Comparative Growth Behaviour and Biofunctionality of Lactic Acid Bacteria During Fermentation of Soy Milk and Bovine Milk

Effect of different strains on quality characteristics of soy yogurt: Physicochemical, nutritional, safety features, sensory, and formation mechanism

The purpose of the study was to explore effect of four different strains on quality characteristics of soy yogurt. The results showed that four strains were all related to the genus Lactobacillus and N1 was Lacticaseibacillus rhamnosus, N2 was Lacticaseibacillus paracasei, N3 was Lacticaseibacillus plantarum, and N4 was Lacticaseibacillus acidophilus. The result analysis of biochemical, sensory, nutritional, functional and safety properties of fermentation process and end products showed that the soy yogurt fermented with L. rhamnosus N1 had the highest isoflavone content and the lowest phytic acid content; the soy yogurt fermented with L. paracasei N2 had the highest content of free amino acids and oligosaccharides, the lowest content of trypsin inhibitors; the soy yogurt fermented with L. plantarum N3 had the lowest oil content; the soy yogurt fermented with L. acidophilus N4 had optimal functional properties. In summary, N4 was suitable as a fermentation strain for soymilk.

Peptidomics-based identification of antihypertensive and antidiabetic peptides from sheep milk fermented using Limosilactobacillus fermentum KGL4 MTCC 25515 with anti-inflammatory activity: in silico, in vitro, and molecular docking studies

This study investigated the synthesis of bioactive peptides from sheep milk through fermentation with Limosilactobacillus fermentum KGL4 MTCC 25515 strain and assessed lipase inhibition, ACE inhibition, α-glucosidase inhibition, and α-amylase inhibition activities during the fermentation process. The study observed the highest activities, reaching 74.82%, 70.02%, 72.19%, and 67.08% (lipase inhibition, ACE inhibition, α-glucosidase inhibition, and α-amylase inhibition) after 48 h at 37°C, respectively. Growth optimization experiments revealed that a 2.5% inoculation rate after 48 h of fermentation time resulted in the highest proteolytic activity at 9.88 mg/mL. Additionally, fractions with less than 3 kDa of molecular weight exhibited superior ACE-inhibition and anti-diabetic activities compared to other fractions. Fermentation of sheep milk with KGL4 led to a significant reduction in the excessive production of NO, TNF-α, IL-6, and IL-1β produced in RAW 267.4 cells upon treatment with LPS. Peptides were purified utilizing SDS-PAGE and electrophoresis on 2D gels, identifying a maximum number of proteins bands ranging 10-70 kDa. Peptide sequences were cross-referenced with AHTPDB and BIOPEP databases, confirming potential antihypertensive and antidiabetic properties. Notably, the peptide (GPFPILV) exhibited the highest HPEPDOCK score against both α-amylase and ACE.

Protein composition and nutritional aspects of pea protein fractions obtained by a modified isoelectric precipitation method using fermentation

Pea albumins are promising for their nutritional, biological, and techno-functional properties. However, this fraction is usually discarded in the industry due to its low protein content compared to globulin fraction and the presence of some anti-nutritional compounds. In the present study, we used an alternative method of pea protein extraction based on alkaline solubilization/isoelectric precipitation in which the reduction of pH was achieved by lactic acid fermentation using specific starters instead of mineral acids. Hence, the main objective of this study was to examine the protein profile and the content of anti-nutritional and nutritional active compounds in pea albumin-rich fractions obtained by the isoelectric extraction method without (control) or with fermentation with different lactic acid bacteria (Streptococcus thermophilus, Lactiplantibacillus plantarum, and their co-culture). Different pea cultivars (Cartouche, Ascension, and Assas) were used here for their differences in protein profile. The results revealed a higher total nitrogen content in albumin-rich fraction for fermented samples and, in particular, for co-culture. The majority of total nitrogen was determined as non-protein (~50%), suggesting the degradation of proteins by LAB to small peptides and amino acids, which were solubilized in the soluble fraction (albumin) as confirmed by size exclusion chromatography (SEC-HPLC) analysis. Moreover, the higher antioxidant activity of fermented albumin samples was attributed to the production of small peptides during extraction. Lactic acid fermentation also resulted in a significant reduction of trypsin inhibitor activity, α-galactoside, and phytic acid content of this fraction compared to control.

Fermentation Kinetics, Microbiological and Physical Properties of Fermented Soy Beverage with Acai Powder

In this study, the effects of the fermentation kinetics, determination of the number of lactic acid bacteria, texture, water holding capacity, and color of fermented soy beverages with acai powder (3 and 6% w/v) were investigated. The addition of acai powder significantly influenced the fermentation kinetics based on changes in pH, accelerating fermentation in the initial period. The results showed that the acai additive did not affect the enumeration of Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis. The presence of acai inhibited the proliferation of Streptococcus thermophilus compared to the soy beverage without acai powder added. However, the higher the acai additive, the more Streptococcus thermophilus bacteria were detected: 4.39 CFU/g for 6% acai powder sample and 3.40 CFU/g for 3% acai powder sample. The addition of acai to the soy beverage reduced its firmness, consistency, cohesiveness, and viscosity index after fermentation. A slight difference was observed in the lightness and whiteness of fermented soy beverages with 3% and 6% acai powder.

Submerged and Solid-State Fermentation of Spirulina with Lactic Acid Bacteria Strains: Antimicrobial Properties and the Formation of Bioactive Compounds of Protein Origin

The aim of this study was to investigate the changes in bioactive compounds (L-glutamic acid (L-Glu), gamma-aminobutyric acid (GABA) and biogenic amines (BAs)) during the submerged (SMF) and solid-state (SSF) fermentation of Spirulina with lactobacilli strains (Lacticaseibacillus paracasei No. 244; Levilactobacillus brevis No. 173; Leuconostoc mesenteroides No. 225; Liquorilactobacillus uvarum No. 245). The antimicrobial properties of the untreated and fermented Spirulina against a variety of pathogenic and opportunistic strains were tested. The highest concentrations of L-Glu (3841 mg/kg) and GABA (2396 mg/kg) were found after 48 h of SSF with No. 173 and No. 244 strains, respectively. The LAB strain used for biotreatment and the process conditions, as well as the interaction of these factors, had statistically significant effects on the GABA concentration in Spirulina (p ≤ 0.001, p = 0.019 and p = 0.011, respectively). In all cases, the SSF of Spirulina had a higher total BA content than SMF. Most of the fermented Spirulina showed exceptional antimicrobial activity against Staphylococcus aureus but not against the other pathogenic bacteria. The ratios of BA/GABA and BA/L-Glu ranged from 0.5 to 62 and from 0.31 to 10.7, respectively. The GABA content was correlated with putrescine, cadaverine, histamine, tyramine, spermidine and spermine contents. The L-glutamic acid concentration showed positive moderate correlations with tryptamine, putrescine, spermidine and spermine. To summarize, while high concentrations of desirable compounds are formed during fermentation, the formation of non-desirable compounds (BAs) must also be considered due to the similar mechanism of their synthesis as well as the possibility of obtaining high concentrations in the end products.

Genomic and probiotic attributes of Lactobacillus strains from rice-based fermented foods of North Eastern India

The probiotic attributes and genomic profiles of amylase-producing Lactobacillus strains from rice-based fermented foods of Meghalaya in the North-Eastern India were evaluated in the study. A preliminary screening of 17 lactic acid bacteria strains was performed based on their starch hydrolysis and glucoamylase activities. Out of 17 strains, 5 strains (L. fermentum KGL4, L. rhamnosus RNS4, L. fermentum WTS4, L. fermentum KGL2, and L. rhamnosus KGL3A) were selected for further characterization of different probiotic attributes. Whole-genome sequencing of two of the best strains was carried out using a shotgun sequencing platform based on their rich probiotic attributes. The EPS production was in the range of 2.89-3.92 mg/mL. KGL2 (41.5%) and KGL3A (41%) showed the highest antioxidant activity. The highest antibiotic susceptibility was exhibited by all the five Lactobacillus strains against ampicillin, ranging from 24.66 to 27.33 mm. The lactobacilli isolates used in the study could survive the simulated gastric/intestinal juices. Genomic characterization of KGL4 and KGL3A illustrated their possible adherence to the intestinal wall, specialized metabolic patterns, and possible role in boosting host immunity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05633-8.

Purification and Characterization of Novel Antihypertensive and Antioxidative Peptides From Whey Protein Fermentate: In Vitro, In Silico, and Molecular Interactions Studies

OBJECTIVE

The goal of this research was to purify and characterize the novel angiotensin-converting enzyme (ACE)-inhibitory and antioxidant peptides from fermented whey protein concentrate produced by Lactobacillus paracasei and Saccharomyces cerevisiae in a co-fermentation system.

METHOD

Whey protein fermented with lactic acid bacteria and yeast culture was analyzed for antioxidative, ACE inhibition, as well as anti-inflammatory activity followed by SDS-PAGE, isoelectric focusing, and 2-dimensional (2D) analysis. Anti-inflammatory activity of whey protein fermentate was also studied on the RAW 264.7 cell line. The bioactive peptides were separated from the whey protein fermentate using reverse-phase high-performance liquid chromatography (RP-HPLC) and reverse-phase liquid chromatography mass spectrometry (RPLC/MS), and thus identification and characterization of purified bioactive peptide was performed.

RESULTS

Whey protein fermentate samples' bioactivity was analyzed at specific time intervals at 12, 24, 36, and 48 hours at 37 °C for M11 and at 25 °C for WBS2A. The development settings (incubation time [12, 24, 36, and 48 hours) and inoculation rates [1.5%, 2.0%, and 2.5%]) were optimized for peptide synthesis via the o-phthaldialdehyde (OPA) method (proteolytic activity). Maximum proteolytic activity was observed at 37 °C for M11 (6.50 mg/mL) and at 25 °C for WBS2A (8.59 mg/mL) for 48 hours of incubation. Protein profiling was carried out using SDS-PAGE and 2D gel electrophoresis, in which Sodium dodecyl-sulfate (SDS) exhibited protein bands in the 10- to 55-kDa range, while 2D showed protein bands varying from 10 to 70 kDa. Every spot from 2D was digested by trypsin and identified by RPLC/MS. Protein fractionations (3- and 10-kDa permeates) were carried out employing RP-HPLC. Whey protein fermentate has anti-inflammatory action in RAW 264.7 macrophages that have been exposed to lipopolysaccharide. A molecular docking system was also used to investigate the interactions of peptides (AFLDSRTR, ILGAFIQIITFR) with human myeloperoxidase enzyme.

CONCLUSIONS

The antihypertensive and antioxidative peptides discovered from whey protein fermentate may be helpful in the design of pharmacologically active healthy ingredients in the upcoming years.

Bioactivity of Organic Fermented Soymilk as Next-Generation Prebiotic/Probiotics Mixture

Fermented soymilk (soymilk yogurt) was made by fermenting soymilk with five probiotic bacterial strains (Lactobacillus plantarum ATCC 14917, Lactobacillus casei DSM 20011, Lactobacillus acidophilus ATCC 20552, Lactococcus thermophilus DSM 20259, and Bifidobacterium longum B41409) that were used as monocultures and combined with them as consortia cultures. Seven pathogenic strains, E. coli O157H7, S. aureus As4, S. typhimurium As3, S. shigae As2, L. monocytogenes As1, P. aeruginosa ATCC 27853, and B. cereus Dsmz 345, were used to study the antibacterial activity of fermented soymilk by agar well diffusion assay. Results indicated that Gram-negative pathogenesis was more sensitive to probiotic cultures than Gram-positive pathogenesis. E. coli O15H7, S. typhimirium As3, and Shigella shigae As2 were more sensitive to probiotic cultures, presenting inhibition zone diameters (IZA) ranging from 10 to 20 mm, 12 to 16 mm, and 10 to 16 mm, respectively. At the same time, P. aeruginosa Atcc 27853 showed the lowest (IZA), ranging from 3 mm to 8 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at various concentrations of soymilk fermented by T1, T4, and T5, ranging from 0.031 mg/mL to 1 mg/mL against pathogenic bacterial strains. The sensory properties of FSM were evaluated, and sensory analysis during soymilk fermentation showed significant improvement. The effect of shelf life (storage period) on FSM quality and properties was evaluated; during shelf life (storage period), FSM saved its properties and quality after 28 days of cold storage. Finally, it was stated that the soymilk yogurt can be used as a substitute for buffalo and cow milk for therapeutic feeding in the future.

Facile synthesis of starch and tellurium doped SrO nanocomposite for catalytic and antibacterial potential: In silico molecular docking studies

A chemical co-precipitation route was used to synthesize novel strontium oxide (SrO), SrO-starch composite and various tellurium (Te) concentrations were incorporated in SrO-starch composite. This study aims to enhance the catalytic activities and bactericidal behavior of SrO, SrO-starch composite with different percentage concentrations of Te doping and a fixed amount of starch nanoparticles. XRD affirmed that the dopant contribution was investigated to improve crystallinity. Surface morphological characteristics and elemental composition evaluation were determined using an FE-SEM and EDS exhibit a doping concentration of an element in the synthesized products. The configuration of Sr-O-Sr bonds and molecular vibrations has been indicated by FTIR spectra. In addition, dye degradation of prepared samples was investigated through catalytic activity (CA) in the existence of NaBH₄ act as a reduction representative. The Te-doped SrO-starch composite indicates superior catalytic activity and shows a degradation of Methylene blue dye (91.4 %) in an acidic medium. The synthesis nanocatalyst demonstrated impressive antibacterial activity against Staphylococcus aureus (S. aureus) at high and low concentrations exhibiting zones of inhibition 9.30 mm as compared to ciprofloxacin. Furthermore, molecular docking studies of synthesized nanocomposites were performed against selected enzyme targets, i.e., β-lactamase_E.coli and DNA Gyrase_E.coli.

Characterization of Angiotensin I-Converting Enzyme (ACE) inhibitory peptides produced in fermented camel milk (Indian breed) by Lactobacillus acidophilus NCDC-15

Fermented camel milk provides many health benefits like antidiabetic activity, anti-hypertensive activity etc. Fermented camel milk contains IPP or VPP rich ACE inhibitory peptides. The aim of this study was to spot the novel Angiotensin I-Converting Enzyme inhibitory peptides liberated by the potent proteolytic Lactobacillus acidophilus NCDC-15 from camel milk (Indian breed). NCDC-15 had exhibited maximum PepX activity (0.655) and ACE-inhibitory activity (78.33%) at 12 and 48 h of incubation at 37 °C respectively. Proteolytic activity was measured using o-phthaldialdehyde method and observed maximum (0.976 OD) at 2% of inoculation for 12 h of incubation at 37 °C. Water soluble extracts derived from fermented camel milk were ultrafiltered through 3 kDa, 5 kDa and 10 kDa membrane filters from which 3 kDa permeates (48.01% peptides production & 49.46% ACE-inhibition) and 10 kDa permeates (55.04% peptides production & 42.40% ACE-inhibition) had shown maximum peptides production and ACE-inhibitory activity. Overall, 24 peptides were identified from the samples of 3 kDa permeates [6 fractions (K1, L1, M1, N1, O1 and P1)] and 10 permeates [5 fractions (S, T, U, V and W)]. Novel peptide (AIGPVADLHI) was matched with k-casein in AHTPDB database and other peptides were also found matched with α and β-caseins of camel milk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05357-9.

Biological and Cosmetical Importance of Fermented Raw Materials: An Overview

The cosmetics industry is currently looking for innovative ingredients with higher bioactivity and bioavailability for the masses of natural and organic cosmetics. Bioferments are innovative ingredients extracted from natural raw materials by carrying out a fermentation process with appropriate strains of microorganisms. The review was conducted using the SciFinder database with the keywords “fermented plant”, “cosmetics”, and “fermentation”. Mainly bioferments are made from plant-based raw materials. The review covers a wide range of fermented raw materials, from waste materials (whey with beet pulp) to plant oils (F-Shiunko, F-Artemisia, F-Glycyrrhiza). The spectrum of applications for bioferments is broad and includes properties such as skin whitening, antioxidant properties (blackberry, soybean, goji berry), anti-aging (red ginseng, black ginseng, Citrus unshiu peel), hydrating, and anti-allergic (aloe vera, skimmed milk). Fermentation increases the biochemical and physiological activity of the substrate by converting high-molecular compounds into low-molecular structures, making fermented raw materials more compatible compared to unfermented raw materials.

Inulin addition improved probiotic survival in soy-based fermented beverage

Currently, the growing demand for non-dairy functional foods leads to the constant development of new products. The objective of the present work was to obtain a soy-based fermented beverage employing the strains Lactiplantibacillus plantarum CIDCA 8327 or Lacticaseibacillus paracasei BGP1 and to analyze the effect of post-fermentation addition of inulin of low or high average polymerization degree on the bacterial resistance. Also, the antimicrobial and antioxidant activity of the fermented soy-based beverages were analyzed. The soy-based matrix was shown to be a suitable substrate for the growth of both lactic acid bacteria, and the fermented beverages obtained presented bioactive properties such us antioxidant activity and bactericidal effect against pathogen microorganisms. The addition of inulin after the fermentation process avoid the hydrolysis and so, preserve its polymerization degree and thus the potential prebiotic effect. The incorporation of inulin to the soy-based fermented beverages increased the bacterial count after 30 days of refrigerated storage up to 8.71 ± 0.15 and 8.41 ± 0.10 log CFU/mL for L. paracasei and L. planatrum respectively. The resistance to the gastrointestinal conditions of the strain L. paracasei BGP1 in the fermented beverage was improved up to 70% when inulin of high polymerization degree was added. Meanwhile the strain L. plantarum CIDCA 8327 showed a survival of 97 and 94% in the fermented beverage added with inulin of low or high polymerization degree, respectively. These results contribute to the development of non-dairy products containing inulin and probiotics and the diversification agri-based functional foods.

Peptidomic profiling of fermented goat milk: considering the fermentation-time dependent proteolysis by Lactobacillus and characterization of novel peptides with Antioxidative activity

In this study, antioxidant activities were evaluated for goat milk fermented with Lactobacillus helveticus MTCC 5463. The fermentation conditions (inoculation rate and incubation time) were optimized by estimating proteolytic action of Lactobacillus. SDS-PAGE and 2D gel electrophoresis were carried out for identification of molecular weight and purification of identified peptides. 3 and 10 kDa peptides fractions were obtained through ultrafiltration and also by using RP-HPLC. Then, spots from 2D and fractions from RP-HPLC were also evaluated in RP-LC/MS for identification and characterization of peptides. Identified peptides were matched with online database of goat milk i.e. BLASTp (NCBI) and Protein information resource database (PIR) and subsequently, antioxidant activity of these peptides were also confirmed with BIOPEP database. However, antioxidative peptides from fermented goat milk with Lactobacillus helveticus MTCC 5463 could be produced in developing functional goat milk yoghurt.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05243-w.

Development of probiotics beverage using cereal enzymatic hydrolysate fermented with Limosilactobacillus reuteri

Although most probiotic products are milk based, lactose intolerance and vegetarianism inspired the idea of developing nondairy probiotic products. In this study, probiotic beverages were produced from four enzymatically hydrolyzed cereal substrates (coix seed, quinoa, millet, and brown rice) and fermented by Limosilactobacillus reuteri. Fermentation parameters, including pH, titratable acidity, viable count, organic acids, and volatile components were determined. Results showed that the pH values decreased and titratable acidity increased with the fermentation process (p < .05). Although the final pH in all samples was below 4.0, the growth of L. reuteri was not significantly inhibited by low pH. The number of viable bacteria (12.96 log CFU/ml) in coix seed substrate was significantly higher than that in other samples after the fermentation for 24 h (p < .05). Lactic acid and acetic acid were the main organic acids after fermentation and the highest in quinoa (lactic acid: 7.58 mg/ml; acetic acid: 2.23 mg/ml). The flavor analysis indicated that there were differences in the flavor components of different cereal beverages. Forty‐nine volatile compounds were identified in four beverages, including acids, alcohols, aldehydes, ketones, and esters. The results of the electronic tongue showed that the umami taste of the fermented coix seed was better than that of other samples, displaying the more pleasant taste characteristics. In conclusion, it is feasible to prepare probiotic symbiotic cereal beverage with L. reuteri as starter culture. This study provides a reference for the development of nondairy probiotic products.

Effect of Coix Seed Extracts on Growth and Metabolism of Limosilactobacillus reuteri

Coix seed (Coix lachryma-jobi L.) is an important nourishing food and traditional Chinese medicine. The role of their bioactive constituents in physiology and pharmacology has received considerable scientific attention. However, very little is known about the role of coix seed bioactive components in the growth of Limosilactobacillus reuteri (L. reuteri). This study aimed to evaluate the effects of coix seed extract (CSE) on the growth, acidifying activity, and metabolism of L. reuteri. The results showed that CSE can increase the growth and acidifying activity of L. reuteri compared with the control group. During the stationary phase, the viable bacteria in the medium supplemented with coix seed oil (CSO, 13.72 Log₁₀ CFU/mL), coix polysaccharide (CPO, 12.24 Log₁₀ CFU/mL), and coix protein (CPR, 11.91 Log₁₀ CFU/mL) were significantly higher (p < 0.05) than the control group (MRS, 9.16 Log₁₀ CFU/mL). CSE also enhanced the biosynthesis of lactic acid and acetic acid of L. reuteri. Untargeted metabolomics results indicated that the carbohydrate metabolism, amino acid metabolism, and nucleotide metabolism activities of L. reuteri were increased after adding CSE. Furthermore, CSE increased the accumulation of bioactive metabolites, such as phenyl lactic acid, vitamins, and biotin. Overall, CSE may have prebiotic potential and can be used to culture L. reuteri with high viable bacteria.

Angiotensin-I-Converting Enzyme Inhibitory Peptides in Goat Milk Fermented by Lactic Acid Bacteria Isolated from Fermented Food and Breast Milk

In this study, angiotensin-I-converting enzyme inhibitory (ACEI) activity was evaluated in fermented goat milk fermented by lactic acid bacteria (LAB) from fermented foods and breast milk. Furthermore, the potential for ACEI peptides was identified in fermented goat milk with the highest ACEI activity. The proteolytic specificity of LAB was also evaluated. The 2% isolate was inoculated into reconstituted goat milk (11%, w/v), then incubated at 37°C until pH 4.6 was reached. The supernatant produced by centrifugation was analyzed for ACEI activity and total peptide. Viable cell counts of LAB and titratable acidity were also evaluated after fermentation. Peptide identification was carried out using nano liquid chromatography mass spectrometry (LC-MS/MS), and potential as an ACEI peptide was carried out based on a literature review. The result revealed that ACEI activity was produced in all samples (20.44%-60.33%). Fermented goat milk of Lc. lactis ssp. lactis BD17 produced the highest ACEI activity (60.33%; IC50 0.297±0.10 mg/mL) after 48 h incubation, viable cell counts >8 Log CFU/mL, and peptide content of 4.037±0.27/mL. A total of 261 peptides were released, predominantly derived from casein (93%). The proteolytic specificity of Lc. lactis ssp. lactis BD17 through cleavage on the amino acid tyrosine, leucine, glutamic acid, and proline. A total of 21 peptides were identified as ACEI peptides. This study showed that one of the isolates from fermented food, namely Lc. lactis ssp. lactis BD17, has the potential as a starter culture for the production of fermented goat milk which has functional properties as a source of antihypertensive peptides.

Bioactivities and ACE-inhibitory peptides releasing potential of lactic acid bacteria in fermented soy milk

Abstract

This study was designed to evaluate the bioactivities such as β-glucosidase activity, α-galactosidase activity, and the growth behavior of the Lactobacillus cultures in soy milk medium. Ten Lactobacillus cultures were considered in this study. L. fermentum (M2) and L. casei (NK9) were selected due to their better α-galactosidase, β-glucosidase activity and growth behavior in soy milk medium during fermentation. Further, soy milk fermented with M2 showed higher proteolytic activity (0.67 OD) and ACE-inhibitory (48.44%) than NK9 (proteolytic activity: 0.48 OD and ACE-inhibitory activity: 41.33%). Bioactive peptides produced during the fermentation of soy milk using the selected Lactobacillus cultures were also identified with potent ACE-inhibitory activity by MALDI-TOF spectrometry, and the identified ACE inhibitory peptide sequences from fermented soy milk were characterized using Biopep database.

Graphical abstract

Technological and Functional Assessment of Riboflavin Enriched Probiotic SoyCurd

Preparation of soymilk-based product with probiotics is reasonably a novel approach in the field of fermented functional foods. The aim of this study was to develop riboflavin enriched fermented soy curds with either or combination of the two riboflavin producing probiotic strains of Lactobacillus plantarum i.e., MTCC 25432 (BBC32B) and MTCC 25433 (BBC33), and to compare the technological and functional properties of its developed products. Acidification rate and lactic acid production were enhanced with L. plantarum and its combination in a shorter time to reach pH 4.7. Hardness and cohesiveness were significantly (p < 0.05) higher for fermented soymilk by co-culture of L. plantarum followed by individual strains. Similarly, higher G′ (6.25 × 102 Pa), G” (2.30 × 103 Pa) and G* (8.00 × 102 Pa) values observed for the combination of both L. plantarum strains showed that the gel formed was firmer and had solid character. The riboflavin content of product developed with a combination of test cultures was significantly higher (342.11 µg/L) than individual cultures and control. The final product had a higher probiotic count (more than 9 log cfu/mL), which is also required for functional food containing probiotics.

Improving the survival of Lactobacillus plantarum NRRL B-1927 during microencapsulation with ultra-high-pressure-homogenized soymilk as a wall material

Probiotic foods and supplements have been shown to offer multiple potential health benefits to consumers. Dried probiotic cultures are increasingly used by the food industry because they are easily handled, transported, stored, and used in different applications. However, drying technologies often expose probiotic cells to extreme environmental conditions that reduces cell viability. Hence, this study aimed to evaluate the effect of using ultra high-pressure homogenization (UHPH) on soymilk's microencapsulating ability, and the resultant effect on the survivability of probiotic Lactobacillus plantarum NRRL B-1927 (LP) during drying. Liquid suspensions containing LP (~10⁹ CFU/g of solids) were prepared by suspending LP cultures in soymilk which had been either treated with UHPH at 150 MPa or 300 MPa or left untreated. LP suspensions were then dried by concurrent spray drying (CCSD), mixed-flow spray drying (MXSD) or freeze-drying (FD). Cell counts of LP were determined before and after microencapsulation. Moisture, water activity, particle size and morphology of LP powders were also characterized. LP powders produced with 300 MPa treated soymilk had 8.7, 6.4, and 2 times more cell counts than those produced with non-UHPH treated soymilk during CCSD, MXSD, and FD, respectively. In the 300 MPa treated samples, cell survival (%) of LP during drying was the highest in MXSD (83.72) followed by FD (76.31) and CCSD (34.01). Using soymilk treated at higher UHPH pressures resulted in LP powders with lower moisture content, smaller particle sizes and higher agglomeration. LP powders produced via MXSD showed higher agglomeration and fewer signs of thermal damage than powders produced via CCSD. This study demonstrates that UHPH improves the effectiveness of soymilk as a microencapsulant for probiotics, creating probiotic powders that could be used in plant-based and non-dairy foods.