Antioxidant Activity Of Phenolic Compounds Research Articles

How Does the Phenol Structure Influence the Results of the Folin-Ciocalteu Assay?

Plants produce a diverse array of secondary metabolites that are generally nonessential but facilitate ecological interactions. Fruits, vegetables, seeds and nuts can accumulate bioactive secondary metabolites with health-promoting properties, including the potent antioxidant activities of phenolic compounds. Several in vitro assays have been developed to measure the polyphenol content and antioxidant activity of plant extracts, e.g., the simple and highly popular Folin-Ciocalteu (FC) assay. However, the literature contains a number of different descriptions of the assay and it is unclear whether the assay measures the polyphenol content or reducing capacity of the sample. To determine the influence of phenolic structures on the outcome of the FC assay, we tested phenols representing different subgroups (phenolic acids, flavonols, flavanols, dihydrochalcones and flavanones). We observed different results for each reference substance and subgroup. Accordingly, we concluded that the FC assay does not measure the polyphenol content of a sample but determines its reducing capacity instead. Assigning the substances to five structural classes showed that the FC results depend on the number of fulfilled Bors criteria. If a molecule fulfills none of the Bors criteria, the FC results depend on the number of OH groups. We did not find a correlation with other single electron transfer assays (e.g., ABTS and DPPH assays). Furthermore, the FC assay was compatible with all five subgroups and should be preferred over the DPPH assay, which is specific for extracts rich in dihydrochalcones or flavanones.

HPLC-UV Analysis and Antioxidant Activities of Phenolic Compounds from Bark of Tamarix articulata vahl Shrubs Grown in Mosul Province.

Analytical trial was carried out to investigate phenolic compounds of Tamarix articulata (vahl.) Karst shrubs were extracted from dry powdered bark with different solvents: Ethyl acetate; Industrial methylated spirits (IMS) and distilled water, and their antioxidant activity were assayed via in vitro radical scavenging activity using DPPH assay. HPLC analysis showed that there were at least 6 remarkable phenolic compounds identified of bark, which included: (Apigenin, Caffeic acid, Chlorogenic acid, kaempferol, Quercetin and Rutin). Furthermore, both of crude extracts IMS and distilled water was better than crude ethyl acetate extract for extracting the bioactive compounds particularly the number and concentration of phenolic compounds identified in bark. The crude extract of IMS achieved the highest total concentration of 0.471 (mg g−1), followed by the crude extract for hot water was 0.226 (mg g−1) and the lowest crude extract for ethyl acetate was 0.031 (mg g−1). However, all the phenolic compounds separated from the crude extracts were free radical inhibitors of DPPH but both the IMS crude extract and ethyl acetate at the same concentration of 200 (µ ml−1), and at rates of (96.7% and 96) (%), respectively, were significantly superior, on the phenolic compounds separated from the aqueous crude extract. Additionally, it’s superior on the standard sample.

Support vector regression-based QSAR models for prediction of antioxidant activity of phenolic compounds

The Support vector regression (SVR) was used to investigate quantitative structure–activity relationships (QSAR) of 75 phenolic compounds with Trolox-equivalent antioxidant capacity (TEAC). Geometric structures were optimized at the EF level of the MOPAC software program. Using Pearson correlation coefficient analysis, four molecular descriptors [n(OH), Cosmo Area (CA), Core-Core Repulsion (CCR) and Final Heat of Formation (FHF)] were selected as independent variables. The QSAR model was developed from the training set consisting of 57 compounds and then used the leave-one-out cross-validation (LOOCV) correlation coefficient to evaluate the prediction ability of the QSAR model. Used Artificial neural network (ANN) and multiple linear regression (MLR) for comparing. The RMSE (root mean square error) values of LOOCV in SVR, ANN and MLR models were 0.44, 0.46 and 0.54. The RMSE values of prediction of external 18 compounds were 0.41, 0.39 and 0.54 for SVR, ANN and MLR models, respectively. The obtained result indicated that the SVR models exhibited excellent predicting performance and competent for predicting the TEAC of phenolic compounds.

Recovery and antioxidant activity of phenolic compounds extracted from walnut press-cake using various methods and conditions

Walnut (Juglans regia L.) press-cake is a residue of oil processing from which the phenolic compounds were extracted using ethanol 60 % by batch and semi-continuous operations, or by ultrasound-assisted maceration in the case of de-oiled cake, with particular attention to the variables time and solid-solvent ratio. For batch extraction, the conditions maximizing total phenolic yield (TPC) and radical scavenging activity evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay were 60 °C without the addition of phospholipids, provided however for phenolic yield, that an extraction time of 60 min and a ratio of 25 mL of solvent per g of cake were applied. Values of up to 14.8 mg gallic acid equivalent (GAE)/gcake and 136.9 μmol Trolox equivalent/gcake were obtained. The semi-continuous variant gave a TPC of 19.8 mg GAE/gcake and an overall extract containing 8% phenolic compounds and 46 % oil. After de-oiling, the cake was subjected to ultrasound-assisted extraction. The TPC and DPPH varied slightly with the applied conditions, between 10.4 and 13.3 mg GAE/gcake and 83–107 μmol Trolox Equiv./gcake respectively, unless the solid/solvent ratio increased to 1/200 (TPC of 29 mg GAE/gcake). It was also shown that the oxidative stability of Camelina sativa L. Crantz oil increased from 24 to 72 h by enrichment with walnut extract.

Composition and Antioxidant Activity of Phenolic Compounds in Fruit of the Genus Rosa L.

We investigated the qualitative and quantitative composition of phenolic compounds in the fruit of Rosa L. cultivars grown in Lithuania. The highest total content of phenolic compounds (50.13 ± 4.17 mg GAE/g, p < 0.05) was determined in fruit samples of Rosa pimpinellifolia L. cultivar “Single Cherry”. The highest levels of hydroxycinnamic acid derivatives were determined in fruit samples of Rosa rugosa Thunb. cultivars “Dart’s Defender” and “Adam Chodun”. The highest flavonoid content was determined in fruit samples of Rosa multiflora Thunb. cultivar “Nana” and R. multiflora species. The strongest antioxidant activity evaluated by applying DPPH and FRAP assays was determined in fruit extracts of R. pimpinellifolia cultivar “Single Cherry” and R. rugosa cultivar “Adam Chodun”. Qualitative and quantitative analysis of phenolic compounds in Rosa L. fruit was performed by applying UHPLC. The following phenolic compounds were identified in fruit samples: caffeic acid, chlorogenic acid, quercetin, quercitrin, (+)-catechin, (−)-epicatechin, (−)-epicatechin gallate, rutin, phloridzin, and kaempferol-3-O-glycoside. A strong correlation was determined between the total amount of phenolic compounds determined in extracts of the fruit samples of Rosa L. cultivars and the radical scavenging and reducing activity of their extracts in vitro (R = 0.767 and 0.727, respectively, p < 0.05).

Effects of two drying methods on the stability and antioxidant activity of phenolic compounds in mulberry fruits

Mulberry is a health-promoting fruit with abundant phenolic compounds. The effects of vacuum drying (VD) and vacuum freeze-drying (VFD) on oxidation resistance and polyphenols, including extractable and non-extractable phenols, were compared in the present work. The total polyphenols and antioxidant capacity of mulberry fruits treated with VFD were higher than those treated with VD. Thirteen phenolic compounds in fresh and dried mulberry fruits were identified and quantified by UPLC-QqQ/MS. The content of extractable phenol was significantly higher than that of non-extractable phenol. In addition, correlation analysis showed that flavonoids cyanidin-3-O-glucoside and phloretin were closely related to the total polyphenols and antioxidant activity. These results provide the basis for further development of dried mulberry products containing high content of total polyphenols and antioxidant activity.

Effect of in vitro gastrointestinal digestion on phenolic compounds and antioxidant properties of soluble and insoluble dietary fibers derived from hulless barley.

In this study, the bioaccessibility and antioxidant activity of phenolic compounds in insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) derived from hulless barley were evaluated by an in vitro gastrointestinal (GI) digestion model. The total phenolic and flavonoid contents, as well as antioxidant activity of phenolic compounds in IDF and SDF following GI digestion were studied. The results obtained showed an increase in total phenolic and flavonoid contents, as well antioxidant activity compared with undigested extracts. Moreover, the bioaccessibility indexes of phenolic compounds in IDF and SDF were 490.90± 3.10% and 1608.79± 40.63% respectively, after GI digestion. Similarly, the bioaccessibility indexes of flavonoids in IDF and SDF were 179.20± 15.16% and 814.36± 26.31%, respectively. Based on our findings, individual phenolic compounds show different stability in the digestion process. The content of ferulic acid has different trends in IDF and SDF during GI digestion. This study could provide a scientific basis for hulless barley DF as valuable food additives. PRACTICAL APPLICATION: Hulless barley is a unique cereal with potential health benefits due to high dietary fiber (DF) content and phenolic compounds. Phenolic compounds could be linked to DF through chemical bonds. Phenolic compounds in DF can be slowly and continuously released under acidic, alkaline, and enzymatic conditions by in vitro gastrointestinal digestion, which could maintain a higher phenolic concentration in the bloodstream and be beneficial for human health. This study could provide a scientific basis for hulless barley DF as valuable food additives.

Antioxidant activities of phenolic compounds from Ziziphus jujuba Mill extract using subcritical water

Antioxidant activities of phenolic compounds from Ziziphus jujuba Mill extract using subcritical water

Isolation and Antioxidant Activity of Phenolic Compounds from Halban Leaves (Vitex pinnata Linn) in Aceh

Abstract: An isolation and identification of phenolic compounds from Halban Leaves (Vitex pinnata Linn), a traditional medicinal plant in Aceh, has been done. Halban leaves were extracted through methanol maceration followed by isolation. The methanol extract went into n-hexane and ethyl acetate partition consecutively resulting in 3 different fractions of ethyl acetate and n-hexane extract. The ethyl acetate fraction demonstrated the most promising antioxidant and cytotoxic activity. Therefore, purification of ethyl acetate fraction was done by column chromatography [SiO2; (i) n-hexane-ethyl acetate 10:1, 1:1 ; (ii) n-hexane-ethyl acetate = 2 : 1); (iii) n-hexane-acetone = 1:1]. The pure isolate as identified by using UV, IR, NMR, and MS spectra afforded 2 phenolic compounds, namely (1) 4-hydroxymethyl benzoate and (2) p-hydroxymethyl benzoic acid (PHBA). The antioxidant activity of compound 1 and cytotoxicity activity of 2 expressed in IC50 and LD50 was 41.08 ppm and 59.41 ppm, respectively.Abstrak: Isolasi dan identifikasi senyawa fenolik dari Daun Halban (Vite xpinnata Linn) tanaman obat tradisional asal Aceh telah dilakukan. Isolasi ini dilakukan dengan cara mengekstraksi daun halban dengan cara maserasi menggunakan pelarut metanol, Ekstrak metanol kemudian dipartiisi dengan n-heksan dan etilasetat secara berturut-turut sehingga diperoleh tiga ekstrak yaitu ekstrak etil asetat, n-heksan dan air. Ekstrak etil asetat memiliki bioaktivitas sebagai antioksidan dan juga toksisitas. Pemurnian dilanjutkan dengan cara kromatografi kolom [SiO2; (i) n-heksan-etilasetat 10:1, 1:1 ; (ii) n-heksan-etilasetat = 2 : 1); (iii) n-heksan-aseton = 1:1] dan diperoleh isolat murni. Isolat murni tersebut diidentifikasi berdasarkan interpretasi data spektra UV, IR, NMR dan MS. Hasil interpretasi data menunjukkan daun halban (V. pinnata Linn) mengandung dua senyawa fenolik yaitu (1) 4-hidroksi metil benzoat dan (2) asam para hidroksi benzoat (PHBA). Senyawa 1 memiliki aktivitas antioksidan dengan nilai IC50 = 41,08bpj dan senyawa 2 memiliki aktivitas toksisitas dengan nilai LC50 = 59,41.

Microbiological and Antioxidant Activity of Phenolic Compounds in Olive Leaf Extract.

According to many reports, phenolic compounds isolated from olive leaves have very good biological activities, especially antimicrobial. Presently, the resistance of microorganisms to antibiotics is greater than ever. Therefore, there are numerous recent papers about alternative solutions for inhibiting their influence on human health. Olive leaf is studied as an important source of antimicrobials with low cost and used in medicine. Numerous publications on involving green technologies for isolation of active compounds from olive leaves have appeared over the past few decades. The present review reports on current knowledge of the most isolated phenolic compounds from olive leaf extract as well as methods for their isolation and characterization. This paper uses recent research findings with a wide range of study models to describe the antimicrobial potential of phenolic compounds. It also describes the vast range of information about methods for determination of antimicrobial potential focusing on effects on different microbes. Additionally, it serves to highlight the role of olive leaf extract as an antioxidants and presents methods for determination of antioxidant potential. Furthermore, it provides an overview of presence of enzymes. The significance of olive leaves as industrial and agricultural waste is emphasized by means of explaining their availability, therapeutic and nutritional effects, and research conducted on this field.

Fermented rice bran: an alternative ingredient in baking

The idea that associated agro-industrial by-products only with the production of animal feed has been gradually being replaced, as the scientific community is interested in these products, as low-cost nutrients for the composition of food and/or culture media in research biotechnological to increase or improve nutrients or characteristics inherent in the raw material. Thus, this work aims to characterize input for baking with claim of natural fortification from the fermentation by Saccharomyces cerevisiae. For this, biomass was characterized in terms of its composition (ashes, fibers, lipids, proteins, and carbohydrates) and antioxidant activity of phenolic compounds. The results show an increase in nutrients such as ash, proteins and fibers, in addition the free and bound phenolic compounds present in the biomass showed antioxidant potential. Therefore, fermented rice bran is a potential input to be used in baking.

KOMPOSISI SENYAWA FENOL DAN POTENSI ANTIOKSIDAN DARI KACANG-KACANGAN: REVIEW

Legumes are good dietary source of bioactive phenolic compounds which play significant roles in many physiological as well as metabolic processes. Flavonoids, phenolic acids and condensed tannins are the main phenolic compounds that are provide in legume seeds. Majority of the phenolic compounds are serving in the legume seed coats. The majority of seed coat of legume seeds are phenolic acids and flavonoids (mainly catechins and procyanidins). Gallic and protocatechuic acids are common in kidney bean and mung bean. Almost 70% of total phenolic compounds in lentils and cranberry beans (seed coat) are catechins and procyanidins. The antioxidant activity of phenolic compounds is in lineal intercourse with their chemical structures such as number as well as position of the hydroxyl groups. Processing mostly conducts to the alleviation of phenolic compounds in legumes because of chemical rearrangements. Phenolic content also lessen due to leaching of water-soluble phenolic compounds into the cooking water. This review provides comprehensive information of phenolic compounds identified in grain legume seeds along with discussing their antioxidant.&#x0D; Keywords: antioxidant activity, legume seeds, phenolic compounds, processing

Drosera tokaiensis extract containing multiple phenolic compounds inhibits the formation of advanced glycation end-products

The accumulation of advanced glycation end-products (AGEs) correlates with aging and accompanies the onset of age-related diseases, such as diabetes and arteriosclerosis. Therefore, a daily intake of natural compounds that inhibit the production of AGEs may be beneficial in preventing these diseases. In this study, we evaluated the inhibitory effects of 14 natural crude extracts, including those of Drosera species, which possess anti-inflammatory activity, on the formation of AGEs, such as Nω-(carboxymethyl)arginine (CMA) and Nε-(carboxymethyl)lysine (CML). Crude extracts of Drosera inhibited the formation of CMA and CML by incubation on gelatin with ribose more effectively than with other extracts, so active compounds that prevent AGE formation were purified from Drosera tokaiensis, which is endemic to Japan. Several compounds were purified from D. tokaiensis extracts using HPLC and identified by NMR analysis. These compounds included ellagic acid, 3,3′-di-O-methylellagic acid 4′-glucoside, myricitrine, and quercimelin. Furthermore, all compounds showed a significantly higher inhibitory effect on CMA and CML formations than aminoguanidine. Specifically, ellagic acid and myricitrine had the highest inhibitory effects of the compounds tested. However, not all compounds showed inhibition of CMA formation in a mixture of gelatin and glyoxal (GO). These results suggest that the compounds in D. tokaiensis inhibit CMA and CML formations via the antioxidative activity of phenolic compounds, rather than GO trapping action. This study provides the first evidence that D. tokaiensis inhibits CMA and CML formations and that phenolic compounds such as ellagic acid and myricitrine play an important role as active components of D. tokaiensis extracts.

Antioxidant activity of phenolic compounds extracted from fresh and dried water caltrop pulp (Trapa taiwanensis Nakai)

Water caltrop (Thapa taiwanensis Nakai) was used as the raw material to investigate the effects of drying treatments on the antioxidant activities and phenolic compounds of water caltrop. For methanolic extracts from fresh, freeze dried, and hot air dried samples, at 10 mg/ mL, the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals was 87.2%, 61.4% and 52.1%, respectively. At 10 mg/mL, the reducing power was 1.63, 0.81 and 0.52, respectively. At 40 mg/mL, the chelating ability on copper ions was 29.6%, 14.8% and 34.3%, respectively. The IC50, half inhibition concentration is the concentration, at which the radicals or ions was scavenged or chelated by 50%. The total phenolics and flavonoids contents were higher in the fresh samples, while the IC50 values were lower. The HPLC analysis showed that four phenolic compounds (gallic acid, quercetin, ferulic acid, and hydroxycinnamic acid were found in water caltrop), and that only had three phenolic compounds (gallic acid, quercetin, and ferulic acid were found after drying). While the freeze-drying treatment could preserve more antioxidant activity of the water caltrop pulps than hot-air drying treatment, different drying water caltrop pulps exhibited different antioxidant mechanisms.

Evaluation of phenolic contents and antioxidant activities of some medicinal plants growing in Algerian Aurès Mountains

Abstract The objective of this study is to evaluate the antioxidant activities of six medicinal plants growing in Algerian Aurès Mountains. Total phenolic and flavonoids contents were measured using colorimetric methods, and the antioxidant capacities were evaluated using the DPPH radical scavenging and β-carotene bleaching tests. Juniperus phoenica L. had significantly the higher total phenolic compounds (53.6±3.86 mg GAE.g−1 DM) (p&lt;0.05); followed by Romarinus officinalis L. (26.1±3.15 mg GAE.g−1 DM) and Artemisia campestris L. (20.5±1.99 mg GAE.g−1 DM). Artemisia campestris L. had significantly the higher flavonoid contents (11.1±0.56 mg QE.g−1 DM) than other studied plants (p&lt;0.05). The best antiradical activity was observed in Thymus algeriensis extracts (EC50=11.1±0.33 µg.ml−1) and Romarinus officinalis L. (EC50=15.3±0.9 µg.ml−1). β-carotene bleaching test showed that the herbs’ phenolic compounds Antioxidant Activity (AA%) value was found in the range of 64-84%, whereas that of the standard antioxidant ascorbic acid was 51±2.4%. The present results indicate that medicinal plants from the Algerian Aurès mountains could be explored in food and pharmaceutical industries for development of natural’s antioxidant agents.

In Vitro Rat intestinal α‐glucosidase inhibitory and Antioxidant Activities of Phenolic Compounds isolated from Colored Rice Keun‐nun‐Jami (Oryza sativa L.) Germ Extracts

Excessive carbohydrate‐based meals may result in postprandial hyperglycemia of type 2 diabetes patients, a modern human metabolic disorder. Therefore Inhibition of α‐glucosidase involved in the digestion and absorption of carbohydrates can significantly decrease the postprandial increase of blood glucose level after a carbohydrate diet. In the screening of anti‐hyperglycemic and antioxidant compounds from the extract of Keun‐nun‐jami Germ (KGE), several bioactive ingredients were isolated and identified from ethyl acetate extraction of KGE using HPLC and MPLC systems. Their structures were elucidated by extensive spectroscopic analysis, including 1D and 2D NMR, and FTICR‐MS. To prove the anti‐hyperglycemic effect of purified compound A and B, inhibitory activities of these compounds against rat intestinal α‐glucosidases (sucrase) were investigated. Furthermore, antioxidant activities of these compounds were also evaluated by oxygen radical absorbance capacity (ORAC) method. A major bioactive compound A in KGE had high rat intestinal sucrase inhibitory activity as well as antioxidant activity. Although we need to identify full structure analysis of these compounds and in‐vivo assay, a major bioactive compound A which has high antioxidant and anti‐hyperglycemic activities has the potential to contribute as a useful food supplements for controlling postprandial hyperglycemia.

Phenolic composition and antioxidant capacity of hawthorn (Crataegus oxyacantha L.) flowers and fruits grown in Algeria.

Background To the best of our knowledge, up to now, there are no reports on the antioxidant activity of phenolic compounds of Crataegus oxyacantha flowers and fruits. Such detailed information is essential to advance the existing knowledge and to promote the use of this species growing in Africa. Therefore, the objective of this investigation was to analyze the content of phenolic compounds as well as the antioxidant activities of flowers and fruits of C. oxyacantha from Bejaia (Northeastern Algeria) by different analytical methods, and to determine the relationship between them. Methods Phenolic compounds and antioxidant activity of Algerian hawthorn flowers and fruits (C. oxyacantha L.) were studied. Total phenolics, flavonoids and flavonols were determined using colorimetric methods. The phenolic profile was analyzed by high-performance liquid chromatography with diode array detection, and the in vitro antioxidant activity was measured using scavenging assay (FRAP) and Fremy's salt, using electronic paramagnetic resonance. Results Different classes of phenolic compounds were identified and quantified. Hawthorn flowers contained higher levels of hydroxycinnamic acids, vitexin derivatives and flavonols compared to fruits, while anthocyanins were present only in fruits. Significant correlations were found between phenolic content and antioxidant activity. The results also showed that although the phenolic content of the two parts was different, their antioxidant capacity was not statistically different. Conclusions The results of this study indicate that hawthorn flowers and fruits of C. oxyacantha may be considered as a natural source of bioactive compounds.

RYE (SECALE CEREALE L.) PHENOLIC COMPOUNDS AS HEALTH-RELATED FACTORS

The diversity of phenolic compounds found in rye grain makes this cereal the valuable source of these substances in everyday food. Simple phenolic compounds, as well as their metabolites, show a pro-health effect. Phenolic acids and ferulic acid dehydrodimers are included in the group of cereal antioxidants. The antioxidant activity of phenolic compounds is an essential factor in the prevention of cancer and cardiovascular diseases.

Polyphenols as natural antioxidants in cosmetics applications.

Currently, there is a great interest in cosmetics prepared on natural resources bases and this may restrict the use of synthetic substances. Plants play a relevant role as a source of biologically active natural products with cosmetic and dermatological importance. According to this context, polyphenolic extracts are highlighted because they have proven antioxidant, anti-inflammatory, anti-aging, antimicrobial, and supporting activity in solar photoprotection. The purpose this study were reviewed at reporting the antioxidant activity of phenolic compounds, mainly applied to dermatological therapy, and highlighting the action mechanisms and structure-activity relationship. In September 2017, we performed a literature search in PubMed and Scielo for scientific researches, antioxidant studies, and systemic reviews. The search terms we used were "PHYTOCOSMETICS" AND "ANTIOXIDANT ACTIVITY" OR "PHENOLIC COMPOUNDS" (from 2000). As inclusion criteria were used relevant original articles, scientific research in the area of interest, and crucial reference articles. Exclusion criteria were: duplicate publications, non-relevant articles and not published in English. The potential cosmetic application of phenolic compounds as natural antioxidants has been attributed to the chemical structure of these compounds, which to interfere in different phases of the oxidation mechanism. The use of phenolic extracts emerges as a viable alternative for cosmetic application, ensuring a commitment to sustainability. However, it is of crucial importance to evaluate the toxicity risks of raw materials and finished products.

Effects of Milk Proteins on the Bioaccessibility and Antioxidant Activity of Oat Phenolics During In Vitro Digestion.

This study investigated the effects of milk solution or milk proteins (casein and whey protein) on the bioaccessibility and antioxidant activity of oat phenolics during in vitro gastric and pancreatic digestion. During digestion, most of oat phenolics were partially degraded by alkaline pH of pancreatic fluid (pH 7.5). For phenolic acids, both milk solution and milk protein only had a slight influence on their bioaccessibility, while exhibited a significant effect on antioxidant activity of oat phenolic extracts and bioaccessibility of avenanthramides (AVs), a kind of bioactive phenols exclusively found in oats. The antioxidant activity and bioaccessibility of AVs were decreased by adding milk and casein, while significantly improved when mixed with milk whey protein. Remarkably, the bioaccessibility of AV 2c, which had the highest antioxidant activity among all phenolic compounds detected in oats, increased above 360% after intestinal digestion by mixing with whey protein. This result suggested the possibility of protecting AVs against digestive alteration and oxidation by milk whey protein. PRACTICAL APPLICATION: In recent years, oats are often consumed with milk under different conditions of preparation, and there have been many oat milk products manufactured by food companies all over the world. The results of this paper showed that the adding of milk may reduce the absorption and antioxidant activity of phenolic compounds from oat. However, the antioxidant activity and bioaccessibility of oat phenolics were significantly increased when mixed with milk whey protein, suggesting that oats could be consumed with milk whey protein to improve their functional properties.