scholarly journals Optimization of the Bioactivation of Isoflavones in Soymilk by Lactic Acid Bacteria

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 963
Author(s):  
Jon Kepa Izaguirre ◽  
Leire Barañano ◽  
Sonia Castañón ◽  
Itziar Alkorta ◽  
Luis M. Quirós ◽  
...  

Soybeans and soy-based products contain isoflavones which can be used for nutraceutical and medical applications. In soybeans and in unfermented soy foods, isoflavones are normally present as glycosides. Isoflavone glycosides can be enzymatically converted to isoflavone aglycones, thus releasing the sugar molecule. The effective absorption of isoflavones in humans requires the bioconversion of isoflavone glycosides to isoflavone aglycones through the activity of the enzyme β-glucosidase. The objective was to assess the capacity of 42 bacterial strains (belonging to Lactobacillus, Streptococcus and Enterococcus) to produce β-glucosidase activity. The strain that showed the highest β-glucosidase activity (Lactobacillus plantarum 128/2) was then used for the optimization of the bioconversion of genistin and daidzin present in commercial soymilk to their aglycone forms genistein and daidzein. The contribution of process parameters (temperature, inoculum size, time) to the efficiency of such bioactivation was tested. Lactobacillus plantarum 128/2 was able to completely bioactivate soymilk isoflavones under the following conditions: 25 °C temperature, 2% inoculum size and 48 h process time. These results confirm the suitability of lactic acid bacteria for the bioactivation of isoflavones present in soymilk and provide an interesting candidate (L. plantarum 182/2) for food industries to perform this transformation.

2020 ◽  
Vol 74 (5) ◽  
pp. 391-397
Author(s):  
Janine Anderegg ◽  
Florentin Constancias ◽  
Leo Meile

Tyramine is a health-adverse biogenic amine, which can accumulate in fermented foods like cheese by decarboxylation of the free amino acid tyrosine by either starter cultures or resident microbes such as lactic acid bacteria including Enterococcus spp., respectively. Our study aimed to show the effect of sodium chloride concentrations on tyramine production as well as to characterise bacterial strains as anti-tyramine biocontrol agents in a 2 mL micro-cheese fermentation model. The effect of sodium chloride on tyramine production was assayed with tyramine producing strains from eight different species or subspecies. Generally, an increase in sodium chloride concentration enhanced tyramine production, e.g. from 0% to 1.5% of sodium chloride resulted in an increase of tyramine of 870% with a Staphylococcus xylosus strain. In the biocontrol screening among lactic acid bacteria, a Lactobacillus plantarum JA-1199 strain was screened that could consume in successful competition with other resident bacteria tyrosine in the micro-cheese model as a source of energy gain. Thereby tyramine accumulation was reduced between 4% to 99%. The results of this study disclose a feasible strategy for decreasing tyramine concentration and increasing the safety level of fermented food. It is an example of development and application of bacterial isolates as starter or protective cultures in food, a biocontrol topic, which Oreste Ghisalba – in his project evaluation function of SNF and later on CTI – was promoting with great emphasis in our ETH Food Biotechnology research group.


1999 ◽  
Vol 65 (12) ◽  
pp. 5590-5593 ◽  
Author(s):  
Masja N. Nierop Groot ◽  
Jan A. M. de Bont

ABSTRACT We examined the involvement of Mn(II) in the conversion of phenylalanine to benzaldehyde in cell extracts of lactic acid bacteria. Experiments performed with Lactobacillus plantarumdemonstrated that Mn(II), present at high levels in this strain, is involved in benzaldehyde formation by catalyzing the conversion of phenylpyruvic acid. Experiments performed with various lactic acid bacterial strains belonging to different genera revealed that benzaldehyde formation in a strain was related to a high Mn(II) level.


2021 ◽  
Vol 11 (13) ◽  
pp. 5765
Author(s):  
Joo-Yun Kim ◽  
Eun-Jung Choi ◽  
Jae-Ho Lee ◽  
Myeong-Seok Yoo ◽  
Keon Heo ◽  
...  

Vitamin B2, also known as riboflavin, is essential for maintaining human health. The purpose of this study was to isolate novel lactic acid bacteria that overproduce vitamin B2 and to validate their potential as probiotics. In this study, Lactobacillus plantarum HY7715 (HY7715) was selected among lactic acid bacteria isolated from Kimchi. HY7715 showed a very high riboflavin-producing ability compared to the control strain due to the high expression of ribA, ribB, ribC, ribH, and ribG genes. HY7715 produced 34.5 ± 2.41 mg/L of riboflavin for 24 h without consuming riboflavin in the medium under optimal growth conditions. It was able to produce riboflavin in an in vitro model of the intestinal environment. In addition, when riboflavin deficiency was induced in mice through nutritional restriction, higher levels of riboflavin were detected in plasma and urine in the HY7715 administration group than in the control group. HY7715 showed high survival rate in simulated gastrointestinal conditions and had antibiotic resistance below the cutoff MIC value suggested by the European Food Safety Authority; moreover, it did not cause hemolysis. In conclusion, HY7715 could be considered a beneficial probiotic strain for human and animal applications, suggesting that it could be a new alternative to address riboflavin deficiency.


2015 ◽  
Vol 6 (4) ◽  
pp. 505-512 ◽  
Author(s):  
M. Yakovlieva ◽  
T. Tacheva ◽  
S. Mihaylova ◽  
R. Tropcheva ◽  
K. Trifonova ◽  
...  

In recent years, many authors have investigated the possible antidiabetic effect of lactic acid bacteria. Lactobacillus species constitute a major part of the lactic acid bacteria group and have been found to exhibit beneficial effects on the development of diabetes and its complications. In the current study, we investigated the effects of newly characterised Bulgarian Lactobacillus strains, Lactobacillus brevis 15 and Lactobacillus plantarum 13, on blood glucose levels and body weight of rats fed a fructose-enriched diet. An experiment was conducted over a period of 8 weeks with 24 2-month-old Wistar rats randomly assigned to receive a standard diet (Con, control group), fructose-enriched diet (Fr group), standard diet with probiotics given twice a week (Pro group), and fructose-enriched diet with probiotics given twice a week (Pro+Fr group). At the end of the experimental period, a statistically significant increase in body weight was observed in all experimental groups (P<0.0001). The highest rise was seen in the fructose group (Fr, 169±19 g), followed by the Pro+Fr group (153±15 g), Pro group (149±13 g), and Con group (141±5 g). Moreover, the final blood glucose levels had risen significantly in the groups receiving fructose either without (Fr; P<0.0001) or with lactobacilli (Pro+Fr; P=0.002), while the rise was insignificant in the group of rats given probiotic supplementation only (Pro, P=0.071) and inexistent in the Con group (P=0.999). The highest elevation of blood glucose levels was observed in the Fr group (3.18 mmol/l), followed by the Pro+Fr group (2.00 mmol/l) whereas the Pro group showed the lowest levels (0.60 mmol/l). The results of our study suggest that the newly characterised Bulgarian Lactobacillus strains, L. brevis 15 and L. plantarum 13, could be considered as possible probiotics and might be able to prevent some metabolic disturbances.


1991 ◽  
Vol 54 (5) ◽  
pp. 349-353 ◽  
Author(s):  
AMECHI OKEREKE ◽  
THOMAS J. MONTVILLE

Twenty-three strains of lactic acid bacteria were tested by deferred antagonism methods for bacteriocin-like activity against types A and B spores from 11 proteolytic and nonproteolytic Clostridium botulinum strains. Pediococcus pentosaceus ATCC 43200, Pediococcus pentosaceus ATCC 43201, Lactococcus lactis subsp. lactis ATCC 11454, Lactobacillus acidophilus N2, Lactobacillus plantarum Lb75, Lactobacillus plantarum Lb592, and Lactobacillus plantarum BN exhibited bacteriocin-like inhibition of all C. botulinum strains tested. By excluding inhibition due to hydrogen peroxide, acid, and lytic phage and confirming their proteinaceous nature, the inhibitors were confirmed as bacteriocins. The minimum inhibitory cell concentrations (MICC) required to produce 1 mm radius inhibition zones were determined by direct antagonism testing. Only strains 43200, 43201, 11454, and N2 were inhibitory when cultured simultaneously with the botulinal spores. The MICCs of strains antagonistic to C. botulinum spores by simultaneous testing ranged between 1.6 × 105and 4.7 × 107CFU/ml. Based on the MICCs, P. pentosaceus 43200 was most inhibitory to C. botulinum.


2018 ◽  
Vol 6 (2) ◽  
pp. 500-508
Author(s):  
Julie Ann A. Arcales ◽  
Garner Algo L.Alolod

Isolation and characterization of bacteria in food products are important to determine and distinguish the beneficial or harmful effects of microbiota in certain samples. Lactic acid bacteria in food products had long been associated to good factors as food preservatives and with added fermentation metabolites. This study isolated and characterized lactic acid bacteria from burong bangus. The culture and purification process of bacteria isolation resulted to 4 strains of lactic acid bacteria namely Enterococcus faecalis, Tetragenococcus muriaticus, Lactobacillus delbrueckii subp. delbrueckii and Carnobacterium divergens. High enzymatic activity were observed with E. faecalis particularly on lipase and protease assay. While C. divergens have no enzymatic activity against lipase, protease, amylase and cellulase. The antimicrobial property of L. delbrueckii is only susceptible to amoxicillin unlike the other three bacteria isolates. No antagonistic activity were observed with the four bacterial strains against Bacillus subtilis, Staphylococcus aureus and Escherichia coli. The result of this study showed promising benefits to the industry especially in developing countries like the Philippines because population are not yet so aware of this organisms and the benefits that can be derived through their consumption.


Pro Food ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 673
Author(s):  
Ade Irma Juliana ◽  
Moegiratul Amaro ◽  
Nazaruddin Nazaruddin

ABSTRACT               This study aims to determine the effect of Lactobacillus plantarum bacterial starter concentration on some quality of the porang flour. This study used experimental design one-factor Completely Randomized Design (CRD) consisted of BAL concentration (KB) of Lactobacillus plantarum with 6 treatments which is 0%, 5%, 10%, 15%, 20% and 25%. Each of treatment were repeated three times to obtain 18 unit samples. Data from observations were analyzed using analysis of variance (Analysis of Variance) at 5% significance level using Co-stat software. If there are significant differences, a further Polynomial Orthogonal and Honestly Significant Difference (BNJ) test is performed at a level of 5%. The parameters observed included pH value, protein content, water content, yield, total lactic acid bacteria, organoleptic parameters of color and aroma (hedonic and scoring). The results showed that the concentration of Lactobacillus plantarum bacterial 20% was the best treatment in producing porang flour, pH value 5.72, protein content 6.49%, yield 9.33%, total lactic acid bacteria 6.66 log CFU / g and color rather brown and slightly acidic aroma and somewhat preferred by panelists. Keywords: Porang flour, starter concentration, Lactobacillus plantarum   ABSTRAK             Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi starter bakteri Lactobacillus plantarum terhadap beberapa komponen mutu tepung porang. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan satu faktor yakni konsentrasi BAL (KB) jenis Lactobacillus plantarum dengan 6 perlakuan yaitu 0%, 5%, 10%, 15%, 20% dan 25%. Masing-masing perlakuan diulang sebanyak 3 kali sehingga diperoleh 18 unit percobaan. Data hasil pengamatan dianalisis menggunakan analisis keragaman (Analysis of Variance) pada taraf nyata 5% menggunakan software Co-stat. Apabila terdaapat beda nyata, dilakukan uji lanjut Polynomial Orthogonal dan Beda Nyata Jujur (BNJ) pada taraf 5%. Adapun parameter yang diamati meliputi nilai pH, kadar protein, kadar air, rendemen, total bakteri asam laktat, parameter organoleptik warna dan aroma (hedonik dan scoring). Hasil penelitian menunjukkan bahwa konsentrasi strater bakteri Lactobacillus plantarum 20% merupakan perlakuan terbaik dalam menghasilkan tepung porang nilai pH 5,72, kadar protein 6,49%, rendemen 9,33%, total bakteri asam laktat 6,66 log CFU/g serta warna agak coklat dan aroma agak asam serta agak disukai panelis.    Kata Kunci: Tepung porang, konsentrasi starter, Lactobacillus plantarum


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