Effect of various processing techniques on digestibility of starch in Red kidney bean (Phaseolus vulgaris) and two varieties of peas (Pisum sativum)

The effect of common domestic processing methods, such as splitting, soaking, boiling and pressure-cooking on the nutritionally significant starch fractions such as rapidly and slowly digestible starches (RDS and SDS), resistant starch (RS) and total starch (TS) in two legumes, Red kidney bean (Phaseolus vulgaris) and Yellow and Green peas (Pisum sativum) were studied. The legumes had comparatively high amount (>30%, dry basis) of RS. Soaking of all legumes resulted in reduced starch fractions, possibly due to leaching of soluble fractions. Ordinary cooking of soaked as well as unsoaked seeds led to a significant (P < 0.01) decrease in RS and increase in RDS, SDS and TS. Pressure-cooking led to even greater reduction in RS and a greater increase in RDS. Cooking of legumes gelatinizes the starch and opens up the starch structure which makes them vulnerable to α-amylase hydrolysis. Splitting of legumes markedly affects the digestibility as well as RS content of raw as well as processed legumes indicating that the seed coat plays a key role in the digestibility of starches in these seeds. Overall, the enzyme resistant starch fraction of legumes was rendered more digestible by all the domestic cooking methods used.     

Effect of processing on in vitro digestibility of protein and starch in quinoa seeds

The in vitro digestibility of protein in raw quinoa assessed by an enzymic method was 78%, significantly ( P > 0.01 ) lower than that of casein, 91%, and also somewhat lower ( P > 0.01) than that of the raw washed quinoa sample, 83%. the process used to remove the outer layers of the seeds containing saponins increased the protein digestibility significantly ( P > 0.01), by 7%. Heat treatments increased protein digestibility over that of raw quinoa samples. Only the cooked sample treated for 60 min presented a slightly lower protein digestibility, 77%, than those obtained for other heat-treated samples.
The temperature, time and moisture used in cooking and autoclaving of whole seeds of quinoa did not improve starch digestibility significantly. the digestibility of the starch in the raw and precooked samples was 72 and 77%, respectively, after drum drying and about 64% after extrusion in both cases. Precooking at 60°C for 20 min does not improve the digestibility of the quinoa starch.     

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.     

Effect of moisture content on compressive strength of whole snap bean (Phaseolus vulgaris L.) seeds and separated cotyledons

The compressive strength and force of three cultivars of whole snap bean ( Phaseolus vulgaris L.) seeds and cotyledon sections were measured over a range of water activity from 0.45 to 0.65 in 0.1 increments. Compressive strength was measured with a flat platen for whole bean compression and with a 1 mm diameter cylindrical probe for cotyledon strength tests. At high moisture content seeds had a plastic behaviour. The compressive force for seed breakage increased with increasing moisture content, and the breeding line NY537-Dark was the most resistant to fracture. Cotyledon compression strength decreased with increasing moisture content regardless of seed coat presence.     

Effect of heat-moisture treatment on the formation and physicochemical properties of resistant starch from mung bean (Phaseolus radiatus) starch

Mung bean starch was subjected to a range of heat-moisture treatments (HMT) based on different moisture contents (15%, 20%, 25%, 30%, and 35%) all heated at 120 °C for 12 h. The impact on the yields of resistant starch (RS), and the microstructure, physicochemical and functional properties of RS was investigated. Compared to raw starch, the RS content of HMT starch increased significantly, with the starch treated at 20% moisture having the highest RS content. After HMT, birefringence remained at the periphery of the granules and was absent at the center of some granules. The shape and integrity of HMT starch granules did not change but concavity was observed under scanning electronic microscopy. Apparent amylose contents of HMT starch increased and the HMT starch was dominated by high molecular weight fraction. Both the native and HMT starches showed A-type X-ray diffraction pattern. Relative crystallinity increased after HMT. The gelatinization temperatures (To, Tp, and Tc), gelatinization temperature range (Tc–To) and enthalpies of gelatinization (ΔH) increased significantly in HMT starch compared to native starch. The solubility increased but swelling power decreased in HMT starches. This study clearly shows that the HMT exhibited thermal stability and resistance to enzymatic hydrolysis owing to stronger interactions of starch chains in granule.     

Anti-oxidant activities of mung bean starch and starch gels prepared from whole and hulled seeds

Anti-oxidant activities of ethanol extracts from whole and hulled mung bean starches (WMS and HMS) isolated using distilled water, and gels (WMSG and HMSG) were investigated. Total chlorophyll contents of WMS and WMSG were 4.61 and 2.14 μg/mL, respectively. WMS at 0.29 mg of gallic acid/g of MS and 0.54 mg of quercetin/g of MS had higher total phenolic compounds and flavonoid contents than HMS at 0.11 mg of gallic acid/g of MS and 0.28 mg of quercetin/g of MS. Total phenolic contents of WMSG and HMSG increased by 2.14x and 1.64x, respectively. Total flavonoid contents decreased by 0.98x and 0.57x. The 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activities and reducing powers of WMS and WMSG were higher than for HMS and HMSG. Cheongpomuk made using WMS exhibits increased anti-oxidant activities of gels and is a good food for improvement in health functionality.     

Effect of pre-dehydration treatment on the in vitro digestibility of starch in cookie

In order to understand the effect of pre-dehydration on the in vitro digestibility of cookie starch, cookie dough samples were dehydrated by vacuum treatment, and melting temperature (T(m)) of the crystalline amylopectin in the dough, internal temperature and water content of the dough during baking, and non-hydrolysed starch content of the obtained cookies were investigated. The T(m) of crystalline amylopectin increased with decreased water content of the dough, and the result was described as a T(m)-curve. The internal temperature of non-dehydrated dough surpassed the T(m)-curve during baking. Pre-dehydrated dough, on the other hand, always indicated a lower internal temperature than the T(m)-curve. The non-hydrolysed starch content obtained under a given condition increased significantly with a decrease in the initial water content of cookies. This will be because the melting of crystalline amylopectin was prevented, at least partially, during baking.     

The effects of hydrothermal processing on antinutrients, protein and starch digestibility of food legumes

The effects of hydrothermal processing on antinutrients and the protein and starch digestibility of black grams, chick peas, lentils and red and white kidney beans was investigated. The tannins and phytic acid contents in these five food legumes ranged from 770 to 1100 and 970 to 1440 mg/100 g, respectively, whereas protein and starch digestibility of the raw food legumes was found to be from 33.8 to 37.6 and 36.8 to 42.0%, respectively. A reduction in the level of these antinutrients, along with an improvement in protein and starch digestibility, was observed after cooking. The tannins and phytic acid contents were reduced by 33.1–45.7 and 28.0–51.6%, respectively, because of the use of different hydrothermal treatments at 100, 121 and 128 °C. Maximum improvement in protein digestibility (95.7–105.1%) and starch digestibility (116.7–137.7%) was observed on cooking at 121 °C for 10 min. However, cooking in boiling water resulted in improvement in protein and starch digestibility of the food legumes by 86.9–93.3 and 84.0–90.4%, respectively.     

Chemical composition and starch digestibility in flours from Polish processed legume seeds

The study was undertaken to determine the effect of various treatments, i.e. cooking after soaking, freezing after cooking and storage at a low temperature (-18°C, 21days), and autoclaving, of Polish cultivars of bean, pea and lentil seeds on the chemical composition and starch digestibility of the resultant flours. The cooking of seeds caused a significant decrease in contents of ash (by 11-48%), polyphenols (by 10-70%) and protein (to 19%) in flours made of bean. In addition, analyses demonstrated significantly decreased contents of resistant starch, RS (by 61-71%) and slowly digestible starch, SDS (by 56-84%). Storage of frozen seeds resulted in insignificant changes in the chemical composition, and in increased contents of both RS and SDS. The flours produced upon the autoclaving process were characterized by similar changes in the contents of ash and protein as in cooked seeds, yet losses of polyphenols were lower and, simultaneously, contents of RS and SDS were higher. All the analyzed flours were shown to be characterized by a reduced content of amylose in starch, which might have affected its digestibility. This was indicated by a strict negative correlation reported between the value of the starch digestion index (SDRI) and amylose content of starch (r=0.84, p>0.05).     

Simple method of isolation of the major storage protein of bean seed (Phaseolus vulgaris) and its characterization

Fractional extraction of the bean seed major storage protein (MSP) by ammonium sulphate solutions at a concentration corresponding to 65-75% saturation was shown to be a simple and effective method for its isolation. The extraction with 70-75% saturated solutions permits to obtain directly a chromatographic and electrophoretic homogeneous preparation of MSP. The extract obtained with 65% saturated solution contains small quantity of contaminants. One-step DEAE-cellulose chromatography was found to be sufficient for their complete removal. On PAGE the MSP gives one wide, diffuse band with a relative mobility to bromphenol blue of Rm 0.38-0.42, and one additional band with Rm 0.18-0.20. The latter corresponds to tetrameric form of MSP. Reversible pH-dependent protomer-tetramer association was demonstrated by sedimentation velocity behaviour. At pH 7.2 the MSP gives one peak for 7S protomeric form. Below pH 7.0 a second peak for 18S tetrameric appears. SDS-PAGE analysis of subunit pattern shows the existence of 3 main components with molecular weights 53,000, 49,000 and 46,000. Some minor, lower MW polypeptides are also found. It seems that they are products of further dissociation of the main subunits.     

Chemical composition,in vitro starch digestibility and amino acid analysis of a underexplored kidney bean (Phaseolus vulgaris. L.) grown in Chongqing,China

Chemical composition, mineral analysis, in vitro starch digestibility, and amino acid analysis of a kidney bean (Phaseolus vulgaris. L.), grown in Chongqing, China, were carried out in 2011. The results showed that the bean flour contained low reducing sugar (0.79%) and fat (2.72%), but high protein (24.8%) and starch (44.84%). Mineral analysis indicated high Mg and Ca contents with low Na/K ratio (0.04). The proportions of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) were 39.64%, 41.46% and 18.90% respectively. And the variation in their proportions, along with prolonged heating time, showed increase in RDS, and decrease in SDS and RS, but the SDS + RS amount can still account for major parts (51.63%) of the total starch after a 90‐min pre‐cooking. Comparing the amino acid contents of the bean sample with recommended profile FAO/WHO/UNU (1985), the results fulfil the standard except threonine and lysine, whose contents are slightly lower than the requirements (0.93 and 0.85).     

In vitro digestibility of proteins in black gram (Phaseolus mungo) and green gram (Phaseolus radiatus) papads

‘Papads’, a traditional food of India, were prepared with decorticated black gram and green gram flours and toasted, microwaved or deep fat fried. Toasting was done by holding the papads over direct flame for 1–2 min. Sharp carousal microwave oven was used for microwaving at high temperature for 30 – 40 s. Deep fat frying was done by immersing the product in preheated refined groundnut oil for 5 – 10 s. In vitro digestibility of proteins in prepared papads was investigated by pepsin and pepsin + pancreatin. The percent protein hydrolysed in black gram papads was 80.5, 75.3 and 72.5 for toasted, microwaved and fried papads respectively. They were not significantly different from each other. Green gram papads exhibited significantly higher hydrolysis in microwaved product (79.3%) when compared to toasted (65.2%) or fried products (65.0%). Pepsin digestibilities were not influenced to a significant extent by cooking method and were in the range of 51.4 – 54.6% for black gram papads and 34.4 – 35.6% for green gram papads.     

Textural properties of mung bean starch gels prepared from whole seeds

The textural properties of mung bean starch gels (MSG) made by starches purified from whole seeds of Dahyeon were investigated to improve the quality of Korean traditional starch gel, cheongpomuk. Based on our investigation, the protein and dietary fiber contents of starch from whole mung beans (WM) were significantly higher than those from hulled mung beans (HM); however, apparently, WM had lower amylose contents than HM (their respective apparent amylose contents were 32.42 and 33.09%). The fresh gels (WMSG and HMSG), stored gels (WMSG-S4 and HMSG-S4), and reheated gels (WMSG-R4 and HMSG-R4) were also compared. The stored gels showed the highest L and b values, translucence, hardness, and gumminess. While HMSG showed a denser network structure than WMSG, the structure of stored gels was recovered after reheating. The fresh gels showed V type crystallinity, but the stored gel changed into B type crystallinity. WMSG showed higher sensory bending properties and smoothness than HMSG, but more similarities in the overall qualities.     

Characterization of globulin from Phaseolus angularis (red bean)

Phaseolus angularis (red bean) seeds contain about 25% protein (dry basis), almost half of which is globulin. Similar to globulins from other Phaseolus species , 7S vicilin is the major fraction of red bean globulin (RBG), with 11S legumin as a minor component. The amino acid profile of RBG met or exceeded the FAO/WHO standard. Circular dichroism measurements indicate that RBG is a protein rich in α-helical and β-turn structures. RBG exhibited higher protein solubility than Supro 610, a commercial soy protein isolate, especially at acidic pHs, with minimal solubility at around pH 5.0. Compared to Supro 610, RBG had lower water hydration capacity and comparable fat binding capacity, which might be because of its lower surface hydrophobicity. RBG had higher emulsifying activity index and emulsion stability than Supro 610, but with poorer foaming properties.     

湿热处理蜡质玉米淀粉消化性研究

主要研究湿热处理对蜡质玉米淀粉消化性影响,通过测定不同处理条件下快消化淀粉,慢消化淀粉和抗性淀粉含量以评价其消化性。研究结果表明,随水分含量、处理温度升高和处理时间延长,蜡质玉米快消化淀粉含量显著下降,而慢消化淀粉和抗性淀粉含量明显上升。     

Amino acid composition of seed meals of yam bean (Sphenostylis stenocarpa) and lima bean (Phaseolus lunatus)

The amino acid compositions of the seed meals of four varieties of yam bean and one variety of lima bean have been compared with the F.A.O.¹ standard.     

Effect of bean broth on the nutritive value and digestibility of beans

Black, red and white beans were cooked (1:3, water: beans) at 120°C and 16 lb in^?2 for 20 min. Chemical analysis of the broth showed that it contained low levels of protein, ether extract, and carbohydrates and high levels of ash and polyphenols. The effect of the addition of bean broth, on the PER and digestibility of beans was studied in rats. PER values and protein digestibility decreased as the amount of bean broth increased in the diet. White beans showed highest values of PER, weight gain and protein digestibility. The latter was lower in the groups supplemented with methionine than in those not supplemented; there was no interaction beween level of methionine and amount of bean broth in the diet on digestibility. The effect of methionine was not related to either metabolic nitrogen in faeces or amount of food consumed. A high proportion of the faeces nitrogen was soluble in NaOH. When rats from the different groups were fed diets containing 18% bean protein and killed at 6 weeks of age they showed no difference in pancreas weight that could be related to the amount of broth in the diet, nor were the levels of trypsin in the pancreas or the amount of PABA excreted upon ingestion of BT-PABA related to the amount of broth in the diet.