Identification of gas‐producing components in different varieties of Phaseolus vulgaris by in vitro fermentation

Phaseolus vulgaris consumption has been limited as part of the occidental diet owing to flatulence production. Raffinose, stachyose and verbascose have been shown to be the main components responsible for flatulence; however, it is thought that soluble fibre could also be involved in this phenomenon. The aim of the present study was to identify the main components of beans influencing flatus. Ten varieties of P vulgaris originating from South America were first analysed for their main nutrient and carbohydrate fractions. Three of the varieties were then fractionated to extract soluble and insoluble fibres. Various combinations of α‐galactosides and soluble and insoluble fibre fractions, in similar proportions to those contained in cooked grains, were used as substrates for in vitro fermentation studies using human faecal inoculum to determine the fermentative capacity of each of the three fractions. Considering the white varieties, total gas production and acidification of the medium were correlated with fermented organic matter from soluble fibre (R² = 1)) and with α‐galactosides (R² = 0.75). On the other hand, tannins present in pigmented varieties did not seem to interfere significantly in fermentation of soluble fibre. The total production of gas per gram of mixed fractions of soluble fibre and α‐galactosides in proportions found in cooked grains was lower than that expected from each substrate separately. It can be concluded that soluble fibre and α‐galactosides are good substrates for endogenous colonic flora subjected to in vitro fermentation studies and are thus responsible for flatulence induced by legume consumption. © 2001 Society of Chemical Industry     

Influence of natural and controlled fermentations on α-galactosides, antinutrients and protein digestibility of beans (Phaseolus vulgaris L.)

The influence of natural fermentation (NF) and controlled fermentation (CF) in diminishing the content of antinutrients, α‐galactosides and increments in in vitro protein digestibility was investigated. The dry bean (Phaseolus vulgaris) flour was the substrate used in this research study. A decrease in raffinose oligosaccharide, antinutritional components and pH was observed in both types of fermentation. The natural lactic fermentation of ground beans produced significant increase (P < 0.05) in protein digestibility. For all varieties of beans, raffinose concentration reduced significantly to an undetectable level after 96 h of NF. CF did not have any significant effect on the reduction of the α‐galactosides content of the flours during fermentation. NF is an inexpensive method by which consumers can obtain good‐quality protein. Both types of fermentation diminish antinutrients and improve the nutritional value of the bean flour, and indicate the potential to use bean flour as an ingredient for fabricated foods.     

Reduction in flatulence factors in mung beans (Vigna radiata) using low‐dose γ‐irradiation

Mungbeans (Vigna radiata), control and γ‐irradiated at insect disinfestation dose levels (0.25 and 0.75 kGy) were germinated (0–6 days) and the qualitative and quantitative changes in soluble carbohydrates were studied in detail. The key flatulence‐producing raffinose family oligosaccharides in mungbeans were degraded in the irradiated samples at the onset of the germination (0–2 days) compared to the control where it occurred much later (>4 days). However, the reducing sugars, mainly glucose, fructose and galactose, which are metabolised easily, were enhanced in the irradiated samples. At low dose (0.25 kGy), irradiation had no effect on germination and sprout length, indicating that irradiated beans are suitable for use as sprouted beans. These observations clearly indicate that γ‐irradiation at insect disinfestation dose levels improved the digestibility and nutritional quality of mung beans by reducing the content of oligosaccharides responsible for intestinal gas production. © 1999 Society of Chemical Industry     

In vitro inhibitory effects of cranberry bean (Phaseolus vulgaris L.) extracts on aldose reductase, α‐glucosidase and α‐amylase

The in vitro inhibitory activities of different seed extracts prepared from cranberry bean mutant SA‐05 and its wild‐type variety Hwachia against aldose reductase, α‐glucosidase and α‐amylase were examined. The results indicated that the polyphenolics‐rich extracts obtained using 800 g kg^?1 methanol and 500 g kg^?1 ethanol demonstrated inhibitory activities against aldose reductase (IC₅₀ of 0.36–0.46 mg mL^?1) and α‐glucosidase (IC₅₀ of 1.32–1.94 mg mL^?1). The 500 g kg^?1 ethanol extracts also showed α‐amylase inhibitory activities (IC₅₀ of 70.11–80.22 μg mL^?1). Subsequent extracts, prepared further with NaCl and H₂O from precipitates of 800 g kg^?1 methanol or 500 g kg^?1 ethanol extracts, exhibited potent α‐amylase inhibitory activities (IC₅₀ of 17.68–38.68 μg mL^?1). A combination of 500 g kg^?1 ethanol extraction plus a subsequent H₂O extraction produced highest polyphenolics and α‐amylase inhibitors. The SA‐05 α‐amylase inhibitor extracts showed greater inhibitory activities than that of Hwachia. Thus, cranberry bean mutant SA‐05 is an advantageous choice for producing anti‐hyperglycaemic compounds.     

Lactic acid fermentation of black beans (Phaseolus vulgaris): microbiological and chemical characterization

Legumes, and particularly Phaseolus vulgaris, are an important source of nutrients, especially in developing countries. In spite of being part of the staple diets of these populations, their consumption is limited by the flatulence they produce. Natural lactic acid fermentation has proved to be an effective method to decrease flatulence‐producing compounds. However, in order to use this method as a process on a large scale, it is fundamental to identify the microbial flora involved. When fermented seeds of Phaseolus vulgaris (black bean) were analysed microbiologically, it was found that the microorganisms present were Lactobacillus casei and Lactobacillus plantarum. On performing back‐slopping or induced fermentation with different inocula, a 63.35% decrease was found for the soluble fibre and 88.6% for raffinose, one of the main flatulence‐producing compounds. When cooking under atmospheric pressure was applied to the fermented samples, a significant diminution of the trypsin inhibitors and tannins was found as well as an increase in the in vitro and in vivo digestibility of the beans. All these results demonstrate that the lactic acid bacteria used for the induced fermentation can lead to a functional food with improved nutritional quality. Copyright © 2006 Society of Chemical Industry     

Changes in chemical composition of lupin seeds (Lupinus angustifolius) after selective α‐galactoside extraction

A selective procedure for the extraction of α‐galactosides has been employed in two sweet lupin seeds (Lupinus angustifolius var. Troll and var. Emir) in order to reduce flatulence‐causing factors. Different nutritional parameters (proteins, fat, ash, dietary fibre, starch, sucrose, vitamins B₁, B₂, E and C) and antinutritional factors (α‐galactosides, trypsin inhibitor activity and inositol phosphates) were studied in raw and processed seeds. The α‐galactoside content in both varieties was reduced by 87–100%. The extracted lupins seeds presented a high retention in protein and fat (109–136% and 95–104%, respectively). Sucrose and soluble dietary fibre, however, decreased significantly as a result of processing and retentions ranged between 5 and 29%. The vitamin B₁, B₂, and E contents decreased during selective extraction, the retentions being in the ranges 25–47%, 38–40%, and 48–54%, respectively, for var. Troll and Emir. However extracted lupin seeds still contained important amounts of vitamins and insoluble dietary fibre, compounds with nutritional importance. Raw and processed lupins did not contain starch. TIA and vitamin C were not detected, and total inositol phosphates were modified slightly after extraction. In conclusion, the lupin seeds obtained by the extraction of α‐galactosides can be an adequate proteic ingredient to be incorporated in functional foods. Copyright © 2005 Society of Chemical Industry     

Relating consumer preferences to sensory and physicochemical properties of dry beans (Phaseolus vulgaris)

BACKGROUND: Dry beans (Phaseolus vulgaris) have a range of varieties, colours and sizes. Differences in physicochemical and sensory properties influence consumer choices for beans. This study related consumer preferences to sensory and physico‐chemical properties of selected bean varieties—Jenny, Kranskop, PAN 148, AC Calmont, PAN 150 and Mkuzi—grown in Mpumalanga (MP) and Free State (FS) in South Africa. RESULTS: Significant (P < 0.05) variety, location as well as location × variety interaction effects were found for both physico‐chemical and sensory properties of beans. Jenny‐FS, Mkuzi and PAN 148‐MP beans had relatively long cooking times (>60 min). Some beans (e.g. PAN 150 and Mkuzi beans) were described as bitter, soapy and metallic with a raw‐bean flavour whereas more preferred beans (e.g. Jenny‐MP, Kranskop‐MP) were sweet, soft and with a cooked‐bean flavour. CONCLUSION Apart from small seed size, sensory characteristics such as bitter taste, soapy and metallic mouthfeel and hard texture contributed to consumers' dislike of certain bean varieties. The sweet taste, cooked‐bean flavours, soft and mushy textures of the most accepted varieties seemed to be related to beans with good hydration capacities that facilitated softening during cooking. Copyright © 2007 Society of Chemical Industry     

Effect of pre‐germination time of brown rice on serum cholesterol levels of hypercholesterolaemic rats

BACKGROUND: Brown rice is unpolished rice with immeasurable benefits for human health. Brown rice (BR) and pre‐germinated brown rice (PGBR) are known to contain various functional compounds such as γ‐oryzanol, dietary fibre and γ‐aminobutyric acid (GABA). In the present study, the experimental diets containing BR and PGBR (24, 48 h pre‐germination) were used to investigate the influence of pre‐germination time of brown rice on blood cholesterol in Sprague–Dawley male rats. RESULTS: Hypercholesterolaemia and elevation of LDL‐cholesterol were successfully ameliorated by the experimental diets containing BR and PGBR (24 and 48 h pre‐germination). As compared to the control sample, the pre‐germination time had a significant (P < 0.05) effect on blood cholesterol of Sprague–Dawley male rats. It was also found that the significantly (P < 0.05) better effect on lipid profile of hypercholesterolaemic rats was observed by prolonging the pre‐germination time. As compared to non‐germinated brown rice, the germinated brown rice showed the higher cardio‐protective effect on hypercholesterolaemic Sprague–Dawley male rats. CONCLUSION: The present study suggests that the changes of blood cholesterol can be mainly modulated by using the PGBR rather than BR. The prolonging of pre‐germination time led to an increase in the bioactive components, thereby providing a more efficient functional diet affecting the high blood cholesterol. This study suggests that PGBR can be used instead of BR and polished rice in the human diet. Copyright © 2009 Society of Chemical Industry     

Thermal inactivation kinetics of peroxidase and lipoxygenase from fresh pinto beans (Phaseolus vulgaris)

 Thermal inactivation kinetics of crude peroxidase (POX) and lipoxygenase (LOX) in fresh pinto beans were studied over the temperature range of 55–90°C. The inactivation of both enzymes followed first-order kinetics. The biphasic inactivation curves for POX indicate the existence of several isoenzymes of varying heat stability. In the temperature range of 55–70°C, the activation energies (E _a) of POX were 46.5 kcal·mol^–1 for the heat-labile portion and 37.6 kcal·mol^–1 for the heat-stable portion. On the other hand, the LOX enzyme had an E _a value of 42.26 kcal·mol^–1 at 55–75°C and 49.1 kcal·mol^–1 at 55–90°C. Received: 28 July 1997 / Revised version: 16 October 1997     

Thermal inactivation kinetics of peroxidase and lipoxygenase from fresh pinto beans (Phaseolus vulgaris)

 Thermal inactivation kinetics of crude peroxidase (POX) and lipoxygenase (LOX) in fresh pinto beans were studied over the temperature range of 55–90°C. The inactivation of both enzymes followed first-order kinetics. The biphasic inactivation curves for POX indicate the existence of several isoenzymes of varying heat stability. In the temperature range of 55–70°C, the activation energies (E _a) of POX were 46.5 kcal·mol^–1 for the heat-labile portion and 37.6 kcal·mol^–1 for the heat-stable portion. On the other hand, the LOX enzyme had an E _a value of 42.26 kcal·mol^–1 at 55–75°C and 49.1 kcal·mol^–1 at 55–90°C. Received: 28 July 1997 / Revised version: 16 October 1997     

Evaluation and standardisation of small‐scale canning methods for small white beans (Phaseolus vulgaris L.) canned in tomato sauce

Canning and evaluation procedures should be standardised to ensure that beans selected, based on canning quality, meet the requirements set by the market and processors. For the purpose of evaluating the canning qualities of small white beans in tomato sauce, three small‐scale canning techniques were evaluated, one of which was found to deliver a product with quality parameters similar to those of international standards. Using South African small white bean cultivars and the selected method, Teebus, the cultivar used by industry as the standard to indicate acceptable canning quality, displayed better visual appearance and less split beans than with the other two methods. The percentage washed drained weight and texture values of Teebus were also in agreement with international standards. The evaluation procedure for the small white beans after canning was also optimised, by comparing two procedures, which identified texture, visual appearance (scale 1 to 10), splits (scale 1 to 10), hydration coefficient, clumping, size and colour as the statistically most suitable quality parameters. With the aid of the developed method, it was possible to define standard values for South African ‘choice’ and ‘standard’ grade beans, which previously was based only on ‘visual inspection’ by a trained inspection panel. Copyright © 2006 Society of Chemical Industry     

Quality changes during storage of sous vide cooked green beans (Phaseolus vulgaris)

 The acceptability and quality of sous vide cooked green beans (Phaseolus vulgaris) were investigated during chilled storage. A suitable heating procedure was established whereby 2.0-kg packages were heat processed at 90°C for 25 min, corresponding to an average pasteurization value, PV_70,10, of 14 min. During storage for up to 25 days at 3°C drip loss, pH, colour (Minolta L ^* a ^* b ^*), texture (Instron) and microbiological stability were examined and sensory characteristics evaluated by a trained sensory panel. No marked changes in texture, drip loss, pH or microbiological counts were observed but a change of colour from green to olive green was observed by both objective and sensory analyses. This detrimental change in colour, which had begun during the first week, was the limiting factor for shelf-life during storage. Subsequent reheating, however, resulted in further colour changes which partially obscured the initial differences observed during the storage period. Storage for more than 1 week resulted in undesirable quality changes in the odour and flavour of the green beans. Therefore, a maximum shelf-life of 8 days at 3°C was recommended. Inoculation trials showed that psychrotrophic Bacillus cereus were able to germinate and grow to levels of 10⁷ g^–1 in the packages at abuse temperatures (7°C and 17°C), whereafter numbers declined. Received: 21 April 1997     

Light‐induced glycoalkaloid accumulation of potato tubers (Solanum tuberosum L)

The total glycoalkaloid concentration of non‐sprouted potato tubers, cvs Marfona, Fianna, Maris Piper, Kestrel and Golden Wonder, was measured following 15 days of continuous illumination (250 µmol m⁻² s⁻¹ photosynthetically active radiation) using high‐performance liquid chromatography. Comparisons were made of the influence of four sources of illumination: fluorescent tube‐type warm white, high‐pressure sodium, high‐pressure mercury types MB/U and MBFR/U. Irrespective of cultivar, glycoalkaloid concentrations of tubers placed in the dark remained relatively constant from day 0 to day 15 and did not exceed food safety values of 200 mg kg⁻¹ FW. A highly significant cultivar, light and cultivar × light (P < 0.01) interaction was recorded. Cultivar Kestrel was shown to be light‐sensitive with high rates of glycoalkaloid accumulation irrespective of light source, and cv Maris Piper was demonstrated to be light‐insensitive. In the majority of cultivars tested, maximal rates of glycoalkaloid accumulation were recorded following exposure of tubers to sodium or fluorescent light, and minimal rates of accumulation were recorded following exposure of tubers to mercury (MB/U and MBFR/U) illumination. In virtually all cases glycoalkaloid concentrations steadily increased with time during light exposure with no indication of cessation. In some instances the α‐chaconine/α‐solanine ratio decreased over 15 days of illumination (P < 0.05), indicating enhanced α‐solanine synthesis over that of α‐chaconine. The implications of these results in terms of consumer safety are discussed. © 1999 Society of Chemical Industry     

No tillage affects the phosphorus status,isotopic composition and crop yield of Phaseolus vulgaris in a rain‐fed farming system

BACKGROUND: Conservation tillage promotes the accretion of soil organic matter and often leads to improved soil fertility and moisture availability. However, few studies have looked at the physiological response of crop plants to different tillage practices. It was therefore hypothesised that measuring the nutrient concentrations and stable isotope composition (δ¹³C, δ¹⁸O, δ¹⁵N) of shoots could help evaluate the physiological response of common bean (Phaseolus vulgaris L.) to different tillage treatments (no tillage (NT) and mouldboard ploughing (MP)) in a rain‐fed farming system in northern Mexico. RESULTS: NT significantly enhanced shoot phosphorus concentration in bean plants. Tillage exerted a negative effect on the extent of root colonisation (%) by arbuscular mycorrhizal fungi (AMF). Lower shoot δ¹⁸O but unchanged δ¹³C values in plants from the NT system suggest enhanced stomatal conductance but also enhanced photosynthetic rate, which overall resulted in unchanged water use efficiency. Bean plants in the NT system showed lower shoot δ¹⁵N values, which suggests that a larger proportion of total plant nitrogen was obtained through atmospheric nitrogen fixation in this treatment. CONCLUSION: Greater diversity of AMF soil communities and heavier colonisation of roots by AMF in the NT compared with the MP system appeared to contribute to improved crop nutrition, water relations and yield in this rain‐fed agroecosystem. Copyright © 2010 Society of Chemical Industry     

Effect of In Vitro Digestion on Free α‐Dicarbonyl Compounds in Balsamic Vinegars

We investigated the influence of an in vitro simulated digestion process on the content of the free α‐dicarbonyl compounds most frequently found in food. A Glyoxal (GO), methylglyoxal (MGO), and diacetyl (DA) aqueous standard mixture and 2 brands of balsamic vinegar were analyzed before and after exposure to digestive enzymes. A strong matrix effect required adoption of validated RP‐HPLC‐DAD standard addition methods. The results showed that the digestive enzymes markedly alter the concentrations of the exogenous free α‐dicarbonyl compounds ingested with food; the extent of such changes varied with the α‐dicarbonyl compound itself and the diet components, which determined important but different food matrix effects also during digestion. The data also indicate that digestion can reduce the bioavailability of the toxic α‐dicarbonyl compounds ingested with food. However, no firm conclusions can be drawn about a putative positive influence of digestion on the toxic potential of dietary α‐dicarbonyl compounds, because their reaction in the presence of digestive enzymes likely gives rise to advanced glycation end products, which are involved in the development of chronic diseases.     

Phenolics and antioxidative activities in common beans (Phaseolus vulgaris L)

Six bean cultivars grown in southern Manitoba for 2 years were evaluated for variability in yield of millstreams and phenolic constituents. The ethanolic extract of bean cultivars and millstreams was screened for antioxidant activity using the β‐carotene‐linoleate and the 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) in vitro model systems. Cultivar was the main source of variation for yield of millstreams, content of phenolic compounds and antioxidant activities. Phenolic compounds in cultivars varied from 3.3 to 16.6 mg catechin equivalent and from 0.15 to 0.32 mg cyanidin‐3‐glucoside equivalent g^?1 bean for total phenolic and anthocyanin contents, respectively. The bean cultivars exhibited antioxidant activity (AA) of 10–46% inhibition of lipid peroxidation in the linoleate and 0.4–1.3 trolox equivalent antioxidant capacities (TEAC) in the DPPH model systems. The hull millstream with maximum concentration of phenolic compounds exhibited the strongest antioxidant activity of 383 µM trolox equivalent g^?1 hull. Total phenolic content, alone or in combination with other phenolic constituents, is a potential candidate as a selection criterion for antioxidant activity in beans. Copyright © 2005 Society of Chemical Industry     

New source of α-d-galactosidase: Germinating coffee beans

Enzyme activities of α-Gal from dormant and germinating coffee beans (Coffea arabica) were studied and compared to develop one new source of α-d-galactosidase (α-Gal). During the germination, enzyme activity showed a continuous improvement: it increased slowly within 25 days and then rapidly increased. At the beginning of the germination, enzyme activity was lower than that from dormant coffee beans (DCB). It became higher than the latter around the 30th day, and rose to a maximum at the 35th day. The partially purified enzymes from germinating coffee beans (GCB) and DCB were obtained through ammonium sulphate precipitation, acetone precipitation and DEAE Sepharose ion exchange chromatography. The results showed that enzyme activity of purified α-Gal from GCB was 1.73 times greater than that from DCB. It was most stable for six weeks at its optimal pH (4.8) during the storage. GCB could become a new source of α-Gal instead of DCB.     

Effect of α‐tocopherol and α‐tocotrienol on the performance of Chilean hazelnut oil (Gevuina avellana Mol) at high temperature

The high temperature antioxidant efficiency of α‐tocopherol, α‐tocotrienol and a mixture of both on hazelnut oil were evaluated. Crude hazelnut oil (HZO), crude hazelnut oil treated with alumina (THZO), as well as three samples of THZO to which 150 mg kg^?1 of α‐tocopherol, 140 mg kg^?1 of α‐tocotrienol or a mixture containing 70 mg kg^?1 of α‐tocopherol and 70 mg kg^?1 of α‐tocotrienol, were added and submitted to thermal treatment at 180°C for 18 h. The addition of tocols to THZO decreased the formation of polar compounds and increased its oxidative stability in all the systems studied. However, α‐tocopherol showed a higher antioxidant capacity than α‐tocotrienol at high temperature. In addition, α‐tocotrienol showed a more rapid degradation rate than α‐tocopherol under the conditions studied. Copyright © 2004 Society of Chemical Industry