In addition, some α‐L ‐Rhap residues on the backbone terminated with α‐L ‐Araf and some O‐6 in galacturonic acid residues were acetylated or methyl esterified. The molecular structure of AMBG at different concentrations was observed by atomic force microscopy (AFM). It was found that AMBG showed spherical lumps at 1 µg mL^?1 but an irregular worm‐like shape at 10 µg mL^?1, which indicated that the viscosity of AMBG might be caused by its notable molecular aggregation. Copyright © 2007 Society of Chemical Industry     

Colonic availability of polyphenols and D-(-)-quinic acid after apple smoothie consumption

Scope : The aim of this study was to determine the amounts of polyphenols and D ‐(?)‐quinic acid reaching the ileostomy bags of probands (and thus the colon in healthy humans) after ingestion of apple smoothie, a beverage containing 60% cloudy apple juice and 40% apple puree. Methods and results : Ten healthy ileostomy subjects each ingested 0.7 L of apple smoothie (a bottle). Their ileostomy bags were collected directly before and 1, 2, 4, 6 and 8 h after smoothie consumption, and the polyphenol and D ‐(?)‐quinic acid contents of the ileostomy fluids were examined using HPLC‐DAD and HPLC‐MS/MS. The total polyphenol and D ‐(?)‐quinic acid content of the apple smoothie was determined to be 1955.6±124.6 mg/0.7 L, which is very high compared to cloudy apple juices. The most abundant substances found in the ileostomy bags were oligomeric procyanidins (705.6±197.9 mg), D ‐(?)‐quinic acid (363.4±235.5 mg) and 5‐caffeoylquinic acid (76.7±26.8 mg). Overall recovery of ingested polyphenols and D ‐(?)‐quinic acid in the ileostomy bags was 63.3±16.1%. Conclusions: The amounts of polyphenol and D ‐(?)‐quinic acids reaching the ileostomy bags are considerably higher after apple smoothie consumption than after the consumption of cloudy apple juice or cider. These results suggest that the food matrix might affect the colonic availability of polyphenols, and apple smoothies could be more effective in the prevention of chronic colon diseases than both cloudy apple juice and apple cider.     

The effect of certain amino acids and browning inhibitors on the ‘black spot’ phenomenon produced by Carnimonas nigrificans

Black spots are sometimes observed in fermented sausages and raw cured meat products, with resultant economic loss. The effect brought about by some amino acids in the development of this browning was evaluated, in aerobiosis at 30 °C and 90–95% RH, in a pork meat mixture with glucose, NaCl and inoculated with Carnimonas nigrificans CTCBS1^T at 1.0 × 10⁷ CFU g⁻¹. Amino acids and alternative substances to bisulphite and nitrite as preventative agents were studied for their effect on the browning reaction. The effect of NaCl concentration on browning and on the growth of Carnimonas nigrificans CTCBS1^T was also evaluated. Glycine, L ‐arginine, L ‐glutamine and L ‐monosodium glutamate were the amino acids that significantly decreased the L values and increased the browning scores in comminuted meat which was mixed with 40 gkg⁻¹ NaCl and 20 gkg⁻¹ D ‐(+)‐, glucose and inoculated with Carnimonas nigrificans CTCBS1^T. N‐acetyl‐L ‐cysteine, L ‐cysteine, potassium metabisulphite and propil‐3, 4, 5‐trihydroxybenzoate prevented browning at 10 and 5 gkg⁻¹. The optimum concentration of NaCl for the growth of Carnimonas nigrificans CTCBS1^T was 40 gkg⁻¹. © 2000 Society of Chemical Industry     

Thermal properties of Phaseolus angularis (red bean) globulin

The thermal properties of Phaseolus angularis (red bean) globulin were studied by differential scanning calorimetry under various medium conditions. Red bean globulin (RGB) was fractionated by ion-exchange chromatography into a major fraction, with SDS–PAGE pattern corresponding to the 7S vicilin, and two minor fractions, probably representing residual vicilin and the 11S legumin, respectively. The thermogram of RBG showed a major endothermic peak at 86.4°C and a minor transition at 92.2°C. Vicilin exhibited two endothermic peaks (87.7 and 94.1°C), while legumin showed one transition at 89.5°C. The progressive increase in denaturation temperature (T_d) with increase in salt concentration, suggests a more compact conformation for RBG with higher thermal stability. Decreases in enthalpy and T_d were observed under the influence of highly acidic and alkaline pHs, chaotropic salts, and protein perturbants such as sodium dodecyl sulfate, urea and ethylene glycol, indicating partial denaturation and decrease in thermal stability. Dithiothreitol and N-ethylmaleimide have little effect on the thermal properties of RBG since the major protein component, vicilin, is devoid of disulfide bonds.     

Viscosity of solutions of xanthan/locust bean gum mixtures

Xanthan and locust bean gums are polysaccharides able to produce aqueous solutions with high viscosity and non‐Newtonian behaviour. When these solutions are mixed a dramatic increase on viscosity is observed, much greater than the combined viscosity of the separated polysaccharide solutions. In this work the influences of different variables on the viscosity of solutions of mixtures of xanthan/locust bean gum have been studied. Total polysaccharide concentration, xanthan and locust bean ratio on mixture and temperature at which the gum was dissolved (dissolution temperature) for both xanthan and locust bean gums have been considered. Under these different operational mixture conditions shear rate and time have also been considered to describe the rheological behaviour of the solutions studied. The high viscosity increase observed in these mixtures is due to the interaction between xanthan gum and locust bean gum molecules. This interaction takes place between the side chains of xanthan and the backbone of the locust bean gum. Both xanthan molecule conformation in solution – tertiary structure – and locust bean gum structure show great influence on the final viscosity of the solution mixtures. Xanthan conformation changes with temperature, going from ordered structures to disordered or chaotic ones. Locust bean gum composition changes with dissolution temperature, showing a dissolved galactose/mannose ratio reduction when temperature increases, ie the smooth regions – zones without galactose radicals – are predominantly dissolved. The highest viscosity was obtained for the solution mixture with a total polysaccharide concentration of 1.5 kg m⁻³ and a xanthan/locust ratio of 2:4 (w/w) and when xanthan gum and locust bean gum were dissolved at 40°C and 80°C, respectively. © 1999 Society of Chemical Industry     

A modified laboratory canning protocol for quality evaluation of dry bean (Phaseolus vulgaris L)

The effects of calcium (Ca²⁺) level in the soak water, blanch water and brine, blanching temperature, and total seed solids on dry bean canning quality were investigated to optimise a laboratory canning protocol. A linear increase in the Ca²⁺ level of soak water, blanch water and brine resulted in a linear decrease in hydration coefficient and percent washed drained weight but a linear increase in texture. Low Ca²⁺ level (10 mg kg⁻¹) reduced the hydration time for dry bean seed from 14 to 1 h. Blanching temperatures of 50, 70 and 88 °C had non‐significant effects on canning quality traits. Blanching for 30 min at 70 °C for black bean or at 88 °C for navy bean and pinto bean resulted in percent washed drained weight ≥ 60, as required by the Canada Agricultural Products Standards Act. Seed solids levels of 95–97 g per 300 × 407 (14 fl oz) can were sufficient to attain a percent washed drained weight of 60. It was confirmed that the thermal processing conditions (115.6 °C retort temperature, 45 min) used in this study were sufficient to achieve commercial sterility. The optimised lab protocol for evaluation of the canning quality of dry bean breeding lines is as follows. Seed containing 95 g of solids for pinto bean, 96 g for navy bean and 97 g for black bean is soaked in water for 30 min at 20 °C and blanched for 30 min at 70 °C for black bean and 88 °C for navy bean and pinto bean in water containing 10 mg kg⁻¹ of Ca²⁺. The seed is then transferred to a 300 × 407 can, filled with brine containing 10 mg kg⁻¹ of Ca²⁺, 1.3% (w/v) of NaCl and 1.6% (w/v) of sugar. The can is then sealed, processed in steam at 115.6 °C for 45 min and cooled at 20 °C for 20 min. Cans are stored for at least 2 weeks prior to quality evaluation of the canned product. Canning of dry bean seed according to this protocol results in precise estimation of canning quality traits, particularly percent washed drained weight. © 2000 Society of Chemical Industry     

Protex 6L直接酶解红豆粉提取红豆肽的研究

采用Protex 6L直接酶解红豆粉的方法提取红豆肽,通过响应曲面分析得出Protex 6L蛋白酶提取红豆蛋白的最佳条件:pH为9.4,加酶量为3.14%,温度为60℃,时间为3.5h,料液比为1∶6.9(g/mL)。并采用凝胶层析过滤色谱分析了不同水解时间水解物分子量的变化,发现红豆蛋白中存在一些不容易被Protex 6L酶解的成分,红豆粉的Protex 6L酶解过程是一个不均匀的过程。     

Saponins and sapogenins of chick pea,haricot bean and red kidney bean

The saponins of red kidney bean (Phaseolus vulgaris), chick pea (Cicer arientinum) and haricot bean (Phaseolus vulgaris) all contain soyasapogenol B as the only aglycone. The levels of soyasapogenol B estimated were: chick pea, 0·075%; haricot bean, 0·149%; and red kidney bean, 0·102%; on a defatted, dry weight basis. HPLC separation of the saponin preparations indicates the presence of at least five saponins in red kidney bean, five in haricot bean and two in chick pea. Retention time comparison of the saponin preparations indicates the possible presence of soyasaponin I in all three legumes and soyasaponin II in haricot and red kidney beans.     

Antioxidant Activity of Phenolic Compounds from Fava Bean Sprouts

Fava beans are eaten all over the world and recently, marketing for their sprouts began in Japan. Fava bean sprouts contain more polyphenols and l ‐3,4‐dihydroxyphenylalanine (l ‐DOPA) than the bean itself. Our antioxidant screening program has shown that fava bean sprouts also possess a higher antioxidant activity than other commercially available sprouts and mature beans. However, the individual constituents of fava bean sprouts are not entirely known. In the present study, we investigated the phenolic compounds of fava bean sprouts and their antioxidant activity. Air‐dried fava bean sprouts were treated with 80% methanol and the extract was partitioned in water with chloroform and ethyl acetate. HPLC analysis had shown that the ethyl acetate‐soluble parts contained phenolic compounds, separated by preparative HPLC to yield 5 compounds ( 1 ? 5 ). Structural analysis using NMR and MS revealed that the compounds isolated were kaempferol glycosides. All isolated compounds had an α‐rhamnose at the C‐7 position with different sugars attached at the C‐3 position. Compounds 1 ? 5 had β‐galactose, β‐glucose, α‐rhamnose, 6‐acetyl‐β‐galactose and 6‐acetyl‐β‐glucose, respectively, at the C‐3 position. The amount of l ‐DOPA in fava bean sprouts was determined by the quantitative ¹H NMR technique. The l ‐DOPA content was 550.45 mg ± 11.34 /100 g of the raw sprouts. The antioxidant activities of compounds 2 ? 5 and l ‐DOPA were evaluated using the 2,2‐diphenyl‐1‐picrylhydrazyl scavenging assay. l ‐DOPA showed high antioxidant activity, but the isolated kaempferol glycosides showed weak activity. Therefore, it can be suggested that l ‐DOPA contributed to the antioxidant activity of fava bean sprouts.     

Biochemical basis of insect resistance in inged bean (Psophocarpus tetragonolobus) seeds

Mature seeds of the inged bean (Psophocarpus tetragonolobus) are toxic to developing larvae of a range of cosmopolitan storage Bruchidae of economic importance, including the copea seed eevil, Callosobruchus maculatus. Insect feeding trials ere carried out in hich protein fractions from seeds of inged bean ere incorporated at a range of concentrations into artificial seeds, and their effects upon development of C maculatus determined. Both albumin and globulin fractions ere toxic to the developing larvae and their toxicity correlated ith their haemagglutinating activity. Assay of Psophocarpin A, B and C fractions demonstrated Psophocarpin B to be the most insecticidal and to contain the highest haemagglutinating activity. Purified basic seed lectin as highly insecticidal to C maculatus larvae, ith an LC₅₀ value of c. 3·5 g kg^?1. The physiological level of this protein in inged bean seeds is sufficient to account for their resistance to attack by C maculatus. inged bean trypsin inhibitor as also purified and tested in artificial seeds against C maculatus. Hoever, even at concentrations in excess of tice the physiological concentration it had no deleterious effects upon development.     

Detection of Lathyrus sativus in processed chickpea‐ and red gram‐based products by thin layer chromatography

Excessive consumption of Lathyrus sativus leads to crippling, irreversible paralysis of both lower limbs, mainly in males. This is attributed to the presence of a non‐protein amino acid, β‐N‐oxalyl‐L ‐2,3‐diaminopropionic acid or β‐N‐oxalylamino‐L ‐alanine. Using a thin layer chromatography method developed in our laboratory, adulteration of chickpea and red gram with L sativus in pressure‐cooked batters could be detected at levels of 100 and 200 g kg^?1 respectively. When processed as a curried liquid dal, L sativus could be detected at 200 g kg^?1 in chickpea and 100 g kg^?1 in red gram. Processing into fried bhajiyas resulted in a detection limit of 200 g kg^?1 in both red gram and chickpea. © 2003 Society of Chemical Industry     

Pigmented rice a potential source of bioactive compounds: a review

Rice (Oryza sativa L.) is one of the most important food crops in the world. In red rice, black, purple, brown, and brown red rice, major bioactive components are gallic, protocatechuic, hydroxybenzoic, p‐coumaric,ferulic, sinapic acid, cyanidin‐3‐O‐glucoside, peonidin‐3‐O‐glucoside,flavan‐3‐ol (+) catechin and (?) epicatechin,flavanols (flavan‐ 3‐ols), isoflavones, γ‐oryzanol contents, compositions of steryl, triterpene alcohol ferulates proportions, and tocopherols, etc. This review provides information of pigmented rice in the form of bioactive compounds, concentration, activities and its health's benefit. These bioactive compounds are having immense potential for many health benefit effects and can act as antitumour, anti‐atherosclerosis, anti‐diabetic, anti‐allergicagents, alleviating gallstones, anticancer activity, anti‐inflammatoryeffects, and others.     

Improving antioxidant activity of black bean protein by hydrolysis with protease combinations

This study explored the use of a simplex centroid design to produce protein hydrolysates with antioxidant properties using Alcalase^® 2.4L, Flavourzyme^® 500L and Neutrase^® 0.8L. Proteases kinetic parameters and the ultrafiltration of protein hydrolysates were also investigated. The highest antioxidant activity, in the studied conditions, was reached when the mixture of Alcalase^® 2.4L and Flavourzyme^® 500L was used in the hydrolysates production. The antioxidant power of the black bean proteins, measured by the total antioxidant capacity and reducing power assay, increased after hydrolysis by 31% and 70%, respectively. The black bean proteins hydrolysates fractions (3–30 kDa) showed an antioxidant activity decrease along with a reduction in molecular weight, demonstrating that a set of varied molecular weight peptides was responsible for the antioxidant characteristics of black bean protein hydrolysates.     

Multiple forms of β‐galactosidase from mango (Mangifera indica L Alphonso) fruit pulp

Mango (Mangifera indica L cv Alphonso) was found to contain three isoforms (I, II and III) of β‐galactosidase which, upon purification on Sephadex G‐200, had relative abundances of 44, 38 and 18%, respectively. The total specific activity increased from 20 to 727 µmol l^?1 upon purification, representing a ～36‐fold increase with a recovery of 0.28 U U^?1. The optimal pH for activity and stability were in the ranges 3.6–4.3 and 4–6.2, respectively. The optimal temperature for β‐galactosidase activity was between 42 and 47 °C with T_m in the range 45–51 °C. The K_m for pNP‐β‐galactopyranoside was 0.98, 1.11 and 0.95 mM , and V_max was 0.56, 0.53 and 0.35 µmol pNP min^?1, respectively for isoforms I, II and III. Hg²⁺ caused strong inhibition, whereas galacturonic acid, galactose, xylose, fucose and mannose slightly inhibited the activity of β‐galactosidase isoforms. The apparent molecular weights by GPC were 78, 58 and 91 kDa for isoforms I, II and III, respectively. The ability of these isoforms to degrade the endogenous substrate (arabinogalactan) possibly suggests a role in pectin dissolution during tissue softening/fruit ripening. Copyright © 2004 Society of Chemical Industry     

Effect of Lasalocid or Monensin on Lactate Production From In Vitro Rumen Fermentation of Various Carbohydrates,

Lasalocid and monensin effectively reduced the lactate produced during in vitro fermentation of various sugars and ground grains with rumen fluid from either hay- or grain-fed cattle. The minimum effective dose was 6 μg/ml. Both lasalocid and monensin at 6 μg/ml reduced the fermentation rate of glucose, fructose, galactose, sucrose, lactate, mannose, ground corn, ground sorghum, and ground wheat, and raised the pH and substantially lowered lactate concentration compared with controls. Although both antibiotics decreased total lactate production, the proportion of D(?) lactate to L(+) lactate increased. Apparently both antibiotics were less inhibitory to the formation of D(?) than to L(+) lactate isomer. Lasalocid was more effective than monensin in inhibiting lactate production except when rumen fluid from grain-fed cattle was used in fermentation.     

The effect of heating on the haemagglutinating activity and nutritional properties of bean (Phaseolus vulgaris) seeds

The toxic lectins present in red, white and black kidney beans (Phaseolus vulgaris) are sensitive to heat treatment and the efficiency of that treatment is greatly improved by pre-soaking of the seeds. Heating of pre-soaked seeds at all temperatures above 75°C caused a continuous reduction in both their haemagglutinating activity and toxicity. However, the only safe method of eliminating toxicity was to heat the fully hydrated seeds to 100°C for a minimum of 10 min.     

Lipolysis in red clover with different polyphenol oxidase activities in the presence and absence of rumen fluid

This experiment aims to determine whether polyphenol oxidase (PPO) can reduce the extent of lipolysis and the consequent polyunsaturated fatty acid loss through microbial biohydrogenation in red clover when incubated in the presence of rumen fluid. PPO is involved in the browning reaction of red clover leaves when cut or crushed and exposed to air. It starts the browning process by oxidizing endogenous phenols to quinones, which contain electrophilic sites. These sites react with nucleophilic sites of other compounds such as proteins and have been shown to reduce proteolysis and lipolysis in silo. Two lines of red clover (cv. Milvus), a genotypic mutant with reduced PPO activity (L) and the wild type (H) with a high level of PPO activity, were cut 3 cm above soil level, crushed and cut into 1 cm strips before being loaded into incubation bottles. These were then incubated in anaerobic buffer at 39 °C in either the absence (?) or the presence (+) of rumen microorganisms. The incubations were then compared over a 24 h time course in terms of lipolytic activity. Characterization of the tissues showed PPO activities of 25.3 and 5.13 U g^?1 fresh weight for H and L, respectively. Lipolysis, measured as the proportional decline in the membrane lipid, was reduced (P < 0.001) with increasing PPO activity in both the presence (+) and absence (?) of rumen microorganisms. However, values were significantly higher (P < 0.001) in the presence of rumen microorganisms, with values after the 24 h incubation of 0.28, 0.42, 0.72 and 0.82 for H?, L?, H+ and L+, respectively. Biohydrogenation of C18:2 and C18:3 polyunsaturated fatty acids were significantly lower in the H+ treatment than the L+ treatment, with mean values after 24 h incubation of 53% and 57% (P < 0.05) for C18:2 and 65% and 74% (P < 0.01) for C18:3, respectively. Changes that occurred in the lipid fractions (membrane lipid, diacylglycerol, triacylglycerol and free fatty acids) during the incubations are also reported and discussed. These results support the selection of forages high in PPO activity to reduce polyunsaturated fatty acid loses in the rumen. Copyright © 2007 Society of Chemical Industry     

Purification and biochemical characterisation of a novel glutamate decarboxylase from rice bran

BACKGROUND: Glutamate decarboxylase (GAD) is a useful enzyme whose main function is to catalyse the irreversible α‐decarboxylation of L ‐glutamate to produce γ‐aminobutyric acid. The cheap and abundant rice‐processing by‐product rice bran contains a high amount of GAD, the purification and characterisation of which have not yet been reported. In this study, research on rice bran GAD was initiated. RESULTS: Rice bran GAD was purified to homogeneity via a combined purification protocol of ammonium sulfate fractionation, ion exchange chromatography and two gel filtrations, with a purification fold of 128.6 and an activity recovery of 21.3%. The enzyme was active at pH 5.5 and 40 °C and retained 80% of its original activity in the pH range 5–9 and the temperature range 30–50 °C. GAD activity was significantly enhanced in the presence of Ca²⁺ but strongly inhibited by Ag⁺, Hg²⁺, sodium dodecyl sulfate and CH₃COOH. Kinetic determination of the apparent K_m for L ‐glutamate and pyridoxal 5′‐phosphate gave values of 27.4 mmol L^?1 and 1.16 µmol L^?1 respectively. CONCLUSION: Considering that rice bran is cheap and commercially available and that rice bran GAD is relatively stable, the development of cost‐effective rice bran GAD‐related functional foods would seem to be feasible. Copyright © 2010 Society of Chemical Industry     

Val bean (Lablab purpureus L.) proteins: composition and biochemical properties

Val bean (Lablab purpureus L.) proteins were fractionated using the Osborne protein fractionation scheme and biochemically characterized. The seed flour contained 302 g kg^?1 protein (micro‐Kjeldahl N × 6.25) on a dry weight basis. Albumin, globulin, prolamin, and glutelin accounted for 22.8%, 45.1%, 1.8% and 30.3%, respectively, of the total soluble seed proteins. Among the solvents tested, 0.1 mol L^?1 aqueous NaOH was the most effective protein solubilizer. Isoelectric focusing indicated the seed proteins to be predominantly acidic (pI range was ～4–7). Val globulin is a glycoprotein composed of at least three polypeptides in the molecular mass range 51–64 kDa. Albumin fraction had the highest trypsin inhibitory activity, while the globulin fraction registered the highest hemagglutinating activity. Sulfur amino acids were the first limiting amino acids in the total seed proteins. The proportion of essential to total [E/T(%)] amino acids for the bean flour was 36.97%. Among the protein fractions, glutelin fraction had the highest E/T (42.86%) followed by albumin (41.57%), globulin (39.87%), and prolamin (39.15%). Native globulin, although resistant to pepsin, was effectively digested in vitro upon moist heat (100 °C, 30 min) denaturation. Copyright © 2007 Society of Chemical Industry