Dynamic changes in phytochemical composition and antioxidant capacity in green and black mung bean (Vigna radiata) sprouts

The mung bean (Vigna radiata) sprout is a popular fresh vegetable in many parts of the world. In this study, the dynamic change of ascorbic acid, phenolic composition and antioxidant capacity were evaluated in green and black mung bean sprouts. Germination increased ascorbic acid, total phenolic content and antioxidant capacity in both mung beans. The green mung bean sprout generally had higher ascorbic acid, total phenolic content and antioxidant capacity than the black mung bean sprout. Most phenolic compounds, such as caffeic acid, catechin, ferulic acid, gallic acid and rutin, were found to gradually increase after germination. Therefore, mung bean sprouts, especially green mung bean sprout possessing high level of antioxidant phytochemicals, can be valuable functional vegetables and good sources of natural antioxidants.     

Kinetic study of the antioxidant compounds and antioxidant capacity during germination of Vigna radiata cv. emmerald, Glycinemax cv. jutro and Glycine max cv. merit

The purpose of this study was to determine the antioxidant capacity and the content of antioxidant compounds in raw mung bean seeds and sprouts (Vigna radiata cv. emmerald) germinated for 2, 3, 4, 5 and 7 days and of soybean seeds of Glycine max cv. jutro germinated for 2, 3 and 4 days and of Glycine max cv. merit germinated for 2, 3, 4, 5 and 6 days. Antioxidant compounds, such as vitamin C and E, total phenolic compounds and reduced glutathione (GSH) were studied. Antioxidant capacity was measured by superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), trolox equivalent antioxidant capacity (TEAC) and inhibition of lipid peroxidation in unilamellar liposomes of egg yolk phosphatidylcholine (PC). The results indicated that changes in the contents of vitamin C, vitamin E and GSH depended on the type of legume and germination conditions. Sprouts of mung bean and soybeans provided more total phenolic compounds than did raw seeds. The SOD-like activity increased after germination of mung bean seeds for 7 days, by 308%, while no change was observed in sprouts of Glycine max cv. jutro and an increase was observed after 5 and 6 days of germination (∼20%) in Glycine max cv. merit. PRTC and TEAC increased during the germination process and retentions of 28–70% and 11–14%, respectively, for soybean, and 248% and 61%, respectively, for mung bean were observed at the end of germination. The inhibition of lipid peroxidation increased by 389% in 5–7 days’ germination of Vigna radiata cv. emmerald sprouts, and 66% in Glycine max cv. merit sprouts whilst, in Glycine max cv. jutro, germination did not cause changes in lipid peroxidation inhibition. According to the results obtained in this study, germination of mung bean and soybean seeds is a good process for obtaining functional flours with greater antioxidant capacity and more antioxidant compounds than the raw legumes.     

Does Processing have a Considerable Effect on the Nutritional and Functional Properties of Mung Bean (Vigna Radiata)?

Mung bean is an important grain legume which is rich in nutrients and other bioactive compounds with many beneficial physiological effects. However, the effect of processing on properties of mung bean has not been widely studied in Sri Lanka. In the current study, effect of processing (boiling and sprouting) on some nutritional and functional properties of mung bean was investigated in comparison with raw mung bean. Mung bean seeds (Vigna radiata), varity MI6 were obtained from the Government Seed Center, Dambulla, Sri Lanka. Proximate composition, gross energy, insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) contents,total phenolic content (TPC), total flavonoid content (TFC), α-amylase inhibition capacity, DPPH and ABTS scavenging activities were determined. Crude Protein (CP) content of boiled mung bean was significantly (p<0.05) lower than that of raw mung bean while it was significantly (p<0.05) higher in sprouted mung bean than raw mung bean. Crude fat content (CF) was significantly (p< 0.05) lower in sprouted mung bean when compared to raw mung bean. IDF contents in raw mung bean was significantly (p<0.05) higher than that in sprouted and boiled mung bean whereas, SDF content in boiled and sprouted mung bean were significantly (p<0.05) higher than that in raw mung bean.processing significantly (p<0.05) reduced antioxidant activity and total phenol content compared to raw mung bean. However, flavonoids could only be detected in sprouted mung bean. Further, α-amylase inhibition in sprouted mung bean was significantly (p<0.05) higher than that in boiled mung bean. In conclusion, processing (boiling and sprouting) influences the CP content, CF content, dietary fibre content, antioxidant capacity, α-amylase inhibition and fermentation ability in mung bean.     

Comparative analyses of total phenols,flavonoids, saponins and antioxidant activity in yellow soy beans and mung beans

Total phenol, flavonoid and saponin content of soy bean and mung bean were systemically compared in order to evaluate their contribution to overall antioxidant activity. Mung bean extract possessed significantly higher total phenol (2.03 GAE g^?1 vs. 1.13 GAE g^?1) and flavonoid contents (1.49 GAE g^?1 vs. 0.41 CAE g^?1) than soy bean extract, while the saponin content of the soy beans was 4.5 times greater than that of the mung beans. In several antioxidant assays including DPPH and ABTS radical scavenging, FRAP, SOD‐like activity, and a β‐carotene bleaching assay, mung bean extract consistently showed significantly greater antioxidant activity than soy bean extract. The specific antioxidant activity, which was evaluated at the same phenolic content suggested that the phenolic compounds present in the mung bean extract were not only of greater quantity but also had better quality to eliminate radicals. The radical scavenging activities of saponins were only marginal.     

Development of microbiologically safe mung bean sprouts using combination treatment of sodium hypochlorite and gamma radiation

Specific group of people, with impaired immune system, are recommended to consume pathogen‐free foods. In this study, microbiologically safe ready‐to‐eat (RTE) mung bean sprouts were developed using combination treatment (CT) with 200 ppm sodium hypochlorite and 12 kGy dose of gamma radiation. Microbiological analysis of combination‐treated sprout samples showed complete elimination (<10 CFU g^?1 of sprouts) of microbial load in these samples, even during storage at 4 °C up to 12 days. Combination treatment and storage period did not have any significant effect on the sensory qualities of RTE mung bean sprouts. However, reduction in the firmness and vitamin C content of combination‐treated sprout samples, similar to other food processing methods, was observed. These results suggest that CT is effective in sterilisation of mung bean sprouts. These sprouts can be included in the diets of special target groups and thereby improve in their quality of life.     

Effects of probiotic L. plantarum 299v on consumer quality,accumulation of phenolics,antioxidant capacity and biochemical changes in legume sprouts

This study evaluated the influence of Lactobacillus plantarum 299v on the consumer quality of legume sprouts. The probiotic-rich sprouts were produced by soaking the seeds in probiotic water suspension and further sprouting at 25 °C for 4 days. The enrichment of the sprouts with L. plantarum 299v only slightly affected the sensory quality - the overall acceptability of the probiotic-rich sprouts was usually higher. The probiotic-rich sprouts exhibited increased activity of polyphenol oxidase (the highest activity in the mung bean preparations - 73.97 U mg⁻¹ of protein). The peroxidase activity was not altered. The probiotic enrichment increased the phenolic content by 25%, 31% and 23% in the soybean, adzuki and mung bean preparations; however, it was not reflected in the antioxidant activities. The changes in the activity of enzymes involved in mobilisation of stored material (starch and proteins) and the increased content of phenolics only slightly modified the bioavailability of nutrients.     

干酪乳杆菌发酵8种食用豆提取物抗氧化活性研究

该试验分析了干酪乳杆菌（Lactobacillus casei）发酵8种食用豆总酚、总黄酮含量以及抗氧化活性的变化。结果表明,发酵前豇豆总酚含量最高,为（5.53±0.18） mg 没食子酸当量（GAE）/g干质量;红豆总黄酮含量最高,为（11.55±0.16） mg 芦丁当量（RE）/g干质量。发酵后绿豆总酚、总黄酮含量增加最高,分别为182.35%、27.84%;豇豆总酚含量、菜豆总黄酮含量下降最多,分别为43.40%、82.13%。发酵后豌豆提取物1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除活性上升最显著,菜豆提取物下降最显著;绿豆提取物2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）自由基清除活性上升最显著,菜豆提取物下降最显著;豌豆提取物铁离子还原能力上升最显著,菜豆提取物下降最显著。相关性分析结果显示,总酚、总黄酮含量与抗氧化活性均极显著相关（P＜0.01）。发酵对食用豆酚类物质含量和抗氧化活性影响显著,为开发不同食用豆功能食品提供理论基础。     

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.     

Effect of Acidified Processing and Storage on Carotenoids (Provitamin A) and Vitamin C in Mung Bean Sprouts

Blanching of mung bean sprouts has little effect on total carotenoids and β-carotene. Canned sprouts stored at RT for 6 months lost smaller amounts of total and ‘active’ carotenoids compared with bottled sprouts. Blanching resulted in approximately 50% loss of vitamin C in fresh mung bean sprouts but storage temperatures alone produced little change in vitamin C. Canned sprouts stored at RT for 6 months contained only 30% of the vitamin C of stored bottled sprouts. Fresh mung bean sprouts contained 19 μg 100 g⁻¹β-carotene and 15 mg 100 g⁻¹ vitamin C.     

气流超微粉碎对绿豆芽物理特性与抗氧化活性的影响

以经干燥处理后的绿豆芽为原料,比较经气流超微粉碎处理后绿豆芽多酚提取量、抗氧化活性及物理特性的变化。结果表明:气流超微粉碎的最佳条件为压力0.5 MPa,转速5 000 r/min。与常规粉碎相比,绿豆芽多酚提取量提高了10.74%,除DPPH自由基清除能力下降外,绿豆芽多酚对ABTS+自由基及羟自由基的清除能力分别提高了2.8%,13.2%;水含量、水活度、粒径大小明显减小,比表面积、溶解度及堆积密度均有提高,表明气流超微粉碎在一定程度上提高了绿豆芽粉的有效利用率。     

Folacin content of alfalfa and mung bean sprouts: The effect of extraction procedures and maturity

The folacin content of alfalfa (Medicago sativa) and mung bean (Vigna radiata) sprouts was determined by Lactobacillus casei. Several variations of extraction procedures were tested. The optimum conditions for extraction were autoclaving mung bean and alfalfa sprouts in phosphate buffer containing 0.3% and 0.4% ascorbate, respectively, before homogenisation in a blender. The optimum blending time for folacin extraction was 120s for mung bean and 15s for alfalfa sprouts. Folacin content on dry weight basis increased several times in both types of sprouts during germination. Mature alfalfa and mung bean sprouts were found to contain 186 and 178 μg folacin per 100 g fresh weight, respectively.     

CaCl2电解水处理提高绿豆芽品质及其机理

利用CaCl₂电解水(CaCl₂electrolyzedwater,CEW)浸泡绿豆后使其发芽,研究CEW对绿豆芽的保鲜效果及作用机制。结果表明,25 mmol/L CaCl₂浓度的电解水处理后,在贮藏5 d时,与对照组相比,其质量损失率降低,硬度和脆度约是对照组(自来水处理)的1.28倍,并且杀菌作用明显,绿豆芽表面微生物数量减少近一个对数值;低场核磁共振结果表明,绿豆芽水分状态有所改变,结合水含量增加;相对电导率、丙二醛含量和过氧化氢含量分别降低约16.5%、27.5%、36.8%,维持了细胞膜完整性,减少活性氧积累从而减轻膜脂过氧化程度。此外,CEW处理后绿豆芽贮藏期间的褐变现象得到抑制,机理与褐变底物总酚含量降低以及多酚氧化酶、过氧化物酶、苯丙氨酸解氨酶活力下降有关。由此可见,CEW处理可一定程度上延缓绿豆芽在贮藏过程中的品质劣变。     

不同品种绿豆理化特性和抗氧化性研究

对来自不同产区的9个不同品种绿豆的理化特性和抗氧化活性进行分析,研究其品质差异和特异性,为不同品种绿豆的加工和开发利用提供基础数据。结果表明,不同品种绿豆物理性状、营养成分、抗氧化活性等指标存在显著差异,且除羟自由基清除率之外,总酚含量、总黄酮含量、铁离子还原能力及DPPH自由基清除率表现出极显著的相关性(P<0.01)。参试品种中粒长以及明度最大的是洮绿8号,白绿8号籽粒宽最大;参试品种蛋白质、脂肪、淀粉含量范围分别为18.83%~21.99%、0.70%~1.26%、54.63%~70.75%,其中白绿8号蛋白质含量最高,淮绿2号淀粉含量最高;重庆绿豆表现出最小的百粒重,最高的总酚含量、总黄酮含量、铁离子还原能力以及DPPH自由基清除率。     

Effect of UV‐B treatment during the growth process on the postharvest quality of mung bean sprouts (Vigna radiata)

The production patterns and nutritious qualities of mung bean sprouts are in line with the consumption needs of modern people. This study was conducted to explore the effects of low doses of UV‐B irradiation on the 3‐day growth period of mung bean sprouts. The results showed that, when mung bean sprouts were irradiated with UV‐B (0.738 kJ m^?2) for 1 h per day, their total phenolic content increased by 22.80%, and the activity of polyphenol oxidase decreased by 45.45%. Hypocotyl epidermis stomata were closed, reducing water loss and the opportunity for microbes to invade plants, leading to the maintenance of freshness of the sprouts. In conclusion, UV‐B irradiation for 1 h per day during the growth of mung bean sprouts can effectively improve their preservation. This method is a low‐cost, environmental friendly and pollution‐free physical preservation technique, and it has good application prospects.     

萌发绿豆中多酚类物质动态变化规律及其抗氧化活性的研究

以产自山西的明绿豆为实验材料,探究萌发前后绿豆中酚类化合物的动态变化规律及其抗氧化活性。采用传统方法进行绿豆的萌发,通过超声-微波协同萃取法提取绿豆及绿豆芽中的多酚类化合物,结合植物广靶代谢组学的方法对绿豆萌发前后多酚类化合物的提取液进行定性定量分析,明确酚类化合物的组成,分析萌发处理对绿豆多酚组成成分的影响及与其抗氧化活性的关系。结果表明:通过超高效液相色谱-质谱联用仪检测出46种多酚类化合物,筛选出44个差异代谢物,萌发前与萌发后绿豆芽的清除DPPH·能力分别为87.94%和96.24%,总抗氧化能力分别为28.56 U/mL和33.06 U/mL;最后通过KEGG查询得到筛选出的多酚类化合物参与了20个代谢通路。初步明确了绿豆中多酚类活性成分的物质基础,为绿豆的多酚类物质的合理利用与开发提供了参考。     

Effect of ethylene on total phenolics, antioxidant activity, and the activity of metabolic enzymes in mung bean sprouts

Mung bean sprouts are a well-known healthy food and their nutritional enhancement has become an important area of research due to the rapid expansion of the industry and their importance to human health. The purpose of this study was to investigate the effect of ethephon treatment at different concentrations on total phenolics metabolism and free radical scavenging-linked antioxidant activity. Mung bean sprouts treated with 100 mg/L of ethephon gave the highest total phenolics content of 0.594 mg/g FW, which was approximately 31 % higher than that of the control on the second day of germination. Total phenolics content in mung bean sprouts increased significantly by increasing glucose-6-phosphate dehydrogenase activity to resist oxidative stress caused by ethylene during early-stage germination. Total phenolics synthesis was greater than polymerization at this time. In contrast, polymerization of total phenolics gradually increased with the decrease in oxidative stress during late-stage germination. Total phenolics were polymerized to lignin because of the increase in guaiacol peroxidase activity. These results indicated that ethylene could improve the nutritional value of mung bean sprouts, and harmless stress factors could be used to enhance health-promoting compounds in the sprouts.     

Irradiation to kill Escherichia coli O157:H7 and Salmonella on ready-to-eat radish and mung bean sprouts

A study was carried out to evaluate the effectiveness of ionizing radiation in eliminating Escherichia coli O157:H7 and Salmonella on commercial ready-to-eat radish and mung bean sprouts and to assess the chemical and physical quality of these sprouts. The use of ionizing radiation was investigated as a means of reducing or totally inactivating these pathogens, if present, on the sprouts. Treatment of mung bean and radish sprouts with a dose of 1.5 and 2.0 kGy, respectively, significantly reduced E. coli O157:H7 and Salmonella to nondetectable limits. The total vitamin C content was gradually reduced with the increase in irradiation dose (P < 0.0001). However, the effect of storage interval on the loss of vitamin C was nonsignificant for radish sprouts and significant for mung bean sprouts (P < 0.04). The color, firmness, and overall visual quality of the tested sprouts were acceptable when effective doses were applied to both radish and mung bean sprouts. Therefore, ionizing radiation could be useful in reducing the population of pathogens on sprouts and yet retain acceptable quality parameters.     

Effects of plasma-activated water on microbial growth and storage quality of fresh-cut apple

Fresh-cut ‘Fuji’ apples were immersed for 5 min in plasma-activated water (PAW) generated, by plasma generated with sinusoidal voltages at 7.0 kHz with amplitudes of 6 kV, 8 kV, and 10 kV, designated PAW-6, PAW-8, and PAW-10, respectively. The control group was soaked in distilled water for 5 min instead of PAW. The results indicated that the growth of bacteria, molds, and yeasts was inhibited by PAW treatments during storage at 4 ± 1 °C, especially the microbial inactivation with PAW-8, which was the most efficient. PAW-8 reduced the microbial counts by 1.05 log₁₀CFU g⁻¹, 0.64 log₁₀CFU g⁻¹, 1.04 log₁₀CFU g⁻¹ and 0.86 log₁₀CFU g⁻¹ for aerobic bacteria (aerobic plate counts), molds, yeasts and coliforms on day 12, respectively. In addition, the bacterial counts of fresh-cut apples treated with PAW were <5 log₁₀CFU g⁻¹, which did not exceed to the existing China Shanghai local standard (DB 31/2012–2013) during 12 days of storage. PAW treatments reduced superficial browning of fresh-cut apples without affecting their firmness and titratable acidity. In addition, no significant change was observed in antioxidant content and radical scavenging activity between the PAW-treated and control groups. It is suggested that PAW is a promising method for preservation of fresh-cut fruits and vegetables, which is usually beneficial to the quality maintenance of fresh-cut fruits and vegetables during storage.     

Role of elicitation on the health-promoting properties of kidney bean sprouts

The influence of germination of kidney beans for 4, 6 and 8 days in different elicitors (ascorbic acid, folic acid, glutamic acid, glutamic acid/chitosan and lactic acid/chitosan) on the production of health-promoting ingredients was studied. Sprouts were characterized according to their protein profile, soluble phenolic compounds (SPC) and γ-aminobutyric acid (GABA) content. Additionally, the antioxidant and angiotensin-converting enzyme (ACE) inhibition activities of aqueous extracts from kidney bean elicited sprouts were determined. Elicitation by glutamic acid for 8 days led to the highest SPC and GABA accumulation in kidney bean sprouts and their extracts were selected based on their highest phytochemical content. These extracts also showed remarkable antioxidant and ACE-inhibitory activities. The IC₅₀ for ACE inhibition of glutamic acid-extracts increases 89-fold after the in-vitro gastrointestinal digestion. These results will contribute not only to improving the health-promoting potential of kidney bean sprouts but also to obtaining ingredients which might reduce oxidative stress and hypertension.     

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.