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White chocolate, which does not contain cocoa mass, is less healthy than dark and milk chocolate. Due to its milk content, white chocolate can also cause issues for those with lactose intolerance or dairy allergies. To overcome these problems, a study was conducted by adding highly antioxidant encapsulated cinnamon extract (ECE) to vegan white chocolate formulated with different levels of soy protein isolate (SPI) and coconut flour (CF). This study aimed to examine the chocolate’s total phenolics, flavonoids, antioxidant activity (IC₅₀), protein and fat content, particle size distribution, texture, color, melting point, and sensory characteristics. The results showed that the addition of SPI and CF had a significant impact on the properties of the white chocolate, except for hardness. Incorporating 2% (w/w), ECE significantly increased the total phenolics, flavonoids, and antioxidant activity. Total phenolics and flavonoids were positively correlated with antioxidant activity. Vegan white chocolate formulated with 27% SPI, 10% CF, and 2% ECE was acceptable to panelists, and thus, this product can be potentially consumed by lactose-intolerant and vegan consumers.

The effects of gellan gum addition and the ohmic cooking method on the color, starch retrogradation, textural properties, total phenolic contents, and antioxidant activities of refrigerated ready-to-eat cooked brown rice were investigated and compared to those from the conventional cooking method. Brown rice samples of four rice cultivars were used including RD 43, Riceberry, KDML 105, and RD 6. The key objective was to determine the benefits of applying the gellan gum addition and the ohmic cooking method on different quality parameters of the ready-to-eat cooked brown rice products kept in refrigerator. The results indicated that both gellan gum addition and ohmic cooking method led to less color intensity, slower starch retrogradation, a reduction in rice hardness escalation during storage, and greater antioxidant capabilities of the ready-to-eat brown rice products compared to their counterparts. The starch retrogradation was not detected for the samples of 1 night storage; however, it appeared in every sample after 7 days. The retrogradation enthalpy values were different between rice varieties. The effect of gellan gum addition on the starch retrogradation delay was minimal for the glutinous rice. The samples cooked by ohmic method had greater antioxidant activity levels than the conventionally-cooked samples in almost all cases.

Two lactic acid bacteria (LAB) strains of Lactobacillus plantarum 21802 and Lactobacillus brevis 6239 were selected and combined for fermentation of grape juice. The changes of sugars, organic acids, volatiles, phenolic compounds as well as antioxidant capacity of the grape juice were characterized. Results showed that fermentation with LAB led to a slight decrease in sugar content and increased in organic acid content. The sugars were mainly consumed at the initial stage of fermentation, while the malic acid was consumed completely during the fermentation. The contents of total phenolics and flavonoids in grape juice decreased gradually during the fermentation process. As compared with the initial contents in unfermented grape juice, the contents of proanthocyanin B2, rutin, isoquercitrin, rhamnose-3-O-glucoside in the final fermented grape juice were increased by 26.83%, 249.24%, 138.48%, 139.60%, respectively, while the contents of gallic acid, proanthocyanin B1, catechin and epicatechin were decreased by 24.49%, 14.85%, 71.68%, 42.52%, respectively. The mice fed with the fermented grape juice showed higher activity of superoxide dismutase and lower level of malondialdehyde both in serum and liver tissue than those fed with the unfermented grape juice. Fermentation with LAB also enhanced the flavor profile by increasing the total number and content of volatile compounds, especially those of monoterpene alcohols, which are the main and characteristic aroma volatile compounds in Muscat aroma grapes. This research confirmed that fermentation with LAB might be a desirable option for improving the flavor and nutritional attributes of grape juice by altering the ratio of sugar to organic acid, improving the phenolic compounds, enhancing the antioxidant capacity, intensifying of the characteristic aroma and pleasant flavor of the grape juice.

The effects of gellan gum addition and the ohmic cooking method on the color, starch retrogradation, textural properties, total phenolic contents, and antioxidant activities of refrigerated ready-to-eat cooked brown rice were investigated and compared to those from the conventional cooking method. Brown rice samples of four rice cultivars were used including RD 43, Riceberry, KDML 105, and RD 6. The key objective was to determine the benefits of applying the gellan gum addition and the ohmic cooking method on different quality parameters of the ready-to-eat cooked brown rice products kept in refrigerator. The results indicated that both gellan gum addition and ohmic cooking method led to less color intensity, slower starch retrogradation, a reduction in rice hardness escalation during storage, and greater antioxidant capabilities of the ready-to-eat brown rice products compared to their counterparts. The starch retrogradation was not detected for the samples of 1 night storage; however, it appeared in every sample after 7 days. The retrogradation enthalpy values were different between rice varieties. The effect of gellan gum addition on the starch retrogradation delay was minimal for the glutinous rice. The samples cooked by ohmic method had greater antioxidant activity levels than the conventionally-cooked samples in almost all cases. [ABSTRACT FROM AUTHOR]

Two lactic acid bacteria (LAB) strains of Lactobacillus plantarum 21802 and Lactobacillus brevis 6239 were selected and combined for fermentation of grape juice. The changes of sugars, organic acids, volatiles, phenolic compounds as well as antioxidant capacity of the grape juice were characterized. Results showed that fermentation with LAB led to a slight decrease in sugar content and increased in organic acid content. The sugars were mainly consumed at the initial stage of fermentation, while the malic acid was consumed completely during the fermentation. The contents of total phenolics and flavonoids in grape juice decreased gradually during the fermentation process. As compared with the initial contents in unfermented grape juice, the contents of proanthocyanin B2, rutin, isoquercitrin, rhamnose-3-O-glucoside in the final fermented grape juice were increased by 26.83%, 249.24%, 138.48%, 139.60%, respectively, while the contents of gallic acid, proanthocyanin B1, catechin and epicatechin were decreased by 24.49%, 14.85%, 71.68%, 42.52%, respectively. The mice fed with the fermented grape juice showed higher activity of superoxide dismutase and lower level of malondialdehyde both in serum and liver tissue than those fed with the unfermented grape juice. Fermentation with LAB also enhanced the flavor profile by increasing the total number and content of volatile compounds, especially those of monoterpene alcohols, which are the main and characteristic aroma volatile compounds in Muscat aroma grapes. This research confirmed that fermentation with LAB might be a desirable option for improving the flavor and nutritional attributes of grape juice by altering the ratio of sugar to organic acid, improving the phenolic compounds, enhancing the antioxidant capacity, intensifying of the characteristic aroma and pleasant flavor of the grape juice. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the essential oil composition of Inula viscosa leaves by hydrodistillation (HDE), ultrasonic (UDE) and solvent (SE) extractions followed by hydrodistillation. The total polyphenol and flavonoid contents and their antioxidant effects were studied by different solvent of extraction: ethanol (ET), ethyl acetate (EA), methanol (ME) and aqueous (AE). The principal compounds for HDE were: 2-hexenal (3.70%), caryophyllene oxide (3.11%), γ-selinene (3.09%), 3-hexen-1-ol (2.00%), eugenol (1.70%) and trans-caryophyllene (1.34%), while for UDE were: γ-selinene (5.68%), caryophyllene oxide (4.87%), trans-caryophyllene (1.99%) and nerolidol (1.74%). The oil obtained by SE was shown to contain tridecane (3.89%), dodecane (3.08%), trans-caryophyllene (2.94%), caryophyllene oxide (2.56%) and nerolidol (2.53%). Significant changes on phenolic contents were found between the different solvent of extraction. ME and AE extracts led to the highest total polyphenol (PHL) and flavonoid (FL) amounts. The anti-radical activity and reducing power were maximal in AE and ME extract. HPLC examination established that the ferulic acid as major phenolic acid in ME and AE fractions, whereas luteolin was the main compound of EA and ET fractions.

The purpose of this study was to compare the essential oil composition of Inula viscosa leaves by hydrodistillation (HDE), ultrasonic (UDE) and solvent (SE) extractions followed by hydrodistillation. The total polyphenol and flavonoid contents and their antioxidant effects were studied by different solvent of extraction: ethanol (ET), ethyl acetate (EA), methanol (ME) and aqueous (AE). The principal compounds for HDE were: 2-hexenal (3.70%), caryophyllene oxide (3.11%), γ-selinene (3.09%), 3-hexen-1-ol (2.00%), eugenol (1.70%) and trans-caryophyllene (1.34%), while for UDE were: γ-selinene (5.68%), caryophyllene oxide (4.87%), trans-caryophyllene (1.99%) and nerolidol (1.74%). The oil obtained by SE was shown to contain tridecane (3.89%), dodecane (3.08%), trans-caryophyllene (2.94%), caryophyllene oxide (2.56%) and nerolidol (2.53%). Significant changes on phenolic contents were found between the different solvent of extraction. ME and AE extracts led to the highest total polyphenol (PHL) and flavonoid (FL) amounts. The anti-radical activity and reducing power were maximal in AE and ME extract. HPLC examination established that the ferulic acid as major phenolic acid in ME and AE fractions, whereas luteolin was the main compound of EA and ET fractions. [ABSTRACT FROM AUTHOR]

Polyphenol oxidase (PPO) enzyme was extracted from Prunus spinosa L. subsp. dasyphylla plum, partially purified by acetone precipitation, and its biochemical properties were investigated. Different substrates (p-coumaric acid, L-tyrosine, p-hydroxyphenyl propionic acid (PHPPA), catechol, 4-methylcatechol (4-MTC), hydrocaffeic acid, gallic acid, quercetin, catechin, and epicatechin) were analysed to determine their affinities with Prunus spinosa PPO (PsPPO). The substrate specificity was in the following order: 4-MTC > catechol > hydrocaffeic acid > catechin > epicatechin. 4-MTC was the most suitable substrate (Km = 0.97 mM and Vmax = 4753 U/mg protein). The optimal pH values were 7.0 for 4-MTC and catechol, 5.0 for catechin and epicatechin, and 4.0-6.0 for hydrocaffeic acid. Optimal temperatures were 40°C for 4-MTC, 30°C for catechol, and 60°C for catechin, epicatechin, and hydrocaffeic acid. In the inhibition tests, the most potent inhibitor was found to be sodium metabisulphite (IC50 = 0.01 mM), followed by ascorbic acid, thiourea, benzoic acid, L-cysteine, and sodium azide. Approximately 80 and 75% of the diphenolase activity was conserved at pH 5.0 and 7.0, respectively, at 4°C after 7 d incubation. Moreover, native polyacrylamide gel electrophoresis (Native-PAGE) of the enriched extract revealed the presence of at least six bands with PPO activity, suggesting the existence of different PPO isoforms. However, the oxidation of diphenol related to browning significantly, so the data obtained in this research provided a basis for the prevention of enzymatic browning of Prunus spinosa during processing. High-performance liquid chromatography (HPLC) revealed the plum extract contained protocatechuic acid, p-OH benzoic acid, vanillic acid, syringic acid, epicatechin, p-coumaric acid, and luteolin. [ABSTRACT FROM AUTHOR]

This study focuses on the quantification of virgin olive oil phenolic compound while using mid-infrared spectroscopy with chemometrics. For that, 100 samples of virgin olive oils in phenolic compounds which varied between 1.04 and 10.33 g/L were picked up in Morocco’s regions and subjected to infrared analysis. The aim was to develop a calibration model for the prediction of phenolic compounds in olive oil by using Fourier transform-infrared spectroscopy. The spectral transmissions of all samples were obtained in the spectral range of 600–4000 cm–1. The values obtained for correlation coefficient and root mean square errors of prediction were 0.99 and 0.11, respectively. These results showed the capability of the Fourier transform-infrared spectroscopy and the chemometric in developing accurate models to predict the phenolic compounds in virgin olive oil. [ABSTRACT FROM AUTHOR]

The purpose of this research was to evaluate and compare the differences in the phenolic composition, antioxidant properties, and fatty acids of virgin olive oils from the Ayvalik, Gemlik, and Memecik olive varieties cultivated in their respective growing areas over two harvest years. The phenolic composition of olive oils was carried out by liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry analysis and the fatty acid composition was determined by gas chromatography analysis. Fourteen phenolic compounds were identified and, among these, the most dominant were elenolic acid, tyrosol, and hydroxytyrosol. For olives from both years, the highest total phenolic content was determined in Memecik followed by Ayvalik and Gemlik. 2,2-diphenyl-1-picryl hydrazyl and 2,2′-azino-bis- (3-ethyl-benzothiazoline-6-sulphonic acid) methods were used to determine the antioxidant capacity of the olive oil extracts. In both methods, the antioxidant capacity values were higher for oil from cv. Ayvalik. Thirteen fatty acids were identified and quantified in all samples. Oleic acid was the highest concentration and this acid was more dominant in Gemlik oils. [ABSTRACT FROM AUTHOR]

Sixty Brazilian honey samples were analysed for their total phenolic content with the Folin-Denis reagent, total flavonoid content by aluminium chloride method, and antioxidant activity by reaction with 2,2-diphenyl-1-picrylhydrazyl radical. Colour was also classified according to visual analysis and Pfund scale. Linear relationships were observed between colour and flavonoid content, total phenolics and antioxidant capacity, and total flavonoid and phenolic contents. The white-coloured Citrus honey showed the lowest antioxidant activity, while the light ambar Verbenaceae honey showed the highest total phenolics and antioxidant activity. Dark-coloured and polyfloral honeys, though less popularized among consumers, showed average to high antioxidant capacity. [ABSTRACT FROM AUTHOR]

Propolis has highly biologically active natural substances. Propolis is rich in phenolic compounds, and is becoming increasingly popular because of its components' potential role in contributing to human health. Its composition is variable and depends on several factors. In this study, some individual phenolic compounds were analyzed and investigatedin vitrobiological activities of ten different Turkish propolis samples. Seventeen different phenolic constituents were measured by reverse phase-high performance liquid chromatography. Total phenolic compounds and ferric reducing antioxidant power were used as antioxidant capacity determinants. The antimicrobial activity was studied by agar diffusion method using six bacteria and two yeasts. All propolis showed strong antioxidant and antimicrobial activity and contained large amounts of antioxidant compounds. Quercetin, benzoic acid, caffeic acid, ferulic acid, and coumaric acid were detected in all propolis samples in high amounts, while vanillic acid, chlorogenic acid, epicathecin, rutin, syringic acid, and o-coumaric acid were found in very small quantities and cathecin was not found in any of them. The methanolic extracts were active against all bacteria and yeasts. They were especially effective againstPseudomonas aeruginosaATCC®27853. The propolis extracts proved to be a good source of antioxidants and antimicrobial agents that might serve to protect health and fight against several diseases. [ABSTRACT FROM PUBLISHER]

Corn poppy (Papaver rhoeas L.) leaf has been extensively used as garniture in salads and drugs in folk medicine. In this study, the possible antioxidant properties of water (WE), ethanol (EE), and acetone (AE) extracts of corn poppy leaves were investigated using different antioxidant tests, including total antioxidant activity in linoleic acid system, DPPH• scavenging activity, reducing power, chelation activity, and hydrogen peroxide scavenging activity. In addition, the amount of total phenolics was also determined. Total antioxidant activities of all extracts were greater than 85% at 400 μg/mL concentration. The scavenging effects of WE and EE on DPPH• radical were found to be 88.46 ± 0.08% and 86.81 ± 0.37% at 800 μg/mL concentration, respectively, which was comparable to standard antioxidants, such as BHA and α-TP. The reducing power of extracts was in the order of WE > EE > AE. The percentage of metal chelating activity of 800 μg/mL concentration of WE was found to be 79.51 ± 4.05%. Our results indicated that the leaves of Papaver rhoeas L. showed the potential to be used as a natural antioxidant. [ABSTRACT FROM PUBLISHER]

Dill (Anethum graveolens L.) have been extensively used in salads, soups, and pickles for its aromatic odor and flavor. Recently, interest in plant-derived food additives has grown. In this study, the possible antioxidant properties of water, ethanol, and acetone extracts of dill leaves were investigated. In order to evaluate antioxidant activities of all extracts, different antioxidant tests were used, such as total antioxidant activity by ferric thiocyanate method, reducing power, DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging, hydrogen peroxide scavenging, and ferrous ions chelating activities. The content of phenolic compounds was also determined to be the gallic acid equivalent. Among the three extracts, the water extract of dill leaf showed the most potent antioxidative capacity in each assay, showing 79.66% (at 1 mg/mL) in the DPPH• radical scavenging activity, 63% (at 800 μg/mL) in the metal chelating effect, 60% (at 400 μg/mL) in the H2O2 scavenging activity, and 0.61 absorbance (at 1 mg/mL) in the reducing power. [ABSTRACT FROM AUTHOR]