Phenolic Acid Profiles Research Articles

The effect of sprouting and roasting on bioactive compounds, phenolic and fatty acid profiles and some element contents of pumpkin seeds

The effect of sprouting and roasting on bioactive compounds, phenolic and fatty acid profiles and some element contents of pumpkin seeds

Effects of Aqueous Extraction Factors on Commercial Protease Inhibitory Activities, Phenolic Acid Profiles and Chemical Properties of Hom Mali-105 Rice (Oryza sativa L.) Bran Extract

De- oiled rice bran (DRB) is a by-product generated in a large amount from oil extraction processing. The DRB contains a high content of protein and is rich in phenolic components. Phenolic compounds were noticed to exhibit inhibitory activity against protease to some extent in protein hydrolysate production from rice bran. Therefore, this investigation aims to study the factors effecting the extraction of phenolic compounds from DRB and the inhibitory activities of the extracted phenolics against commercial proteases. The aqueous extraction process was employed for extraction of phenolic compounds from DRB. Three extraction factors, including time (30-180 min), temperature (60-80 °C), and pH level (2-10) were used using completely randomized design (CRD). Total phenolic content (TPC) and profiles, total flavonoids content (TFC), and antioxidant activities of all extracts were analyzed. Additionally, the commercial proteases (G6 and GN) inhibitory activities of phenolic extracts were determined. The optimum extraction time, temperature and pH that providing highest total phenolic content, flavonoid content antioxidant activities and protease inhibitory activities were observed at 150 min, 70°C and pH 10, respectively. TPC and TFC values were in the ranges of 2.50 to 5.76 mg GAE/g rice bran and 1.79 to 4.42 mg RTE/g rice bran, respectively. DPPH, ABTS and FRAP values were in the ranges of 0.44 to 0.82 mg GAE/g rice bran, 2.56 to 5.14 mg TE/g rice bran, and 4.40 to 8.10 mg TE/g rice bran, respectively. The main phenolic acids were ferulic acid, p-coumaric acid, protocatechuic acid, vanillic acid, sinapic acid, and p-hydroxybenzoic acid. The protease inhibitory activity of the DRB extract was 42% on protease G6 and 71% on protease GN. This result suggests that the phenolics and flavonoids from rice bran could exhibit protease inhibitory activities to some extent and these compounds might affect the hydrolysis process of protein during protein hydrolysate production.

Cooking, Digestion, and In Vitro Colonic Fermentation of Nigerian Wholegrains Affect Phenolic Acid Metabolism and Gut Microbiota Composition.

Wholegrains contain both fibre and phenolic acids (PAs), and their gastrointestinal modifications are critical for their bioavailability and bioactivity. We evaluated the modifications on the PA profile and gut microbiota composition of selected Nigerian wholegrains, following cooking and gastrointestinal digestion. Red fonio, red millet, red sorghum, and white corn were cooked, digested, and fermented using an in vitro colonic model. A total of 26 PA derivatives were quantified in soluble and bound fractions using Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) analysis. DNA samples were analysed using 16S rRNA amplicon sequencing to profile the microbiota composition. The results show that cooking and digestion significantly affected the levels of PAs in all grains (p ≤ 0.05) compared to raw grains. Colonic fermentation resulted in a peak of total soluble PAs at 4-6 h for red sorghum and white corn and at 24 h for red millet and red fonio. Enterobacteriaceae genera were the most abundant at 24 h in all grains studied. 3-hydroxybenzaldehyde correlated positively with the relative abundance of Dorea and the mucus-degrader bacteria Akkermansia (p ≤ 0.05), whereas hydroferulic acid and isoferulic acid levels correlated negatively with Oscillospira and Ruminococcus (p ≤ 0.05), respectively. Our data indicate that cooking, digestion, and colonic fermentation affect the release of bound PAs from wholegrains and, consequently, their metabolic conversion. Furthermore, PA fermentation in the gut is associated with potentially relevant changes in the microbiota. This in vitro study provides the basis for the design of an in vivo human intervention study that can confirm the trends herein observed but also assess the impact on health outcomes.

The loss of microbial autotoxin degradation functions is associated with the decline of beneficial bacterial agents induced by phenolic acids.

Continuous cultivation of medicinal plants can disrupt the rhizosphere's microbial community. There is still a need to know about the beneficial bacterial community, their putative drivers, and the potential functions they may have. This study used different growth years of Sanqi ginseng (Panax notoginseng) with root rot to look at the beneficial microbial community structure, the function of microbial carbon source utilization, and the function of rhizosphere soil metabolism. The beneficial bacterial community changed and the relative abundance of beneficial agents was suppressed significantly with the successive Sanqi ginseng plantings. The carbon source utilization capacity and diversity increased significantly, whereas three autotoxin degradation-related pathways (biosynthesis of other secondary metabolites, metabolism of terpenoids and polyketides, and xenobiotics biodegradation and metabolism) were downregulated considerably with planting year extended. The changes in the beneficial agents were driven by the shifts in phenolic acid profiles, and the decline of beneficial microbes led to the loss of microbial autotoxin degradation functions. Overall, these results provide insight into beneficial microbes, microbial functions, phenolic acids, and their interactions, and these findings are essential for maintaining healthy and sustainable cultivation of Sanqi ginseng. IMPORTANCE Sanqi ginseng is a valuable perennial Chinese herb with various benefits for human health. However, continuous cultivation causes a high incidence of root rot disease, which leads to decreased yield and serious economic losses and ultimately impedes the sustainable development of Chinese medicine production. The significance of this study is to reveal the pattern of changes in beneficial bacteria and their related functions in root rot diseased rhizosphere with the successive planting years of Sanqi ginseng. This study found that the decline of beneficial bacterial agents mediated by phenolic acid profiles appears to be associated with the loss of microbial autotoxin degradation functions. This result may have new implications for deciphering the causes of Sanqi ginseng's continuous cropping obstacles.

High-intensity, Low-frequency Ultrasound Treatment as Sustainable Strategy to Develop Innovative Biomaterials from Agri-food Byproducts and Wastes

Bioconversion is an important avenue for finding value from biomass waste produced by the agricultural industry. One avenue of conversion is the development of upcycling byproducts and waste from food processing to value-added products. This includes degradable biomaterials which have real potential to reduce waste, improving economic, social and environmental impacts. As such, this research paper was focused on exploring two avenues of bioconversion from waste products of tomato skin, hemp meal and hops vines: identification of phytochemicals and the development of bioplastic. Combined to these researches, the effect of Ultrasound as a green technology was studied in both contexts. It was found that Ultrasound treatment reduced extraction time for saponin and phenolic acid from tomato skin, hemp meal and/or hops vines from 24h to 30 min. However, Ultrasound Assisted Extraction (UAE) was shown to affect the phenolic acid and saponin profiles of certain extracts. 
 
 Ultrasound treatment was shown to positively impact the overall microscopic structure and qualities of bioplastic such as water activity, percentage moisture, hardness, cohesiveness, resilience, and springiness index. This study suggests that Ultrasound can be used as sustainable non-thermal method for extraction of active saponins and phenolics but also in bioplastic formulation to enhance physico-chemical characteristic.

Magnetic Seed Treatment Modulates Phenolic and Fatty Acid Metabolism of Sunflower under Water Scarcity

Environmental and anthropogenic activities are pushing the earth towards warmer years, which is reducing agricultural land and causing water scarcity. It is well documented that sunflower (being drought tolerant) crops can be grown under water deficit conditions with some additional supportive priming applications to compensate for drought-induced challenges. However, finding the most efficient and eco-friendly priming tools is always a top priority among researchers to improve plant growth, adaptive traits, and productivity. In this study, an experiment was performed on oil-producing crops (sunflower) using seed magnetic treatment. The seeds were subjected to 0.1, 0.2, and 0.3 Tesla for 20 min, respectively. Plants were exposed to water limitation (100 and 50%) after 30 days of germination. Sunflower showed its tolerance to water limitation by maintaining the majority of growth parameters, nutritive value, metabolizable energy, and higher proline content. Nevertheless, a reduction in the achene number per capitulum, capitulum weight, chlorophyll, catalase activity, unsaturated to saturated fatty acids, anthocyanin, and hydroxyl derivatives of cinnamic acid supported our hypothesis about the need for some supportive techniques. Better metabolic adjustment and percentage of oil yield were manifested by 0.3 T magnetic seed treatment, which was used for phenolic and fatty acid profiling. To conclude, magnetic treatment of seeds may improve their primary metabolic capacity and antioxidation potential, which in turn may activate their secondary metabolism as evidenced by an excess of gallic acid, quercetin, benzoic acid, curcumin acid, sinapic acid, and chlorogenic acid.

Influence of hot-air and infra-red pretreatments on oxidative stability, physicochemical properties, phenolic and fatty acid profile of white and black chia seed (Salvia hispanica L.) oil

In this research, the effect of hot-air (HAP) and infra-red (IRP) pretreatments at 160 and 180˚C for the time duration of 5, 10, and 15 min on the physicochemical characteristics, phenolic composition, and stability attributes of white (WCO) and black chia seed oil (BCO) were investigated. The WCO and BCO exhibited comparable physicochemical and stability characteristics while the level of phenolic compounds was higher in BCO. The phenolic acids, flavonoids, pigments, oxidative stability, Maillard reaction products, browning index, ΔE and a* value increased significantly while L*, b*, chroma and hue values decreased significantly at higher HAP and IRP exposure duration and temperature. The hydroxybenzoic (protocatechuic, vanillic, and syringic acid), hydroxycinnamic (p-coumaric, chlorogenic, sinapic, and rosmarinic acids) acids and flavonoids (epicatechin, vitexin, rutin, myricetin, luteolin, and apigenin) were highest in oil after HAP at 180°C for 15 min. The infra-red spectral information relates to oxidation and fatty acid composition of pretreated CO. HAP is more effective than IRP for improving oil yield, oxidative stability, and phenolic profile of CO.

Response Surface Methodology as an Experimental Strategy for Ultrasound-Assisted Extraction of Phenolic Compounds from Artichoke Heads.

The accurate quantification of phenolic compounds (PCs) in foods has become mandatory for a reliable estimation of PCs dietary intake. However, the extraction step of these molecules from the food matrix is a challenging and complex task. To manage the current lack of an official or generally accepted procedure for the recovery of phenolics, the application of statistical and mathematical tools, such as the response surface methodology (RSM), that allow the optimization of extraction parameters and the acquisition of the best output, has become the analytical approach of choice. The aim of this study was to apply an RSM-optimized ultrasound-assisted procedure to extract phenolic compounds from artichoke (Cynara cardunculus L. var. scolymus (L.) Hegi, cultivar "Campagnano") heads. The effect of extraction time, temperature, and solvent-to-sample ratio on the profile and content of phenolic acids and flavonoids was investigated. The total phenolic content was 488.13 ± 0.56 mg GAE 100 g-1 dry matter (dm) and total flavonoid content was 375.03 ± 1.49 mg CATeq 100 g-1 dm when the optimum extraction conditions were set. The HPLC analysis showed that caffeoylquinic acid derivatives (i.e., cynarin and 1,5-O-dicaffeoylquinic acid) were the main compounds in globe artichokes. Caffeic and p-coumaric acids were also identified. In regard to flavonoids, only the flavone luteolin-7-O-glucoside was identified.

Inhibitory effects of methanolic extracts from the stem barks of ten Mexican Bursera Jacq. ex L. species on the activity of α-amylase and acetylcholinesterase from Tenebrio molitor

Methanolic stem bark extracts from ten Mexican Bursera Jacq. ex L. species were evaluated in vitro with regard to their inhibitory activity against two Tenebrio molitor-derived enzymes. Seven extracts (B. bicolor, B. copallifera, B. fagaroides, B. grandifolia, B. lancifolia, B. linanoe, and B. longipes) reduced α-amylase activity by 55.37% to 96.25%, with three samples proving to be particularly potent α-amylase inhibitors (B. grandifolia, B. lancifolia, and B. linanoe; IC50 = 162, 132, and 186 µg/mL, respectively). In contrast, no extract inhibited acetylcholinesterase activity by more than 39.94%. Quantitative HPLC analysis did not reveal any clear correlation between the species-specific flavonoid or phenolic acid profiles and the respective extracts’ enzyme inhibitory activity. The findings reported herein do not only contribute to improving the current state of knowledge regarding the enzyme inhibitory potential of the Bursera genus, but could also lead to the development of new sustainable bioinsecticides.

Antioxidant Potential and Phenolic Acid Profiles in Triticale Grain under Integrated and Conventional Cropping Systems

Cereals are a valuable source of biologically active compounds. Phenolic compounds, of which the phenolic acids (PA) found in cereal grains constitute a significant proportion, are characterized by health-promoting properties largely due to their antioxidant capacity. PA, located mainly in the outer parts of the grain, play an important role in preventing environmental stresses. Triticale is a cereal species of increasing economic value, and also value for human consumption. The aim of this study was to demonstrate the effect of conventional (CONV) and integrated (INTEG) cropping systems on antioxidant activity and content of selected PA in triticale cultivars (Meloman, Panteon, Belcanto) grain. The experiment was conducted in seasons from 2019/2020 to 2021/2022. Among the PA tested, ferulic acid (FER) had the highest contribution to total PA content (TPAs), with 519, 99, and 1115 μg g−1 in whole grain, flour, and bran, respectively. The unfavorable hydrothermal conditions occurring in the seasons (rainfall deficit) increased TPA, mainly in whole grain. Grain cv. Meloman had the highest PA content in whole grain, flour, and bran and cv. Belcanto had the lowest, with differences of 22.7, 18.2, and 15.7% respectively. Cultivation of triticale under the CONV vs. INTEG cropping system resulted in reduced amounts of TPAs in flour and bran and PA: p-hydroxybenzoic acid (p-HB) in flour, syringic acid (SYR) in whole grain and bran, and ferulic acid (FER) and sinapic acid (SIN) in bran. The CONV cropping system also caused a decrease in antioxidant activity (AOA) in flour and bran. In most of the cases analyzed, the highest antioxidant activity and content of PA were found in bran, and the lowest were found in flour. The high presence of PA in triticale grain indicates that this cereal, especially when grown under the INTEG cropping system, can be destined for consumption and provide a source of valuable antioxidants for various food and nutraceutical purposes.

Sonoprocessing improves phenolics profile, antioxidant capacity, structure, and product qualities of purple corn pericarp extract

For the first time, purple corn pericarp (PCP) was converted to polyphenol-rich extract using two-pot ultrasound extraction technique. According to Plackett-Burman design (PBD), the significant extraction factors were ethanol concentration, extraction time, temperature, and ultrasonic amplitude that affected total anthocyanins (TAC), total phenolic content (TPC), and condensed tannins (CT). These parameters were further optimized using the Box-Behnken design (BBD) method for response surface methodology (RSM). The RSM showed a linear curvature for TAC and a quadratic curvature for TPC and CT with a lack of fit > 0.05. Under the optimum conditions (ethanol (50%, v/v), time (21 min), temperature (28 °C), and ultrasonic amplitude (50%)), a maximum TAC, TPC, and CT of 34.99 g cyanidin/kg, 121.26 g GAE/kg, and 260.59 of EE/kg, respectively were obtained with a desirability value 0.952. Comparing UAE to microwave extraction (MAE), it was found that although UAE had a lower extraction yield, TAC, TPC, and CT, the UAE gave a higher individual anthocyanin, flavonoid, phenolic acid profile, and antioxidant activity. The UAE took 21 min, whereas MAE took 30 min for maximum extraction. Regarding product qualities, UAE extract was superior, with a lower total color change (ΔE) and a higher chromaticity. Structural characterization using SEM showed that MAE extract had severe creases and ruptures, whereas UAE extract had less noticeable alterations and was attested by an optical profilometer. This shows that ultrasound, might be used to extract phenolics from PCP as it requires lesser time and improves phenolics, structure, and product qualities.

Effect of Cropping Systems and Environment on Phenolic Acid Profiles and Yielding of Hybrid Winter Wheat Genotypes

Wheat is of significant economic importance due to its high yield potential and high nutritional value as well as the technological usefulness of the grain. Field experiments were carried out in the years 2015–2018 in southeastern Poland. A three-factor experiment was used to study the influence of wheat cultivars (hybrid—cvs. Hybred and Hymack; common—cv. Batuta), cultivation systems (organic—ORG, integrated—INT, conventional—CON) and of environmental conditions (using two different locations: Dukla and Nowy Lubliniec) on wheat grains’ phenolic acid (PA) content and grain yield. The research confirms the genetic determinants of grain yield and PA composition in wheat grains, and their different accumulation levels of ferulic acid and other PAs—with the exception of sinapic, p-coumaric, and salicilic—with hybrid cultivars performing better than common cultivars. The ORG system, compared to the INT and CON systems, caused a larger increase in total acids (TPAs)—especially of ferulic, vanillic, and syringic acids—in grains of cv. Hybred, and of caffeic acid in cv. Hymack, compared to cv. Batuta. The lack of interaction between the cultivation systems and the cultivars indicates that similar reactions to increases in grain yield due to increases in the intensity of cultivation take place in cultivars. The more favourable environmental conditions in Dukla favoured the accumulation of ferulic, p-coumaric, vanillic, syringic, p-hydroxybenzoic, and protocatechuic acids in the grains. TPAs were higher by 4.3% and the grain yield by 4.0% on average. Variable conditions in the season 2015/2016 resulted in higher yields of hybrid cvs. grains than of common cv., which proves the greater yielding stability of these cultivars in years with adverse weather conditions. The season 2016/2017 had less rainfall and faced high temperatures during grain ripening, favouring a higher PA content and TPAs, especially in the grains of cv. Hybred. This suggests a need to further assess the genetic progress of hybrid wheat cultivars cultivated under different environmental conditions in terms of their PA composition and content.

Profiling of phenolic acids, flavonoids, terpenoids, and steroid derivatives in coconut (Cocos nucifera L.) haustorium.

The online version contains supplementary material available at 10.1007/s10068-023-01300-6.

Nutritional potential of an edible terrestrial orchid Eulophia nuda LINDL and validation of its traditional claim in arthritis.

Eulophia nuda, locally known as "Amarkand" is an edible orchid, traditionally used as food and ethnomedicine in arthritis, as a blood purifier, vermifuge, in bronchitis, scrofulous glands etc. AIM: The present study focuses on the proximate-nutrient analysis, metabolic profiling of bioactive phenolic acids (PA's) and validation of anti-arthritic activity in E. nuda. The proximate, nutrition and element (macro-micro) content were evaluated as per standard protocols. The anti-arthritic activity was evaluated via different Invitro models and bioactive phenolics were quantified through calibrated HPLC-UV (PDA) method, as per ICH guidelines. The species contains a considerable amount of proximate i.e. ash, fiber, crude alkaloid, total phenolics, and flavonoid. It is a rich source of macro-micro nutrients, carbohydrates and energy, at par with conventional cereals and super-foods like finger millet, foxtail millet etc. It also contains seven PA's viz. gallic acid, protocatechuic acid, caffeic acid, syringic acid, vanillin acid, ferulic acid and quercetin. The PA's content varies from 4.00 to 83.50μg/ml. The anti-arthritic potential of the plant extract based on several in-vitro-models showed a promising inhibitory effect on inflammation and uric acid synthesis. The study scientifically validates the traditional claims of this traditional orchid as food and ethnomedicine. The species can be commercially explored as a supplement to combat nutritional deficiency among rural communities.

Extraction and Analytical Characterization of Phenolic Compounds from Brazil Nut (Bertholletia excelsa) Skin Industrial by-Product

Pressurized liquid extraction (PLE) and ultrasound assisted extraction (UAE) were applied to extract phenolic antioxidants from defatted Brazil nut skin (DBNS) industrial by-product. Water/alcohol solvents (ethanol and methanol) (0 - 50 % v/v water) were used at temperatures of 50 - 200 °C in PLE and 50 °C was set in UAE. The effect on extraction yield, total phenolic compounds content (TPC), antioxidant capacity and phenolic characterization was determined. The temperature and water/alcohol mixture affected the dielectric constant, and this in turn influenced the yield, TPC, antioxidant activity and phenolic composition. In PLE, at 200 °C and 50 % (v/v) water/alcohol (ethanol and methanol) the highest yields (33.8 and 38.4 %, respectively), TPC (4673 and 5435 mg GAE/100 g DBNS) and antioxidant capacity (397 and 502 µmol TE/g DBNS) were obtained. Furthermore, at 50 °C, PLE had better extraction efficiency than UAE. Characterization of the extracts indicated that at 50 - 100 °C the extraction of protocatechuic acid and ellagic acid derivative were predominant, while at 150 - 200 °C catechin and vanillin derivatives stand out. In general, hydroxybenzoic acids and flavonoids were the most abundant phenolics, and the addition of 25 % v/v water to ethanol resulted in extracts with their highest concentration. Then, Brazil nut skin is an interesting phenolic-rich source with potential use to produce bioactive ingredients. HIGHLIGHTS High temperature and water/alcohol mixtures improves TPC and antioxidant capacity At given temperature, TPC values are linearly correlated with water/alcohol dielectric constant Extraction temperature modifies the abundance and profile of phenolic compounds Hydroxybenzoic acids and flavanols are predominant phenolics in Brazil nut skins At 50 °C, PLE have a better extraction efficiency of phenolic compounds than UAE GRAPHICAL ABSTRACT

Phenolic Acids Profiles and Phenolic Concentrations of Emmer Cultivars in Response to Growing Year under Organic Management.

Phenolic compounds, especially phenolic acids (PAs), are believed to be one of the major contributors to the antioxidant activity of cereal grains. This study determined and compared phenolic concentration, radical scavenging activities, individual PA concentrations of emmer cultivars, and breeding lines to common wheat in a three-year controlled field experiment under organic management. It was found that common wheat had the highest ability to scavenge DPPH radicals (51.7%), followed by emmer Farvento (35.4%). DPPH scavenging activity of bound phenolic extracts was higher compared to free ones. Total phenolic concentration was the highest for common wheat (1902.6 µg FAE g-1 DM) compared to the highest level of all emmer cultivars-Farvento (1668.3 µg FAE g-1 DM). The highest PAs concentration was determined for emmer Farvento (431.3 µg g-1 DM) and breeding line PN 4-41 (424.5 µg g-1 DM). Free PAs concentration was the lowest for common wheat (29.5 µg g-1 DM). The dominant free PA was ferulic (66.3%), followed by syringic (11.7%), sinapic (7.4%), p-hydroxybenzoic (5.3%), salicylic (3.8%), p-coumaric (3.6%), and caffeic (2.1%). Bound ferulic acid accounted for 94.0% of total bound PAs, followed by p-coumaric (2.8%), p-hydroxybenzoic (0.8%), syringic (0.8%), caffeic (0.6%), sinapic (0.6%), and salicylic (0.4%). Emmer cultivar Farvento was distinguished by the highest concentration of individual free and bound forms of PAs. Effect of growing year was more evident on the concentration of free PAs compared to bound PAs. Extremely dry and hot weather during maturity stages has a negative impact on analysed free and bound PAs.

Red and blue light-specific metabolic changes in soybean seedlings.

Red and blue artificial light sources are commonly used as photosynthetic lighting in smart farm facilities, and they can affect the metabolisms of various primary and secondary metabolites. Although the soybean plant contains major flavonoids such as isoflavone and flavonol, using light factors to produce specific flavonoids from this plant remains difficult because the regulation of light-responded flavonoids is poorly understood. In this study, metabolic profiling of soybean seedlings in response to red and blue lights was evaluated, and the isoflavone-flavonol regulatory mechanism under different light irradiation periods was elucidated. Profiling of metabolites, including flavonoids, phenolic acids, amino acids, organic acids, free sugars, alcohol sugars, and sugar acids, revealed that specific flavonol, isoflavone, and phenolic acid showed irradiation time-dependent accumulation. Therefore, the metabolic gene expression level and accumulation of isoflavone and flavonol were further investigated. The light irradiation period regulated kaempferol glycoside, the predominant flavonol in soybeans, with longer light irradiation resulting in higher kaempferol glycoside content, regardless of photosynthetic lights. Notably, blue light stimulated kaempferol-3-O-(2,6-dirhamnosyl)-galactoside accumulation more than red light. Meanwhile, isoflavones were controlled differently based on isoflavone types. Malonyl daidzin and malonyl genistin, the predominant isoflavones in soybeans, were significantly increased by short-term red light irradiation (12 and 36h) with higher expressions of flavonoid biosynthetic genes, which contributed to the increased total isoflavone level. Although most isoflavones increased in response to red and blue lights, daidzein increased in response only to red light. In addition, prolonged red light irradiation downregulated the accumulation of glycitin types, suggesting that isoflavone's structural specificity results in different accumulation in response to light. Overall, these findings suggest that the application of specific wavelength and irradiation periods of light factors enables the regulation and acquisition of specialized metabolites from soybean seedlings.

Phenolic acid profile of oat cultivars, and their suppressive effect on intracellular reactive oxygen species

Oat (Avena sativa L.) has rich phenolic contents with nutritional and therapeutic health benefits. The objective of the present work was to perform a cell cytotoxicity assay of three South Asian oat cultivars to determine their suppressive effect on intracellular reactive oxygen species (ROS). Oat cultivars were firstly examined for total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, and phenolic acid profiling through HPLC. Total phenolic contents of oat cultivars ranged from 167.57 to 198.41 mg GAE/100 g, and DPPH scavenging activity was IC50 = 18.81 to 13.18 mg/mL. Oat cultivars displayed average content of phenolic acids such as vanillic acid (0.33 µg/g), syringic acid (6.70 µg/g), caffeic acid (4.16 µg/g), ferulic acid (2.06 µg/g), p-coumaric acid (20.22 µg/g), with the highest being gallic acid (74.32 µg/g). Cell cytotoxicity assay of oat polyphenolic extracts revealed that 10 and 15 µg/mL concentrations had non-significant differences when compared with their respective control treatments. Oat extracts suppressed ROS in Caco-2-cells, with or without hydrogen peroxide stimulation from 65.20 - 86.13%, and 56.36 - 79.56% with 10 and 15 µg/mL concentrations, respectively. In conclusion, oat is a rich source of polyphenols which have strong antioxidant behaviour to suppress the ROS activity.

Valorisation of Three Underutilised Native Australian Plants: Phenolic and Organic Acid Profiles and In Vitro Antimicrobial Activity.

Tasmannia lanceolata, Diploglottis bracteata and Syzygium aqueum are understudied native Australian plants. This study aimed to characterise the non-anthocyanin phenolic and organic acid profiles of the aqueous extracts obtained from the leaves of T. lanceolata and fruits of D. bracteata and S. aqueum by UHPLC-Q-Orbitrap-MS/MS and UHPLC-TQ-MS/MS. A total of 39, 22, and 27 non-anthocyanin polyphenols were tentatively identified in T. lanceolata, D. bracteata, and S. aqueum extracts, respectively. Furthermore, sugars and ascorbic acid contents as well as in vitro antioxidant and antimicrobial activities of the extracts were determined. Response surface methodology was applied to achieve an extract blend with a strong inhibitory effect against Pseudomonas viridiflava, the main cause of soft rot in vegetables, Bacillus subtilis, Rhodotorula diobovata and Alternaria alternata. The identified compounds including organic acids (e.g., quinic, citric and malic acids) and polyphenols (e.g., catechin, procyanidins, and ellagitannins) might contribute to the observed antimicrobial activity. Furthermore, this study provides the most comprehensive phenolic profiles of these three underutilised native Australian plants to date.

Comparison of leaf volatile aroma constituents and phenolic acid profiles of the seedling originated polyembryonic mango (Mangifera indica L.) genotypes

In mango, leaf and fruit volatile aroma profiles are variety specific which can be used as fingerprint of a variety. Such biochemical markers can also discriminate the nucellar and zygotic seedlings in polyembryonic mango varieties. In order to validate the applicability of volatile as well as phenolic acid profiles as biomarkers, the open pollinated seedlings of three polyembryonic varieties of mango were compared with their mother trees. Leaf volatile and phenol acid profiling were done using Gas Chromatography/Mass Spectrometry (GCMS) and Liquid Chromatography/Mass Spectrometry (LCMS) methods respectively. The sesquiterpene hydrocarbons were the most abundant in all the genotypes studied. Monoterpenoids were the major compounds in cultivars Vellaikolumban and Olour, while the sesquiterpenoids were the major compounds in cv. Turpentine. While terpinolene was the major monoterpenoid compound in Vellaikolumban and limonene in cv. Olour, the sesquiterpene á-gurjunene was the major compound in cv. Turpentine. Volatile profiling showed clear differences between the varieties but was similar within a variety. Among the 15 phenolic acids quantified in the leaves, P-coumaric acid, gallic acid, and ferulic acids were predominant whereas, vanillic acid, syringic acid, gentisic acid, benzoic acid, and sinapic acids were low in quantity. Phenolic acid profile did not show significant diversity among the varieties and therefore cannot be used for identification of varieties. The volatile profiling can be used for the identification and differentiation of polyembryonic mango genotypes.