Functional properties of 8S globulin fractions from 15 mung bean (Vigna radiata (L.) Wilczek) cultivars

The functional properties including solubility, water absorption capacity, oil absorption capacity, foaming properties and emulsifying properties of 8S globulin fractions from 15 mung bean cultivars were investigated in this study. In addition, the effects of pH on solubility, foaming properties and emulsifying properties were studied. The functional properties of the 8S globulin fractions varied significantly among the different mung bean varieties and exhibited better performance in solubility and emulsion stability compared with soya bean 7S protein. A negative correlation was found between water absorption capacity and oil absorption capacity. Remarkable differences in polypeptides constituents were observed in 8S globulin fractions, and the ratio of 11S/8S globulins has a positive effect on water absorption capacity while a negative effect on oil absorption capacity. As a function of pH, the emulsifying activity indexes of the 8S globulin fractions were found to be distinctly dependent on the solubility, while no significant correlation was found between the emulsifying stability and solubility, nor between the foaming properties and solubility. The foaming capacity showed a strong correlation with foam stability.     

球磨对绿豆淀粉颗粒形态和理化性质的影响

采用行星式球磨机对绿豆淀粉进行改性研究,以球磨时间为控制变量,对比球磨0、1、2、4、6h时绿豆淀粉颗粒形态和淀粉糊理化性质的变化.结果表明,球磨处理后绿豆淀粉颗粒表面出现凹痕,表皮变皱逐渐破裂,随时间的增加颗粒变得扁平并有抱团现象,偏光十字逐渐模糊直至消失;随球磨时间的延长,损伤淀粉和直链淀粉含量增加,淀粉糊溶解度、透明度和析水率均显著增大,淀粉糊峰值黏度、谷值黏度、最终黏度、回生值和衰减值均呈下降趋势.     

超声波处理对豌豆淀粉糊化、流变及质构特性的影响

以豌豆淀粉为原料,分别用0,150,300,450 W的超声波进行处理,考察超声波处理对豌豆淀粉糊化、流变及质构特性的影响。结果表明:超声波处理对豌豆淀粉的糊化、流变及质构特性都有较大影响。随着超声波功率的增加,豌豆淀粉糊峰值黏度、终值黏度、崩解值及回升值都显著下降,使豌豆淀粉冷稳定性及热稳定性得到提升;稠度系数k减小,流体指数n增大,触变性减小,流动性增加,使豌豆淀粉流变稳定性提高;G′与G″减小,tanδ增大,使豌豆淀粉黏弹性降低。此外,超声作用使豌豆淀粉凝胶的硬度、弹性、内聚性、胶着性及咀嚼性都呈下降趋势,其中硬度与胶着性下降最显著。扫描电镜表明,超声波对豌豆淀粉产生破坏作用,使淀粉颗粒表面出现坑洞及皱褶,部分颗粒结构变得不完整。     

The effects of blackcurrant and strawberry powder on the physicochemical and in vitro glycaemic response of starches derived from sweet potato (Ipomoea batatas) and potato (Solanum tuberosum)

Phenolic compounds have been shown to deliver numerous health benefits. Research has also shown that starch and phenolic compounds interact. This study aimed to investigate the effects of blackcurrant and strawberry powder on the physicochemical and in vitro predicted glycaemic response of sweet potato and potato starches. Sweet potato, or potato, starches were mixed with 0%, 5%, 10% and 15% (w/w) of blackcurrant, or strawberry, powder, to form blackcurrant and strawberry-enriched starch pastes. The results showed that enrichment with 5%, 10% and 15% blackcurrant or strawberry powder for sweet potato and potato starch significantly altered the pasting viscosity and colour profiles (P < 0.05), increased the phenolic content and antioxidant activities of starch pastes (P < 0.05). Blackcurrant or strawberry powders mixed with sweet potato or potato starches reduced amount of reducing sugar released during in vitro digestion. Addition of 15% blackcurrant powder for the starch exerted stronger in vitro antioxidant and hypoglycaemic properties than that of 15% strawberry powder. Collectively, these findings suggested that addition of blackcurrant or strawberry powder into sweet potato and potato starches manipulated the hypoglycaemic property of pastes.     

Amylose content,molecular structure,physicochemical properties and in vitro digestibility of starches from different mung bean (Vigna radiata L.) cultivars

Physicochemical and in vitro digestibility characteristics of starches isolated from six cultivars of mung bean (Vigna radiata L.) were studied. Significant differences (p < 0.05) were observed between the cultivars with respect to amylose content (29.9–33.6%), relative crystallinity (29.0 to 31.7%), particle diameter (16.2–17.1 µm) and molecular weight of amylopectin (260–289 × 10⁶ g/mol). The scanning electron micrographs revealed the presence of large oval to small round shape granules with average particle diameter of 16.2–17.1 µm. The X‐ray diffraction pattern was of the C‐type. The enthalpies of gelatinization and retrogradation were 8.9–10.3 and 4.6–6.3 J/g, respectively. The amounts of slowly digesting and resistant starch of mung bean followed the order: PBM‐1 > SML‐32 > ML‐613 > SML‐134 > ML‐267 > ML‐5 and ML‐5 > ML‐267 > SML‐134 > ML‐613 > SML‐32 > PBM‐1, respectively. The six starches exhibited significant (p < 0.05) differences in their pasting parameters. Correlation analysis showed that amylose content, granule diameter and relative crystallinity values were important in determining thermal, pasting and in vitro digestibility of starches.     

Assessment of phytochemicals,enzymatic and antioxidant activities in germinated mung bean (Vigna radiata L. Wilezek)

Vitamin C, phenolic and flavonoid contents along with enzymatic and antioxidant activities were determined in germinated mung bean (Vigna radiate). Elevated levels of vitamin C 72.31 ± 0.62 mg/100 g FW and flavonoid content 85.57 ± 0.59 mg CE/100 g FW were estimated for euphylla after 6 days of germination. Moreover, maximum peroxyl radical scavenging activity 645.4 ± 28.5 μmol ASA equiv./100 g FW was also determined in euphylla. However, seed coat has the highest content of phenolic content (568.4 ± 8.8 mg GAE/100 g FW), whereas cotyledon depicted the highest ascorbate oxidase and peroxidase activities (396.5 ± 4.0 and 548.4 ± 2.8 min^?1 g^?1 FW, respectively). These findings revealed that euphylla in mung bean sprouts is the most bioactive part with significant level of phytochemicals. Therefore, after germination of 6 days, euphylla is the main source of nutrition in mung bean sprouts.     

A comparative study of physico‐chemical properties and antioxidant activity of freeze‐dried mung bean (Vigna radiata) and adzuki bean (Vigna angularis) sprout hydrolysate powders

Mung bean (MB) and adzuki bean (AZB) sprouts were hydrolysed with Flavourzyme^® at four different concentrations for 6 h. Nongerminated beans subjected to each enzyme concentrations were set as the control. For both bean sprouts, the highest amounts of free amino group, total free amino acids and total phenolic content (TPC) were obtained with 7% (w/w) Flavourzyme^®. Each bean sprout hydrolysate was subjected to freeze‐drying in absence and presence of 5% maltodextrin (w/v). The addition of maltodextrin resulted in a decrease in the free amino group, TPC, surface hydrophobicity and hygroscopicity in resulting freeze‐dried powders. Gallic acid, p‐coumaric acid and vitexin were identified in all freeze‐dried powders, while catechin and rutin were detected only in freeze‐dried AZB hydrolysate powder. Freeze‐dried AZB hydrolysate powder contained higher antioxidant activities. DPPH radical scavenging activity of all samples measured using electron spin resonance spectrometry was higher than that obtained by the colorimetric method.     

Effect of oxidation and esterification on functional properties of mung bean (Vigna radiata (L.) Wilczek) starch

The chemical and physicochemical properties of mung bean starch oxidized by sodium hypochlorite and esterified with succinic anhydride were studied. Mung bean starch was modified by oxidation with sodium hypochlorite and esterified with succinic anhydride. The native mung bean starch (NMBS) granules were shown to have an irregular shape, which varied from oval to round to bean shape with a smooth surface. Succinylation led to partial rupture of the granule integrity while oxidation converted the smooth surface of the native granules to a surface with fissures. Swelling capacity improved through succinylation but was reduced after oxidation. Oxidation enhanced solubility; however, succinylation showed no uniform effect throughout the temperature range studied. Both modifications increased hydrophilic tendency and demonstrated decreased gelatinization temperature compared to the NMBS. Oil absorption capacity and syneresis of native starch was enhanced after oxidation but was reduced after succinylation. Both starch types, native and modified, exhibited non-Newtonian behavior, but to a different extent. The gel formation of oxidized starch revealed the highest storage modulus followed by native starch and then succinated starch.     

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.     

Hypolipidemic and hypoglycemic potential of raw,boiled, and sprouted mung beans (Vigna radiata L. Wilczek) in rats

This study was carried out to investigate the hypolipidemic and hypoglycemic potential of raw, boiled, and sprouted mung beans in rats. Oven dried mung bean powders; raw, sprouted, and boiled were included at 30% level in the diet of seven weeks old male Wistar rats maintained for 5 weeks on high (0.5%) cholesterol diet in comparison with control diet. Low serum glucose and triglyceride concentrations (p < .05) in raw and processed mung bean diets fed rats were supported by low serum insulin level in both raw mung bean diet and boiled mung bean diet fed rats. Hypoglycemic effect in sprouted mung bean fed rats was supported by higher α‐amylase inhibitory activity and α‐glucosidase inhibitory activity of sprouted mung beans. Increase in serum non‐HDL cholesterol concentration and decrease in HDL cholesterol concentration caused by high cholesterol diet were modulated (p < .05) by both boiled and sprouted mung bean diets.

Practical applications

Mung bean is a green legume rich in protein, fiber, antioxidants, and phytonutrients. Hypocholesterolemic and hypoglycemic potential of raw mung beans have been shown previously. It is well known that cooking and processing modulate nutritional and biochemical parameters of foods. However, very limited information is available on the effect of processing on functional properties of legumes. Results of this study showed that boiling and sprouting improved the soluble fiber content and hypocholesterolemic potential of mung beans. Thus, the processed mung beans may be more suitable for developing food supplements for patients with hypercholesterolemia.     

Green method for determination of phenolic compounds in mung bean (Vigna radiata L.) based on near‐infrared spectroscopy and chemometrics

Mung bean grains exhibit high level of antioxidant activity due the presence of phenolic compounds. Near‐infrared spectroscopy (NIRS), in conjunction with chemometrics, was used to develop a rapid, nondestructive, chemical free and easy‐to‐use method to determine these compounds in sixty genotypes of mung bean. NIRS calibration curve with high‐performance liquid chromatography (HPLC) as reference method was used to determine phenolic compounds (catechin, chlorogenic acid, caffeic acid, p‐coumaric acid, t‐ferulic acid, vitexin, isovitexin, myricetin, quercetin and kaempferol). It was observed that partial least square regression (PLSR) model in the wavelength range of 1600–2500 nm with standard normal variate (SNV) and linear baseline correction (LBC) as preprocessing techniques can measure phenolic compound accurately (R² > 0.987) with root‐mean‐square error less than 1.82%. This study shows that NIRS along with chemometrics is an accurate method to estimate the phenolic compounds rapidly and nondestructively.     

Effects of UV‐B on vitamin C,phenolics, flavonoids and their related enzyme activities in mung bean sprouts (Vigna radiata)

In this study, ultraviolet‐B radiation (UV‐B) was used to effect the accumulation of vitamin C, phenolics and flavonoids in mung bean sprouts. Results indicate that the content of vitamin C and flavonoids increased during the initial period, and after a brief decline, reached peak levels of 25.29 ± 1.02 mg/100 g FW and 726.67 ± 7.35 mg/100 g DW, respectively, at 2.5 h (1.845 kJ m^?2), while the peak levels of the phenolics were 10741.33 ± 68.04 mg/100 g DW. The thiobarbituric acid reactive substances (TBARS) content decreases with the increase in irradiation time. The activities of the related enzymes, including phenylalanine ammonia‐lyase (PAL), L‐galactono‐1, 4‐lactone dehydrogenase (GalLDH), peroxidase (POD), polyphenol oxidase (PPO) and chalcone isomerase (CHI) were determined, which showed strong correlations with the change in the content of vitamin C, phenolics and flavonoids. In conclusion, the accumulation of vitamin C, phenolics and flavonoids in mung bean sprouts can be promoted by a low‐dose UV‐B irradiation.     

Composition,molecular structure,and physicochemical properties of starches from four field pea (Pisum sativum L.) cultivars

Starch from four cultivars (Carneval, Carrera, Grande and Keoma) of field pea (Pisum sativum L.) was isolated and its physicochemical properties were compared with those of other legume starches. The yield of starch was in the range 32.7–33.5% on a whole seed basis. The starch granules were round to elliptical with smooth surfaces. The free lipid was 0.05% in all starches. However, bound and total lipids ranged from 0.24 to 0.29% and from 0.28 to 0.34%, respectively. The total amylose content ranged from 48.8–49.6%, of which 10.9–12.3% was complexed by native lipid. The degree of polymerization (DP) of amyloses ranged from 1300 to 1350. The chain length distributions of debranched amylopectins of the starches were analyzed using high performance anion-exchange chromatography equipped with a post-column amyloglucosidase reactor and a pulsed amperometric detector. The proportion of short branch chains, of chain length DP 6-12, ranged from 16.2 to 18.6%. Keoma displayed a larger portion (19.4%) of long branch chains (DP>37) than the other three starches (16.2–16.9%). The average amylopectin branch chain length ranged from 22.9 to 24.2. The maximum detectable DP was higher in Keoma (71) than in the other three starches (64–65). The X-ray pattern was of the ‘C’ type. The relative crystallinity was in the range 20.8–25.1%. The proportion of ‘B’ polymorphic form was higher in Keoma (25.6%) than in the other three starches (22.1–24.1%). There were no significant differences in swelling factor. The extent of amylose leaching at 95°C ranged from 25.20 to 26.85. All four starches exhibited nearly identical gelatinization transition temperatures and enthalpies. However, the gelatinization temperature range (T_c–T_o) followed the order: Grande∼Keoma>Carneval∼Carrera. The four starches showed identical pasting temperatures and exhibited only marginal differences with respect to 95°C viscosity and to the increase in consistency during the holding period at 95°C. However, the set-back viscosity for Carneval was lower than that of the other starches. There were no significant differences in the extent of acid hydrolysis. However, susceptibility towards hydrolysis by α-amylase followed the order: Carneval∼Carrera∼Grande>Keoma. The extent of retrogradation (monitored by changes in enthalpy) during storage at 40°C/24 h followed the order: Carneval>Carrera>Grande>Keoma. However, differences in the extent of retrogradation among starches were not discernable by freeze-thaw stability measurements.     

Desiccant drying prior to hermetic storage extends viability and reduces bruchid (Callosobruchus chinensis L.) infestation of mung bean (Vigna radiata (L.) R. Wilczek) seeds

Seeds of mung bean (Vigna radiata (L.) R. Wilczek) are subject to loss of viability due to aging and damage from pulse beetles (or bruchids; Callosobruchus spp.) infestation during storage. We investigated whether seed drying using desiccants and hermetic packaging would prevent or ameliorate these consequences of storage. Sun-dried mung bean seeds at a moisture content of 10% were subjected to further drying for 72 h using five different desiccants: Drying Beads® (a zeolite-based desiccant), silica gel, sodium aluminum silicate, activated alumina, and cow-dung ash (a traditional desiccant). Seeds were subsequently stored in hermetic plastic containers in the presence of these desiccants under ambient conditions along with sun-dried seeds stored in cloth bags or in hermetic containers. In addition, parallel samples of each treatment were inoculated with one pair of bruchid beetles (C. chinensis L.) and stored under the same conditions. The seed drying treatments did not affect initial seed quality (germination percentage and seedling vigor) significantly. After storage for 9 months at ambient temperatures, seeds dried using Drying Beads, silica gel, sodium aluminum silicate and activated alumina had higher germination percentages, seedling vigor indices and soil emergence, and lower electrical conductivity (leakage upon imbibition) and fungal infestation compared to other conditions. In addition, the mung bean seeds inoculated with bruchids and stored with these effective desiccants had less damage, oviposition, and insect respiratory activity in the hermetic containers and maintained higher seed germination and seedling vigor after six months of storage compared to other treatments and controls. The results demonstrate the superior ability of desiccants to quickly and safely dry seeds prior to and during storage and the benefits of such drying and hermetic storage conditions for preventing seed deterioration and insect damage during storage.     

The health benefits,functional properties,modifications, and applications of pea (Pisum sativum L.) protein: Current status,challenges, and perspectives

In recent years, the development and application of plant proteins have drawn increasing scientific and industrial interests. Pea (Pisum sativum L.) is an important source of high‐quality vegetable protein in the human diet. Its protein components are generally considered hypoallergenic, and many studies have highlighted the health benefits associated with the consumption of pea protein. Pea protein and its hydrolysates (pea protein hydrolysates [PPH]) possess health benefits such as antioxidant, antihypertensive, and modulating intestinal bacteria activities, as well as various functional properties, including solubility, water‐ and oil‐holding capacities, and emulsifying, foaming, and gelling properties. However, the application of pea protein in the food system is limited due to its poor functional performances. Several frequently applied modification methods, including physical, chemical, enzymatic, and combined treatments, have been used for pea protein to improve its functional properties and expand its food applications. To date, different applications of pea protein in the food system have been extensively studied, for example, encapsulation for bioactive ingredients, edible films, extruded products and substitution for cereal flours, fats, and animal proteins. This article reviews the current status of the knowledge regarding pea protein, focusing on its health benefits, functional properties, and structural modifications, and comprehensively summarizes its potential applications in the food industry.     

A quantitative and qualitative assessment of mung bean (Vigna mungo (L.) Wilczek) seed in response to elevated atmospheric carbon dioxide: potential changes in fatty acid composition

The effect of rising atmospheric carbon dioxide concentration ([CO₂]) on seed production and the fatty acid profiles of mung bean (Vigna mungo L. Wilczek) were studied under field conditions. Increased [CO₂] (ca 250 ppm above ambient) resulted in significant increases in pod number, pod weight and total seed weight, but also significantly increased the percentage of immature pods at harvest. Qualitatively, increased [CO₂] significantly decreased the percentages of palmitic and omega‐6 fatty acids, but increased the percentage of omega‐3 fatty acids and the relative proportion of omega‐3 to omega‐6 fatty acids in mature seed. Overall, increased carbon dioxide may significantly increase quantity and alter quality in mung bean seed, a recognized alternative source of fatty acids in the human diet. Copyright © 2007 Society of Chemical Industry