Effect of soaking and sprouting on iron and zinc availability in green and white faba bean (Vicia faba L.)

Effects of Typical Antimicrobials on Growth Performance, Morphology and Antimicrobial Residues of Mung Bean Sprouts

Antimicrobials may be used to inhibit the growth of micro-organisms in the cultivation of mung bean sprouts, but the effects on mung bean sprouts are unclear. In the present study, the growth performance, morphology, antimicrobial effect and antimicrobial residues of mung bean sprouts cultivated in typical antimicrobial solutions were investigated. A screening of antimicrobial residues in thick-bud and rootless mung bean sprouts from local markets showed that the positive ratios of chloramphenicol, enrofloxacin, and furazolidone were 2.78%, 22.22%, and 13.89%, respectively. The cultivating experiment indicated that the production of mung bean sprouts in antimicrobial groups was significantly reduced over 96 h (p < 0.05). The bud and root length of mung bean sprouts in enrofloxacin, olaquindox, doxycycline and furazolidone groups were significantly shortened (p < 0.05), which cultivated thick-bud and rootless mung bean sprouts similar to the 6-benzyl-adenine group. Furthermore, linear regression analysis showed average optical density of 450 nm in circulating water and average production had no obvious correlation in mung bean sprouts (p > 0.05). Antimicrobial residues were found in both mung bean sprouts and circulating water. These novel findings reveal that the antimicrobials could cultivate thick-bud and rootless mung bean sprouts due to their toxicity. This study also proposed a new question regarding the abuse of antimicrobials in fast-growing vegetables, which could be a potential food safety issue.

Comparative Study of the Bioactive Properties and Elemental Composition of Red Clover (Trifolium pratense) and Alfalfa (Medicago sativa) Sprouts during Germination

Considering the growing interest in functional foods, the identification of the individual species of elements is of great importance in understanding specific nutraceutical properties. The present study aims to compare the dynamic of the elemental content (K, Na, Ca, Mg, Fe, Cu, Zn, Mn, Ni, and Se), total polyphenols, and antioxidant activity of Trifolium pratense L. and Medicago sativa L. sprouts in different germination stages. The elemental profile was established by atomic absorption spectroscopy after the microwave acid digestion of the samples, while total polyphenols and anti-radical activity were evaluated by UV-Vis spectroscopic methods. Phenolic compounds and anti-radical activity of both alfalfa and red clover sprouts varied with germination stages. Germination can significantly increase the anti-radical activity in the first 3 days of germination, followed by a decline in the following days. An increase in total polyphenols was noticed, starting from the second day of germination in both plant species. There were significant (p < 0.05) differences for Ca, Na, Fe, K, Zn, and Mg contents among the sprouts, depending on the germination stage and plant species. The calcium contents of alfalfa ranged between 200.74 µg/g DW (raw seeds) and 2765.31 µg/g DW (sprouted), while in red clover between 250.83 µg/g DW and 601.59 µg/g DW. Maximum selenium content in alfalfa sprouts, reached in the 3rd day of germination (11.42 µg/g DW), exceeded the maximum value measured in red clover (9.42 µg/g DW). The data were subject to statistical processing using analysis of variance (ANOVA), multivariate analysis (PCA) and hierarchical clustering analysis (HCA).

Composition of legume soaking water and emulsifying properties in gluten-free bread

Soaking of legumes results in the loss of macronutrients, micronutrients and phytochemicals. Fibre, protein and phytochemicals found in legumes exert emulsifying activity that may improve the structure and texture of gluten-free bread. The legume soaking water of haricot beans, garbanzo chickpeas, whole green lentils, split yellow peas and yellow soybeans were tested in this study for functional properties and use as food ingredients. Composition, physicochemical properties and effect on the quality of gluten-free bread were determined for each legume soaking water. Haricot beans and split yellow peas released the highest amount of solids in the legume soaking water: 1.89 and 2.38 g/100 g, respectively. Insoluble fibre was the main constituent of haricot beans legume soaking water, while water-soluble carbohydrates and protein were the major fraction of split yellow peas. High quantities of phenolics (∼400 µg/g) and saponins (∼3 mg/g) were found in the legume soaking water of haricot beans, whole green lentils and split yellow peas. High emulsifying activity (46 and 50%) was found for the legume soaking water of garbanzo chickpeas and split yellow peas, probably due to their protein content and high ratio of water-soluble carbohydrates to dry matter. Such activity resulted in softer texture of the gluten-free bread. A homogeneous structure of crumb pores was found for split yellow peas, opposing that of whole green lentils. A balance between the contents of yeast nutrients and antinutrients was the likely basis of the different appearances.

Nutritional properties of green gram germinated in mineral fortified soak water: II. Effect of cooking on total and bioaccessible nutrients and bioactive components

The effect of pressure and microwave cooking on total and bioaccessible nutrients and bioactive components in whole and dehulled green gram (GG) germinated in mineral fortified soak water was studied. Whole GG was soaked in water fortified with iron (100 or 200 mg/100 ml) or zinc (50 or 100 mg/100 ml), germinated, cooked by two methods and analyzed. Results showed that method of cooking did not affect the nutrient composition of whole or dehulled grains, however, phytic acid and dietary fiber were higher in microwave cooked samples. Minor differences were noted in total and percent available nutrients in differently cooked samples, significance being observed only for starch, protein and zinc in few samples. Significant differences were observed among variations, wherein the mineral fortified samples had a higher level of bioaccessibility compared to non-fortified samples. Cooking reduced the content of bioactive components in germinated GG, though bioaccessibility was higher. Comparison between raw and cooked grains showed that starch digestibility increased on cooking, though protein digestibility was not affected significantly. Bioactive components were also lower in cooked samples in comparison to the raw counterparts. In conclusion, the cooking methods did not affect the nutrient composition of green gram germinated in mineral fortified soak water, though available nutrients were higher in cooked legumes.

Nutritional properties of green gram germinated in mineral fortified soak water: I. Effect of dehulling on total and bioaccessible nutrients and bioactive components

The study aimed at investigating the effect of germinating green gram (Vigna radiata, GG) in mineral fortified soak water on total and bioaccessible nutrients and bioactive components in whole and dehulled GG. Whole GG was soaked in water fortified with iron (100 or 200 mg/100 ml) or zinc (50 or 100 mg/100 ml), germinated and a portion was dehulled. Whole and dehulled grains were analyzed for selected total and in vitro digestible/bioaccessible constituents. GG germinated in water served as controls. GG germinated in mineral fortified soak water had high iron and zinc content in whole and dehulled grains. Protein and calcium content did not differ significantly. In vitro digestible starch and protein was higher in dehulled grains. A remarkable increase in bioaccessible iron and zinc was seen in grains germinated in mineral fortified water, the increase was more at lower level of fortification of levels for both minerals. Both total and bioaccessible bioactive components, total phenols, tannins and flavonoids were significantly lesser in grains germinated in fortified water. Germinating pulses in fortified water can be used as a pre-processing technology for fortification of minerals.