Lactic Acid Research Articles

Serine and threonine activate Ser/Thr kinase gene to increase the density of Lactobacillus bulgaricus sp1.1 under salt stress

Salt stress significantly impedes high cell-density culture by suppressing the reproductive capacity of lactic acid bacteria. This study examined the effects of salt stress conditions (2% w/v NaCl) on Lactobacillus bulgaricus sp1.1. Although DNA replication and division ring localization remained unaffected, the down-regulation of the ftsZ and dnaA genes inhibited division ring assembly. Consequently, bacteria exhibited filamentation, increased cell length, and accumulated chromosomes and division rings, which obstructed cell division. Under salt stress, sp1.1 experienced several transcriptional changes. The serine/threonine kinase gene was identified as a significant regulator of bacterial division under salt stress. Exogenous addition of serine and threonine could stimulate the expression of Ser/Thr kinase gene, promote the assembly of division ring, and enhance the dividing ability of the bacterium, which led to a density of 7.93 log CFU/mL under the salt stress, which was 6.92 times higher than that of the untreated group. This study provides a new perspective for high-density cultivation of lactic acid bacteria.

Effect of commercial Saccharomyces cerevisiae and non-Saccharomyces yeasts on the chemical composition and bioaccessibility of pineapple wine

Alcoholic fermentation is one of man’s most efficient food preservation processes, and innovations in this area are a trend in food science and nutrition. In addition to the classic Saccharomyces yeasts, various other species may have desirable characteristics for obtaining fruit wines. This study investigated the profile of non-Saccharomyces commercial yeasts compared with S. cerevisiae regarding pineapple wine’s chemical composition and bioaccessibility. The fermentation profile of the yeasts Lachancea thermotolerans, Brettanomyces bruxellensis, Brettanomyces lambicus, and S. cerevisiae was evaluated for sugar and alcohol content, and the pineapple wines obtained were analyzed for amino acids, phenolics, and organic acids by HPLC and volatile profile by GC/MS. All yeast strains were able to produce ethanol and glycerol at acceptable levels. L. thermotolerans produced higher levels of lactic acid (0.95 g/L) and higher consumption of free amino acids. B. bruxellensis produced higher levels of individual phenolics and ethanol 109 g/L. The alcoholic fermentation process improved the bioaccessibility of phenolics such as catechin (237 %), epigallocatechin gallate (81 %), procyanidin B1 (61 %) and procyanidin B2 (61 %). The yeasts differed in their volatile profiles, with Brettanomyces and Lachancea producing higher levels of compounds associated with pineapple aroma, such as ester ethyl butyrate (260–270 µg/L). These results demonstrate the importance of choosing the yeast strain for the conduction of alcoholic fermentation and that the yeasts Brettanomyces and Lachancea showed technological potential in obtaining pineapple wines. This study contributes to developing processes for obtaining fruit wines by highlighting two non-Saccharomyces yeast species with technological potential for alcoholic fermentations.

Beneficial effects of extravascular lung water index-guided volum management in patients with cardiogenic shock

Objective: To evaluate the role of volume management guided by extravascular lung water index(EVLWI) in improving the clinical outcomes and cardiac function for patients with cardiogenic shock. Methods: This study was a single-center, prospective cohort study. Patients with cardiogenic shock admitted to the Department of Cardiovascular Medicine, Shanghai East Hospital from July 2022 to December 2023 were enrolled. Patients were matched 1∶1 by propensity score and divided into EVLWI group and control group. In the control group, the volume management strategy was determined by the attending physician based mainly on conventional factors, including clinical features, biochemical assessments, and certain blood pressure measurements. In EVLWI group, the volume management plan was formulated by integrating conventional factors with EVLWI derived from pulse index continuous cardiac output (PiCCO) monitoring. Baseline clinical data, in-hospital treatment, and hemodynamic data were collected. Major adverse cardiovascular events and cardiac function related parameters were compared at 30 d after treatment between the two groups. Baseline EVLWI levels were compared between the non-survivors and the survivors in the EVLWI group. The receiver operating characteristic curve was plotted to assess the accuracy of baseline EVLWI and central venous pressure in predicting all-cause mortality at 30 d after treatment in patients with cardiogenic shock, and subgroup analysis was performed according to ischemic/non-ischemic etiology and with/without use of inotropic drugs. Kaplan-Meier curve was used for survival analysis, with log-rank tests comparing all-cause mortality, cardiac death, and readmission rate for heart failure at 30 d after treatment. Results: A total of 200 patients with cardiogenic shock were enrolled, aged (71.35±12.82) years, 144(72%) males, EVLWI group and control group 100 patients each. Compared with the control group, EVLWI group had lower all-cause mortality (16%(16/100) vs. 42%(42/100), log-rank P<0.01), cardiac death (14%(14/100) vs. 34%(34/100), log-rank P<0.01), and readmission rate for heart failure (4%(4/100) vs. 12%(12/100), log-rank P=0.03) at 30 d after treatment. Subgroup analysis showed that EVLWI-guided volume management was associated with lower all-cause mortality at 30 d after treatment in patients with cardiogenic shock of ischemic or non-ischemic etiology and with or without inotropic drugs (all P<0.05). In EVLWI group, baseline EVLWI levels were higher in non-survivors than those in survivors [(15.99±6.47) ml/kg vs.(9.75±2.55) ml/kg, P<0.01]. The baseline EVLWI could predicting all-cause mortality at 30 d after treatment in patients with cardiogenic shock, with an area under the receiver operating characteristic curve of 0.84 (95%CI: 0.75-0.94, P<0.01), while the baseline central venous pressure had no predicting value (AUC=0.54, 95%CI: 0.40-0.69, P=0.60). The optimal cutoff value of EVLWI in pridicting all-cause mortality at 30 d after treatment in patients with cardiogenic shock was >10.3 ml/kg. With the optimization of hemodynamic parameters, left ventricular ejection fraction was improved in EVLWI group, and serum levels of N-terminal pro-brain natriuretic peptide, creatinine, alanine aminotransferase and lactic acid were decreased (all P<0.05). Conclusion: EVLWI-guided volume management exerts a beneficial effect on therapeutic decision-making and improves clinical outcomes and cardiac function in patients with cardiogenic shock.

Bimetallic Fe/Co-MOF dispersed in a PVA/chitosan multi-matrix hydrogel as a flexible sensor for the detection of lactic acid in sweat samples

Bimetallic Fe/Co-MOF dispersed in a PVA/chitosan multi-matrix hydrogel as a flexible sensor for the detection of lactic acid in sweat samples

A systematic review of Streptococcus Mutans and Veillonellae species interactions in dental caries progression: Positive or Negative impact?

Background The interaction between Streptococcus mutans (S. mutans) and Veillonella species (Veillonella spp.) is unclear. This study aims to investigate the interaction between S. mutans and Veillonella spp. on caries development using systematic review. Methods This systematic review was accorded to the guideline of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Three electronic databases, namely PubMed, Embase, and the Cochrane library, were used to conduct a systematic search for eligible studies from their inception until July 18, 2023. PROSPERO registration number was No. CRD42023445968. Results We initially identified 4,774 articles. After eliminating duplicates and irrelevant articles, 11 studies met the inclusion criteria. The studies revealed important aspects of the relationship between S. mutans and Veillonellae spp. in dental caries. One significant finding is that Veillonellae spp. can affect the acid production capacity of S. mutans. Some studies indicate that Veillonellae spp. can inhibit the acid production by S. mutans, potentially reducing the cariogenic process. Another aspect is the competition for substrates. Veillonellae spp. utilize lactic acid, which is a by product of S. mutans metabolism, as a source of carbon. This metabolic interaction may decrease the availability of lactic acid for S. mutans, potentially influencing its cariogenic potential. Conclusions This systematic review highlights the emerging evidence on the interaction between S. mutans and Veillonellae spp. in dental caries. The findings suggest that Veillonellae spp. can modulate the acid production, and substrate competition of S. mutans, potentially influencing the cariogenic process.

Single mode optical fiber sensor based on surface plasmon resonance for the detection of the Lactic acid for the chemical sensor

Single mode optical fiber sensor based on surface plasmon resonance for the detection of the Lactic acid for the chemical sensor

Hierarchically Nano-Decorated Poly(lactic acid) Nanofibers for Humidity-Resistant Respiratory Healthcare and High-Accuracy Disease Diagnosis.

The application of biodegradable and eco-friendly poly(lactic acid) (PLA) nanofibrous membranes (NFMs) toward respiratory healthcare has long been thwarted by the poor electroactivity and low surface activity of PLA. Herein, we unravel a microwave-assisted route to fabricate rod-like ZnO nanodielectrics, which were decorated with dopamine (ZnO@PDA) and anchored at the PLA nanofibers via an electrospinning-electrospray approach. The PLA/ZnO@PDA NFMs featured a substantially elevated specific surface area (up to 20.7 m2/g), increased dielectric constant (nearly 1.8) and a surface potential as high as 9.5 kV, resulting in superior air filtering performance (99.45% for PM0.3, 94.1 Pa, 32 L/min) compared with the pure PLA counterpart (90.04%, 169.0 Pa, 32 L/min). The notably increased electroactivity endowed the PLA/ZnO@PDA NFMs with significant improvements in triboelectric properties (output voltage of 11.5 V at 10 N, 0.5 Hz), laying down the cornerstone for self-powered monitoring of personal respiration. More importantly, a deep learning-assisted diagnostic system was developed based on respiration-driven signal patterns, enabling intelligent and real-time disease diagnosis with 100% accuracy for the protective membranes. The proposed hierarchical nanodecoration strategy opens up new possibilities for engendering eco-friendly nanofibers with an exceptional combination of efficient respiratory healthcare and intelligent diagnosis.

A Novel 5-Chloro-N-Phenyl-1 H-Indole-2-carboxamide Derivative as a Glycogen Phosphorylase Inhibitor: Evaluating the Long-Term Drug Effects on Muscle Function for the First Time

Compound 1 was previously identified by our team as a glycogen phosphorylase (GP) inhibitor with glucose-lowering activity and demonstrated to have protective effects against myocardial and cerebral ischemia. However, its impact on muscle function has not been clarified. This study is the first to evaluate the long-term effects of GP inhibitors on muscle function and metabolism. After a 28-day administration of Compound 1, we performed assays to assess muscle function and biochemical parameters in rats. We observed reductions in peak holding force, duration, tetanic contraction force, single-contraction force, and electromyographic signals under 20 s and 10 min contraction stimuli. The metabolic analysis showed no significant effects on muscle glycogen, ATP, lactic acid, and uric acid levels at low doses. In contrast, medium to high doses resulted in increased glycogen, decreased ATP, and reduced lactic acid (only at high doses), without affecting uric acid. These findings suggest that Compound 1 may adversely affect muscle function in rats, potentially due to the glycogen inhibition effects of GP inhibitors. This study provides crucial safety data and insights into the long-term effects of GP inhibitors on rat muscles, which will guide future developments and applications.

Thermal conductivity of 3D-printed block-copolymer-inspired structures

This study primarily focuses on examining the impact that geometric structure has on thermal conductivity of multi-phase constructs in different 3D-printed poly(lactic acid), PLA, samples. The investigated structures are inspired by morphologies formed by diblock copolymers: lamellae, hexagonally packed cylinders, and gyroid. This research also investigates how volume percentage and material combination influence the thermal conductivity of these structures. The samples can be tailored to simulate various thermal management structures observed in practical applications, such as thermal interface materials in electronic devices. Thermal conductivity ratio is controlled using air, the least conductive material at 0.026 W/(m K), PLA at 0.136 W/(m K), and thermal paste at 5.11 W/(m K). Different models were tested against thermal conductivity measurements in order to capture the effect of material type (PLA-Air versus PLA-Thermal Paste), volume percentage, structure, and orientation. Simple, effective medium models were good predictions of thermal conductivity in lamellar structures, but it was necessary to develop models for conduction through cylindrical and gyroid structures. Finally, all results were normalized to find a universal model that is independent of structure and material. This approach provides a simple method to predict how to reduce or enhance transport properties and heat management capabilities of 3D printed objects.

Acidocin A and Acidocin 8912 Belong to a Distinct Subfamily of Class II Bacteriocins with a Broad Spectrum of Antimicrobial Activity

Within class II bacteriocins, we assume the presence of a separate subfamily of antimicrobial peptides possessing a broad spectrum of antimicrobial activity. Although these peptides are structurally related to the subclass IIa (pediocin-like) bacteriocins, they have significant differences in biological activities and, probably, a mechanism of their antimicrobial action. A representative of this subfamily is acidocin A from Lactobacillus acidophilus TK9201. We discovered the similarity between acidocin A and acidocin 8912 from Lactobacillus acidophilus TK8912 when analyzing plasmids from lactic acid bacteria and suggested the presence of a single evolutionary predecessor of these peptides. We obtained the C-terminally extended homolog of acidocin 8912, named acidocin 8912A, a possible intermediate form in the evolution of the former. The study of secondary structures and biological activities of these peptides showed their structural similarity to acidocin A; however, the antimicrobial activities of acidocin 8912 and acidocin 8912A were lower than that of acidocin A. In addition, these peptides demonstrated stronger cytotoxic and membranotropic effects. Building upon what we previously discovered about the immunomodulatory properties of acidocin A, we studied its proteolytic stability under conditions simulating those in the digestive tract and also assessed its ability to permeate intestinal epithelium using the Caco-2 cells monolayer model. In addition, we found a pronounced effect of acidocin A against fungi of the genus Candida, which might also expand the therapeutic potential of this bacterial antimicrobial peptide.

Effect of fruits granola (Frugra®) consumption on blood pressure reduction and intestinal microbiome in patients undergoing hemodialysis

AbstractCardiovascular diseases (CVDs) are a major cause of death in patients undergoing hemodialysis (HD). Blood pressure (BP) and uremic toxins are well-known risk factors for CVDs, which are influenced by diet. Dietary fiber supplementation in patients undergoing HD may reduce the risk of CVDs by improving lipid profiles and inflammatory status and lowering the levels of the uremic toxin indoxyl sulfate (IS). In this study, we investigated the relationship between the intestinal microbiota and risk factors for CVDs, such as BP and serum IS, in patients undergoing HD who consumed fruits granola (FGR). The study participants were selected from patients undergoing HD at the Izu Nagaoka Daiichi Clinic and consumed FGR for 2 months. Body composition and blood samples were tested at months 0, 1, 2 and fecal samples were collected at months 0 and 2 for intestinal microbiota analysis. FGR consumption decreased systolic and diastolic BP, estimated salt intake, and serum IS levels and improved the stool characteristics according to the Bristol Stool Form Scale (N = 24). Gut microbiota analysis showed an increase in the alpha diversity and abundance of Blautia and Neglecta. The abundance of lactic acid- and ethanol-producing bacteria also significantly increased, whereas the abundance of indole-producing bacteria significantly decreased. FGR consumption could be a useful tool for salt reduction, fiber supplementation, and improvement of the intestinal environment, thus contributing to improvement of BP and the reduction of other risk factors for CVDs in patients undergoing HD.

Probiotic Properties of Lactobacilluscasei and L. plantarum Isolated From Overripe Avocado Pear

Probiotics have been researched for their benefit to gut health. Research for sources of probiotic bacteria has moved from milk to plants, as they have been found to be an inexhaustible source of lactic acid bacteria (LAB). The probiotic properties of lactic acid bacteria isolated from Over ripe Avocado pear on selected bacterial species were assessed. Fifty Unripe Avocado pears were purchased from different markets and allowed to ferment. Enumeration of the microorganisms and pure culture isolation were done on MRS agar supplemented with1.0% CaCO3 at 37 oC for 48 hours; using the pour plate and streak plate methods respectively. The isolates were identified based on their microscopic, macroscopic, biochemical and molecular characteristics. They include Lactobacillus casei and L. plantarum. LAB isolates were tested for their phenol tolerance, bile salt tolerance, acid tolerance and antimicrobial activity. All the isolates were tolerant to simulated gastrointestinal conditions. Growth of the isolates was observed at different temperature between 15 oC to 60 oC. They exhibited tolerance to phenol ranging from 0.085±0.01% to 2.40±0.02%. Tolerance to bile salt ranged from 1.06x101± 0.96x101 to 3.04x103±1.15x102. The acid tolerance level of the LAB obtained ranged from 2.98x102±1.30x102 to 8.78x102±2.22x102. Agar-well diffusion method was used to determine the antimicrobial susceptibility of the bacterial species. The test showed that the isolates were susceptible to the LAB isolates as zones of inhibition were observed. The inhibition zones diameter obtained ranged from 8.35±1.34mm to 13.77±2.21mm. Avocado pear, asides from their high nutritional content, also have the potential to serve as source of probiotic bacteria.

Overproduction of gamma-aminobutyric acid and increased antioxidant capacity by Lactiplantibacillus pentosus TEJ4 through optimization by response surface methodology

Lactic Acid bacteria (LAB) are the main producers of bioactive compounds (peptides, exopolysaccharides, antioxidant compounds, gamma-aminobutyric acid-GABA, etc.). Different strains produce at least one metabolite in high quantities as part of their metabolism, however, there are few reports of LAB with the capacity to produce two or more metabolites simultaneously. Due, the ability of 35 LAB strains previously isolated from dairy products, fermented beverages, and honey to produce gamma-aminobutyric acid (GABA) and the antioxidant capacity was determined. Based on analysis of variance and subsequent comparison of means, the Lactiplantibacillus pentosus strain was selected, and subsequently, using a Draper-Lin small composite design, the conditions of the culture medium (MRS broth) were optimized to achieve the highest production of GABA and increase the antioxidant capacity evaluated by the DPPH assay. The optimal conditions for obtaining 7.99 mg/mL of GABA were 100 mM glutamic acid, a pH of 6, a temperature of 40 °C, and 72 h of fermentation. To obtain the highest antioxidant capacity (6.87 µmol TE/mL), 200 mM glutamic acid and a pH of 4.0 were used. We reported an isolated strain of nondairy product (L. pentosus TEJ4) with the capacity to produce both bioactive, GABA, and antioxidants in a single fermentation process in a non-dairy defined medium, which is a feasible alternative to the normal process of producing bioactive compounds.

Dipeptide metabolite, glutamyl-glutamate mediates microbe-host interaction to boost spermatogenesis

The decrease in sperm count and infertility is a global issue that remains unresolved. By screening environmental bacterial isolates, we have found that a novel lactic acid bacterium, Lactiplantibacillus plantarum SNI3, increased testis size, testosterone levels, sperm count, sexual activity and fertility in mice that have consumed the bacteria for four weeks. The abundance of L. plantarum in the colon microbiome was positively associated with sperm count. Fecal microbiota transplantation (FMT) from L. plantarum SNI3-dosed mice improved testicular functions in microbiome-attenuated recipient animals. To identify mediators that confer pro-reproductive effects on the host, untargeted in situ mass spectrometry metabolomics was performed on testis samples of L. plantarum SNI3-treated and control mice. Enrichment pathway analysis revealed several perturbed metabolic pathways in the testis of treated mice. Within the testis, a dipeptide, glutamyl-glutamate (GluGlu) was the most upregulated metabolite following L. plantarum SNI3 administration. To validate the pro-reproductive feature of GluGlu, systemic and local injections of the dipeptide have been performed. γ-GluGlu increased sperm count but had no effect on testosterone. These findings highlight the role of γ-GluGlu in mediating spermatogenetic effects of L. plantarum on the male mouse host and –following relevant human clinical trials- may provide future tools for treating certain forms of male infertility.

Application of Response Surface Methodology Experimental Design to Optimize Tribological Lubrication Characteristics

Total Knee Replacement (TKR) has become a standard operation for patients with joint disorders. Despite the fact that the number of procedures is increasing all the time, the short service life of implants remains a persistent concern for researchers. Understanding lubrication may aid in explaining tribological processes that lead to replacements that last well into the third decade of service. Likewise, wear and friction in total knee replacement (TKR) components are among the most common causes of implant failure. As a result, this study will evaluate the feasibility of using the polymer Poly Lactic Acid (PLA) for cartilage replacement in Total Knee Replacement (TKR) using plant-based oils as lubricants. Furthermore, the modifier will be added to plant-based oils as an additive to make them analogous to human bodily fluids. The present paper is applying the Box-Behnken design to optimize the performance and mechanical responses of bio-lubricants toward Poly Lactic Acid (PLA) as a tibial insert for cartilage replacement in Total Knee Replacement (TKR). The main objective of this paper is to develop an optimized method for the selection of plant-based oil parameters using Response Surface Methodology (RSM). A three-level three-factor Box-Behnken design (BBD) was used to investigate the interactions between the essential factors comprising load (45 kg to 90 kg), speed (60 rpm, 90 rpm and 360 rpm), and concentration (0ml, 5ml and 10ml) of bio-lubricants to accomplish the indicated prospect of using polymer for cartilage replacement. Canola oil, castor oil, and sunflower seed oil are considered vegetable oils, whereas Hyaluronic Acid (HA) is the friction modifier. The parameters are used to create a Box-Behnken design for predicting lubricant anti-wear qualities stated in terms of coefficient of friction, wear rate and frictional force as determined by the pin-on-disk experimental procedure. As a result, the optimization using RSM successfully interpreted the experimental data, according to the analysis of variance, with coefficients of determination of R2 = 0.91 and adjusted R2 = 0.77. The Coefficient of Friction (CoF) and wear rate were investigated following tribological testing. Castor oil had a lower coefficient of friction than canola and sunflower seed oil, according to the findings. In terms of friction reduction, castor oil surpasses canola and sunflower seed oil.

Optimizing the fermentation parameters in the Lactic Acid Fermentation of Legume-based Beverages– a statistically based fermentation

BackgroundThe market for beverages is highly changing within the last years. Increasing consumer awareness towards healthier drinks led to the revival of traditional and the creation of innovative beverages. Various protein-rich legumes were used for milk analogues, which might be also valuable raw materials for refreshing, protein-rich beverages. However, no such applications have been marketed so far, which might be due to unpleasant organoleptic impressions like the legume-typical “beany” aroma. Lactic acid fermentation has already been proven to be a remedy to overcome this hindrance in consumer acceptance.ResultsIn this study, a statistically based approach was used to elucidate the impact of the fermentation parameters temperature, inoculum cell concentration, and methionine addition on the fermentation of lupine- and faba bean-based substrates. A total of 39 models were found and verified. The majority of these models indicate a strong impact of the temperature on the reduction of aldehydes connected to the “beany” impression (e.g., hexanal) and on the production of pleasantly perceived aroma compounds (e.g., β-damascenone). Positively, the addition of methionine had only minor impacts on the negatively associated sulfuric compounds methional, dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide. Moreover, in further fermentations, the time was added as an additional parameter. It was shown that the strains grew well, strongly acidified the both substrates (pH ≤ 4.0) within 6.5 h, and reached cell counts of > 9 log10 CFU/mL after 24 h. Notably, most of the aldehydes (like hexanal) were reduced within the first 6–7 h, whereas pleasant compounds like β-damascenone reached high concentrations especially in the later fermentation (approx. 24–48 h).ConclusionsOut of the fermentation parameters temperature, inoculum cell concentration, and methionine addition, the temperature had the highest influence on the observed aroma and taste active compounds. As the addition of methionine to compensate for the legume-typical deficit did not lead to an adverse effect, fortifying legume-based substrates with methionine should be considered to improve the bioavailability of the legume protein. Aldehydes, which are associated with the “beany” aroma impression, can be removed efficiently in fermentation. However, terminating the process prematurely would lead to an incomplete production of pleasant aroma compounds.

Development of a Ready-to-Drink (RTD) Beverage Formulated with Whey and Beetroot Juice

Whey, a large by-product of cheese manufacturing, is nutritionally valuable, mainly because of its whey proteins. Beetroot juice, purple–red in colour, has numerous benefits for human health; if used as an ingredient in a whey-based RTD beverage, it could mask whey’s less pleasant organoleptic characteristics. This research aimed to develop such a beverage by mixing whey with beetroot juice in a ratio that would yield a nutritionally valuable product with acceptable sensory characteristics. To this end, three RTD beverage formulations, prepared with beetroot juice and whey in different ratios (10:90, 15:85, and 20:80 v/v), were subjected to sensory analysis. The one with a 20:80 v/v ratio of beetroot juice and whey was found to be preferred by consumers, registering the highest overall score (7.8). Next, this formula was prepared with (RTD20:80a) and without citric acid (RTD20:80a) and analysed physiochemically and microbiologically. RTD20:80a was also sensory tested and proved to be the optimum one (with an overall score of 8.1); it showed a content of 1.18 g/100 mL fat, 1.07 g/100 mL protein, 0.56 g/100 mL ash, 9.90 g/100 mL carbohydrate, total soluble solids of 11.69 °Brix, an energy value of 54.44 kcal/100 mL, titratable acidity of 0.77% lactic acid, pH of 3.75, content of 1.16 mg/mL betacyanins, 0.86 mg/mL betaxanthins, and 0.36 mg GAE/mL total phenolics. Based on the microbiological results, RTD20:80a revealed a shelf-life of 14 days. By producing this beverage, a dairy plant could reduce its whey-related losses while increasing its profitability through selling it.

Assessment of the Impact of Pretreatment of Spent Coffee Grounds with Diluted Sulfuric Acid on the Efficiency of Methane and Lactic Acid Fermentation

Lignocellulosic materials are composed of three major biocomponents such as cellulose, hemicellulose and lignin, which form a compact lignocellulosic complex. Characterized by high caloric content, lignocellulosic biomass, including coffee grounds, is a valuable energy source that can be efficiently used in various bioconversion and biotransformation processes. Due to the high consumption of coffee in the world, there is an increasing amount of coffee grounds, which is a rich waste and at the same time a valuable secondary raw material, and its use fits perfectly into a closed-loop economy. Coffee grounds biomass contains polysaccharides, mainly mannans, proteins, lipids, polyphenols, which will allow the development of different biorefinery strategies, the creation of new value-added products with reduced waste generation. The research describes the pre-treatment of coffee grounds with dilute sulfuric acid to evaluate the effect of acid concentration, hydrolysis time on biogas yield, including methane and lactic acid biosynthesis during anaerobic fermentations. A yield of 381.12 mL of CH4/g-VS methane was obtained, accounting for 72.48% of the total biogas composition. It was found that the most efficient sample in terms of substrate pre-treatment for lactic acid biosynthesis was coffee grounds after 90 min hydrolysis with 1.5% H2SO4 at 121 °C.

Pomegranate Peel Flour as a Co-encapsulant Improves the Survival of Lactic Acid Bacteria to Thermal Treatment and Simulated Gastrointestinal Conditions

AbstractPomegranate peel flour was employed as a co-encapsulant of two lactic acid bacteria, by alginate emulsion templated microencapsulation, to enhance their resistance to thermal treatment, acidic pHs, and gastric conditions. Samples with pomegranate peel flour increased the tolerance to heat treatment, results consistent with thermal properties related to higher denaturation enthalpy of microcapsules. Co-encapsulated microcapsules also enhanced the survival to low pHs and enhanced almost 60% up the tolerance to bile salts. There was also an increase in survival rate against in vitro gastric acid conditions due to use of the co-encapsulant. In scanning electron microscopy, the incorporation of pomegranate peel flour resulted in a rough and porous structure, probably due to certain interference with the formation of spherical microcapsules, although it presented similar mean diameter, plus higher cell viability as confirmed by confocal laser microscopy. The obtained results indicate that co-encapsulation with a prebiotic ingredient represents a reinforcement of the physical microcapsule integrity to tolerate food process temperatures, besides retarding the adverse effect of acidic, bile salts, and simulated gastrointestinal conditions. The micro alginate co-encapsulation by ionic gelation with a prebiotic as pomegranate peel flour is a suitable alternative to develop thermal processed functional foods.

Effect of inoculum sources on caproic acid production from food waste through lactate-based chain elongation: Properties and microbial succession

Caproic acid (CA) production is a promising way to valorize food waste (FW), but the low CA yield seriously restricts its application. Inoculum source as a key factor can affect the microbial communities and CA fermentation processes, but was not fully explored. In the present study, three common inoculum sources namely anaerobic digestion sludge (AD), pit mud (PM) and raw FW (RFW) were selected as inocula to initiate CA production from FW. The organics conversion properties, microbial community succession processes and bacterial metabolism pathways were investigated. Results showed that carbohydrates were effectively degraded into lactic acid and then to CA based on lactate-based chain elongation. The CA yield (0.37 g-COD/g-VS) using AD was higher than that inoculated with PM (0.26 g-COD/g-VS) and RFW (0.32 g-COD/g-VS). Although microbial communities in inocula were totally different, they exhibited similar succession with Firmicutes and Bacteroidetes as the dominant functional phyla. Logically, lactic acid-producing bacteria (e.g. Lactobacillus, Limosilactobacillus and Sporolactobacillus) were enriched at the early stage to prepare electron donor (lactate), and then were replaced by chain elongation bacteria for CA production. However, unclassified_Ruminococcaceae was dominant in reactor with AD, unclassified_Ruminococcaceae, Bifidobacterium, Clostridium_sensu_stricto and unclassified_Prevotellaceae were largely detected in reactors inoculated with PM and RFW, which resulted in different CA yield. This study provides useful information for caproate production from FW, and widens the knowledge of cleaner production from wastes.