Stability Of Phenolic Compounds Research Articles

Antioxidant Capacity and Stability of Phenolic Compounds in Aronia Kefir during in vitro Digestion

Aronia (Aronia melanocarpa) is an underutilized berry that is rich in bioactive compounds, such as anthocyanins and phenolic acids. Phenolic compounds are strong antioxidants that may provide health benefits for chronic diseases, such as type 2 diabetes. Kefir is a fermented dairy beverage which contains several species of live micro‐organisms and may help to maintain gut health. The live microbes in kefir create a dynamic environment with an acidic pH which could protect the anthocyanins in aronia from degradation. In this study, aronia juice was incorporated into a fermented kefir product. Aronia kefir was subjected to an in vitro digestion process to evaluate the antioxidant capacity, stability of bioactive components and the potential effects on carbohydrate‐hydrolyzing enzymes. Mouth, stomach, and small intestinal environments were simulated using corresponding digestive juices (containing enzymes) where pH, time and temperature were controlled. An aliquot was removed from each step for analysis. UPLC‐DAD was used to quantify anthocyanins and phenolic acids in each fraction. The antioxidant capacity was measured using 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging assay. The inhibitory effects of digested aronia kefir on carbohydrate‐hydrolyzing enzymes were assessed by measuring the IC20 values against α‐amylase and IC50 values against α‐glucosidase. The control sample was processed under the same conditions with the absence of digestive enzymes. The results of this study showed that mouth digestion did not alter the quantity of phenolic compounds or the antioxidant capacity of aronia kefir. After gastric digestion, the amount of phenolic compounds was elevated compared to the mouth digesta, which led to an improvement in the antioxidant capacity. Intestinal digestion resulted in a slight increase in cyanidin‐3‐galactoside and a decrease in neo‐chlorogenic acid. The amount of chlorogenic acid was enhanced significantly compared to gastric digesta. Antioxidant capacity of intestinal digesta was also improved. After digestion, aronia kefir exhibited strong inhibitory activity toward α‐glucosidase and moderate inhibition to α‐amylase. This result indicates that digested aronia kefir has the potential to decrease or slow the absorption of carbohydrates, thus helping to maintain blood glucose levels. This study demonstrates that accessible anthocyanins and phenolic acids in aronia kefir were stable during digestion and exhibited high antioxidant capacity. Hence, incorporating aronia kefir into a healthy diet is potentially beneficial to diabetic patients to help decrease oxidative stress and to better control their blood glucose level.Support or Funding InformationUniversity of Maine start up funds

Effect of storage conditions on phenolic content and antioxidant capacity of spray dried sour cherry powder

The stability of phenolic compounds, antioxidant capacity and colour changes in spray dried Marasca sour cherry juice powders (MP), packaged in two laminates (Pet 12 μm/PP 18 μm met/PE 100 μm vs. Pet 12μm/Al 9 μm/PE85μm), stored under different temperatures (4,20,37 °C) over a storage period (0,3,6,9,12 months) were evaluated. Individual anthocyanins, flavonol glycosides and phenolic acids were identified by HPLC-DAD and antioxidant capacity was monitored by DPPH assay. The anthocyanins, as predominant compounds, were more susceptible to degradation during storage compared to other phenolic compounds. Packaging laminates did not significantly influence phenolics stability, whilst the most pronounced were the impacts of temperature and storage length. Obtained results confirmed that MP has potential as functional food ingredient with attractive natural pigment of red colour whereas optimal storage conditions could preserve the nutritive quality and biological value of the powder.

SELECTION AND ROLE OF A MIX ROSEMARY (Rosmarinus officinalis) - PALMITATE ASCORBYL AS ANTIOXIDANT IN A FRYING PROCESS

Background: Several studies have found that rosemary has active components with antioxidant potential, and that is why, an extract combined with ascorbyl palmitate provides protection for systems with high fat content was obtained. Aims: The aim of this study was to evaluate the effect of the addition of two extracts of rosemary (Rosmarinus officinalis): AP10R and AP30R at three concentrations 1000, 1500 and 2000ppm, on the oxidative stability of palm oil subjected to accelerated oxidation and frying conditions, Methods: controlling the concentration of hydroperoxides, total polar compounds and the thermal stability of phenolic compounds it is conducted in the oil through fluorescence spectroscopy and were evaluated with and without addition of the extract. Results: The extract AP10R to 2000ppm inhibited the oxidation of olein in 30.38% and 60.84% in terms of the concentration of total polar compounds and hydroperoxides, respectively. In addition, Conclusions: Results indicated that heating decreases the concentration of polyphenols; this decrease was most evident in the olein without extract, reflecting the effect of rosemary extract on the stability of used oil polyphenols.

The effect of microwave pretreatment of seeds on the stability and degradation kinetics of phenolic compounds in rapeseed oil during long-term storage.

Storage stability and degradation kinetics of phenolic compounds in rapeseed oil pressed from microwave treated seeds (0, 2, 4, 6, 8, 10min, 800W) during long-term storage (12months) at a temperature of 20°C was discussed in the current study. The dominant phenolic compound detected in rapeseed oil was canolol, followed by minor amounts of free phenolic acids and sinapine. The most pronounced effect of seeds microwaving was noted for canolol formation - after 10-min exposure the quantity of this compound was approximately 63-fold higher than in control oil. The degradation of phenolics during storage displayed pseudo first-order kinetics. Differences in the initial degradation rate (r0) demonstrated significant impact of the period of seeds microwave exposure on the degradation rates of phenolic compounds. Results of the half-life calculation (t1/2) showed that the storage stability of phenolic compounds was higher in oils produced from microwave treated rapeseeds than in control oil.

Analisys of the nutritional composition and stability of phenolic compounds and anthocyanis of guabiju

The objective of this study was to determine the nutrient composition and stability of phenolic compounds and anthocyanins in guabiju, stored at room temperature at 25 °C and cooled at 7°C. The fruit had an average weight of 3.41 g, 78.79 % yield in pulp and peel, pH 4.33 and acidity 0.03 %, 9.67 % of total soluble solids, 82.85 % moisture, 4.48 % of fiber, 0.63 % protein, 0.59 % ash or mineral total, 0.31 % lipids; 219.58 mg of phenolic compounds and 0.8 mg of total anthocyanins. There were 83.75 mg of phenolic compounds and 0.29 mg of anthocyanins to guabiju juice. The phenolic compounds of the juice guabiju decreased both in storage at room temperature (25 °C), and cooling. The amount of total anthocyanins guabiju juice decreased under refrigeration, as at room temperature (25 °C) increased its quantity. The fruit guabiju deserves greater attention of producers and consumers in relation to the possible benefits that provides to the body, because with the presence of antioxidants.

Storage stability of phenolic compounds in powdered BRS Violeta grape juice microencapsulated with protein and maltodextrin blends

The stabilities of the phenolic compounds, antioxidant activity and colour parameters of microencapsulated powdered BRS Violeta red grape juice were evaluated throughout storage at 5, 25 and 35°C for up to 150days. Different soy protein (S) or whey protein (W) blends with maltodextrin (M) were used as carrier agents, added at diverse concentrations and proportions. The treatment combining S and M with the highest carrier agent concentration (1SM) preserved almost all the anthocyanins. Except for 1SM, the proportion of p-coumaroylated anthocyanins increased during storage, and the flavonol content of the 1SM powder decreased after 150days. The hydroxycinnamate content decreased for all treatments, independent of storage temperature, and flavan-3-ols were lost at 35°C. The time and temperature did not influence the antioxidant activity of the powder or the colour of the reconstituted grape juice after 150days.

ANTIOXIDANT ACTIVITY OF DRIED STRAWBERRIES JUICES (Fragaria vesca L.) EMULGEL PREPARATION USING CANDLENUT OIL AND IT’S DIFFUSION

Strawberries (Fragaria vesca L.) is a fruit that contains nutrients with many benefits and used as an antioxidant because it contains phenolic, ascorbic acid, pelargonidin-3-glucoside and cyanidin-3-glucoside. In addition, strawberries contain flavonoids, which have high antioxidant capacity. Double emulsion can improve the stability of phenolic compounds from dried strawberry juice. Primary emulsion is dispersed in a gel base (emulgel) and it is expected to produce more stable and better preparation with the ability to release the active ingredient topically. The production of double emulsion preparation (A / M / A) using candlenut oil as the oil phase with high level of total flavonoid and total anthocyanins of formula respectively - were 22.86% and 55.915%. The total flavonoid in dried strawberry juice emulgel was able to pass the membrane shed snake skin with higher flux value than the total flavonoid in the form of emulsion type A / M.

Stability of Hydroxycinnamic Acid Derivatives, Flavonol Glycosides, and Anthocyanins in Black Currant Juice.

The stability of phenolic compounds was followed in black currant juice at ambient temperatures (in light and in dark conditions) and at +4 °C for a year. Analyses were based on high-performance liquid chromatography-diode-array detection-electrospray ionization-mass spectrometry (or tandem mass spectrometry) and high-performance liquid chromatography-diode-array detection-electrospray ionization-quadrupole time-of-flight mass spectrometry methods supported by nuclear magnetic resonance after selective high-performance liquid chromatography isolation. Altogether, 43 metabolites were identified, of which 2-(Z)-p-coumaroyloxymethylene-4-β-d-glucopyranosyloxy-2-(Z)-butenenitrile, 2-(E)-caffeoyloxymethylene-4-β-d-glucopyranosyloxy-2-(Z)-butenenitrile, 1-O-(Z)-p-coumaroyl-β-d-glucopyranose, (Z)-p-coumaric acid 4-O-β-d-glucopyranoside, and (Z)-p-coumaric acid were novel findings in black currant juice. Hydroxycinnamic acid derivatives degraded 20-40% at room temperature during one year of storage, releasing free hydroxycinnamic acids. O-Glucosides of hydroxycinnamic acid compounds were the most stable, followed by O-acylquinic acids, acyloxymethyleneglucosyloxybutenenitriles, and O-acylglucoses. Light induced the isomerization of (E)-coumaric acid compounds into corresponding Z-isomers. Flavonol glycosides stayed fairly stable. Flavonol aglycones were derived mainly from malonylglucosides. Over 90% of anthocyanins were lost at room temperature in a year, practically independent of light. Storage at low temperatures, preferably excluding light, is necessary to retain the original composition of phenolic compounds.

“Influence of storage conditions on phenolic compounds stability, antioxidant capacity and colour of freeze-dried encapsulated red wine”

A concentration of 9% (w/w) maltodextrin (DE 10) and gum arabic was added to red wine C. sauvignon and freeze dried to obtain a dealcoholized wine powder having a polyphenols concentration 7.1 times higher than in liquid red wine. Malvidin 3-G and total anthocyanins were the phenolics showing greater losses during storage. Moreover, an increase of water activity from 0.11 to 0.58 greatly enhanced the losses. The decrease in malvidin 3-G content was associated with the decrease on redness (colour parameter a*) of wine powder. Gallic acid was the most stable phenolic and its content remained constant during storage at all water activity levels under investigation. Contents of epicatechine, catechine, caffeic acid and resveratrol remained constant at aw = 0.11, although at aw = 0.33 catechine and epicatechine suffered important losses. Results indicated that water activity was a key factor affecting phenolics stability during storage.Antioxidant activity of the wine powder remained constant over 145 days at accelerated storage conditions.

Stability and metabolism of Arbutus unedo bioactive compounds (phenolics and antioxidants) under in vitro digestion and colonic fermentation

The natural antioxidants of Arbutus unedo highlight the importance of this fruit as natural source of bioactive compounds. In the present study, to evaluate the stability of phenolic compounds, ascorbic acid and fat-soluble antioxidants (α-tocopherol, β-carotene and lutein), in vitro gastrointestinal digestion was applied to A. unedo fruit. After that, the non-absorbable fraction was anaerobically incubated with human faeces and the metabolic pathway for gallotannins, ellagitannins, flavan-3-ols and anthocyanins from A. unedo fruit was proposed. The results showed that the presence of pectin from the fruit hampered the solubilization of the phenolic compounds (with exception of gallic and ellagic acids) and fat-soluble vitamins during gastric digestion. Degradation of pectin-gel during the duodenal digestion favored the release of the phenolic compounds and fat-soluble antioxidants to the media. The catabolic activity of human microbiota led to the generation of a wide range of simple phenols, such as p-hydroxybenzoic acid and catechol, derived from the catabolism of gallotannins, ellagitannins, flavan-3-ols and anthocyanins.

Diffusion and thermal stability of phenolic compounds during fortified rice rehydration process

The diffusivity of phenolic constituents in rice as well as the kinetics of their leaching in boiling water were studied during fortified rice rehydration. Phenolic concentrations in fortified rice grains during cooking were modeled using a Fickian diffusion model and seemed to be in good agreement with the calculated data. The apparent diffusivity of 4 specific phenolic compounds was estimated to be in the range of 4.90–16.97*10−10 m2/s and the retention of these compounds in rehydrated rice was found to be at least 24% of their amount in dry fortified rice. This indicates that a significant amount of antioxidants was not released even after intense thermal processing in excess water and this may be a result of strong interactions between rice macromolecules and phenolic antioxidants. Moreover, a great thermal stability of individual phenolic compounds in fortified rice was observed during rehydration at boiling temperatures.

Stability of phenolic compounds, antioxidant activity and colour through natural sweeteners addition during storage of sour cherry puree

The aim of this study was to describe the changes in phenolic compounds, antioxidant activity and colour of sour cherry puree supplemented with different natural sweeteners (sucrose, palm sugar, erythritol, xylitol, steviol glycoside, Luo Han Kuo), and natural prebiotic (inulin). A total of 18 types of polyphenolic compounds were assessed in the following sour cherry puree by LC–MS-QTof analysis, before and after 6months of storage at 4°C and 30°C. Total phenolics determined by UPLC–PDA–FL was 1179.6mg/100gdm. In samples with addition of sweeteners the content of phenolic compounds ranged from 1133.1 (puree with steviol glycoside) to 725.6mg/100gdm (puree with erythritol), and the content of these compounds strongly affected on antioxidant activity. After 6-month storage, protective effects of some additives (palm sugar, erythritol, steviol glycoside, xylitol and inulin) on the polyphenol content, especially on anthocyanins and consequently on colour, and antioxidant activity were noticed. The results showed that some natural sweeteners might be interesting from a nutritional as well as commercial and pharmaceutical perspective.

Gas phase plasma impact on phenolic compounds in pomegranate juice

The aim of the study was to evaluate the effect of gas phase plasma on phenolic compounds in pomegranate juice. The potential of near infrared reflectance spectroscopy combined with partial least squares for monitoring the stability of phenolic compounds during plasma treatment was explored, too. Experiments are designed to investigate the effect of plasma operating conditions (treatment time 3, 5, 7min; sample volume 3, 4, 5cm3; gas flow 0.75, 1, 1.25dm3min−1) on phenolic compounds and compared to pasteurized and untreated pomegranate juice. Pasteurization and plasma treatment resulted in total phenolic content increasing by 29.55% and 33.03%, respectively. Principal component analysis and sensitivity analysis outputted the optimal treatment design with plasma that could match the pasteurized sample concerning the phenolic stability (5min/4cm3/0.75dm3min−1). Obtained results demonstrate the potential of near infrared reflectance spectroscopy that can be successfully used to evaluate the quality of pomegranate juice upon plasma treatment considering the phenolic compounds.

HIGH HYDROSTATIC PRESSURE TREATMENT OF FRUIT, FRUIT PRODUCTS AND FRUIT JUICES: A REVIEW ON PHENOLIC COMPOUNDS

Phenolic compounds are healthy substances, therefore amount of phenolic compounds in fruits/fruit juices are important for customers. Flavonoids are the most com­mon and widely distributed group of plant phenolics. Fruits and fruit juices are among the best sources of polyphenols in the human diet because of their high content in most fruits. Processing fruits can change their content of phenolic compounds and heat treatments usually decrease phenolic compounds in fruits. Minimising losses of these bioactive compounds during processing and storage are one of the priorities and challenge for manufacturers. High hydrostatic pressure (HHP) is a technology which can be used instead of thermal process such as pasteurization and can be combined with thermal process for sterilization. This study discusses the impact of HHP processing conditions on the stability of phenolic compounds in fruits and their products after process, during storage and compares with thermal process. Matrix of food and processing parameters such as pressure, temperature, time are important for retaining of phenolic compounds. In general, several authors have proven that HHP treatment on different fruit products slightly modified their content of phenolic compounds. There has not been much research comparing HHP with thermal processes on effects of phenolic compounds in fruits and fruit products, and researches generally indicate that HHP is better than thermal processes on retaining phenolic compounds.

Effect of stevia and citric acid on the stability of phenolic compounds and in vitro antioxidant and antidiabetic capacity of a roselle (Hibiscus sabdariffa L.) beverage

Plant infusions are consumed due to their beneficial effects on health, which is attributed to their bioactive compounds content. However, these compounds are susceptible to degradation during processing and storage. The objective of this research was to evaluate the effect of stevia and citric acid on the stability of phenolic compounds, antioxidant capacity and carbohydrate-hydrolysing enzyme inhibitory activity of roselle beverages during storage. The optimum extraction conditions of roselle polyphenolic compounds was of 95°C/60min, which was obtained by a second order experimental design. The incorporation of stevia increased the stability of colour and some polyphenols, such as quercetin, gallic acid and rosmarinic acid, during storage. In addition, stevia decreased the loss of ABTS, DPPH scavenging activity and α-amylase inhibitory capacity, whereas the incorporation of citric acid showed no effect. These results may contribute to the improvement of technological processes for the elaboration of hypocaloric and functional beverages.

Influence of thermal treatment on the stability of phenolic compounds and the microbiological quality of sucrose solution following osmotic dehydration of highbush blueberry fruits.

Osmotic dehydration is a process of the partial removal of water which is based on immersion of material having cellular structure in a hypertonic solution. Osmotic dehydration is used as a pretreatment for the dehydration of foods before they are subjected to further processing such as freezing, freeze drying, vacuum drying. Management of spent syrup is one of the most important problems related to osmotic dewatering. Osmotic solutions are heavily polluted with of carbohydrates, remains of the dehydrated material and microorganisms. The aim of this study was to determine the effect of thermal treatment on the content of phenolic compounds and the microbiological quality of sucrose solution used in 15 cycles of osmotic dehydration of highbush blueberry (Vaccinium corymbosum L.) fruits. The tested material was 65.0 ±0.5°Brix sucrose solution used for 15 cycles of osmotic dehydration of highbush blueberry (Vaccinium corymbosum L.). Osmotic dehydration was conducted at 40°C for 120 min using fruits previously subjected to enzymatic pretreatment. The thermal treatment of sucrose solution was conducted at 70, 80, 90, 100 and 115°C for 20, 40 and 60 s. The sucrose solution was analysed in terms of total polyphenols, particular polyphenols using high performance liquid chromatography and microbiological analysis was subjected. Thermal treatment at 70-115°C for 20 s caused degradation of 8.5% to 12.7% of polyphenols, while as much as 23.1% of polyphenols were degraded at 115°C after 60 s. The present paper proposes heating parameters that are optimal from the point of view of phenolic compound retention and microbiological quality: thermal treatment of syrup at 100°C for 40 s. Under these conditions, total polyphenols retention was 94.5%, while the retention of individual phenolic compounds varied from 89.2% to 37.2%, and that of flavan-3-ols amounted to 89.5%. The studied manner of syrup treatment eliminated the problem of syrup contamination with yeasts and molds (reducing their levels to less than 1 CFU/mL).

Stability of phenolic compounds and antioxidant capacity of regular and decaffeinated coffees

This study compared the regular and decaffeinated coffees in relation to antioxidant capacity, levels of some antioxidant molecules and stability of these parameters over a six-month period under different storage conditions. The regular coffee samples analyzed right after the industrial production showed higher antioxidant capacity (ORAC and DPPH), the same levels of phenolic compounds and higher levels of phenolic acids than decaffeinated coffee. After six months, the closed packs of both the grades kept under vacuum at 20°C did not show significant changes from the initial results; the open packs stored at 4°C showed small but statistically significant reductions and the open packs stored at 20°C showed higher and statistically significant losses (p < 0.05). Oxygen was the most important factor for these losses but temperature also played an important role. Tests showed that the storage conditions were very important to preserve the quality of coffees regarding the analyzed parameters.

Stability of phenolic compounds in dry fermented sausages added with cocoa and grape seed extracts

The level of eleven target phenolic compounds was evaluated in dry fermented sausages added with vegetable extracts. Grape seed (GSE1 and GSE2) and cocoa extracts, rich in phenolic compounds, were added in the formulation of dry fermented sausages (“salchichón” and “fuet”). Evolution of the major monomeric and oligomeric phenolic compounds of these extracts was evaluated during sausage shelf life by UHPLC-MS/MS. Kind of sausage did not affect significantly overall stability of the target compounds. At the end of the ageing process, catechin and epicatechin were at 54–61%, gallic acid and galloylated flavan-3-ols at 59–91%, oligomeric flavan-3-ols at 72–95% and glycosylated flavonols at 56–88% (in cocoa treatment) and 82–94% (in GSE treatment) of the contents that were added to the meat batter. All phenolic compounds levels did not decrease further significantly after ageing until the end of shelf life. Sensory analyses showed no important differences between control and cocoa added products, while grape seed addition gave these products abnormal sensory profiles. The 0.5% (w/w) addition of vegetal extracts was suitable to enrich dry fermented sausages with health-beneficial polyphenols.

Effect of Inorganic Salt Mixtures on Phenol Mineralization by Photo-Fenton-Analysis via an Experimental Design

Effluents of resin production, petrochemicals, refineries, paper mills, and iron foundry industries may present high concentrations of phenol. The high toxicity, solubility, and stability of phenolic compounds hamper the treatment of this wastewater by conventional methods. In this work, the effect of inorganic ion mixtures, such as chloride, nitrate, sulfate, carbonate, and monophosphate on the phenol mineralization by the photo-Fenton process, was investigated. The kinetic of phenol mineralization was monitored with the analysis of total organic carbon. Two experimental designs were employed to evaluate the influence of inorganic ions on mineralization efficiency: fractional experimental design and central composite rotatable design (CCRD). The pollutant degradation reached 100 % at 60 min in the absence of salts, but in a saline medium, this value was reduced to 10 %. The sequence of the inhibitory effect was H2PO4 − ≫ Cl− > SO4 2− > NO3 − ≈ CO3 2. The statistical data analysis showed that the phosphate and chloride ion concentrations were studied variables and statistically significant on the mineralization process. The analysis of variance showed: (1) good fit between the observed and prediction values for fractional experiment design and CCRD and (2) according to Fisher distribution, the models that were obtained were considered significant and predictive.

The effect of natural antioxidants extracted from plant and animal resources on the oxidative stability of soybean oil

The objective of this study was to evaluate and compare the antioxidant activity of protein hydrolyzates isolate (PHI) from Crucian carp (Carassius carassius) fish and cow's intestine along with microwave-assisted olive leaf extract (OLE) encapsulated by Arabic gum and maltodextrin, in soybean oil. The antioxidant activity of PHIs at three concentrations of 200, 500 and 1000 mg/kg and OLE samples containing 70 mg/kg total phenolics during 20 days storage was evaluated by peroxide value, TBA value, p-anisidine value and Rancimat stability test. The fish PHI at concentration of 1000 mg/kg, cow's intestine PHI at 500 and 1000 mg/kg and OLE encapsulated with Arabic gum showed best oxidative protection activity (more than BHT at 100 and 200 mg/kg). OLE had a suitable antioxidant activity in soybean oil and encapsulation improved the thermal stability of phenolic compounds, but on the other hand, it decreased the antioxidant efficiency of OLE.