Antioxidant Potential and α-galactosides Content of Unhulled Seeds of Dark Common Beans Subjected to Tempe-type Fermentation with <i>Rhizopus microsporus</i> var. <i>chinensis</i> and <i>Lactobacillus plantarum</i>

Abstract

in tempe was 67%, 53% and 57% lower, respectively.Keywords: tempe, antioxidants, phenols, α-galactosides, common beans, processing IntroductionCommon bean (Phaseolus vulgaris) is consumed worldwide as rich and inexpensive source of protein, dietary fibers, vitamins and minerals. Dark common bean is also considered functional food (Vadivel et al., 2011) due to the high level of phenolic compounds present in the seed coat (Boateng et al., 2008).However, processes usually applied in order to prepare dry beans for the consumption (soaking and cooking) significantly diminish the antioxidant activity of the seeds, therefore decreasing their functional properties (Xu and Chang, 2009 (Granito et al.,2005;Reyes-Bastidas et al.,2010;Stodolak et al. 2013). When common beans are used as the fermentation substrate, the important advantage may be the decomposition of flatulence-producing α-galactosides, which limit the consumption of common beans in Western countries. However, the results are dependent on the enzymatic capabilities of a fungal strain used (Granito et al.,2005).Our previous study showed that the modified tempe-type fermentation with mixed inoculum consisting of Rhizopus microsporus var. chinensis tempe strain and Lactobacillum plantarum DSM 20174 improved the nutritional and some bioactive parameters of tempe from unhulled common beans, as compared to fungal fermentation alone (Starzyńska-Janiszewska et al.,2014).The aim of present research was to study the effect of mixedculture tempe-type fermentation of unhulled dark common beans on the antioxidant capacity and selected functional compounds (phenols and α-galactosides), as compared to raw and traditionally processed seeds (soaked and cooked). Materials and MethodsMaterials The fermentation substrate was color common bean Next, the spore density in the inoculum was measured by sporecounting in a Thoma chamber and optical microscopy.Raw beans Dry common bean seeds were lyophilised and stored at 4℃ for further analysis.Hydrothermally processed (soaked and cooked) beans Seeds (60 g) were thoroughly cleaned and rinsed three times with distilled water. Next, the seeds were soaked for 18 h at 24℃ in sterile distilled water (1:5 v/v) and then cooked in tap water (1:3 v/v) until soft (60 min). After that, water was discarded and the seeds were lyophilised and stored at 4℃.Mixed-culture tempe Dry common beans were thoroughly cleaned and rinsed three times with sterile distilled water. Next, they were dried for 24 h at 55℃ and then parted into halves with a universal seed grinder (Porkert, Czech Republic). Seeds portions Inoculated material was put into perforated plastic bags, 3 cm in height, and fermented for 24 h at 30℃. Fresh tempe products were sliced and steamed for 10 min. Tempeh samples were prepared in triplicate and mixed within the treatment. Next, they were lyophilized and stored at 4℃ for further analysis.Analytical methods Hydroxyl radical scavenging activity was measured in phosphate buffer (0.02 M, pH 7.4) extracts according to Marambe et al.(2008). T...

Thermal and enzymatic treatments reduced α‐galactooligosaccharides in common bean ( Phaseolus vulgaris L.) flour

“…The enzyme complex could also have a hydrolyzing effect on tannins. The results agree with those reported by Starzyńska‐Janiszewska, Stodolak, and Wikiera (), they obtained a reduction of 85.9% on tannins content from water‐soaked and cooked common beans.…”

“…This tendency is different for the results obtained by Piecyk et al () of 25.7% on autoclaved Raba beans. The flavonoids level did not decrease ( p > .05) with any of the processes, which is consistent with the results from Starzyńska‐Janiszewska et al (), where there was a minimum reduction of flavonoids (6.9%). On the anthocyanins content, the levels were nondetectable after treatments for both beans (Table ).…”

“…Singh and Kayastha (2013) were able to reduce the α-GOS content from soybean flour, specifically 80.0% of raffinose and 85.0% of stachyose, using a Cicer α-galactosidase purified from white chickpea. Song, Chang, and Ibrahim (2009) successfully eliminated the α-GOS from a pinto bean paste treated with a crude α-galactosidase produced by Aspergillus awamori NRRL 4869. The soaking process using 1% NaHCO 3 solution increases the permeability of the coat and cotyledon, compared to distilled water, probably due to a mechanism of ion exchange or chelation.…”

Polyphenols in Common Beans (Phaseolus vulgaris L.): Chemistry, Analysis, and Factors Affecting Composition

“…Generally, thermal processing methods, such as cooking and steaming, cause a significant decrease in antioxidant activity (Table ). For instance, Starzyńska‐Janiszewska, Stodolak, and Wikiera () reported that soaking and cooking significantly reduced the free radical scavenging activity and reducing power of common beans. Chen et al.…”

“…Generally, thermal processing methods, such as cooking and steaming, cause a significant decrease in antioxidant activity (Table 5). For instance, Starzyńska-Janiszewska, Stodolak, and Wikiera (2015) reported that soaking and cooking significantly reduced the free radical scavenging activity and reducing power of C 2018 Institute of Food Technologists ® Vol. 17, 2018 r Comprehensive Reviews in Food Science and Food Safety 1533 Abbreviations, TOSC, total oxyradical scavenging capacity; VCE, vitamin C equivalent; TEAC, Trolox equivalent antioxidant activity; TE, Trolox equivalent; ABTS, 2, 2 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging assay; DPPH, 1, 1-diphenyl-2-picrylhydrazyl free radical scavenging assay; OH, hydroxyl radical absorbance capacity; ORAC, oxygen radical absorbance capacity; LPI, lipid peroxidation inhibition; OH, hydroxyl free radical scavenging assay; FRAP, ferric reducing antioxidant potential assay; RP, reducing power.…”