Phenolic Composition Research Articles

Determination of phenolic content and bioactive characterization of Anatolian propolis

In this study, propolis referred to as of Türkiye Anatolian propolis was utilized. This work was aim to prepare a 70% ethanolic extract of propolis and subsequently determine certain biochemical parameters, total phenolic content (TPC), total flavonoid content (TFC), phenolic and flavonoid composition, inhibitory effects on certain enzymes [acetylcholinesterase (AChE), urease, and alpha-amylase], along with assessments of antiviral activity against Vero cells, lung cancer cells (A549), and breast cancer cells (MDA-MB-231). The richness of phenolic content in Anatolian propolis clearly indicates a high inhibitory effect on these enzymes. Additionally, it was observed to exert significant effects on cancer cells and demonstrated effective antiviral activity. It can be contemplated that the Anatolian propolis might serve as a potential source for novel drugs, and the isolation of its compounds could offer opportunities for utilization in traditional medicine.

Characterization of the active components and bioaccessibility of phenolics in differently colored foxtail millets

Differently colored foxtail millet (Setaria italica) cultivars were compared regarding their amylose, B-complex vitamin, vitamin E, and phenolic compositions, as well as the bioaccessibility of their phenolics in simulated in vitro digestion. Dark-colored foxtail millets contained more thiamine, pyridoxine, and tocopherols, but less riboflavin, than light-colored ones. Phenolics were more abundant in dark-colored cultivars. Insoluble bound fractions accounted for 75%–83% of the total phenolics, with ferulic acid detected as the most plentiful compound. The major bioaccessible phenolic was free ferulic acid, with 100%–120% bioaccessibility, depending on cultivar, followed by p-coumaric acid and isoferulic acid (50%–80%). These relatively high bioaccessibilities were likely due to the release of soluble conjugated or insoluble bound phenolics during digestion. However, the contents of other free phenolics were largely decreased following in vitro digestion, resulting in low bioaccessibility, which also means that the release from the conjugated and bound fractions was poor.

Phenolic compounds in sea buckthorn (Hippophae rhamnoides L.) and their health‐promoting activities: a review

SummarySea buckthorn (SB) is used in cuisines and herbal remedies due to its remarkable nutritional composition and health‐enhancing properties. The phenolic compounds present in SB plant include phenolic acids (gallic, p‐coumaric, protocatechuic and ferulic acids), flavonols (isorhamnetin, quercetin and kaempferol), flavan‐3‐ols and polymeric procyanidins. The highest content of these compounds was reported in branches and leaves than corresponding edible parts of the plant. The antioxidant properties of SB are related to content and composition of phenolic compounds in different plant parts. The studies reported SB flavonoids (isorhamnetin and quercetin) as main phenolic compounds with medicinal potential and health‐promoting effects. The present review summarises information available in recent studies on phenolic composition, phenolic content, flavonoid content, antioxidant activity and health‐promoting activities (anti‐oxidant, hepatoprotective, cardioprotective, anti‐inflammatory, anti‐diabetic and obesity management) of SB that can be used in curtailing various acute and chronic maladies. SB can be projected as a promising source of bioactive constituents with the potential to be used in healthy foods for beneficial effects on human health.

The role of germination on changes in bioactive properties, fatty acids and biogenic element profiles of tigernut tubers germinated at different times

SummaryIn this study, the effects of different germination times on some chemical characteristics, total phenol and flavonoid quantity, antioxidant capacities, phenolic and fatty acid compositions and biogenic element contents of tigernut tubers were investigated. Total phenolic and flavonoid quantities of raw and tigernut tubers germinated at certain germination periods were reported to be between 24.40 (first period of germination) and 63.84 mgGAE/100 g (third period of germination) to 33.00 (control) and 184.24 mgRE/100 g (third period of germination), respectively. Antioxidant capacities of raw and germinated tigernut tubers were recorded to be between 0.91 (first period of germination) and 1.57 mmolTE kg−1 (third period of germination). Gallic (except control), catechin, caffeic acid, rutin and kaempferol values of tubers were higher especially in the second and third periods of germination compared to the first period of control and germination. Oleic and linoleic acid values of raw (control) and germinated tigernut oils were identified between 69.41% (third period of germination) and 72.53% (control) to 9.77 (control) and 11.77% (third period of germination), respectively. P, K, Ca, Mg, S and Na were the dominant elements of raw and germinated tigernuts. The bioactive properties, phenolic component amounts and element quantities of germinated tubers were increased.

Phenolic composition and in vitro bioactive and enzyme inhibitory properties of bell pepper (Capsicum annuum L.) plant extracts

The phenolic composition and bioactive properties of Holland and Italian bell pepper plant (Capsicum annuum L.) hydroethanolic extracts were investigated by HPLC-DAD-ESI/MS and in vitro cell- and enzyme-based assays, respectively. O-Glycosylated luteolin derivatives were identified as the major compounds, representing ∼60% of the phenolic fraction. Both extracts displayed remarkable antioxidant activity and ability to inhibit α-glucosidase and the formation of advanced glycation end products (AGEs) compared to the positive controls, which yielded statistically higher or equal IC50 values. Notably, the extracts were up to 57 times more effective than aminoguanidine in inhibiting AGEs. The lipase enzyme involved in fat metabolism and the pro-inflammatory mediator nitric oxide were also inhibited in some extent, with orlistat and dexamethasone being 10–13.4-fold and ∼17-fold more effective than the extracts, respectively. A notable cytotoxicity occurred on the tested human tumor cell lines, mainly on Caco-2 with GI50 values ranging from 18 to 65 μg/mL. Furthermore, activity greater than that of food preservatives was observed against some foodborne fungi and bacteria. These results highlight bell pepper plant by-products as a renewable source of functional ingredients that could be utilized in food, nutraceutical, and medicinal formulations to manage type 2 diabetes, obesity, and other oxidative stress-mediated conditions.

Effect of Soaking, Germination, and Roasting on Phenolic Composition, Antioxidant Activities, and Fatty Acid Profile of Sunflower (Helianthus annuus L.) Seeds

This study investigates the impact of soaking, germination, and roasting under various conditions on the phenolic content, antioxidant activities, and fatty acid profile of sunflower seeds of striped and black oil seed varieties. Ferulic acid emerged as the predominant phenolic acid across all samples. The study highlights the influence of different treatments and processing conditions on the levels of phenolic acids and flavonoids. Results revealed that soaking striped seeds for 24 h and roasting black oil seeds for 6 min exhibited the highest total phenolic content (TPC) and total flavonoid content (TFC). Antioxidant activities varied, with striped seeds soaked for 24 h demonstrating the highest ferric-reducing antioxidant power (FRAP) values, while black oil seeds roasted for 6 min exhibited superior 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity. Oleic acid and linoleic acid were identified as major fatty acids in all processed samples, with striped seeds germinated for 24 h and black oil seeds germinated for 48 h displaying the highest concentrations. Soaking led to a reduction in both unsaturated and saturated fatty acids in both varieties. Roasting further influenced fatty acid concentrations, with a significant increase in striped seeds after 5 and 6 h of roasting, followed by a gradual decrease. Our findings suggest that incorporating appropriate processing methods, such as soaking striped seeds for 24 h and roasting black oil seeds for 6 min, enhances the potential health benefits of sunflower seeds.

Characterization, Bioaccesibility and Antioxidant Activities of Phenolic Compounds Recovered from Yellow pea (Pisum sativum) Flour and Protein Isolate.

This study focused on studying the bioaccesible phenolic compounds (PCs) from yellow pea flour (F) and protein isolate (I). Total phenolic contents (TPC), PCs composition and antioxidant activities were analysed in ethanol 60% extracts obtained by applying ultrasound assisted extraction (UAE, 15min/40% amplitude). The preparation of I under alkaline conditions and the elimination of some soluble components at lower pH produced a change of PCs profile and antioxidant activity. After simulated gastrointestinal digestion (SGID) of both ingredients to obtain the digests FD and ID, notable changes in the PCs concentration and profiles could be demonstrated. FD presented a higher ORAC activity than ID (IC50 = 0.022 and 0.039mg GAE/g dm, respectively), but lower ABTS•+ activity (IC50 = 0.8 and 0.3mg GAE/g dm, respectively). After treatment with cholestyramine of extracts from FD and ID in order to eliminate bile salts and obtain the bioaccesible fractions FDb and IDb, ROS scavenging in H2O2-induced Caco2-TC7 cells was evaluated, registering a greater activity for ID respect to FD (IC50 = 0.042 and 0.017mg GAE/mL, respectively). These activities could be attributed to the major bioaccesible PCs: OH-tyrosol, polydatin, trans-resveratrol, rutin, (-)-epicatechin and (-)-gallocatechin gallate for FD; syringic (the most concentrated) and ellagic acids, trans-resveratrol, and (-)-gallocatechin gallate for ID, but probably other compounds such as peptides or amino acids can also contribute.

Matcha Green Tea: Chemical Composition, Phenolic Acids, Caffeine and Fatty Acid Profile.

Matcha-Japanese powdered tea-is a variety of green tea (Camellia sinensis L.), one of the most popular beverages in the world. Due to the unique way it is grown, it contains high concentrations of health-promoting phytochemicals. The aim of this study was to determine the basic nutritional and phenolic composition of dry matcha green tea powder. The fibre content was determined according to the enzymatic-gravimetric method. Crude protein was measured by the Kjeldahl method. The total fat content was measured by the Soxhlet method, and the fatty acid profile was defined by the GC method. The determination of the phenolic acid and caffeine content was performed using high-performance liquid chromatography. The total fibre content of matcha was 56.1 g/100 g, with 52.8 g/100 g (94.1% of total fibre) of insoluble dietary fibre and 3.3 g/100 g of soluble fibre (5.9% of total fibre). The total protein content was 17.3 g/100 g. The total fat content in dry matcha was 7.285 g/100 g, comprising varying proportions of individual fatty acids, the highest ones being those of linoleic acid and α-linolenic acid. The caffeine content of matcha tea was 2213.492 µg/g. With regard to phenolic acids, the highest content was estimated for gallic acid (252.3755 µg/g). Matcha showed a particularly high content of total dietary fibre, with a predominance of the insoluble fraction. Matcha was found to be a valuable source of plant protein and unsaturated fatty acids, mostly of the omega-3 fatty acid family.

Enhancing Rumen Fermentation and Bacteria Community in Sika Deer (Cervus nippon) through Varying Levels of Dragon Fruit Peel Polyphenolic Extract: An In Vitro Study.

The aim of this study is to investigate the effect of dragon fruit peel polyphenolic extract (DFPE) on gas production, rumen fermentation, and bacterial communities in sika deer using an in vitro technique. Three treatments with different DFPE levels (DFPE0, base diet; DFPE5, base diet + 5 mg/g DFPE; DFPE10, base diet + 10 mg/g DFPE, respectively; n = 6) were implemented. The phenolic composition of DFPE, gas production (GP), ammonia nitrogen (NH3-N), volatile fatty acid (VFA), and bacteria communities was evaluated after 24 h of incubation. The results showed that GP and NH3-N were reduced by DFPE supplementation. Total VFA, isovaleric acid, and valeric acid were increased (p < 0.05) by the addition of DFPE. No changes (p > 0.05) were observed in pH, acetic acid, propionic acid, isobutyric acid, butyric acid, and the ratio of acetic acid to propionic acid. Additionally, the alpha indexes, including Sobs, Shannon, and Ace, were increased by DFPE supplementation. Moreover, at the phylum level, DFPE supplementation increased (p = 0.01) Bacteroidota but reduced (p < 0.01) Firmicutes. At the genus level, compared to DFPE0, the DFPE10 had increased relative abundances of Rikenellaceae_RC9_gut_group (p < 0.01), norank_f_Muribaculaceae (p = 0.01), Lachnospiraceae_NK3A20_group (p < 0.01), Christensenellaceae_R-7_group (p < 0.01), and NK4A214_group (p < 0.01), decreased relative abundances of Streptococcus (p < 0.01), Oribacterium (p = 0.01), and Enterococcus (p < 0.01). Compared to DFPE0, DFPE5 had no change (p > 0.05) in all bacteria at the genus level except for decreased relative abundance of Enterococcus (p < 0.01). These results indicated that DFPE may be able to be used as a feed additive to enhance fermentation parameters and improve ruminal bacteria communities in Sika deer.

Phytochemical profile, in vitro antioxidant and antibacterial activities of different extracts of an Algerian endemic: Teucrium atratum

Teucrium atratum Pomel. is a species belonging to the Lamiaceae family used in Algerian folk medicine. The present work essentially aimed to assess the phenolic composition and to evaluate some of the biological effects of different extracts, never previously studied, of T. atratum growing in Algeria. High levels of total phenolic and flavonoids were recorded in the hydromethanolic extract. Chlorogenic acid, isoquercetin, coumarin, cinnamic acid, quercetin dihydrate, and catechin were identified in the methanolic extract by mean of HPLC. The antioxidant activity assessed showed that the methanolic extract was the most active, while, the hydromethanolic extract showed a great power to reduce iron. In addition, all extracts had a significant antibacterial effect against the four tested bacterial strains, with Staphylococcus aureus as the most sensitive one. These findings can be a starting point to evaluate the plant as a source of natural bioactive compounds with antioxidant and antibacterial effects.

Composition of Whole Grain Dietary Fiber and Phenolics and Their Impact on Markers of Inflammation.

Inflammation is an important biological response to any tissue injury. The immune system responds to any stimulus, such as irritation, damage, or infection, by releasing pro-inflammatory cytokines. The overproduction of pro-inflammatory cytokines can lead to several diseases, e.g., cardiovascular diseases, joint disorders, cancer, and allergies. Emerging science suggests that whole grains may lower the markers of inflammation. Whole grains are a significant source of dietary fiber and phenolic acids, which have an inverse association with the risk of inflammation. Both cereals and pseudo-cereals are rich in dietary fiber, e.g., arabinoxylan and β-glucan, and phenolic acids, e.g., hydroxycinnamic acids and hydroxybenzoic acids, which are predominantly present in the bran layer. However, the biological mechanisms underlying the widely reported association between whole grain consumption and a lower risk of disease are not fully understood. The modulatory effects of whole grains on inflammation are likely to be influenced by several mechanisms including the effect of dietary fiber and phenolic acids. While some of these effects are direct, others involve the gut microbiota, which transforms important bioactive substances into more beneficial metabolites that modulate the inflammatory signaling pathways. Therefore, the purpose of this review is twofold: first, it discusses whole grain dietary fiber and phenolic acids and highlights their potential; second, it examines the health benefits of these components and their impacts on subclinical inflammation markers, including the role of the gut microbiota. Overall, while there is promising evidence for the anti-inflammatory properties of whole grains, further research is needed to understand their effects fully.

Enhanced phenolic content and antioxidant activity of broad bean natto following simulated in vitro digestion

SummaryBroad bean can be processed into various forms such as steamed broad beans (SBB) and broad bean natto (BBN), with potential variations in their nutritional profiles upon digestion. This study aimed to explore the differences in phenolic content, composition, and antioxidant activity between SBB and BBN during simulated in vitro digestion. Findings demonstrated that BBN exhibited a significant surge in total phenolic and flavonoid contents post‐gastrointestinal digestion compared to SBB. UHPLC‐MS/MS analyses identified major phenolic compounds in BBN including protocatechuic acid and p‐hydroxybenzoic acid and key flavonoids like luteolin and catechins. P‐hydroxybenzoic acid and catechins underwent significant changes throughout the digestion. Furthermore, BBN's antioxidant activity was higher than that of SBB after digestion, with superior DPPH, ABTS +· scavenging abilities, and FRAP reducing power. A correlation emerged between antioxidant activity and phenolic contents, notably with p‐hydroxybenzoic and benzoic acids. BBN's digestive stage exhibited superior polyphenol release and antioxidant capacity than SBB, offering insights into polyphenol‐rich food consumption.

Physical Traits and Phenolic Compound Diversity in Maize Accessions with Blue-Purple Grain (Zea mays L.) of Mexican Races

Consumer interest in foods enriched with phytochemical compounds for health benefits has prompted plant breeders to focus on developing new cultivars with an enhanced content of specific compounds. Studies regarding the exploration of germplasms of species of great economic importance, such as maize, could be useful in this task. This study aimed to assess the physical grain traits and phenolic compound variations (including anthocyanins, flavonoids, and proanthocyanidins) in blue-purple maize accessions from various Mexican races. We examined 207 accessions from 21 Mexican maize races, evaluating physical grain traits such as weight of one hundred grains (W100G), endosperm type (ET), pigment location, and grain color. Phenolic composition analysis encompassed total soluble phenolics (TSP), total anthocyanin content (TAC), flavonoids (FLAV), and proanthocyanidins (PAs). The predominant endosperm type was floury, with W100G values indicating a large grain size and the pigment primarily located in the aleurone layer. Among phenolic composition variables, only TSP exhibited a normal distribution, while others skewed towards the left side. A hierarchical analysis of phenolic composition data revealed three distinct groups comprising different numbers of Mexican varieties, with TAC proving the most effective for grouping. Our comprehensive exploration of maize diversity featuring blue-purple grain coloration has led to the identification of novel maize varieties with outstanding phenolic contents.

Distribution of antioxidants and phenolic compounds in flour milling fractions from hard red winter wheat

Mature wheat kernels contain three main parts: endosperm, bran, and germ. Flour milling results in multiple streams that are chemically different; however, the distribution of antioxidants and phenolic compounds has not been well documented in terms of conventional milling by-product streams. In this study, multiple analytical methods were used to investigate antioxidant activity and phenolic compound compositions of hard red winter wheat (whole ground wheat), the parts of a wheat kernel (bran, flour, germ), and wheat by-product streams (mill feed, red dog, shorts) for the first time. For each mill stream, phenolic compounds (total, flavonoid, and anthocyanin contents) were determined and antioxidant activities were evaluated with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, ferric reducing/antioxidant power (FRAP), and total antioxidant capacity assays. Significant differences (P < 0.05) were observed in phenolic concentrations among fractions of bran, flour, and germ milled from the same kernels and noted that germ accounts for the majority of antioxidant properties, whereas bran contains a substantial portion of phenolic compounds and anthocyanins. Mill feed was high in phenolic content (5.29 mg FAE/g), total antioxidant capacity (866 mg/g), and antioxidant activity (up to 75% DPPH inhibition and 20.26 μmol FeSO4/g). The comprehensive information on distribution of antioxidants and phenolic compounds provides insights for future human consumption of commonly produced co-products from flour milling, and for selecting and using different milling fractions to make foods with improved nutritional properties.

Changes in phenolic composition, antioxidant, sensory and microbiological properties during fermentation and storage of maize products

In this study, we assessed the potential of maize (Zea mays) flour to serve as a substrate for the growth, metabolism, and survival of the Fresco culture cocci (Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris and Streptococcus thermophilus) and Bifidobacterium spp. (B. choerinum K1/1, B. pseudolongum K4/4, B. animalis subsp. animalis J3II, B. thermophilum DSM 20212), which could result in improved nutritional and sensory properties. Maize dairy-free mashes (flavoured with saccharose or caramel) were effectively fermented with Fresco culture for 8 h at 37 °C (3 log increase of counts on average). The functionality of products was proven within the cold storage period (21 days at 6 °C) when viable cell densities of potentially probiotic bacteria were sufficient to demonstrate health-promoting effects (> 5 log CFU/mL). Fermentation process positively changed the contents and compositions of phenolic compounds. Total phenolic content was higher by about 11.5–94.68% in comparison to initial values (0 h). Caffeic acid recorded the highest increase, by about 21.7–151.7%. The antioxidant activity of fermented mashes was also improved. Overall sensory acceptance was enhanced from 2.1 (8 h) to 3.1–3.6 from 4.0 (21 d), which revealed pleasant acceptance of the final caramel products.Graphical

Formulation of Chicken Nuggets Supplemented with Mutton and Fish Livers: Insights from Antioxidant and Textural Studies.

The use of byproducts from the food industry and the investigation of substitute sources are becoming progressively significant in fulfilling the consumer demand for animal-based protein. This study aimed to investigate the nutritional value of mutton and fish livers and their future application as a source of high-added-value proteins for supplement formulation. We performed compositional analysis (moisture, ash, crude protein, crude fat), free fatty acid (FFA) analysis, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the color, peroxide value (POV), and total phenolic composition (TPC) were assessed to evaluate the nutritional value and shelf stability of mutton and fish livers. The optimized proximate and kinetics were later used to develop chicken nuggets with different percentages of mutton and fish liver added. The formulation was tested for the textural and organoleptic properties of value-added chicken nuggets that predict consumer acceptability. Comparative analysis of the variance between mutton and fish liver showed a highly significant (P<0.01) decrease in moisture, ash, protein, fat, DPPH, and TPC at different days and hours. The mutton liver had relatively high antioxidant potential (25.9% DPPH and 154-mg GAE/100 g TPC) compared with the fish liver. However, the fish liver's FFA and POV (2.4% for both) were higher than those of the mutton liver. The results showed that, after formulation, an increase in the amount of liver led to a highly significant (P<0.01) rise in the nutritional value of the nuggets, including a 1.5%∼2.0% increase in protein content. This research indicates that valuing mutton and fish liver as a protein replacer in processed foods can be useful in developing healthy food products.

Antioxidant activity of dried açaí extract: is it a functional food?

Açaí is a native Amazonian plant rich in antioxidant compounds such as polyphenols, anthocyanins and phenolic compounds, substances capable of neutralizing oxidative stress and helping to prevent various diseases. As a result, there has been much discussion about its use as a functional food. One alternative for the industry is the commercialization of dried extracts from plants. To this end, the aim of this study was to evaluate the antioxidant action of powdered açaí extract, in order to assess the composition of phenolics and DPPH present in a dry extract of açaí. The extracts evaluated were called samples A and B. In both tests, Sample A obtained lower values than Sample B for both phenolic compounds (6.42 ± 0.12) and DPPH antioxidant capacity (20.69 ± 0.16). In this context, it is necessary to investigate more rigorously the composition and efficacy of extracts made from açaí pulp and sold on the market, in order to provide consumers with a safer guarantee of the bioactive compounds present in the food.

Towards an index of damage of olive paste during virgin olive oil extraction: The role of β-OH-acteoside diastereomers for risk assessment of the fusty/muddy sediment sensory defect

The aim of this study was to propose an index/marker of thermal/oxidative damage of olive paste during virgin olive oil extraction to assess the risk of sensory defects in the obtained oil. Several olive oil extraction trials were carried out over two production years applying different time, temperature, and oxygen exposure conditions during malaxation. The phenolic composition of the olive pastes was analyzed by High Performance Liquid Chromatography-Diode Array Detector-Mass Spectrometry (HPLC-DAD-MS). The chemical (legal quality indexes, phenolic compounds by HPLC-DAD-MS, volatile compounds by Head Space-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS)) and sensory characteristics of the obtained oils were analyzed. The content of the β-OH-acteoside diastereomers in olive paste increased linearly with malaxation time as a function of malaxation temperature and oxidative conditions, following a pseudo-zero order kinetic. At the same time, two volatile compounds linked to sensory defects (2- and 3-methylbutanal) increased in the obtained oils when increasing malaxation time and temperature, and a relationship between them and the fusty/muddy sediment defect in olive oil samples was observed. A further direct relationship between the β-OH-acteoside content in the olive pastes and the 2+3-methylbutanal content in the oils was observed. Therefore, the β-OH-acteoside diastereomers content in olive pastes has been suggested as an index/marker to indicate the risk of sensory defects in virgin olive oil as a function of the thermal and oxidative conditions during malaxation. A threshold value of 100 mg/kg of the content of β-OH-acteoside diastereomers was proposed, above which the fusty/muddy sediment defect is perceptible.

In Vitro Determination of Nitric Oxide Synthase Inhibition, Antioxidant Capacity and Phenolic Content of Various Natural Products (Bee and Herbal Products).

It is obvious that the oxidation process is an undeniable fact and when it comes to aging, one of the first solutions that come to mind is natural products. When it comes to natural products, both plants and bee products play an important, almost combative role against oxidation. For this purpose, natural products of both plant and animal origin were considered together in our study: Linden, green tea, aronia, wild grapes, myrtle, blueberries and basil, honey, pollen and propolis. Total phenolic content values of the extracts ranged between 49.28 and 3859.06 mg gallic acid equivalent/100 g, and propolis, green tea, chestnut flower and aronia samples were found to have the highest values. When looking at the NOS inhibition potential, it was determined that propolis, pollen and aronia samples had the highest percentage inhibition values of 98.11, 92.29, 83.44, respectively. Antioxidant activities of methanolic extracts were investigated using iron(III) reducing/antioxidant capacity (FRAP), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity test and NOS inhibition tests. The phenolic composition of methanolic extracts was tested using the RP-HPLC-UV (high-performance liquid chromatographic method with ultraviolet) method with 19 phenolic standards.

Analyzing the Effect of Extraction Parameters on Phenolic Composition and Selected Compounds in Clove Buds Using Choline Chloride and Lactic Acid as Extraction Agents

Utilizing a deep eutectic solvent-like mixture such as choline chloride and lactic acid in a 1:2 molar ratio, clove buds underwent extraction. Furthermore, the determination of the primary components in the clove extracts, namely eugenol, eugenol acetate, and β-caryophyllene, was conducted using the HPLC-DAD method. The total phenolic content (TPC) was also established. Extraction conditions using choline chloride and lactic acid encompassed variables such as extraction temperature (within the range of 40 to 80 °C), water addition (ranging from 5.6 to 40%), and extraction time (ranging from 30 to 90 min). Optimal operational conditions for TPC were pinpointed at 77 °C, 30 min, and a water addition of 40%. The findings showed that clove extracts obtained at 60 °C, 22.8%, and 30 min had the highest amount of eugenol (307.26 ± 8.44 mg/g dry raw material).