Stability Of Phenolic Compounds Research Articles

Plant Phenolics: Bioavailability as a Key Determinant of Their Potential Health-Promoting Applications.

Phenolic compounds are secondary metabolites widely spread throughout the plant kingdom that can be categorized as flavonoids and non-flavonoids. Interest in phenolic compounds has dramatically increased during the last decade due to their biological effects and promising therapeutic applications. In this review, we discuss the importance of phenolic compounds’ bioavailability to accomplish their physiological functions, and highlight main factors affecting such parameter throughout metabolism of phenolics, from absorption to excretion. Besides, we give an updated overview of the health benefits of phenolic compounds, which are mainly linked to both their direct (e.g., free-radical scavenging ability) and indirect (e.g., by stimulating activity of antioxidant enzymes) antioxidant properties. Such antioxidant actions reportedly help them to prevent chronic and oxidative stress-related disorders such as cancer, cardiovascular and neurodegenerative diseases, among others. Last, we comment on development of cutting-edge delivery systems intended to improve bioavailability and enhance stability of phenolic compounds in the human body.

Stability of phenolic compounds, antioxidant activity and colour parameters of a coloured extract obtained from coloured-flesh potatoes

Potato (Solanum tuberosum) tubers stand out for their natural pigmentation granted by anthocyanins. There is currently little information about their stability in terms of concentration, antioxidant activity and colouration to certain storage factors; therefore, we aimed to analyse such variables during storage for four months under different pH and temperature conditions and in the presence or absence of light. In general, the most deleterious condition for maintaining total anthocyanins was under light at room temperature, which presented a decrease of ~85%. In contrast, in liquid extracts the optimal storage conditions were 4 °C in the dark, with a loss of ~4%. The antioxidant activity and colour analyses showed optimal stability in the liquid extracts. This would make it possible to deliver added value to purple fleshed potato extracts because they are a good source of natural antioxidant pigments with potential applications in the agri-food industry as an alternative to artificial dyes.

Impact of an in vitro dynamic gastrointestinal digestion on phenolic compounds and antioxidant capacity of apple treated by high-pressure processing

The aim was to evaluate the effect of an in vitro dynamic gastrointestinal digestion (GID) on the recovery index and bioaccessibility, the stability of phenolic compounds, and the changes in antioxidant capacity (AC) of apples 'Golden Delicious' treated by high-pressure processing (HPP-treated). All the phenolic compounds decreased during GID in untreated and HPP-treated apple and in consequence a decrease in the antioxidant capacity (DPPH, ABTS+, TP-FC and FRAP) and in the effect on the inhibitory capacity of lipoxygenase (LOX) and xanthine oxidase (XO) activities was also observed. The dynamic-GID increased the release of quercetin-aglycone and led to low quercetin-glycosides bioaccessibility (~10%). HPP-treated compared to untreated-apple presented higher recovery index for hydroxycinnamic acids (~67% and 52%) and higher bioaccessibility for hydroxycinnamic acids (40% and 31%) and dihydrochalcones (30% and 19.5%). The bioaccessible fraction of HPP-treated apple showed a high retention of the undigested AC: 24% (DPPH), 14% (ABTS+), 86% (TP-FC), 48% (FRAP) and the 68% and 100% of XO and LOX inhibitory capacities. Industrial relevanceThe consumer is willing to pay for added value in functional foods or ingredients that represent a substantial improvement in terms of quality of life and health. Therefore, functional food industries need to find valid methods to guarantee that the bioactive compounds present in the functional food or ingredient are effective and should do the biological action for which they were designed. The functional food industry relies more and more on the technology implemented in in vitro digestion models that simulate gastrointestinal digestion, to assess the bioaccessibility of bioactive compounds as the first step to investigate their bioavailability. The current study provides relevant information for the use dynamic gastrointestinal models instead of the more frequently employed static models to obtain more exact data about the bioaccessibility of phenolic compounds of a functional apple ingredient obtained by high-pressure processing of apples pieces with peels.These results should provide realistic information to the functional food industry about the amounts should be consumed of a certain functional food or ingredient to achieve the promised biological effect. This information can suppose an added value to these functional foods which will revert in the economic improvement and the prestige of the food industry.

Stability of Phenolic Compounds in Grape Stem Extracts.

Grape stem is rich in phenolic compounds, especially stilbenes. These antioxidants can be degraded during the storage of grape stem extracts for long periods of time. The aim of this work was to analyze the stability of Mazuelo stem extracts during storage at 25 and 40 °C, in two different light conditions (amber and transparent vials). The stability of the antioxidants was studied after 2, 4 and 6 months of conservation. Gallic acid and the quercetin derivative concentration were stable throughout the storage period. In contrast, catechin disappeared from all the extracts in just two months of storage. Anthocyanins were significantly affected by temperature, and light enhanced their degradation when the extracts were kept at 40 °C. Resveratrol and viniferin showed a similar behavior. Their concentration decreased from the beginning of storage, and in both cases, they were significantly affected by both temperature and light.

Insights into the Vastly Different Effects of Eutectic Solvents on the Stability of Phenolic Compounds.

Eutectic solvents (ESs) have shown stabilizing effects on several molecules. Due to the potential applicability of bioactive compounds, understanding how ESs stabilize them is of great interest in pharmaceutical and related fields. Here, among various ESs, CTU, which comprise thiourea and choline chloride (ChCl), exerted remarkably high stabilizing effects on various phenolic compounds, whereas CU consisting of urea and ChCl exhibited the opposite effects. Using a potent polyphenol, (-)-epigallocatechin gallate (EGCG), as a model compound, we conducted experimental and in silico studies to unravel the underlying mechanisms of the two very similar ESs for the contrasting effects. The results suggest that ESs can affect with great diversity the stability of EGCG by complicated interactions arising from the unique properties of both ESs and their components.

The influence of different strains of Oenococcus oeni malolactic bacteria on profile of organic acids and phenolic compounds of red wine cultivars Rondo and Regent growing in a cold region.

Wines produced from grapes cultivated in cool climate areas are characterized by high levels of organic acids. One method to correct this is malolactic fermentation (MLF). The aim of this study was to determine the effectiveness of different strains of Oenococcus oeni bacteria (Viniflora CH11, Viniflora CH16, Viniflora CH35, Viniflora Oenos, SIHA LACT Oeno) during the biological acidity reduction process. Red wine from Rondo and Regent cultivars was obtained by ethanol fermentation of the pulp, at 20 °C for 14 days. The profile of organic acids was examined with a particular focus on changes in the content of l-malic and l-lactic acids. Additionally, the impact on profile and quantity of phenolic compounds and antioxidant capacity was measured. The results showed that MLF had a positive influence on content of organic acids through the reduction of l-malic acid content with a simultaneous increase of the amount of l-lactic acid. The best effect was obtained with the CH11 and CH35 bacterial strains. The biological acidity reduction process had no significant (P>0.05) impact on phenolic content or antioxidant capacity. However, the wine making process (ethanol fermentation, maturation) contributed to the reduction of polyphenols and in consequence lower antioxidant capacity of the final tested wines. PRACTICAL APPLICATION: The present study provides useful information on the impact of different Oenococcus oeni bacterial strains on MLF in red wines, reduction of l-malic to l-lactic acid, and stability of phenolic compounds during MLF and the maturation period. Also, this article provides information about phenolic compounds and antioxidant capacity during malolactic fermentation and maturity of red wines made from hybrids of Vitis vinifera such as Rondo and Regent cultivars.

Stability of blueberry polyphenols subjected to in vitro digestion with human gastrointestinal enzymes

AbstractBlueberries (Vaccinium corymbosum, L.) are a valuable source of health-promoting bioactive compounds, particularly polyphenols. The beneficial effects of polyphenols on health depend not only on food sources but also on their stability, which can vary depending on the post-harvest processing methods, the matrix in which they are incorporated, and endogenous factors such as microbiota and digestive enzymes. The aim of this study was to investigate the influence of high-intensity ultrasound treatment on in vitro gastrointestinal stability of the total polyphenol content and antioxidant capacity of blueberries. Blueberry puree was treated with high-intensity ultrasound using different amplitudes (30, 45 and 60μm) and treatment times (3, 6 and 9 min), and a part of sample was used as a control (untreated sample). Total phenolic content (TPC) and antioxidant capacity (by DPPH and FRAP methods) were determined prior to and after two-phase in vitro digestion process (gastric and duodenal) using human gastrointestinal enzymes. The results showed a high stability of total blueberry polyphenols and antioxidant activity during simulated gastric digestion step, both in untreated and ultrasound treated samples. The use of high-intensity ultrasound had a significant effect on the stability of polyphenols and their antioxidant activity after simulated digestion in duodenum. Significant increase in polyphenol content after duodenal digestion step was determined in three ultrasound treated samples with longer treatment time (6 and 9 minutes), and only sample with significant reduction of TPC was untreated sample. Modification of the food matrix as a result of cavitation from ultrasound treatment may be the reason for higher stability of polyphenol during in vitro digestion. After in vitro digestion blueberry polyphenols still possessed antioxidant activity that may be directly related to their beneficial effects on health. The highest antioxidant activity measured with DPPH and FRAP method was determined for sample treated with maximum amplitude (60μm) and longest time (9 minutes). Determination of the stability of phenolic compounds is important as it affects their bioavailability for uptake as well as their possible beneficial effects on intestinal epithelial tissue such as reduction of oxidative stress and cancer prevention. Our results showed that ultrasound treatment can preserve the blueberry phenolics and their antioxidant characteristics after in vitro digestion.

Effect of moderate electric field on peroxidase activity, phenolic compounds and color during ohmic heating of sugarcane juice

The influence of moderate electric field was evaluated during thermal treatment of sugarcane juice. Conventional and ohmic heating (OH) experiments at temperatures of 60 and 80°C were conducted to investigate the effect of frequency (0–10⁵ Hz), waveform (sine, square, and triangle) and voltage gradient (0–16.7 V/cm) on inactivation of peroxidase (POD), phenolic compounds stability and color changes. Enzyme activity was significantly (p < .05) affected by OH; the nonthermal effects promoted POD activation at 60°C (mainly at 10 Hz) and inactivation at 80°C (mainly at 100 kHz). It was not found variation of phenolic compounds with the different operational conditions applied. Moreover, the color of the juice was modified using low frequency (possibly due to electrochemical reactions) and different waveforms. Overall, OH is suitable for POD inactivation at 80°C with the usual process parameters (sine wave and 60 Hz) or higher frequencies. PRACTICAL APPLICATIONS: Sugarcane juice is a popular energy drink, nonalcoholic, with sweet and pleasant taste. It is commercialized predominantly in the informal marketplace because its processing and marketing are limited due to its rapid deterioration. The objective of this work is to provide an alternative technology for sugarcane juice processing, ensuring safety, and lower impact on nutritional compounds, allowing its commercialization in formal markets. Ohmic heating (OH) is a faster heating technology, appropriate for pasteurization of heat‐sensitive products. The study of the effect of the process variables (temperatures, electric field frequency, waveform, and electric field strength) on enzyme inactivation, degradation of total phenolic compounds, and color stability is important to support modeling and optimization, making OH a viable technology for sugarcane juice pasteurization.

Microencapsulated Brazil nut (Bertholletia excelsa) cake extract powder as an added-value functional food ingredient

The aim of this study was to produce and to characterize a new functional food ingredient from Brazil nut (Bertholletia excelsa) cake extract, microencapsulated by inulin and octenyl succinic anhydride modified starch (OSA-starch). Varying proportions of the encapsulating agents were tested, and the particles morphology, average diameter, and contents of total phenolic compounds, antioxidant capacity, and chemical stability were determined. Microparticles containing OSA-starch and inulin (1:1) were selected for their properties, and stability of phenolic compounds and antioxidant capacity for 120 days of storage. Analysis of these microparticles by HPLC and LC-HRMS revealed seven phenolic acids: gallic, protocatechuic, p-hydroxybenzoic, 2,4-dihydroxybenzoic, p-coumaric, sinapinic and 2-hydroxybenzoic, and five flavonoids: quercetin 3-β-D-glucoside, (+)-catechin, (−)-epicatechin, myricetin and quercetin. β-Tocopherol was the major tocol identified and microparticles showed high selenium contents (4.95 μg/g), determined by ICP-MS. The Brazil nut microparticles produced consist of a food-grade powder with interest for use in functional foods, combining the bioactive compounds in their core with the prebiotic encapsulating agent, while simultaneously adding-value to the byproduct of Brazil nut oil production.

Microencapsulation by complex coacervation as a tool to protect bioactive compounds and to reduce astringency and strong flavor of vegetable extracts

Many plant extracts are rich in phenolic compounds. The cinnamon extract is a rich source of proanthocyanidins, polyphenolic compounds that have several beneficial effects to health. However, this extract presents strong flavor, bitterness, causing a sensation of astringency, and its compounds can suffer degradation. In this context, the aim of this work was to encapsulate the Ceylon cinnamon extract by complex coacervation using gelatin and five polysaccharides (gum arabic, pectin, cashew tree gum, carboxymethylcellulose, and κ-carrageenan) as encapsulating materials and to apply the free and encapsulated extracts in ice creams. The morphology of the particles in different temperatures, pH, salt and sugars concentrations was studied, as well as the stability of phenolic compounds and proanthocyanidins during particles storage. Free extract and encapsulated extracts prepared with gelatin/gum arabic and gelatin/κ-carrageenan pairs were added in ice creams that were evaluated by two-sided paired-comparison test and sensory acceptance. Particles presented resistance when submitted to different stress condition, except pH lower than 2 and temperatures higher than 50 °C. The encapsulation mainly using gelatin/κ-carrageenan and gelatin/cashew tree gum as wall materials promoted greater stability of the total phenolic compounds and proanthocyanidins during storage (until 80% of the initial content). Sensorial analysis results showed that the encapsulation using gelatin/gum arabic and gelatin/κ-carrageenan was able to mask the flavor and the astringency of the extract. These results prove that microencapsulation by complex coacervation is an alternative to increase the stability of the cinnamon extract and to overcome some of the challenges for its application in food.

Spray Drying Encapsulation of Elderberry Extract and Evaluating the Release and Stability of Phenolic Compounds in Encapsulated Powders

Elderberry (Sambucus nigra L.), rich in polyphenols, has recently attracted great interest in functional food, nutraceutical, and pharmaceutical industries, due to their potential health benefits to humans. However, polyphenols are very sensitive compounds and unstable. The utilisation of encapsulated polyphenols, instead of free compounds, can overcome some of their limitations. The extraction of the polyphenols from the elderberry flowers and stems was made, followed by the microencapsulation of the extract by a spray drying process. The microparticles were characterised by size, morphology, and release profile. The microencapsulated polyphenols were completely released, with total release times that range from 600 to 1140 s. The kinetic models that have a better adjustment to the practical results are the zero order, the Korsmeyer-Peppas, and the Weibull models, with correlation coefficients that range from 0.900 to 0.999. The encapsulation efficiency was similar for all the analysed particles, being the results located in a range from 92.3 to 99.8%. After 8 months of storage, the microparticles were revaluated, being possible to conclude that the elderberry microparticles present very similar release profiles comparing with the ones obtained with fresh microparticles, which proves the successful encapsulation of the elderberry extract and the stability of the microparticles over time. This experimental work leads to a very successful encapsulation of elderberry extract.

Assessment of Phenolic Compounds Stability and Retention during Spray Drying of Phyllanthus niruri Extracts

This paper presents a method to enhance the thermal stability of Phyllanthus niruri polyphenols during spray drying. The major polyphenol content of the extracts derived from the aerial part of the plant was analyzed, using ultra-high-performance liquid chromatography, whereas the surface composition of the microcapsule was analyzed by X-ray photoelectron microscopy (XPS). Three encapsulant formulations that were made of maltodextrin (MD), whey protein isolate (WPI), and their combinations (WPI:MD = 1:9) were compared with a control formulation without encapsulation. The microencapsulation method by WPI:MD proposed in this work increased the average polyphenols retention percentage after spray drying from 72.7% (without encapsulation) to 87.2%. The powder encapsulated with WPI:MD (1:9) yielded the best retention of phyllanthin (84.33%), gallic acid (88.93%), and quercetin (88.39%), compared to the system encapsulated solely by WPI or MD. The XPS results confirmed the existence of surface protein, which acts as a protective layer, thereby enhancing the polyphenols stability in the microcapsule. The finding from this work shows that quercetin is more susceptible to thermal degradation than phyllanthin and gallic acid during spray drying.

Determination of Antioxidant Activity and Total Anthocyanin Content of Frozen and Thawed Strawberries under Different Conditions

Strawberries are among the summer fruits popularly consumed by consumers. High antioxidant activity, anticancer, anti-inflammatory effect and high bioactive substance content are also beneficial to human health. However, their shelf life is short due to their high water content and active metabolismThey can be kept frozen and processed in order to be consumable in all seasons. During freezing, when the water in the contents turns into ice crystals, the expansion occurs. For this reason, frozen and thawed fruit is generally softer than fresh fruit. These effects can vary with different types of freezing condition. In addition, freezing and thawing conditions can affect the stability of phenolic compounds, anthocyanins and antioxidant activity. In this study, fresh strawberries were frozen at different temperatures; -18 °C, -86 °C, and individually quick frozen (IQF) as freezing methods. Frozen strawberries were thawed at 24 °C at room condition, +4 °C in the refrigerator and microwave oven with thawing mode. Total phenolic compounds, total flavonoid and total anthocyanins content, and total antioxidant activity were performed to examine the effect of freezing and thawing on biocompatibility. According to the results, the total phenolic compounds in the range of 0.77-2.76 mg gallic acid equivalent/g, flavonoid content 0.32-0.90 mg catechin equivalent/g, total anthocyanin content 0.02-0.16 mg/g and total antioxidant capacity 49.06 and 55.64% were found in strawberries. According to these results, it was determined that the loss of bioactive components was minimized by frozen with IQF and thawing in the microwave oven. In addition, the shortness of the thawing time in this process provides an extra advantage.

Effect of different encapsulating agent combinations on physicochemical properties and stability of microcapsules loaded with phenolics of plum (Prunus salicina lindl.)

Microencapsulation improves the bioavailability and stability of phenolic compounds, while encapsulating agents affect the quality of microcapsules. In order to improve the stability and application range of phenolics from plum (Prunus salicina Lindl.), microencapsulation was applied by using spray drying method. The present work evaluated the influence of maltodextrin/gum arabic (MD/GA),maltodextrin/gelatin (MD/GEL), maltodextrin/chitosan (MD/CHI) and maltodextrin/β-cyclodextrin/gum arabic (MD/β-CD/GA) on physicochemical properties and stability of microcapsules loaded with phenolics of plum. These four kinds of encapsulating agent combinations significantly improved the product yield and storage stability of the microcapsule powder, but there were differences among them in microencapsulated efficiency, microstructure and color. Using encapsulating agents markedly increased the glass transition temperature (Tg) of spray-dried powders, and Tg of the powder was positively correlated with its product yield. Furthermore, the powder prepared by MD/CHI had the best stability, and the retention rate of total phenol was 94.60% after storage at 25°C for 60days. The powder prepared by MD/GA and MD/β-CD/GA preferably retains the original red color of plum, and can be used as natural nutrient red pigments in the food industry.

Nanoencapsulation of quercetin and curcumin in casein-based delivery systems

Direct incorporation of hydrophobic nutraceuticals into liquid foods faces different technological challenges, namely low water-solubility and limited physiochemical stability. Nanoencapsulation may facilitate dissolution and protection of lipophilic bioactives. In this study, a hierarchical approach (ligand binding to sodium caseinate and then either re-assembling the micellar nanostructures or formation casein nanoparticles) was used to encapsulate two phenolic compounds, including curcumin and quercetin. As determined by spectrofluorometry, the binding stoichiometry of quercetin and curcumin were 0.96 and 0.78, respectively. The average particle size of re-assembled casein micelles (r-CMs) was smaller than that of casein nanoparticles (CNPs). The effect of quercetin loading on increasing the particle size of r-CMs was higher than that of curcumin loading due to the higher binding affinity of quercetin. The entrapment efficiency of both ligands was higher than 90%. The ejection of ligands from the nanocarriers was negligible over time, but not as a function of pH in the case of quercetin-loaded nanocarriers. Both CNP and r-CM significantly improved the chemical stability of phenolic compounds during an accelerated shelf-life test. Formation of r-CMs was confirmed, likely for the first time, by measuring the changes in the relative viscosity during the re-assembly process. The aqueous solubility of curcumin and quercetin after loading in r-CMs was higher than that of free polyphenol molecules. Generally, the viability of MCF-7 human breast cancer cells in the presence of different samples followed this order: digested polyphenol-loaded r-CMs < non-digested polyphenol-loaded carriers < free polyphenol molecules. TEM images confirmed the formation of r-CMs.

Effect of ohmic heating parameters on peroxidase inactivation, phenolic compounds degradation and color changes of sugarcane juice

The non-thermal effects of electricity on enzymatic inactivation kinetics of peroxidase (POD) and on phenolic compounds degradation during ohmic heating (OH) of sugarcane juice were investigated. Experiments with different frequencies (10–105Hz), waveforms (sine, square, triangle and pulsed waves) and voltage gradients (3.9 and 20.5V/cm) were conducted at 75°C for 25min and compared with the conventional treatment, performed with similar temperature histories. Overall, the results indicated that the non-thermal effects of OH (voltage gradient up to 20.5V/cm, with different frequencies and waveforms) did not influence the biochemical reactions that occur during POD inactivation in sugarcane juice. Moreover, there was no effect of electric field frequency or voltage gradient on phenolic compounds stability; on the other hand, some waveforms promoted higher degradation of these compounds. Some color changes were observed when 10Hz/25V and 60Hz/130V were applied, with higher magnitude at the higher electric field strength.

Stability of phenolic compounds and antioxidant capacity of concentrated mulberry juice-enriched dried-minced pork slices during preparation and storage

Functional foods have been of increasing demand due to the growing consumer awareness of the relationship between diet and health. Addition of healthy ingredients to meat products is an important method for development of functional meat products. In this contribution, functional dried-minced pork slices incorporated with concentrated mulberry juice (CMJ) were developed and stability of phenolic compounds and antioxidant capacity during product preparation and storage were evaluated. The CMJ contained high amounts of total phenolics, anthocyanin and flavonoids (19.13 ± 0.64 mg GAE/g d.m., 4.91 ± 0.18 C3GE mg/g d.m. and 18.39 ± 1.21 mg CE/g d.m., respectively) and showed excellent antioxidant activities in all assays used. CMJ incorporation drastically minimized lipid and protein oxidation of dried-minced pork slices by decreasing thiobarbituric acid-reactive substances (TBARS) value and carbonyls content during processing and storage. Thermal treatment significantly destroyed the main antioxidant ingredients including anthocyanins, flavonoids, and phenolics in dried-minced pork slices with added CMJ; however, this deterioration could be effectively counteracted by using β-cyclodextrin. The redness increased but lightness decreased with CMJ added, and color of the product remained stable during storage. Therefore, CMJ rich in phenolic compounds could be used as a natural antioxidant and pigment in dried-minced pork slices with suitable protective strategy.

Stability of the phenolic compounds and antioxidant capacity of five fruit (apple, orange, grape, pomelo and kiwi) juices during in vitro‐simulated gastrointestinal digestion

SummaryThe in vitro digestive stability of phenolic compounds and the antioxidant capacity of five kinds of commonly consumed fruit juices in the daily diet, including apple juice (AJ), orange juice (OJ), grape juice (GJ), pomelo juice (PJ) and kiwifruit juice (KJ), were studied. Following in vitro digestion, the total phenolic (TP) content of fruit juices decreased to different extents by 35%, 25.3%, 23.5%, 22.2% and 7.8% for KJ, OJ, PJ, GJ and AJ, respectively. The individual phenolic content showed similar changes to the TP content, showing reductions of naringenin‐trisaccharide in OJ and PJ, epicatechin in GJ, and chlorogenic acid in AJ by 43.74%, 27.59%, 47.11% and 33.28%, respectively. Conversely, the antioxidant capacity of fruit juices during digestion measured by ABTS assay increased from 4.79% to 35.53%, except in KJ, which decreased by 19.34%. These results show the health benefits of fruit juices after processing and contribute towards establishing suitable dietary recommendations.

The impact of high voltage electrical discharge plasma on the chromatic characteristics and phenolic composition of red and white wines

Abstract The cold plasma is an emerging electrotechnology for the improvement of food safety without loss of physicochemical or sensory properties. The purpose of this study was to evaluate the effects of plasma treatments on the chromatic characteristics and phenolic composition of red and white wines. The red wine Cabernet Sauvignon and white wine Grasevina were treated with high voltage electrical discharge plasma considering the variations in frequency (60, 90 and 120 Hz) and processing time (3, 5 and 10 min). Total phenolics, total anthocyanins, total tannins and chromatic characteristics were analyzed by spectrophotometry while free anthocyanins, phenolic acids and flavan-3-ols by the HPLC-UV/Vis. Obtained results illustrated that plasma treatments have influenced the stability of phenolic compounds in wines without major changes in color parameters. Also, among two different processing parameters, the duration time was the most significant factor inducing changes on wines. Industrial relevance High voltage electrical discharge plasma has been shown to affect the stability of wine phenols without any significant change in the color. An increase in the concentration of certain phenolic compounds in white wine suggest that this technique could be used in the wine industry as an alternative technique for enhancing the oxidative stability of wine and consequently the wine quality during the aging process.

Characterization of antioxidant and antimicrobial properties of spray-dried extracts from peanut skins

This study aimed to produce dried extracts from peanut skin using spray-drying technology for application as a natural antioxidant and antimicrobial in foods. The extracts were spray-dried with 10, 20, or 30% of maltodextrin (carrier) at different temperatures (130, 150, and 170°C), to establish the best conditions to produce the powders. The powders were characterized with regards to moisture, hygroscopicity, particle size, and solubility, and the stability of phenolic compounds was evaluated throughout 120days at 25°C. The antimicrobial and antioxidant activities of powders were also evaluated. Powders produced at higher temperatures and 30% of maltodextrin presented the best results for hygroscopicity, solubility, and particle size, and the powder produced at 150°C with 30% of maltodextrin showed the high stability of phenolic compounds during storage. All powders presented remarkable antioxidant activity and showed bacteriostatic activity against Listeria monocytogenes, and bactericidal activity against Staphylococcus aureus. Taken together, these results indicate that the best conditions (of those tested) for spray drying peanut skin extracts were at 150°C and with 30% of maltodextrin. The resultant powders have technological potential due to the high stability, good physical properties, and remarkable antioxidant/antimicrobial activities, which could be applied as natural additives to improve food quality.