Activities of amine and phenolic antioxidants and their changes in broad beans (Vicia faba) after freezing and steam cooking

Antioxidant properties and changes in the levels of active compounds in fresh and processed broad beans were determined in the study. Activity of extracted substances was much higher against ABTS (2,2'-azino-bis [3-ethylbenzothiazoline-6-sulphonic acid]) than towards DPPH (2,2'-diphenyl-1-picrylhydrazyl) radicals. Phenolics extracted with 70% acetone were also more active comparing to amine compounds obtained with water both in experiments applying radicals and during oxidation of linoleic acid. Steam cooking and freezing had a negative influence on the content of polyphenols and in consequence on their activity. Cooking fresh broad beans decreased the content of those compounds by 16% and freezing – by over 30%, while cooking frozen material resulted in a much lower further decrease (2–8%). Processes applied on fresh material reduced the activity against ABTS^•+ to a smaller extent (cooking by 11% and freezing by around 20%), while cooking frozen beans caused a further decrease by 10–17%.     

Cellulase inhibition by tannins in the testa of field beans (Vicia faba)

The testa of field bean varieties with coloured flowers contained 4–8 % tannin (measured as total phenolics) compared with less than 0.6 % in the testa of white flowered varieties. The tannin present in whole beans was almost entirely contained in the testa. The presence of high levels of tannin reduced in vitro digestibility and solubility in cellulase solutions of the testa and addition of high tannin testa decreased the solubility of cotyledon protein in acid pepsin. Water extracts of the testa from coloured-flower varieties inhibited the action of fungal cellulase and reduced the in vitro digestibility of white flowered testa and cellulose. A highly significant relationship (r= ?0.93***) was found between the tannin content and solubility in cellulase of testa for a range of 24 varieties. It is concluded that the effect of testa tannins on in vitro digestibility can be mainly attributed to their effect on cell wall digesting enzymes rather than an effect on protein solubility per se.     

Physico-chemical and enzymatic studies on acetylated protein isolates from faba beans (Vicia faba L.)

Selected physico-chemical properties of a faba bean protein isolate before and after being acetylated have been investigated using analytical ultracentrifugation, SE- and RP-HPLC, viscometry and hydrophobicity measurements using fluorescence probe techniques. The time course of relative chymotryptic hydrolysis rates was followed by means of the TNBS method and RP-HPLC analysis. The extensive decrease of the 11 S and 7 S protein components of the isolate in favour of a low molecular weight 2 S component after exhaustive acetylation is the proof of the dissociated state of the highly modified derivatives. Both the viscometric measurement and the study of proteolysis breakdown give arguments for a rather unfolded state both of the unmodified and the modified protein isolates. The course of relative chymotryptic hydrolysis rate points to a successive transition from a globular state into a more unfolded one depending on the degree of acetylation. Both the viscometric data and the hydrophobicity measurements revealed a conformational transition at about 60% N-acetylation. This level of modification corresponds to that where a sharp increase of OH-acetylation takes place.     

The effect of germination on seed trypsin inhibitors in Vicia faba and Cicer arietinum

During germination, trypsin inhibitor (TI) content increased relative to total protein and dry weight in cotyledons from two varieties of Vicia faba. These data, together with changes in total protein profiles and amounts, suggest that TI proteins are not hydrolysed in parallel with other seed proteins and dry matter. In contrast, TI content in germinating Cicer arietinum seeds remained constant during the germination period; in this case, however, substantial changes in the total protein profile were not observed. TI isoform analyses indicated that compositional changes occurred during germination in both species. Copyright © 2004 Society of Chemical Industry     

Carbohydrates of spring and winter field beans (Vicia faba L.)

The proportions of available and unavailable carbohydrate were determined in samples of eight varieties of field beans (Vicia faba L.). Available carbohydrate consisted of dextrins, water-soluble and insoluble starches and ethanol-soluble sugars; the unavailable carbohydrate fraction contained lignin, cellulose, hemi-cellulose and water-soluble polysaccharides. The component sugars of extracts and hydrolysates of all fractions except lignin were measured by anion-exchange, thin-layer and paper chromatography. Winter-sown beans contained 46 to 48% available and 19 to 20% unavailable carbohydrate, while spring-sown beans contained 30 to 42% available and 22 to 37% unavailable carbohydrate on a dry matter basis. Two of the spring-sown varieties were atypical in certain respects: Strubes had a high percentage of available carbohydrate (42.4%), similar to the level found in winter-sown beans, while Ackerperle had a high percentage of total carbohydrate (67.4%) but the lowest percentage of available carbohydrate (30.1%). The protein content of Strubes (30.2%) was typical of spring-sown varieties, but that of Ackerperle (27.7%) corresponded to the lower level of winter varieties.     

The relationship between maturity and quality of canned broad beans (Vicia faba L.)

Summary. This paper describes a co-operative investigation carried out by the Fruit and Vegetable Preservation Research Association and eight of its member firms to determine optimum maturity of broad beans for canning.
The results indicate that (a) there was no difference in flavour in canned broad beans harvested at tenderometer readings from 90 to 200, (b) there was a significant linear deterioration in texture as beans matured, (c) alcohol insoluble solids of raw and canned beans increased linearly as beans matured, (d) a linear relationship was found between tenderometer readings and sample size, (e) consumers equally preferred canned broad beans harvested at tenderometer readings of 120 and 160 and (f) optimum maturity of broad beans for canning from the data obtained was at a tenderometer reading of 136 using a 5 oz sample of raw beans.     

Phytate and total phosphorus content of field beans (Vicia faba L.)

Considerable variation was found in the phytate and total phosphorus contents of varieties, selections and genotypes of field beans (Vicia faba L.) The phytate phosphorus content of seeds taken from single plants of the variety Dacre indicated that large variations (1.93-4.03 g kg^?1), not significantly correlated with protein content, existed within an established variety. Although some variation in the ratio of phytate to total phosphorus was observed (0.40-0.60), highly significant correlation coefficients were obtained for total and phytate phosphorus contents. The significance of the results obtained is discussed in relation to the potential for improving the nutritive value of field beans by breeding for lower phytate content.     

In vitro starch digestibility of fresh and sun‐dried faba beans (Vicia faba L.)

Fresh and sun‐dried faba beans (Vicia faba L.) were cooked, stored for various times at 4 °C and analysed for available starch (AS), resistant starch (RS) and fibre‐associated resistant starch (FARS) contents as well as α‐amylolysis. Fresh beans required a shorter cooking time (25 min) than dried beans (158 min). Cooked fresh faba beans had a higher AS content than cooked dried faba beans. The AS content in both decreased during cold storage, with fresh beans showing a smaller decrease than dried beans with increasing storage time. Cooked fresh faba beans also had a higher total RS content than cooked dried faba beans, although a greater increase in RS content was recorded in the latter upon storage. Starch retrogradation was more prominent in cooked dried faba beans than in cooked fresh faba beans, as indicated by the consistently higher FARS content. The α‐amylolysis rate decreased with increasing storage time, i.e. long‐stored (72 h) cooked faba beans exhibited slower starch digestion, and differences were recorded between fresh and dried beans. The predicted glycaemic index ranged between 60.9 and 58.0% for cooked fresh faba beans and between 57.9 and 55.8% for cooked dried faba beans, which is suggestive of slow glucose release from starch in faba beans. Copyright © 2007 Society of Chemical Industry     

Varietal variation in the anti-nutritive effects of field beans (Vicia faba) when fed to rats.

Testa and cotyledons were separated from white and coloured flowered varieties of field beans (Vicia faba) and incorporated into complete diets for rats. Diets containing 10% testa from the coloured variety caused a 15% reduction in live weight gain compared with the diets containing testa from the white flowered variety. This was accompanied by a reduction in the true digestibility of nitrogen and the apparent digestibility of carbohydrates and lipids. The protein efficiency ratio and the net protein utilisation were also reduced but the biological value of protein was not significantly affected. The efficiency of utilisation of ingested feed dry matter was significantly reduced for the diets containing coloured flower testa but when live weight gain was expressed as a fraction of ingested digestible dry matter there were no significant differences. Live weight gain and digestibility of organic matter components were highly negatively correlated with the total phenolic content of the diet. It was concluded that the reduction in live weight gain of animals fed diets containing testa of a coloured variety compared with that of a white flowered variety was caused mainly by the reduction in digestibility of organic matter brought about by the complexing of dietary and digestive enzyme proteins by the high content of phenolic compounds present in the testa of the coloured variety. A 10% reduction in live weight gain was recorded for animals consuming diets containing cotyledons of coloured varieties compared with those consuming white flowered cotyledons. This reduction was not accompanied by any change in the digestibility of organic matter components and the true digestibility of nitrogen and protein efficiency ratio were not significantly different. There was, however, a significant reduction in the biological value which was a result of increased urinary nitrogen output. It was concluded that the cotyledons of the coloured flowered variety contained an anti-nutritive factor which was not a tannin-like compound and which had an effect on the protein metabolism of the animal.     

Effects of micronising on the utilisation of field beans (Vicia faba L.) by the young chick

The major changes in the composition of field beans (Vicia faba L.) caused by micronising were as follows: the moisture content was reduced from 16.5 to 13.2%, the trypsin inhibitor activity reduced from 2.49 to 0.21 trypsin inhibitor units/mg dry matter and the available carbohydrate content raised from 40.6 to 50.2%. Growth and food consumption of broiler chicks from 1 to 2 weeks of age were not affected significantly when micronised beans replaced raw beans in their diets at a level of 300 g/kg. However, food conversion efficiency, apparent dry matter digestibility and nitrogen retention were significantly improved and pancreas size significantly reduced when the birds were fed the diet containing the micronised beans. The nitrogen-corrected metabolisable energy (m.e.) of the diet containing 500 g of micronised beans/kg (10.88 MJ/kg) was significantly higher than that of a diet containing 500 g of raw beans/kg (10.33 MJ/kg). It was calculated that the m.e. of the beans had been raised from 10.59 to 11.67 MJ/kg dry matter by micronisation. The improvement in nutritive value is attributed partly to the destruction of the trypsin inhibitor and partly to the increased availability of the carbohydrate fraction of the beans.     

The effect of soaking,germination and cooking on the protein quality of mash beans (Phaseolus mungo)

The protein quality of mash beans (Phaseolus mungo) as affected by soaking, germination and cooking was determined at the 10% dietary protein level using weanling rats. Gains in body weight were 11.5 g for raw beans, 68.5 g for soaked-cooked and 33.0 g for germinated-cooked beans. The protein efficiency ratio values were 0.4, 1.9 and 1.1 for raw beans, soaked-cooked and germinated-cooked beans respectively. Net protein utilisation was improved from 44% for raw beans to 58% after soaking and cooking, but reduced to 47% after germinating and cooking. These changes were entirely accounted for by changes in digestibility, 72, 90 and 81% respectively, and biological values were unchanged at 61, 64 and 59 respectively.     

Variation in the oil content and fatty acid composition of field beans (Vicia faba) and peas (Pisum spp.)

Oil content has been found to range from 1.2–1.9% in a wide range of diverse field bean (Vicia faba) cultivars, populations and selections and from 1.4–2.8% in a narrower range of pea cultivars. The ranges in fatty acid composition for beans and peas respectively were palmitic, 13.9–21.0% and 12.0–16.6%, stearic 2.2–3.5% and 2.5–4.2%, oleic 15.0–33.0% and 14.2–33.3%, linoleic 41.3–59.7% and 43.7–60.9%, linolenic 2.6–4.9% and 6.4–13.4%. Environment exerted a significant effect on the oil content of field beans but cultivar differences remained apparent. The analysis of whole or milled field beans stored for up to 5 years showed only minor losses of oil and component fatty acids. In both species over 90% of the total oil content was found in the cotyledons. Cultivar differences in whole grain oil content were associated with the concentration of oil in the cotyledons and appeared independent of the relative proportions of either embryo or seed coat. The interrelationships between oil content and other seed characteristics were also determined and the significance of these results in relation to plant breeding are discussed.     

Effects of S, N and P on amino acid composition of field beans (Vicia faba) and responses of the biological value of the seed protein to S-amino acid content

In pot experiments dry matter yield of seed of Vicia faba was increased by increasing application of S at all N- and P-levels and, by P at all S- and N-levels. Significant interactions were found for PxN (0.1%) and SxP (1%). N-concentrations generally increased with S-additions, but decreased with large applications of N and P. Significant interactions were found for PxN fl-1%) and SxP (5%) with regard to N concentration. Maximum increases in cystine and methionine contents from S-application were respectively 39.1 and 13.7% expressed as % of dry matter and 37.9 and 12.3% expressed as g/16 g N. Highly significant correlation coefficients were obtained between concentrations (g/16 gN) ofa number of protein am/no acids in seeds and total-N content. In a feeding trial with rats, the biological value of non-S treated seed was 40.8 and increased to about 60 in seed from S-treatments Addition of synthetic cystine and methionine to seed from the non-S treatment could not entirely substitute these acids present in the protein of seed from S-treatments with regard to effects on the biological value of seed protein.     

The effect of cooking with kanwa alkaline salt on the chemical composition of black beans (Phaseolus vulgaris)

The effect of cooking with kanwa alkaline solution on the chemical composition of black beans (Phaseolus vulgaris) was analyzed. Crude lipids and water-soluble fractions were extracted from three flour samples obtained from raw black beans and black beans cooked in kanwa solution or distilled water. Heat processing resulted in significant reduction in crude lipids, proteins and neutral sugars. Neither heat treatment induced changes in the levels of palmitic, stearic, oleic or linoleic acids, present in the crude lipid fraction. There was a significant change in both the total amino acids and the total essential amino acids. Heat treatment in alkaline solution decreased the levels of isoleucine, lysine, tyrosine, phenylalanine, threonine and valine. There was also a decrease in the galactose content after this heat processing.     

Effects of dehulling,soaking and germination on chemical composition,mineral elements and protein patterns of faba beans (Vicia faba L.)

The effects of dehulling, soaking and germination on the changes in general chemical composition, nine mineral elements and the protein patterns of whole faba beans were studied. Such pretreatments had a significant effect on the changes in the chemical composition of whole beans. Dehulling of beans significantly increased the contents of copper, zinc and potassium, while it significantly decreased the amounts of iron, manganese, phosphorus, calcium, magnesium and sodium compared with whole beans. Whole beans soaked for 12 h, followed by dehulling, had higher amounts of iron, copper, zinc, calcium and sodium, and quite a lower level of potassium, than unsoaked dehulled beans. All of the mineral elements except zinc were significantly increased on germination. No obvious changes in the electrophoretic pattern of faba bean proteins were observed as the seeds were soaked for up to 12 h. Extending soaking time for a further 4 h led to the disappearance of one band at the region of MW 67 KD. Germination of seeds for 3 days initiated disappearance of some bands while other new bands were observed.     

Functional properties of the system gelatine/Vicia faba protein in dependence on the acetylation degree of the Vicia faba protein

By acetylation of Vicia faba protein it becomes in aqueous solution compatible with gelatine up to a substitution degree of about 50%. The swellability and brittleness of foils and the viscosity of aqueous solution of Vicia faba protein are increased by its acetylation and these changes can be observed in mixtures of gelatine with acetylated Vicia faba protein, too. A heat denaturation of aqueous solutions of acetylated Vicia faba protein or mixtures with gelatine leads to an increase of the viscosity; all these solutions show pseudo-plastic flow behaviour.     

Relationships between adsorption and emulsifying of acetylated protein isolates from fabe beans (Vicia faba L.)

The influence of acetylation on surface adsorption and emulsifying properties of faba beans protein isolates (FBPI) was studied. Generally, acetylation improved the interfacial activity of FBPI. The plateau value of the Gibbs' adsorption isotherms measured with the Wilhelmy-plate was between 22.97 and 24.22 mN/m. The critical association concentration (CAC), i.e. the inflection point of the adsorption isotherms, was shifted from 2.06. 10^?5 to 5.35. 10^?7 g/ml with progressive acetylation. The dependence of the CAC on the degree of acetylation was found to be significant. For FBPI stabilized n-decane/water emulsions with varying volume fraction of oil (?) the emulsifying activity index increased from 166 to 593 m²/g whereas the droplet size decreased from 7.79 to 3.4 μm with acetylation. The correlation between emulsifying activity of FBPI and both degree of acetylation and adsorption behaviour was only significant for emulsions with ? 0.4.     

Distribution and degradation of tetrachlorvinphos on stored faba beans and soya beans

The distribution and degradation of [CH₃-¹⁴C]tetrachlorvinphos in stored fabe beans and soya beans were studied for 30 weeks at moisture contents and temperatures similar to those prevailing under normal storage conditions. Tetrachlorvinphos penetrated the seed coat and the insecticide residues inside the beans increased with storage time. A considerable portion of radioactivity, amounting to about 20–30% of the applied dose in faba beans and 30–40% in soya beans, was present in a non-extractable form. Residues on the seed coat consisted mainly of unchanged insecticide. The internal extract contained both unchanged insecticide and desmethyltetrachlorvinphos which was present in a free and a conjugated form. Dimethyl phosphate and monomethyl phosphate were identified as hydrophilic ¹⁴C-degradation products. The degradation of tetrachlorvinphos proceeded mainly via cleavage of methoxy groups. The nature and percentage of metabolites varied slightly with storage period. A scheme for possible degradation routes of tetrachlorvinphos on stored beans is suggested.