Malate Research Articles

Antioxidant Capacity and Bioactive Ingredients of Asian Pear

The combinations of soluble sugars, organic acids, and volatile organic compounds (VOCs) are crucial for how food is perceived and accepted. In order to evaluate the volatile organic compounds (VOCs) in Asian pears (Pyrus pyrifolia), headspace solid-phase microextraction (HS-SPME) was combined with gas chromatography-mass spectrometry (GC-MS) in this study. Among the 19 aroma compounds identified in the study conducted with a PDMS fiber, acetaldehyde and ethanol were found to be the most abundant. In addition, two more significant organic acids found in Asian pears were found to be malic acid (46.89 mg/100 g) and tartaric acid (45.08 mg/100 g). Glucose (84.70 mg/100 g) and sorbitol (65.75 mg/100 g) were identified in significant concentrations among the soluble sugars that directly affect fruit quality. LC-MS was used to investigate the phenolic content of Asian pears, and important phenolic compounds such as quinic acid (19227 g/L), chlorogenic acid (8445 g/L), procyanidin B2 (3146 g/L), liquiritin (435.1 g/L), and benzoic acid (363.1 g/L) were found.

Isolation and Characterization of Compounds from Truffle Melanogaster broomenaus and their Bioactivities.

Melanogaster broomeanus Berk. is a type of truffle common in pine, oak, and hazelnut forests and which naturally spreads in the Black Sea, Mediterranean, South-West Anatolia in Turkey, is consumed as food and traded. Chemical investigation of M. broomenaus led to isolate of ten known compounds namely, brassicasterol (1), ergosterol (2), ergosterol peroxide (3), 5α, 6α-epoxy ergosta-7,22-diene-3β-ol (4), trametenolic acid (5), maleic acid (6), fumaric acid (7), mannitol (8), kojibiose (9) and trehalose (10). Assessments of the antioxidant, anticholinesterase, anti-urease, and cytotoxic properties of extracts and isolated compounds were carried out. Compound 5 showed the highest cytotoxic activity against H-1299 with IC50: 23.78±0.98 μg/mL, while compound 2 demonstrated most potent cytotoxicity against MCF-7 with IC50: 30.91±0.15 μg/ml. Also, compound 5 showed the highest antioxidant activity in all methods, particularly in DPPH and ABTS assays with IC50 values of 90.24±0.87, 75.41±0.10 μg/mL, respectively. Similarly, compound 5 exhibited highest activity with 38.84±1.22 % and 44.58±0.96 % inhibitions against AChE and BChE, respectively, while compound 7 were found to be most potent inhibitory against urease with value of 55.20±0.45 % at 100 μg/mL concentration. These findings suggest that M. broomenaus, like numerous other edible mushrooms, is a steroid-rich truffle and a potential source of steroids.

81 Evaluating the metabolome of beef carcasses with varied Longissimus lumborum color

Abstract Beef carcasses with non-normal color costs the United States industry billions of dollars annually. While dark cutters have long been attributed to long-term stress and glycogen depletion, few studies have aimed to understand other potential metabolomic markers of dark and light-colored beef. The objective of this study was to determine the metabolomic profile of carcasses possessing dark, intermediate, normal, and light lean according to RGB instrumental color evaluation. Over 9 consecutive months, 216 carcasses (n = 24/mo) from 4 color categories were collected from 2 commercial abattoirs. Carcasses were identified using L* values from industry grading cameras. Carcasses were classified into categories based on the least L* value from either side: dark (L* ≤ 55; n = 53), intermediate (55 < L* < 60; n = 54), normal (60 ≤ L* < 80; n = 54), or light (L* ≥ 80; n = 54). A 5.08 cm steak was collected from the longissimus lumborum from both carcass sides. Steaks were aged until 5 d postmortem, snap-frozen and homogenized into a powder. Metabolites were extracted by weighing 50 mg of sample into a tube with 50 μL of ribitol and 1.5 mL of 80% methanol and homogenized using a bead beater. Sample extract was dried with nitrogen gas before being reconstituted with 50 μL of methoxyamine hydrochloride and 50 μL of N-methyl-N-trimethylsilyltrifluoroacetamide with 1% trimethylchlorosilane. Untargeted metabolomics was conducted via gas chromatography-mass spectrometry. Mass spectral data were deconvoluted, aligned, and annotated using MS-DIAL. Total ion counts were normalized by the internal standard and log10 transformed prior to analysis. Data were analyzed using MetaboAnalyst by analysis of variance. Pathway analyses were conducted using the KEGG Bos taurus pathway library. Significance for all analyses was declared at FDR P < 0.05. Metabolite analyses identified 137 total features with 74 identified by the reference library and 45 were differentially expressed between carcass color categories. Malic acid was greatest in dark carcasses and least in normal and light carcasses (FDR P < 0.05). 1-methylgalactose, beta-D-galactose, sorbose, and phosphohexonoic acid was greatest in light carcasses, second in normal, third in intermediate, and least in dark carcasses (FDR P < 0.05). Methyl O-D-galactopyranoside, L-iditol, D-fructose-phosphate, and D-sorbitol 6-phosphate were greatest in light, intermediate in normal and intermediate, and least in dark carcasses (FDR P < 0.05). Uridine 5-diphospho-N-actetylglucosamine was greatest in light and normal and least in dark carcasses (FDR P < 0.05). Pathway analyses identified the pentose phosphate pathway, galactose metabolism, neomycin, kanamycin, and gentamycin biosynthesis, and valine, leucine, and isoleucine biosynthesis as the likely metabolic pathways causing differences (FDR P < 0.05) between carcass color categories. These results identify metabolites of interests and pathways that may contribute to variation in beef color and indicate that differences within beef carcass color is a multifactorial problem centered around energy and protein metabolism.

Deacidification of concentrated cranberry juice by electrodialysis with bipolar membranes: A feasibility and comprehensive study

Electrodialysis with bipolar membranes (EDBM) recently shown promising outcomes as a novel green technology to deacidify cranberry juice without altering its polyphenolic compounds, responsible for many health benefits. The performance of EDBM depends on many factors, including the concentration of the treated solution. While previous research only deacidified cranberry juice by EDBM with concentration of 8°B, the present study aimed to assess the physicochemical attributes of more concentrated juices and the effect of using specific ones (5°B, 15°B, 25°B and 35°B) during EDBM on deacidification and electrodialytic parameters evolution. Optimal juice characteristics for EDBM use (viscosity, conductivity) were exhibited at 25°B. The 4 selected juice concentrations were successfully deacidified by 39.0 ± 2.5 % but with significantly different process times (from 46 ± 2 min to 471 ± 16 min). Extended treatment duration led to a slight loss in anthocyanins and proanthocyanidins, likely due to increased polyphenols-membranes interactions, which contributed to system resistance growth. However, the reduction in citric (32 ± 3 %) and malic (61 ± 4 %) acids remained consistent, regardless of the juice concentration. This work confirmed the feasibility of producing a concentrated and deacidified cranberry juice by EDBM, that can represent a great potential to the functional food market.

Enhancing cider quality through co-fermentation with acid protease and esterase-producing Metschnikowia species and Saccharomyces cerevisiae.

To date, cider production has primarily relied on Saccharomyces cerevisiae. Introducing novel non-Saccharomyces yeasts can enhance the diversity of cider properties. Among these, the Metschnikowia genus stands out for its ability to produce hydrolytic enzymes that may impact the sensorial and technological properties of cider. This study focused on evaluating the impact of three Metschnikowia species - Metschnikowia koreensis (Mk), M. reukaufii (Mr), and M. pulcherrima (Mp) - which exhibit acid protease and esterase activity, on the quality enhancement of cider. The research findings indicate that the overall quality of cider produced through co-fermentation with these species surpassed that of cider fermented with mono-fermentation of S. cerevisiae (Sc). The cider fermented with the Sc + Mk combination exhibited the lowest levels of harsh-tasting malic acid and higher levels of softer lactic acid. Sensory array analysis also demonstrated that the Sc + Mk fermented cider exhibited high sensor response values for compounds contributing to a complex overall olfactory composition and richness. Furthermore, the Sc + Mk fermented cider exhibited the highest total quantity and variety of volatile organic compounds (VOCs). Specifically, the concentrations of phenethyl alcohol, 3-methyl-1-butanol, ethyl octanoate, and decanoic acid were notably elevated in comparison with other groups. This study illustrates that Metschnikowia species, particularly M. koreensis, show significant potential as starters for cider due to their various technological properties, including acidity modulation, aroma enhancement, and color improvement. The findings of this study provide a foundation for improving cider quality by co-fermenting S. cerevisiae with innovative starter cultures. © 2024 Society of Chemical Industry.

Predictive models for estimating the sugar content and organic acids in processed mangoes based on the initial content

SummaryThe quality of processed products can be adversely affected by uncontrollable batches of mangoes, which exhibit heterogeneous characteristics. This study aimed to establish predictive models for sugar and organic acid contents (dependent variables) in processed products using the initial compositions of fresh mangoes. Three mango cultivars (cv. ‘Kent’, cv. ‘Keo Romeat’, and cv. ‘Keo Chen’) were classified as low‐density and high‐density groups. Each group of mangoes at the green‐mature, mid‐ripe, and ripe stages was processed into pasteurised purees, dried slices, and mango chips. Prediction models were established using a mix of simple linear regression (SLR) based on the initial content and Analysis of Variance (ANOVA) to identify the impact of qualitative variables (ripening stage, cultivar‐density, and processing technique). In processed mangoes, 13% sucrose content was estimated to accumulate with the three qualitative variables, whereas glucose and fructose contents decreased from their initial levels by 10% and 7%, respectively. Processing techniques can predict the ratio of sugars/acids (S/A) in processed products, regardless of the ripening stage or cultivar‐density. Similar to S/A, citric acid and malic acid contents in mango products were significantly increased by processing techniques. The initial content and processes were insufficient to predict the final contents of the same parameters in processed mangoes; therefore, some models need to include the effects of ripening stage and cultivar‐density to improve the prediction. These relevant explanatory variables contributed significantly to the development of the models, resulting the accuracy of predictive models with normalised root mean square errors (NRMSEs) lower than 10%, except for malic acid (14.04%). In conclusion, it is feasible to estimate the sugar and acidity levels in processed mangoes, offering promising possibilities for ensuring consistent quality of mango‐based products.

Characterization of fine-flavor cocoa in parent-hybrid combinations using metabolomics approach

Fine-flavored cocoa is generally characterized by fresh bean color and sensory characteristics. However, these methods cannot be applied to progenies/hybrids because their colors may vary depending on their parents. Additionally, sensory evaluation lacks universal quality standards, necessitating robust complementary characterization methods. This study aimed to characterize the fine-flavor cacao in parent-hybrid combinations using widely targeted Gas Chromatography-Mass Spectrometry (GC–MS) and bean phenotype analysis. Fine-flavored cacao exhibits white-bean characteristics and a lighter color than forastero. Conversely, the hybrids displayed varying percentages of fresh bean color. Caffeine and organic acids (malic acid, fumaric acid, citric acid, lactic acid, and tartaric acid) were found to correspond to the characteristics of fine-flavored cacao. Each parent-hybrid combination demonstrated distinct flavor characteristics, with the ICCRI03-hybrid emerging as a promising clone, exhibiting flavor characteristics similar to those of its female parent (fine-flavor cacao). This information on flavor characteristics will be beneficial for further fine-flavored cacao selection.

Extraction of apple pomace polyphenols using natural deep eutectic solvents: A sustainable approach

To effectively utilize apple pomace resources, we extracted apple pomace polyphenols using natural deep eutectic solvent (NADES) as the medium, with a solvent-to-solid ratio of 50 mL/g, for a duration of 120 min. Compared to conventional extraction solvents (ethanol and methanol), four NADES significantly enhanced the extraction efficiency of polyphenols from apple pomace. Notably, NADES 1 (betaine: urea = 1:1, 30% water) and NADES 2 (betaine: malic acid = 1:1, 30% water) exhibited superior extraction capabilities, with maximum values reaching 5.245 ± 0.124 mg GAE/g pomace and 5.157 ± 0.164 mg GAE/g pomace, respectively, in Qinguan apple pomace. Both solvents reached their maximum extraction efficiency within 120 min, with NADES 1 achieving a maximum extraction amount of 4.8325 mg GAE/g and NADES 2 achieving 5.3039 mg GAE/g from Fuji apple pomace. NADES 1 and NADES 2 were more efficient in extracting monophenols such as quercetin, rutin, gallic acid, and procyanidin, whereas organic solvents (methanol and ethanol) were more effective for monophenols like methyl gallate and phlorizin. Furthermore, polyphenol extracts obtained using NADES from Fuji apple pomace displayed varying levels of antibacterial effectiveness, with NADES 4 (glucose: lactic acid = 1:5, 60% water) and NADES 2 showing superior efficacy against Escherichia coli and Staphylococcus aureus. This comprehensive study not only demonstrated the potential of NADES in extracting polyphenols from apple pomace but also highlighted their applicability as natural preservatives in the food industry.

Comparison of germanium recovery from copper(II) sulfate-based solution using tertiary amine and oxime extractant

Germanium is considered by many world economies, including the USA and EU, as a critical raw material. One of the methods, which may be used in its recovery is solvent extraction. Using it application of more environmentally harmful processes like tannin concentrate precipitation or chlorination may be reduced. Solvent extraction of germanium from solution after oxidative leaching of copper cake by two extractants, chelating Mextral 63H (LIX 63 equivalent) and basic trioctylamine (TOA), were compared. For TOA influence of complexant addition, tartaric acid, malic acid, malonic acid, and succinic acid, on germanium recovery yield was also tested. It was found that under investigated conditions, i.e. pH∼1.0 TOA was a better and more selective germanium extractant. The highest Ge extraction yields (>96 %) were achieved when tartaric acid was used as a germanium complexant in an aqueous phase. It was determined that germanium may be stripped from the organic phase using > 5 wt% NaOH solution with > 93 % yield.

Effect of postharvest cold storage and subsequent shelf-life on fruit quality and endogenous phytohormones in nectarine fruit

Cold storage is the main approach to extend the postharvest storage period of nectarines. The objective of this study was to investigate fruit quality (flavor and nutrition) and endogenous phytohormone changes and their related transcriptional changes in nectarine fruit after cold storage and subsequent shelf-life, which was performed metabolome, transcriptome and physiological analysis. Cold storage led to irreversible flavor loss due to the inhibition of aroma biosynthesis genes at low temperature. Sugar and organic acid content was affected, with an increase in glucose, fructose and malic acid, and a decrease in sorbitol and citric acid after cold storage or shelf-life. For fruit nutritional quality, total flavonoids or total carotenoids was not significantly affected by cold storage, whereas shelf-life process enhanced their accumulation. The activities of key enzymes for flavonoid biosynthesis, PAL and C4H, were enhanced during the shelf-life process, resulting in a significant increase in flavonoids and enhanced free radicals scavenging capacity. Meanwhile, shelf-life process increased carotenoids content by improving the expression of carotenoid biosynthesis genes PSY, ZDS and ZISO. Additionally, cold storage significantly increased the IAA content and ethylene production, thereby inducing the up-regulation of related signaling transduction genes. The shelf-life process further increased ethylene production, as well as salicylic acid and jasmonic acid content. This study unravels these crucial physiological and associated transcriptional changes of nectarines after cold storage, and may provide a theoretical foundation for improving fruit quality of peaches after cold storage.

The Effects of L-Citrulline and Malic Acid on Substrate Utilisation and Lactate Elimination

Endurance athletes often aim to improve their aerobic metabolism. The aim of this pilot study was to examine if malic acid and L-citrulline supplementation can improve aerobic metabolism and lactate elimination. Nine young (23.9 ± 1.9 years) recreational male athletes participated in this study. Following a standardised breakfast and a body composition analysis (InBody720), 6000 mg of citrulline and 3000 mg of malic acid or a placebo of 300 mL of water were consumed on three separate days in a cross-over design using a double-blind method. Sixty minutes after the supplementation, participants completed a ramp bicycle spiroergometer protocol (35 W/3 min) until reaching a respiratory exchange ratio (RER) of 1.1, followed by a 9 min active recovery. Cadence, heart rate (HR), rate of perceived exertion (RPE), respiratory parameters and lactate levels were registered. The RPExHR value was calculated to accurately characterise exhaustion. During the exercise protocol, citrulline supplementation induced significantly lower RER values at 70-105-140 W compared to malic acid and the placebo, respectively. There was no difference in lactate levels neither during rest nor at RER 1.1. RPExHR rate values were significantly lower after malic acid supplementation compared to placebo at 175 and 210 W. Power at RER 1.1 was higher after malic acid (+4 W) and citrulline (+5 W) supplementation. Although the supplementation failed to decrease lactate levels, lower RER and RPE values may indicate a performance-enhancing benefit.

Chemometric Approach Application in Modern Wine Studies

The wine market is affected by the origin of wines, but the current wine traceability system has some limitations. The idea of geographical authenticity and quality has increased as one of the most important parameters influencing consumers’ preferences. Chemical parameters such as total polyphenolic content (TPC), alcohol and organic acid content (total acids, malic and tartaric acids), and antioxidant activity were observed in this work at 15 dry white wines of varieties Pinot blanc, Riesling, Sauvignon blanc, and Chardonnay, which originated from three different countries. FTIR and spectrophotometry methods (TPC and DPPH) were used and chemometric approaches such as ANOVA and PCA were selected as the most important for evaluation. In general, high levels of malic acid, TPC, and antioxidant activity were detected in Austrian wines. Pinot blanc, Chardonnay, and Sauvignon from the same producing region in Austria showed higher results. The higher overall acid concentration was a distinguishing feature of the Slovakian Sauvignon and Riesling varieties, particularly in the case of tartaric acid. Austrian samples showed significantly higher antioxidant activity compared to Hungarian Chardonnay (p = 0.002) and Sauvignon (p = 0.007), comparable to TPC. The application of statistical analysis was useful in demonstrating many discrepancies, particularly by application of the PCA method.

Changes in primary metabolism and associated gene expression during host-pathogen interaction in clubroot resistance of Brassica napus.

The role of primary metabolism during Brassica napus-Plasmodiophora brassicae interaction leading to clubroot resistance has not yet been investigated thoroughly. In this study, we investigated some of the primary metabolites and their derivatives as well as expression of the genes involved in their biosynthesis to decipher this host-pathogen interaction. For this, two sets (clubroot resistant and susceptible) of canola lines were inoculated with P. brassicae pathotype 3A to investigate the endogenous levels of primary metabolites at 7-, 14-, and 21-days after inoculation (DAI). The associated pathways were curated, and expression of the selected genes was analyzed using qRT-PCR. Our results suggested the possible involvement of polyamines (spermidine and spermine) in clubroot susceptibility. Some of the amino acids were highly abundant at 7- or 14-DAI in both resistant and susceptible lines; however, glutamine and the amino acid derivative phenylethylamine showed higher endogenous levels in the resistant lines at later stages of infection. Organic acids such as malic, fumaric, succinic, lactic and citric acids were abundant in the susceptible lines. Conversely, the abundance of salicylic acid (SA) and the expression of benzoate/salicylate carboxyl methyltransferase (BSMT) were higher in the resistant lines at the secondary stage of infection. A reduced disease severity index and gall size were observed when exogenous SA (1.0 mM) was applied to susceptible B. napus; this further supported the role of SA in clubroot resistance. In addition, a higher accumulation of fatty acids and significant upregulation of the pathway genes, glycerol-3-phosphate dehydrogenase (GPD) and amino alcohol phosphotransferase (AAPT) were observed in the resistant lines at 14- and 21-DAI. In contrast, some of the fatty acid derivatives such as phosphatidylcholines represented a lower level in the resistant lines. In conclusion, our findings provided additional insights into the possible involvement of primary metabolites and their derivatives in clubroot resistance.

Electrocatalytic oxidation of glycerol performed by nickel/cobalt alloys: Adding value to a common subproduct of chemical industry

The present work shows the electrocatalytical performance of nickel/cobalt alloys towards the conversion of glycerol into higher value molecules, such as glycolic acid, oxalic acid, maleic acid, diethylene glycol and ethylene glycol, identified by chromatographic technique. To do so, the alloy was directly electrodeposited on graphite electrodes, which is a simple, readily available and cheap material, the modified electrodes were characterized by scanning electron microscopy, infrared spectroscopy and electrochemical analysis. Kinetic parameters were obtained using by both Galus methodology and rotating disc electrode (RDE), obtaining the better electrocatalytic modified electrode and the total number of electrons transferred per mol of glycerol. The modified electrode labeled as Ni0.8Co0.2(OH)2 proportion has achieved the highest glycerol conversion after 4 h of reaction, approximately 99.8%, with an energy consumption of 36.38 W/mol.

Phytochemistry, Nutritional, and Pharmacological Potential of Citrus Limonum

The current research aimed to provide an overview of the phytochemical configuration, nutritional value, and therapeutic uses of Citrous Limonum (lemon). Its fruit contains a variety of phytochemicals including citric acid, polyphenols, terpenes, limonene, flavonoids, vitamin C, sugar, pectin, citric acid, malic acid, flavonoids, carotenoids, terpineol, fellander, camhenium, citrain, calcium oxalates, and mucilages. Vitamin C is abundant in citrous fruits, as well as macronutrients (dietary fibre and simple sugar) and micronutrients (copper, magnesium, phosphorus, calcium, potassium, pantothenic acid, riboflavin, vit B6 niacin thiamin, and folate). Lemon oil is composed of 70% limonene and 20% monoterpenes, along with significant amounts of aldehydes, such as citral, alcohols (linalool), and esters (coumarin). Lemon peel contains high concentrations of flavonoids, glycosides, coumarins, steroids (beta, gamma, sitosterol), dietary fibers, carbs, and volatile oils, all of which are necessary for good health and appropriate development. However, citrus fruits are low in calories, salts, and cholesterol. They find uses in herbal remedies due to their antioxidant, antifungal, anti-cholesterol, anticancer, antiulcer, antidiabetic, antibacterial, and anti-inflammatory characteristics. It is also important to mention that the excessive use of lemon may also be associated with some risks, such as the lowering of sperm count.

Effective removal of phosphate using La(OH)3@magnetic graphene: A sustainable approach for water remediation

The global environmental concern over dissolved phosphate (P) in surface water has intensified due to its detrimental impact on water quality, particularly through eutrophication. To address this issue, lanthanum hydroxide (LaH)@magnetic graphene (MG) was synthesized via a green method. The MG, prepared using maleic acid, features a highly intricate pore structure and significant surface area, providing numerous active sites for P adsorption. The adsorbent demonstrated exceptional efficiency, achieving 98.8 % removal at neutral pH and a maximum phosphate uptake capacity of 275.5 mg/g. Characterization techniques including SEM-EDS, FT-IR, and XPS, along with density functional theory (DFT) calculations, were used to elucidate the adsorption mechanism of LaH@MG. These studies indicate that the adsorption mechanism involves chemical interactions through hydrogen bonding and ligand exchange. Additionally, the recyclability and phosphate adsorption performance of LaH@MG in real wastewater were evaluated, underscoring its potential for practical environmental remediation applications.

Enhancing physicochemical properties, organic acids, antioxidant capacity, amino acids and volatile compounds for ‘Summer Black’ grape juice by lactic acid bacteria fermentation

To investigate the effect of lactic acid bacteria fermentation on the quality of ‘Summer Black’ grape juice, this study characterized the differences in physicochemical properties, organic acids, antioxidant capacity, amino acids and volatile compounds among different treatments. The results showed that the pH and total sugar of all fermentation groups were lower than those of the CK (control group) sample. ZR (Lactobacillus plantarum) sample had the highest DPPH and OH− scavenging ability, and the total phenol and total flavonoid content of SR (Streptococcus thermophilus) sample were increased by 5.2% and 4.1%, respectively. The contents of tartaric acid, malic acid, and citric acid were improved significantly by LAB fermentation. The content of Asp, Thr, Ser, Glu, and Gly in the SR sample was significantly higher than in the CK sample. Phenylethyl alcohol, lactic ethyl ester, L-menthol, citronellol, and nerol were produced by LAB fermentation, giving fruit and floral aroma, and streptococcus thermophilus has a higher potential to enhance the aromatic flavor of ‘Summer Black’ grape juice. 20 chemical indicators were determined to explain the differences between groups by OPLS-DA.

Lipid vesicle formation by encapsulation of SMALPs in surfactant-stabilised droplets

Understanding the intricate functions of membrane proteins is pivotal in cell biology and drug discovery. The composition of the cell membrane is highly complex, with different types of membrane proteins and lipid species. Hence, studying cellular membranes in a complexity-reduced context is important to enhance our understanding of the roles of these different elements. However, reconstitution of membrane proteins in an environment that closely mimics the cell, like giant unilamellar vesicles (GUVs), remains challenging, often requiring detergents that compromise protein function. To address this challenge, we present a novel strategy to manufacture GUVs from styrene maleic acid lipid particles (SMALPs) that utilises surfactant-stabilised droplets as a template. As a first step towards the incorporation of membrane proteins, this work focusses on the conversion of pure lipid SMALPs in GUVs. To evaluate the method, we produced a new form of SMA linked to fluorescein, referred to as FSMA. We demonstrate the assembly of SMALPs at the surfactant-stabilised droplet interface, resulting in the formation of GUVs when released upon addition of a demulsifying agent. The released vesicles appear similar to electroformed vesicles imaged with confocal light microscopy, but a fluorescein leakage assay and cryo-TEM imaging reveal their porous nature, potentially as a result of residual interactions of SMA with the lipid bilayer. Our study represents a significant step towards opening new avenues for comprehensive protein research in a complexity-reduced, yet biologically relevant, setting.

Improvement of pasting behavior and retrogradation inhibition of normal corn starch treated with phytic acid and malic acid

Phytic acid (PA) and malic acid (MA), as environmentally friendly, plant-based water-soluble acids, were applied to normal corn starch during dry heating at mildly acidic pH to improve its gelatinization and retrogradation behaviors. A significant increase in peak viscosity (5011–6338 mPa·s) was observed in starch treated with MA compared to native corn starch (1162 mPa·s). The treatment with PA and MA further increased the peak viscosity (8140–8621 mPa·s). The interactions of PA and MA with starch were analyzed using ICP-OES, FTIR, and 13C CP/MAS NMR. Swelling power and solubility increased in MA and PA + MA starches. After storage at 4 °C for 14 d, MA and PA + MA starches produced transparent and fluid gels without forming B-type crystals, which indicated inhibition of starch retrogradation by PA and MA treatments. In conclusion, dry heating with PA and MA produced starch with remarkably superior paste viscosity, swelling, and inhibition of retrogradation.

Natural deep eutectic solvents: A paradigm of stability and permeability in the design of new ingredients

Ascorbic Acid (AA) is a crucial component in the food industry, serving as both a quality and safety criterion. It is used to fortify foods due to its significant role in human health, acting as an antioxidant. Its benefits extend to both product quality and consumer health in the food and cosmetic industry. Due to their physicochemical properties, Natural Deep Eutectic Solvents (NADES) have the potential to be used for the extraction and stabilization of bioactive compounds. The objective of this study is to characterize various NADES, simulate the solubility of AA, evaluate the antioxidant and protective capacity of NADES, and investigate the permeability of this vitamin through the skin and gastrointestinal membrane. Antioxidant capacity was measured using three methods: TEAC, DPPH, and ORAC. The solubility of AA in NADES systems was simulated using the COSMOTherm software. The degradation of AA was monitored by HPLC/UV–Vis for 30 days at two different storage temperatures. Additionally, the membrane solubility was measured using the PAMPA method in both skin and gastrointestinal. The results indicate that organic acid-based NADES are more polar than sugar and polyalcohol-based NADES. The solubility prediction shows that reduced ln(γ) in Choline chloride-based NADES results in low AA solubility, which positively correlates with higher pH values. AA degradation increased at lower pH, and its half-life time was longer at 4 °C, being the best choline chloride (ChChl):xylose. Moreover, betaine:malic acid, ChChl:tartaric acid, and ChChl:lactic acid gave worse stabilizing results than control. According to the PAMPA study, AA in lactic acid:glucose had the highest Pe (permeability coefficient) for both gastrointestinal (Log Pe: −4.99) and skin (Log Pe: −4.78). Malic acid:glucose, on the other hand, had the lowest LogPe value (−6.9). In this study, some NADES can play a protective role in the preservation of ascorbic acid. This statement could be extended to other bioactive compounds found in NADES extracts that may be impacted by oxidative processes. Moreover, not all NADES stabilized equally AA. These findings could be applied to the formulation of ascorbic acid-containing drugs, cosmetics, and food products.