Addition Of Lactic Acid Research Articles

Pengujian Mutu Silase Ikan Tembang yang Ditambahi Bakteri Asam Laktat (Konsentrasi 20%) Tepung Jagung Dengan Atau Tanpa Larutan Urea

Fish silage is a semi-liquid product of fish preservatives with the addition of lactic acid, to change the fermentation process that converts carbohydrate sources into acids. Silage can be processed using lactic acid bacteria (LAB). The lactic acid bacteria used in this study were sourced from palm sap isolates. Lactic acid bacteria are a type of beneficial non-pathogenic bacteria that are very helpful in the fermentation process of feed and food ingredients. To determine the effect of adding 10% LAB concentration combined with corn flour and urea on the quality of fish silage and to compare the quality of fish silage based on various aspects of sensory evaluation, namely (aroma, texture, color) and the degree of fish silage. The stages of implementing this research include sampling, making fish silage, fermentation and organoleptic testing and testing the degree of storage. Based on the results of the study, it was found that the results of the organoleptic tests carried out showed that the fish silage produced was of good quality which was characterized by an acidic silage aroma, a silage texture that was not lumpy and not too soft, and an increase in the color of brown silage. The results of the study that the addition of 10% LAB combined with ground maize and urea gave a significantly different effect (P<0.05) on the quality of fish silage. Combined use of fish silage will affect the pH of the silage.

Optimization of Cyclodextrin-Assisted Extraction of Phenolics from Helichrysum italicum for Preparation of Extracts with Anti-Elastase and Anti-Collagenase Properties

Helichrysum italicum is a plant traditionally used for skin-related disorders that is becoming an increasingly popular ingredient in cosmetic products. In this work, a "green" ultrasound-assisted extraction method for H. italicum phenolics was developed using skin-friendly cyclodextrins (CDs). Extraction conditions needed for the greatest yield of target compounds (total phenolics, phenolic acids, and flavonoids) were calculated. The composition of the extracts was determined using LC-MS and spectrophotometric methods. Among the tested CDs, 2-hydroxylpropyl-beta-CD (HP-β-CD) was the best suited for extraction of target phenolics and used to prepare two optimized extracts, OPT 1 (the extract with the highest phenolic acid content) and OPT 2 (the extract with the highest total phenol and flavonoid content). The extracts were prepared at 80 °C, using 0.089 g of plant material/g solvent (0.6 mmol of HP-β-CD), with or without addition of 1.95% (w/w) lactic acid. The main metabolite in both extracts was 3,5-O-dicaffeoylquinic acid. It was found that the addition of lactic acid greatly contributes to the extraction of arzanol, a well-known anti-inflammatory agent. IC50 values of the anti-elastase (22.360 ± 0.125 μL extract/mL and 20.067 ± 0.975 for OPT-1 and OPT-2, respectively) and anti-collagenase (12.035 ± 1.029 μL extract/mL and 14.392 ± 0.705 μL extract/mL for OPT-1 and OPT-2, respectively) activities of the extracts surpassed those of the applied positive controls, namely ursolic and gallic acids. This activity deems the prepared extracts promising ingredients for natural cosmetics, appropriate for direct use in cosmetic products, removing the need for the evaporation of conventional solvents.

Kinetics of biodegradation of strengthening polymer systems based on copolymers of lactic acid and biogenic activators

The production of bioplastics based on copolymers of maleic anhydride with the addition of lactic acid and furyl alcohol is described. The obtained copolymers are promising for use as reinforcing polymer systems of cellulose-containing materials used in packaging. It has been shown that the use of lactic acid and furyl alcohol makes it possible to obtain synthetic bioplastics that are rapidly degradable in natural conditions, which is favorable for environmental protection.

Enhanced degradation of poly(ethylene terephthalate) by the addition of lactic acid / glycolic acid: composting degradation, seawater degradation behavior and comparison of degradation mechanism

The degradability improvement of poly(ethylene terephthalate) (PET), one of the most widely used but non-degradable disposable packaging material, is of great significance. However, the balance between degradability and mechanical properties remains a huge challenge. Herein, simple hydroxy acids, lactic acid (LA) and glycolic acid (GA) as easy hydrolysis sites were introduced into non-degradable PET via melt polycondensation. A series of high molecular weight poly(ethylene terephthalate-co-L‑lactide) (PETL) and poly(ethylene terephthalate-co-glycolate) (PETG) copolyesters were synthesized with an excellent tensile strength greater than 50 MPa, much higher than that of most commercially available degradable polymers. The introduction of hydroxy acid endows PET with significantly improved composting and seawater degradation performance. Furtherly, the degradation rate of PETG with hydrophilic GA unit was faster than that of PETL, and the mineralization rate of PETG80 reaches 22.0%. The density of functional theory (DFT) calculation revealed that adding hydroxy acid to the PET molecular chain reduced the energy barrier of the hydrolysis reaction. The molecular polarity index (MPI) analysis furtherly confirmed that the higher affinity between the GA unit and water may be the primary reason for the faster degradation of PETG.

Chemotaxis of Clostridium Strains Isolated from Pit Mud and Its Application in Baijiu Fermentation.

Clostridium is the key bacteria that inhabits the pit mud in a fermentation cell, for the production of strong-flavor Baijiu. Its activities in the process of Baijiu fermentation is closely related to the niches of pit mud and cells. After multiple rounds of underground fermentation, Clostridium has been domesticated and adapted to the environment. The mechanisms of clostridia succession in the pit mud and how they metabolize nutrients present in grains are not clear. In this study, 15 Clostridium species including three firstly reported ones (Clostridium tertium, Clostridium pabulibutyricum and Clostridium intestinale) in strong-flavor Baijiu pit mud, were isolated from the pit mud. Eighty one percent of these Clostridium strains are motile, and most of them show chemotaxis to organic acids, glutathione, saccharides and lactic acid bacteria. In a simulated Baijiu fermentation system, Clostridium migrated from pit mud to fermented grains with the addition of chemokine lactic acid, resulting in the production of acetic acid and butyric acid. The results help to understand the succession mechanism of Clostridium in pit mud, and provide a reference for regulation of lactic acid level in fermented grains during Baijiu fermentation.

Construction and metabolic analysis of acetone-butanol-ethanol fermentation using mixed acetic acid and lactic acid in wastewater

To reuse organic acids in wastewater, efficient acetone-butanol-ethanol (ABE) fermentation was constructed using mixed acetic acid and lactic acid. The mixed acids were co-consumed with glucose, producing higher butanol concentration (6.96 g/L) and butanol yield (0.494 C-mol/C-mol) than using each single acid (6.22 g/L and 0.432 C-mol/C-mol). This result was verified by 13 C tracer experiment that addition of lactic acid improved carbon distribution to butanol instead of acetone , while acetic acid was readily consumed than lactic acid at initial fermentation stage. Subsequently, pH-stat fed batch fermentation at low pH of 5.5 further improved acid consumptions (6.34 g/L acetic acid and 9.06 g/L lactic acid) and solvent productions (12.4 g/L butanol and 6.50 g/L acetone). Finally, ABE fermentation using wastewater of lactic acid fermentation was performed without inhibition. Thus, efficient ABE fermentation can be implemented using mixed acetic acid and lactic acid, which is superior to using single acid. • This is the first study using mixed acetate and lactate for ABE fermentation. • 13 C experiment verified the metabolic flux to butanol was improved by the acids. • pH and glucose played an important role in acid consumption and solvent production. • Fermentation from lactic acid fermentation broth was performed without inhibition.

Study of the factors affecting growth of Celerinatantimonas sp. and gas pocket formation in Spanish-style green olives

The defect of gas pocket formation still leads to substantial losses of yield and quality of Spanish-style green olives worldwide. This spoilage has recently been associated with the growth of Celerinatantimonas sp., and this study was aimed at investigating the influence of several factors on the growth of Celerinatantimonas , both in synthetic media as well as in the olive brines of the three olive cultivars Gordal, Manzanilla and Hojiblanca. Using synthetic media, it was found that the concentration of NaCl within current industrial levels (3.5–7.0%) did not affect the growth of Celerinatantimonas , whereas the pH was a crucial factor, the range of growth being 4.5–7.5 units. Among the acids tested, lactic acid presented the highest inhibitory action against this microorganism. The assays carried out with olive brines disclosed that the population of Celerinatantimonas and its normal fermentation products (acetic acid and ethanol) increased in all of the inoculated brines, while the reduction of gas pocket defect depended on the combined use of several factors including addition of lactic acid, control of pH and inoculation with a lactic acid bacteria starter. Hence, the maintenance of a pH below 4.5 units at the beginning of fermentation along with the addition of 0.2–0.8% lactic acid was considered necessary to inhibit growth of Celerinatantimonas and to prevent gas pocket defect. The tools proposed as conclusions of this work should be used by table olive processors in the future to reduce the incidence of this olive spoilage. • Celerinatantimonas caused gas pocket defect in processed green olives. • NaCl up to 10% did not inhibit the growth of Celerinatantimonas . • Celerinatantimonas grew in a pH range of 4.5–7.0 units. • Lactic acid at 0.2–0.8% retarded growth of Celerinatantimonas . • The combined use of pH and lactic acid may control growth of Celerinatantimonas .

Application of the Hurdle Technology Concept to the Fresh Za'atar (Origanum syriacum) Preservation.

Oregano (Origanum syriacum) is popularly called za’atar in the Middle East region. It is widely used in the Mediterranean diet as an aromatic herb. This study aimed to evaluate the preservation effect of natural additives, vacuum packaging, and refrigeration on the quality traits of fresh oregano. In total, 132 fresh oregano samples were formulated and split into 4 groups (n = 33) labeled group A (100% fresh oregano leaves, Control), group B (fresh oregano 63.2%, 15% fresh onion, 20% oil, 1.8% salt), group C (fresh oregano 61.91%, 15% fresh Allium cepa, 20% oil, 1.8% salt, 1.29% sumac), and group D (fresh oregano 59.2%, 15% fresh Allium cepa, 20% corn oil, 1.8% salt, 4% lactic acid, ultimate pH 4.4). Different quality traits such as color index (L*a*b*), microbiological analysis (total aerobic, anaerobic, and psychrotrophic bacteria and yeasts and molds), and sensory features (taste, flavor, appearance, saltiness, and overall acceptance) were assessed during the storage period (42 days) for all groups. Our study showed that the addition of lactic acid (group D) exhibited a strong preservation effect against aerobic and anaerobic bacteria. In this context, group D had significantly lower aerobic and anaerobic bacterial counts (5.12 vs. 6.7, 6, and 6.7 log (cfu/g); p < 0.05) and (4.75 vs. 6.6, 6.1, 6.77 (cfu/g); p < 0.05) than group A, B, and C; respectively. Group D exhibited significantly (p < 0.05) lower psychrotrophic bacterial count (3.6 log (cfu/g)) during the whole period of storage compared with control. Group B had a lower redness index (a*) (−3.3 vs. −1.8, −1.65, −1.23; p < 0.05) than groups A, C, and D; respectively. In conclusion, our study showed that there is a possibility of improving the preservation of oregano (Origanum syriacum) by using lactic acid and sumac combined with vacuum packaging under refrigeration conditions.

Effects of Acidulants on the Rheological Properties of Gelatin Extracted from the Skin of Tilapia (Oreochromis mossambicus).

This study aimed to evaluate the effects of lactic acid (LA), citric acid (CA), and malic acid (MA) varying in concentration (0.5–2.0% w/w) on the rheological properties of fish gelatin (1.5–6.67% w/w) obtained from the skin of tilapia (Oreochromis mossambicus). The addition of LA, CA, or MA in gelatin dispersions significantly (p < 0.05) weakened their gel strengths, leading to a 14.3–62.2 reduction in gel strength. The gel strength, elastic (G′), and viscous (G″) moduli, as well as the gelling (TG) and melting (TM) temperatures of gelatin dispersions decreased with an increased level of acid added, implying the weakening effects of these acids on junction zones of the gelatin network in aqueous media. The addition of LA had less effect on these rheological properties of gelatin dispersions as compared to that of MA and CA, which were consistent with their effects on the pH of gelatin dispersions. Moreover, the reductions of TG and TM for gelatin dispersions with a higher gelatin concentration (e.g., 6.67% gelatin with 0.5% LA, TG dropped 0.4 °C) due to the addition of LA, CA, or MA were less pronounced compared to those with a lower gelatin content (e.g., 2% gelatin with 0.5% LA, TG dropped 7.1 °C), likely attributing to the stronger buffering effect of the high gelatin dispersion and less percentage reduction in the junction zones in the dispersion due to the addition of an acid. Incorporation of the effects of acids on the linear relationships (R2 = 0.9959–0.9999) between the square of gelatin concentrations and G′ or G″ could make it possible to develop a model to predict G′, G″, phase transition temperatures of gelatin dispersions containing different amounts of gelatin and acid (within the tested range) in the future.

Activated Hepatic Stellate Cells Promote the M1 to M2 Macrophage Transformation and Liver Fibrosis by Elevating the Histone Acetylation Level.

Liver fibrosis results from the formation of fibrous scars of hepatic stellate cells by various chronic liver diseases. Considering that the liver is the most important metabolic organ in the human body, exploring the metabolic characteristics of liver fibrosis is expected to discover new markers and therapeutic targets. In this study, we first used mouse model to verify that both lactate content and histone acetylation levels were significantly increased in hepatic fibrosis mice. At the same time, it was confirmed that activated hepatic stellate cells (HSCs) cocultured with M1 macrophages can promote their transformation into M2 macrophages in hepatic stellate cell line and primary hepatic stellate cells. In addition, the addition of lactic acid to the medium in which M1 cells are cultured can promote their transformation into M2 macrophages. Therefore, we concluded that activated HSCs can promote the transformation of M1 to M2 macrophages through lactate accumulation, thereby causing liver fibrosis.

Combined addition of biochar, lactic acid, and pond sediment improves green waste composting

Composting, as an eco-friendly method to recycle green waste (GW), converts the GW into humus-like compounds. However, conventional GW composting is inefficient and generates poor-quality compost. The objective of this research was to investigate the effects of the combined additions of biochar (BC; 0, 5, and 10 %), lactic acid (LA; 0, 0.5, and 1.0 %), and pond sediment (PS; 0, 20, and 30 %) on GW composting. A treatment without additives served as the control (treatment T1). The results showed that treatment R1 (with 5 % BC, 0.5 % LA, and 20 % PS) was better than the treatments with two additives or no additive and required only 32 days to generate a stable and mature product. Compared with T1, R1 improved water-holding capacity, electrical conductivity, available phosphorus, available potassium, nitrate nitrogen, OM decomposition, and germination index by 51 %, 48 %, 170 %, 93 %, 119 %, 157 %, and 119 %, respectively. R1 also increased the activities of cellulase, lignin peroxidase, and laccase. The results showed that the combined addition of BC, LA, and PS increased the gas exchange, water retention, and the microbial secretion of enzymes, thus accelerating the decomposition of GW. This study demonstrated the effects of BC, LA, and PS addition on GW composting and final compost properties, and analyzed the reasons of the effects. The study therefore increases the understanding of the sustainable disposal of an important solid waste.

Extension of growth/no growth predictive models for the preservation of low-acid pasteurized sauces by incorporating water activity and model validation in sauces

Combined preservation methods have awakened a growing interest in low-acid pasteurized sauces under ambient storage, aiming to produce more ‘natural’ foods with enhanced microbial stability. However, limited information and predictive models are available to assess the microbial stability of this kind of products, for which the spoilage is mainly caused by acid-tolerant spore-forming spoilage bacteria (ATSSB). In this study, a set of growth/no growth (G/NG) models developed previously (Sun et al., 2021a) for spores of two ATSSB strains (Bacillus velezensis and Bacillus subtilis) from pasteurized sauces were upgraded to incorporate the effect of water activity (aw). The growth from heat-treated spores (80 °C, 10 min) was assessed during three months in Nutrient Broth under 320 combinations of storage temperatures (22 and 30 °C), aw (0.95 and 0.965), pH (4.4–5.6), total acetic acid (0.0–0.3 % (w/w)), and total lactic acid (0.00–1.00 % (w/w)). Twelve replicates were tested for each combination. After merging the dataset collected previously at aw 0.98, a set of 4-variate (4V) models were developed for each strain under a single temperature after 30, 60 and 90 days separately. Additionally, the developed models were validated by challenge tests in different industrially produced low-acid pasteurized sauces for three months.The results showed that lowering aw significantly enhanced the antimicrobial effect of decreased pH and the addition of acetic and lactic acid against the ATSSB spores, while the enhancement was less evident at high acetic acid concentrations. In the challenge tests, the developed models exhibited accurate predictions for the sauces, with the % correct-predicted values ≥90 %. The developed models can be used in microbiological risk assessments or the innovation of preservation strategies for low-acid pasteurized sauces.

Enhanced Antibacterial Activity of Dermaseptin through Its Immobilization on Alginate Nanoparticles-Effects of Menthol and Lactic Acid on Its Potentialization.

Dermaseptin B2 (DRS-B2) is an antimicrobial peptide secreted by Phyllomedusa bicolor, which is an Amazonian tree frog. Here, we show that the adsorption of DRS-B2 on alginate nanoparticles (Alg NPs) results in a formulation (Alg NPs + DRS-B2) with a remarkable antibacterial activity against Escherichia coli ATCC 8739 and E. coli 184 strains, which are sensitive and resistant, respectively, to colistin. The antibacterial activity, obtained with this new formulation, is higher than that obtained with DRS-B2 alone. Of note, the addition of lactic acid or menthol to this new formulation augments its antibacterial activity against the aforementioned Gram-negative bacilli. The safety of DRS-B2, and also that of the new formulation supplemented or not with a small molecule such as lactic acid or menthol has been proven on the human erythrocytes and the eukaryotic cell line types HT29 (human) and IPEC-1 (animal). Similarly, their stability was determined under the conditions mimicking the gastrointestinal tract with different conditions: pH, temperature, and the presence of digestive enzymes. Based on all the obtained data, we assume that these new formulations are promising and could be suggested, after in vivo approval and completing regulation aspects, as alternatives to antibiotics to fight infections caused by Gram-negative bacilli such as E. coli.

Real-time monitoring the efficacy of 7-hydroxycoumarin to cells cultured on microfluidics in different extracellular pH environments by chip-mass spectrometry.

The extracellular microenvironments play a key role in tumor metabolism. To online dynamic monitoring the efficacy of 7-hydroxycoumarin (7-OHC) to cells cultured on microfluidics in acidic microenvironment, we developed an integrated multi-channel chip-mass spectrometry system. This system has six drug-loading units, cell culture chamber, metabolite collection, filtration, HPLC separation and MS detection. The cells in each microchannel will be incubated with continuous flow of culture medium, metabolites will be collected by the fixed card slot, automatic sampling needle will be precise positioned and sampled. Through this new system, the 7-hydroxycoumarin-sulfonate (7-OHC-sulfonate) and 7-hydroxycoumarin-glucuronide (7-OHC-glucuronide) can be determined in real-time. The results revealed that the addition of lactic acid promoted the formation of inactive 7-OHC-sulfonate and 7-OHC-glucuronide metabolites. Besides, acidic extracellular environment amplified cancer cell proliferation, indicating the anticancer effect of 7-OHC was weakened by low extracellular pH.

Characterization and effect of edible alginate acidified coatings associated with photodynamics on cheese preservation

The use of edible coating is an option to improve food quality and increase product shelf life. Photodynamic therapy and acid addition may be another option which decreases the number of viable microorganism cells, including Gram-negative bacteria. The present work aimed to evaluate the application of edible coatings that have the ability to inhibit the growth of Escherichia coli, using acidic pH and photodynamic therapy, in order to increase shelf life of fresh cheese. Coatings were prepared with the addition of lactic, malic and citric acids. The control coating micrograph showed surface stains, and crystal formation was apparently accentuated by the presence of citric and malic acid, not observed in the control coating or lactic acid coating. The surface micrograph of the lactic acid alginate coating showed greater homogeneity without stains and cracks. The addition of citric acid to the coating was the best result for in vitro bacterial survival tests and was therefore chosen, this coating decreased microbiological counts in the first 7 days with smaller weight loss, controlled acidity and pH and lipid oxidation remained as expected.

Triple isozyme LDH Inhibition in breast cancer cells does not alter energy production but negatively regulates cell proliferation independent of the absence of lactic acid

Several aggressive human malignant tumors are characterized by an intense glycolytic rate, over‐expression of lactic acid dehydrogenase A (LDHA), and subsequent lactate accumulation, all of which contribute toward an acidic peri‐cellular immunosuppressive tumor microenvironment (TME). While recent focus has been directed at how to inhibit LDHA, it is now becoming clear that the multiple isozymes of LDH must simultaneously be inhibited to suppress lactic acid and halt glycolysis. In this study, we explore the biochemical and genomic consequences of the administration of triple LDH isozyme inhibitor (A, B &amp;C) (GNE‐140) in MDA‐MB‐231 triple‐negative breast cancer cells (TNBC) cells. The findings confirm that GNE‐140 does, in fact, fully block the production of lactic acid, which also results in a block of glucose utilization and severe impedance of the glycolytic pathway. Without a fully functional glycolytic pathway, breast cancer cells continue to thrive, sustain viability, produce ample energy, and maintain mitochondrial potential (ΔΨM). The only observable negative consequence of GNE‐140 in this study was the attenuation of cell division, evident in both 2D and 3D cultures and occurring in fully viable cells. Of important note, the cytostatic effects were not reversible by the addition of exogenous lactic acid. The effects of GNE‐140 on the whole transcriptome were mild (12 up‐regulated differential expressed genes (DEGs) / 77 down‐regulated DEGs) out of the 48,226 evaluated, and downregulated DEGS collectively centered around a loss of genes related to mitosis, cell cycle, G0/G1; G1/S transition, and DNA replication. These data were observed by digital fluorescence cytometry and flow cytometry, both corroborating a G0/G1 phase blockage. In conclusion, the findings in this work suggest that there is an unknown element linking LDH enzyme activity to the cell cycle and that this factor is completely independent of lactic acid. The data also establish that complete inhibition of LDH in cancer cells does not affect cell viability or energy production.

Turning food waste to antibacterial and biocompatible fungal chitin/chitosan monofilaments

Here, cell wall of a zygomycete fungus, Rhizopus delemar, grown on bread waste was wet spun into monofilaments. Using the whole cell wall material omits the common chitosan isolation and purification steps and leads to higher material utilization. The fungal cell wall contained 36.9% and 19.7% chitosan and chitin, respectively. Solid state NMR of the fungal cell wall material confirmed the presence of chitosan, chitin, and other carbohydrates. Hydrogels were prepared by ultrafine grinding of the cell wall, followed by addition of lactic acid to protonate the amino groups of chitosan, and subsequently wet spun into monofilaments. The monofilament inhibited the growth of Bacillus megaterium (Gram+ bacterium) and Escherichia coli (Gram- bacterium) significantly (92.2% and 99.7% respectively). Cytotoxicity was evaluated using an in vitro assay with human dermal fibroblasts, indicating no toxic inducement from exposure of the monofilaments. The antimicrobial and biocompatible fungal monofilaments, open new avenues for sustainable biomedical textiles from abundant food waste.

Recovery of Rare-Earth Elements from Brazilian Ion-Adsorption Clay: A Preliminary Study

Ion-adsorption clays (IAC) are alumino-silicate ores, considered an essential source of heavy rare-earth elements (REE). With the increasing discovery and exploitation of IAC deposits, the present work sought to evaluate different methods of solubilization of REE through the use of different concentrations of inorganic acids (H 2 SO 4 , HCl, and HNO 3 ), as well as different concentrations of ammonium sulfate and lactic acid. According to the results, the sulfuric acid solution favored the solubilization of both La 3+ and Sm 3+ elements. The solubilization of REE in the presence of ammonium sulfate showed no significant differences as a function of the leaching time but favored the solubilization of Y 3+ and Tb 3+ . More efficient solubilization of Sm 3+ was observed with the addition of lactic acid at a concentration of 30 g L -1 , leading to 90% (4.5 ppm) of Sm 3+ extraction. The solubilization of La 3+ was favored by the contact time, with higher Sm 3+ extraction yields in 14 days of leaching. DOI: http://dx.doi.org/10.17807/orbital.v14i1.1569

Effect of the Use of a Cream with Leucine and Lactic Acid Associated with Electrostimulation in Contouring and Facial Tonus: A Randomized Clinical Controlled Trial

Evidence has supported the use of leucine as a promising agent for the maintenance of muscle tone. This study aimed to assess the combined effect of leucine and cream-based lactic acid (novel cosmetic product), associated with the use of surface electrical stimulation to improve contour and facial tonus in women. A total of 23 women were randomly allocated into two groups: Experimental (EG)—use of the leucine-based cream and lactic acid + electrostimulation for facial toning (mean intensity 13 Hz and protocol in progression); and placebo (GP)—use of the placebo cream (without the addition of leucine and lactic acid) + stimulation with the same protocol as the EG. Each group used their cream daily and underwent the intervention protocol three x/week with stimulation for 40 min, for a total of 8 weeks. Three main outcomes were reported: angular variation of facial contour by means of photogrammetry, muscle tone through the electromyographic activity of the masseter and zygomatic muscles during rest and functional tasks of biting and smiling. A significant effect of the intervention and between the groups was obtained for the experimental group against the placebo group for facial contour and muscle tone. An increased muscular activity of the masseter (average 28%) when smiling, and a reduction of zygomatic activity (in average 41%) when biting were found. The use of cream containing leucine and lactic acid combined with electrostimulation contributes to the improvement of facial contour and muscle tone when biting and smiling.

Absorption and Conversion of SO2 in Functional Ionic Liquids: Effect of Water on the Claus Reaction.

The absorption of SO2 from flue gas and its conversion to chemicals is important in the industry. Functional ionic liquids (ILs) have been broadly used to absorb SO2 in flue gas, but seldom convert it to chemicals. As we know, water is inevitable in a desulfurization process. In this work, three functional ILs (monoethanolaminium lactate-[MEA][Lac], 1,1,3,3-tetramethylguanidinium lactate-[TMG][Lac], tetraethylammonium lactate-[N2222][Lac]) with or without water were used as absorbents to absorb SO2 in flue gas, and then the absorbed SO2 in the absorbents was converted to sulfur via a Claus reaction. The result shows that the three ILs can efficiently absorb SO2 and convert it to sulfur. But the addition of water in the ILs can reduce the conversion of absorbed SO2, and the conversion increases with increasing the acidity of absorbents. To explain this phenomenon, we studied the Claus reaction in H2SO3, NaHSO3 and Na2SO3 aqueous solutions. It turns out that the conversion of the Claus reaction is related to the species of S (IV) in the order of the oxidability: H2SO3 > HSO3– > SO32–, and their proportions dependent on the pH of solutions. On the basis of the absorption mechanism of SO2 in functional ILs aqueous solution, H2S reacts with HSO3– and SO32– with weaker oxidability, resulting in the lower conversion. Importantly, we found that the addition of lactic acid could increase the conversion of SO2 via the Claus reaction.