Ultrasound-assisted extraction of anthocyanins from grape pomace using acidified water: Assessing total monomeric anthocyanin and specific anthocyanin contents.

This study aimed to optimize the ultrasound-assisted extraction (UAE) of anthocyanins from oven-dried and freeze-dried Vitis labrusca grape pomace, using acidified water as the solvent. The effects of power density (8.3-16.7 W/mL), pulse interval (0-2 s), and extraction time (1-5 min) on both total and specific anthocyanins were investigated. The findings suggested that acidified water can be a viable alternative to conventional solvents and that oven drying was an effective method for drying the pomace. Using response surface methodology, the study identified power density and extraction time as key factors influencing total anthocyanin content, with extracts reaching contents up to 2.56 mg/g. The analysis using LC-MS identified 14 anthocyanins, while NMR quantified 3 and malvidin diglucoside was generally the most abundant. However, higher power and longer extraction times were found to reduce its content while increasing malvidin monoglucoside content, suggesting ultrasound-induced anthocyanin hydrolysis. In conclusion, this study presents a sustainable method for extracting anthocyanins using acidified water, contributing to the valorization of Vitis labrusca grape pomace for industrial use.

Anti-Staphy Peptides Rationally Designed from Cry10Aa Bacterial Protein.

Bacterial infections pose a significant threat to human health, constituting a major challenge for healthcare systems. Antibiotic resistance is particularly concerning in the context of treating staphylococcal infections. In addressing this challenge, antimicrobial peptides (AMPs), characterized by their hydrophobic and cationic properties, unique mechanism of action, and remarkable bactericidal and immunomodulatory capabilities, emerge as promising alternatives to conventional antibiotics for tackling bacterial multidrug resistance. This study focuses on the Cry10Aa protein as a template for generating AMPs due to its membrane-penetrating ability. Leveraging the Joker algorithm, six peptide variants were derived from α-helix 3 of Cry10Aa, known for its interaction with lipid bilayers. In vitro, antimicrobial assays determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) required for inhibiting the growth of Staphylococcus aureus, Escherichia coli, Acinetobacter baummanii, Enterobacter cloacae, Enterococcus facallis, Klebsiella pneumonia, and Pseudomonas aeruginosa. Time-kill kinetics were performed using the parental peptide AMPCry10Aa, as well as AMPCry10Aa_1 and AMPCry10Aa_5, against E. coli ATCC, S. aureus 111 and S. aureus ATCC strains showing that AMPCry10Aa_1 and AMPCry10Aa_5 peptides can completely reduce the initial bacterial load with less than 2 h of incubation. AMPCry10Aa_1 and AMPCry 10Aa_5 present stability in human serum and activity maintenance up to 37 °C. Cytotoxicity assays, conducted using the MTT method, revealed that all of the tested peptides exhibited cell viability >50% (IC50). The study also encompassed evaluations of the structure and physical-chemical properties. The three-dimensional structures of AMPCry10Aa and AMPCry10Aa_5 were determined through nuclear magnetic resonance (NMR) spectroscopy, indicating the adoption of α-helical segments. Electron paramagnetic resonance (EPR) spectroscopy elucidated the mechanism of action, demonstrating that AMPCry10Aa_5 enters the outer membranes of E. coli and S. aureus, causing substantial increases in lipid fluidity, while AMPCry10Aa slightly increases lipid fluidity in E. coli. In conclusion, the results obtained underscore the potential of Cry10Aa as a source for developing antimicrobial peptides as alternatives to conventional antibiotics, offering a promising avenue in the battle against antibiotic resistance.

Effects of different cold plasma treatments on chemical composition, phenolics bioaccessibility and microbiota of edible red mini-roses.

This study evaluated the effect of dielectric barrier discharge (DBD) and glow discharge (glow) cold plasma treatments in color, sugars, organic acids, phenolics (concentration and bioaccessibility), antioxidant activity, volatiles, and microbiota of edible mini-roses. Plasma treatments did not affect the flowers' color, while they increased organic acids and phenolics. Flowers treated with DBD had a higher concentration of most phenolics, including hesperidin (84.04 µg/g) related to antioxidant activity, and a higher mass fraction of most volatiles, including octanal (16.46% after 5 days of storage). Flowers treated with glow had a higher concentration of pelargonidin 3,5-diglucoside (392.73 µg/g), greater bioaccessibility of some phenolics and higher antioxidant activity. Plasma treatments reduced the microbiota diversity in mini-roses. Regardless of the plasma treatment, phylum Proteobacteria, family Erwiniaceae, and genus Rosenbergiella were the dominant groups. Results indicate plasma treatments as promising technologies to improve the quality and increase phenolic and specific volatile compounds in mini-roses.

Effect of virgin coconut oil on body weight, white fat depots, and biochemical and morphological parameters in mice fed standard or high-fat diets.

This study investigated the effects of virgin coconut oil (VCO) on body weight, white fat depots, and biochemical and morphological parameters in male Swiss mice fed standard (SD) or high-fat (HFD) diets. Thirty-three adult animals were assigned to one of four groups, as follows: SD, SD plus VCO (SDCO), HFD, and HFD plus VCO (HFDCO). VCO had no effects on the Lee index, subcutaneous fat, periepididymal fat, retroperitoneal fat, area under the curve for glucose, or pancreas weight, all of which were increased by HFD. Low-density lipoprotein cholesterol increased in the SDCO group compared with the SD group and decreased in the HFDCO group compared with the HFD group. VCO increased total cholesterol only in the SDCO group compared with the SD group, with no differences between the HFD and HFDCO groups. In conclusion, low-dose VCO supplementation did not improve obesity, had no effects on hepatic or renal function, and had beneficial effects on the lipid profile only in animals fed HFD.

Geometric deep learning as a potential tool for antimicrobial peptide prediction.

Antimicrobial peptides (AMPs) are components of natural immunity against invading pathogens. They are polymers that fold into a variety of three-dimensional structures, enabling their function, with an underlying sequence that is best represented in a non-flat space. The structural data of AMPs exhibits non-Euclidean characteristics, which means that certain properties, e.g., differential manifolds, common system of coordinates, vector space structure, or translation-equivariance, along with basic operations like convolution, in non-Euclidean space are not distinctly established. Geometric deep learning (GDL) refers to a category of machine learning methods that utilize deep neural models to process and analyze data in non-Euclidean settings, such as graphs and manifolds. This emerging field seeks to expand the use of structured models to these domains. This review provides a detailed summary of the latest developments in designing and predicting AMPs utilizing GDL techniques and also discusses both current research gaps and future directions in the field.

Cold plasma as a pre-treatment for processing improvement in food: A review.

Thermal processes can be very damaging to the nutritional and sensory quality of foods. Non-thermal technologies have been applied to reduce the impact of heat on food, reducing processing time and increasing its efficiency. Among many non-thermal technologies, cold plasma is an emerging technology with several potential applications in food processing. This technique can be used to preserve and sanitize food products, and act as a pre-treatment for drying, extraction, cooking, curing, and hydrogenation of foods. Furthermore, the reacting plasma species formed during the plasma application can change positively the sensory and nutritional aspects of foods. The aim of this review is to analyze the main findings on the application of cold plasma as a pre-treatment technology to improve food processing. In its current maturity stage, the cold plasma technology is suitable for reducing drying time, increasing extraction efficiency, as well as curing meats. This technology can convert unsaturated into saturated fats, without forming trans isomers, which can be an alternative to healthier foods. Although many advantages come from cold plasma applications, this technology still has several challenges, such as the scaling up, especially in increasing productivity and treating foods with large formats. Optimization and control of the effects of plasma on nutritional and sensory quality are still under investigation. Further improvement of the technology will come with a higher knowledge of the effects of plasma on the different chemical groups present in foods, and with the development of bigger or more powerful plasma systems.

Influence of Dielectric Barrier Discharge Cold Plasma Treatment on Starch, Gelatin, and Bacterial Cellulose Biodegradable Polymeric Films.

The environmental damage caused by plastic packaging and the need to reduce pollution requires actions to substitute plastic materials for more sustainable and biodegradable materials. Starch, gelatin, and bacterial cellulose films are three potential biodegradable polymeric films for use in packaging. However, these materials need improvements in their physical, chemical, and mechanical properties to be used in packaging. In this work, these films were treated with cold plasma to evaluate the effects of treatment conditions on several physical, chemical, and mechanical properties. The dielectric barrier discharge plasma technology was applied with varying treatment times (0 to 20 min) and excitation frequencies (50 to 900 Hz) at 20 kV. The optimal excitation frequency for starch films (50 Hz) was different from the optimal frequency for gelatin and bacterial cellulose films (900 Hz), indicating a high dependency on the treatment in this variable that is often neglected. Plasma treatment improved the hydrophobicity, surface morphology, water resistance, and mechanical properties of all three films, with the advantage of not recurring to chemical or biological additives.

Optimization of Sonication Parameters to Produce a Cashew Apple Bagasse Puree Rich in Superoxide Dismutase.

The effects of ultrasound processing parameters on the extraction of antioxidative enzymes and a toxicity assessment of cashew apple bagasse puree were investigated. Ultrasound directly affects the formation of reactive oxygen species such as H2O2, and consequently, superoxide dismutase, catalase, and ascorbate peroxidase activities. S.O.D. activity increased up to 280% after U.S. processing at 75 W/cm2, 1:3 bagasse: water ratio, and 10 min compared to non-processed bagasse. Therefore, the effect of ultrasound in delaying browning could be correlated to the enhanced antioxidant enzyme activity and decrease in peroxidase activity. At center point conditions (226 W/cm2, 1:3 bagasse: water ratio; 6 min), a decrease of 20% and 50% on POD and PPO activities was observed, respectively. No significant acute toxicity or protective effect was observed in unprocessed and sonicated cashew apple bagasse. Although cashew bagasse processed at 75 W/cm2 prevented nauplii death after 24 h of exposure, this data cannot assure the protective effect once the number of dead nauplii on 100 µg/mL was similar. However, these data indicate a possible protective effect, especially in higher cashew bagasse concentrations. The results suggest that sonicated cashew apple bagasse puree, a coproduct obtained from a traditional valued fruit in Brazil, may be used as a source of antioxidative enzymes, which further has great importance in therapeutics.

Production of tung oil epoxy resin using low frequency high power ultrasound.

Epoxy resins made from vegetable oils are an alternative to synthesize epoxy resins from renewable sources. Tung oil is rich in α -eleostearic fatty acid, which contains three double bonds producing epoxy resins with up to three epoxy groups per fatty acid. This work studied the production of tung oil epoxy resin using hydrogen peroxide as an oxidizing agent and acetic and formic acid as percarboxylic acid precursors, applying low frequency high power ultrasound. This study evaluated the effects of ultrasound power density, hydrogen peroxide concentration, acetic acid concentration, and formic acid concentration on the yield into epoxy resin, selectivity, and by-products formation. Application of ultrasound was carried out using a 19 kHz probe ultrasound (horn ultrasound) with a 1.3 cm diameter titanium probe, 500 W nominal power, 2940 W L-1 maximum effective power density applied to the reaction mixture. Ultrasound technology yielded up to 85% of epoxy resin in 3 h of reaction. The use of formic acid resulted in a slightly lower oil conversion than acetic acid but with a much higher selectivity towards epoxidized tung oil. However, using acetic acid resulted in the production of high-value by-products, such as 2-heptenal and 2,4-nonadienal. The ultrasound-assisted epoxidation showed to be particularly efficient when applied to oils containing conjugated double-bonds.

Cold plasma technique as a pretreatment for drying fruits: Evaluation of the excitation frequency on drying process and bioactive compounds.

The present work aims to evaluate the effect of different excitation frequency (200, 500 and 800 Hz) of cold plasma technique as a pretreatment for drying tucumã. SEM images showed changes on the pretreated tucumã's surface, favoring the drying rate and diffusivity of water as well as reducing the drying time. Marginal variation of color and reduced drying time were observed in the samples treated using 200 and 800 Hz. The pretreatment improved the concentration of phenolic (45.3 mg GAE g-1) and antioxidant compounds (799.8 µM ET) (p-value < 0.05). Carotenoids were more sensitive to the drying time, presenting significant degradation at 500 Hz. For this reason, the propose pretreatment based on the application of cold plasma technique for drying foods can preserve/improve their nutritional quality.

Atmospheric cold plasma frequency imparts changes on cashew apple juice composition and improves vitamin C bioaccessibility.

This study evaluated the atmospheric cold plasma (ACP) effect on cashew apple juice composition at different frequencies (200 and 700 Hz). The impact of this non-thermal technology on the organic juice compounds after the processing and along with the in vitro digestion carried out in a simulated digestion system at 37 °C/6 h was evaluated. The changes in the juice composition were determined by NMR spectroscopy and chemometric analyses. Vitamin C and total phenolic compounds were also quantified in processed and non-processed (control) juices and after each digestion phase. The results showed decreased glucose and fructose in samples treated by ACP and an increment in malic acid concentration for ACP700. ACP increased the amount of vitamin C in the juices and did not affect the total phenolic content. The gastric digestion highlighted the pronounced effect of plasma on the juice composition, increasing all of the components detected by NMR. Cashew apple juice processed by ACP700 presented a higher concentration of malic acid and phenylalanine. An increased bioaccessibility of vitamin C was also found for ACP700. Although ACP processing has decreased some compounds' concentration, this technology improved the bioaccessibility of vitamin C - the main bioactive compound of cashew apple juice.

Corn starch based films treated by dielectric barrier discharge plasma.

Cold plasma is an innovative strategy to strengthen the polysaccharide-based films characteristics. This study evaluated the effects of dielectric barrier discharge (DBD) plasma on the hydrophilic character, water vapor permeability (WVP), and tensile properties of corn starch-based films. Starch films were exposed to plasma processing operating at an excitation frequency of 200 Hz for 10, 15, and 20 min. DBD plasma resulted in further enhanced tensile strength and stiffness, and lower hydrophilicity and water solubility; however, it did not present significant effects on the WVP of the resulting films within the ranges studied. Higher hydrophobicity, strength, and stiffness were verified after 20 min. The results presented in this work suggest that the DBD plasma has the potential to make starch-based films a more suitable packaging material.

Dielectric barrier atmospheric cold plasma applied to the modification of Ariá (Goeppertia allouia) starch: Effect of plasma generation voltage.

The goal of this paper was to evaluate the influence of a range of plasma generation voltages on the physicochemical, structural, and technological properties of Aria (Goeppertia allouia) starch. Untreated (0 kV) and high voltages of cold plasma generation (7, 10, 14, and 20 kV) treated samples were evaluated according to their amylose content, pH, groups carbonyl/carboxyl, molecular size distribution, structure and technological properties (empirical viscosity, hydration properties, thermal analysis and gel strength). The applied voltage of 14 kV resulted in the greatest depolymerization of the starch chains, while 20 kV allowed the formation of oxidized complexes, promoting crosslinking of the starches chain. The cold plasma technique did not affect the levels of resistant starches, but increased the starch digestibility. The increased carbonyl and carboxyl groups also influenced the paste viscosity, improved hydration properties. This study suggests that the cold plasma technique can be useful in the controlled modification of starches, producing starches with different technological properties.

Thermal and non-thermal processing effect on açai juice composition.

This study evaluated the effects of High-Temperature Short Time (HTST), Ultra High Temperature (UHT), and the non-thermal processes High Power Ultrasound (US), UV-pulsed-light and Low Pressure Plasma (LPP) on the composition, stability, and bioactive compounds bioaccessibility of açai juice. 1H NMR based approach, coupled to chemometrics, was applied to evaluate the changes in the juice composition. All the non-thermal processes increased the sugars content (glucose and fructose), and the amino acid betaine, except the combined processing of ultrasound followed by low-pressure plasma (US.LPP). HTST and UHT increased the fatty acids and phenolic compounds content in the açai juice. The bioaccessibility of phenolic compounds decreased due to the processing. After thermal sterilization (UHT), the anthocyanin bioaccessibility was 2-fold higher. The combined non-thermal treatment reduced the biocompounds bioaccessibility to 40% of the non-processed juice. However, the combined US.LPP improved the bioaccessibility of vitamin C by 8%. UHT increased the anthocyanin's bioaccessibility but sharply decreased vitamin C bioaccessibility. Higher impact of thermal processing on vitamin C, anthocyanins, total phenolics, PPO, POD, DPPH, ABTS, and FRAP was verified after 45 and 60 days of storage compared to the non-thermally processed samples.

Effect of dielectric barrier discharge plasma excitation frequency on the enzymatic activity, antioxidant capacity and phenolic content of apple cubes and apple juice.

Cold plasma is a potential alternative to traditional thermal conservation methods because of its high efficiency in the preservation and retention of quality parameters. The objective of this study was to evaluate the application of atmospheric cold plasma on some qualitative aspects of apple cubes and apple juice. The research used dielectric barrier discharge plasma and studied different excitation frequencies of plasma: 50, 200, 400, 600, and 900 Hz. The effects of plasma application were evaluated on enzymatic activity (PPO and POD), total phenolic compounds, antioxidant capacity, and colorimetry. Plasma treatment partially inactivated the polyphenol oxidase enzyme in apples cubes and juice. Inactivation of peroxidase occurred only in apple juice. Total phenolic content and antioxidant capacity presented no significant difference between the treated and control samples of apple cubes, while significant changes were observed in apple juice. The changes in color parameters were slight and did not compromise the product quality. Plasma application was able to partially inactivate the enzymes responsible for browning while maintaining the quality and sensory properties of apple cubes and juice.

Ozone and plasma processing effect on green coconut water.

In this study, the effect of plasma and ozone processing on the quality of coconut water was evaluated. For ozone processing, the samples were submitted to different ozone loads and temperatures. For atmospheric cold plasma processing (ACP), samples were exposed to plasma under different frequencies and voltages. The coconut water pH, soluble solids, titratable acidity, color, total phenolic content, and enzymatic activity were determined before and after treatments. The main compounds were also determined by NMR spectroscopy and chemometric analysis. Both processes did not change the pH values, total soluble solids, titratable acidity, and color. Chemometrics analysis of 1H NMR dataset showed no relevant changes after the processing. All ozone treatments promoted complete inactivation of POD activity and did not affect the content of phenolic compounds. After ACP, the smallest POD residual activity was observed when higher frequencies were applied, and slight changes in phenolic compounds content were observed.

Dielectric barrier atmospheric cold plasma applied on camu-camu juice processing: Effect of the excitation frequency.

The aim of this paper was to evaluate the effect of cold plasma excitation frequency on camu-camu juice processing. Different levels of frequency (200, 420, 583, 698 and 960 Hz) were applied on camu-camu juice to measure the contents of ascorbic acid and anthocyanins, as well as to evaluate the antioxidant compounds (DPPH, ABTS, FRAP and phenolic compounds), peroxidase and polyphenol oxidase enzymatic activity and color. Furthermore, the juice bioaccessibility was evaluated after simulated digestion. The ascorbic acid concentration was increased when higher excitation frequencies were employed, increasing their bioavailability. Anthocyanins, peroxidase and polyphenol oxidase presented considerable degradation with increasing the plasma excitation frequency. For this reason, the juice processing proposed herein represents an alternative to enhance its nutritional quality. Moreover, the use of cold plasma reduced the activity concentration of endogenous enzymes, presenting considerable degradation for higher excitation frequency.

Green ultrasound-assisted extraction of chlorogenic acids from sweet potato peels and sonochemical hydrolysis of caffeoylquinic acids derivatives.

Sweet potato peels are rich in chlorogenic acids. In this work, we applied ultrasound technology to extract the main compounds from sweet potato peel and used multivariate analysis and principal component analysis (PCA) to evaluate the effects of different extraction conditions on the extraction of chlorogenic acids. The extraction was studied varying ultrasonic power density (20, 35 and 50 W/L) and processing time (5, 10, 20 and 40 min) using an ultrasonic bath operating at 25 kHz. The chemical analysis was carried out by UPLC-qTOF-MS, and the results were evaluated by PCA and PLS-DA chemometric analysis. Results show that both ultrasonic power density and processing time influences in the extraction of different chlorogenic acid, and that different extraction conditions can be used to selectively extract specific caffeoylquinic acids and feruloylquinic acids in higher amounts. Ultrasound promoted the hydrolysis of tricaffeoylquinic acid when subjected to ultrasonic waves (20-50 W/L), and of 3,4-caffeyolquinic acid at high ultrasonic power density (50 W/L).

An integrated analytical approach based on NMR, LC-MS and GC-MS to evaluate thermal and non-thermal processing of cashew apple juice.

Innovative chemometric approaches by NMR and LC-MS data fusion (multiblock analysis) and decomposition of the GC-MS raw data by PARADISe were applied to evaluate the influence of thermal and non-thermal processing on the composition of cashew apple juices. Comparative investigations by Principal Component Analysis (PCA) highlighted pronounced effect of thermal processing on juice compared to non-thermal processing, as decreases of anacardic acids, sucrose, malic acid, tyrosine, phenylalanine, and important flavor compounds (esters, aldehydes, and ketones). Ultrasound presented relevant influence on increase of anacardic acids concentration. Non-thermal processing carried out at more intense conditions (10 min of ultrasound, 5 min of ozone, and pulsed light at 10 V) showed pronounced effect compared to other non-thermal processing. Although individual PCA enables to detect the influence of different processing technologies, data fusion and PARADISe presented advantages, since a more comprehensive understanding of the relationship among chemical changes from different analytical techniques were established.