Their Total Phenolic Research Articles

Phytochemical, antioxidant, lipid peroxidation inhibition and sensory properties of roasted coffee mixed with various quantities of pomposia fruit (Syzygium cumini L.) powder

PurposeThis study aims to find out how pomposia fruit powder (Syzygium cumini L.) mixed with roasted coffee (RCO) affected antioxidants, phytochemicals, lipid peroxidation inhibition and sensory attributes.Design/methodology/approachPomposia fruits (Syzygium cumini L.) powder (PFP) was integrated with RCO at levels of 0.0%, 5.0%, 10.0%, 15.0% and 20.0%. RCO, PFP and binary mixtures containing RCO: PFP were evaluated for their total phenolics (TP), total flavonoids (TF), anthocyanin content (AC), antioxidant activity and phenolic compounds fractionation. The oxidative indices of coffee oil samples were measured throughout different storage intervals. Additionally, sensory characteristics of RCO enriched with different PFP doses were evaluated.FindingsPFP samples exhibited the greatest TP content (1910 mg/100 g), whereas RCO samples had the lowest concentration (1090 mg/100 g). As more PFP was added, the corresponding coffee blends’ concentrations of TP, TF and AC were improved significantly. PFP possesses a radical-scavenging activity that is about 1.20 times more than RCO’s. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity jumped significantly from 74.13% in control (untreated) samples to 77.64%, 78.39% and 80.15% for samples enriched with 10.0%, 15.0% and 20% PFP, respectively. Significant increases in gallic acid, hesperidine, benzoic acid, chlorogenic acid, hispertin, catechol, quercetin, pyrogallol and rutin were detected when RCO was mixed with different quantities of PFP. At the end of storage trial, the coffee oil treated with 20% PFP had AV, PV and TBA values that were about 1.70, 1.95 and 1.66 times lower, respectively, than those of the control sample that had not had PFP addition. The RCO with 5.0% PFP achieved the greatest over acceptability grades.Originality/valueTo the best of the authors’ knowledge, this study was the first study to evaluate the effect of incorporating various level of pomposia fruit powder into RCO. The findings shows that adding different concentrations of pomposia fruit powder into RCO can indeed enhance the radical-scavenging activity of the coffee and potentially extend its shelf life.

Phytochemical composition, antioxidant, antibacterial, and enzyme inhibitory activities of organic extracts from flower buds of Cleistocalyx operculatus (Roxb.) Merr. et Perry.

Cleistocalyx operculatus flower buds have been widely used in traditional medicine because of their rich content of bioactive constituents. In this study, we obtained seven solvent extracts from the flower buds and evaluated their total phenolic (TPC), flavonoid (TFC), tannin (TTC), triterpenoid saponin (TSC), and alkaloid (TAC) contents. We assessed antioxidant activities using the DPPH assay and also looked at antimicrobial and enzyme inhibitory effects. The water extract possessed the highest TPC (328.9 mg GAE/g extract), followed by ethanol, methanol, and hexane extracts (85.4-101.5 mg GAE/g extract). Chloroform, butanol, ethyl acetate, and ethanol extracts had high TSCs (245.4-287.2 mg OAE/g extract). The hexane extract was richest in TTC and TFC (32.7 mg CE/g extract and 81.1 mg QE/g extract, respectively). Ethanol and methanol extracts exhibited the strongest antioxidant activities (IC50 values of 25.2 and 30.3 μg/ml, respectively), followed by the water extract (IC50 of 40.2 μg/ml). The hexane extract displayed the most growth-inhibitory activity against Helicobacter pylori ATCC51932 and ATCC43504 strains and Salmonella enterica serovar Typhimurium ATCC13311 (MIC values of 0.06, 0.13, and 0.4 mg/ml, respectively). Moreover, the hexane extract revealed the strongest inhibition of H. pylori urease activity (IC50 of 4.51 μg/ml), whereas the water and methanol extracts had potent inhibitory effects on α-glucosidase activity (IC50 values of 9.9 and 15.1 μg/ml, respectively). These flower bud extracts could be used for health protection, especially in preventing bacterial infections and inhibiting enzymes associated with various human diseases. Further investigation into the application of C. operculatus flower buds in the food and pharmaceutical industries is necessary.

Screening of 20 species from Lamiaceae family based on phytochemical analysis, antioxidant activity and HPLC profiling

The Lamiaceae family encompasses numerous species highly valued for their applications in medicine, food, and cosmetics. In order to screen the Lamiaceae family and discover new sources of phytochemicals and antioxidants, we comprehensively evaluated 20 species from this family, including Phlomis herba-venti, P. tuberosa, P. olivieri, P. kurdica, Nepeta sp., N. cataria, N. saccharata, Stachys sp., S. inflata, Scutellaria albida, Marrubium parviflora, Mentha pulegium, Thymus kotschyanus, Lamium album, Salvia officinalis, S. multicaulis, S. macrochlamys, S. candidissima, S. verticillata, and S. nemorosa. The aerial parts of these species were analyzed to determine their total phenolic (TPC) and flavonoid (TFC) contents, total tannin content (TTC), ascorbic acid content (AAC), antioxidant capacity (assessed by FRAP and DPPH assays), and polyphenolic components (by HPLC). The phytochemical compounds and antioxidant properties varied widely among different species. The highest concentrations of TPC (70.93 mg GAE/g DW), TFC (17.89 mg Que/g DW), TTC (6.49 mg TAE/100 g), and AAC (1.15 mg AA/g DW), as well as the greatest antioxidant activity, were observed in different Salvia species. Additionally, chlorogenic and rosmarinic acids were the primary phenolic compounds identified in the extracts from the investigated Lamiaceae family. According to Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA), three groups of species were identified, characterized by variations in phytochemical composition and antioxidant capacity. The results obtained can provide new natural sources of phytochemicals and antioxidant agents, particularly from Salvia species, for the advancement of new products in the food, agricultural, cosmetics and health industries.

α-Glucosidase inhibition by green, white and oolong teas: in vitro activity and computational studies

Natural α-glucosidase inhibitors from plant-based foods such as catechins offer an attractive strategy for their potential anti-diabetic effects. In this study, infusions of three different tea types (green, white, and oolong) were investigated for their total phenolic (TPC) and catechins (EGCG, ECG, EGC, and EC) content, and for their α-glucosidase inhibitory activities. We observed that the level of TPC in white tea was significantly higher compared to oolong and green tea, which suggests higher content of EGCG and ECG catechins in fresh young leaves. Our findings showed that the higher content of such catechins in the infusion of white tea well correlated with a strong inhibition of α-glucosidase, and such inhibition was demonstrated to be more effective than the FDA-approved drug acarbose. Then, we computationally explored the molecular requirements for enzyme inhibition, especially for the most active catechins EGCG and ECG, as well as their disposition/stability within the active site.

Bioaccessibility and antioxidant activity of PCL‐microencapsulated olive leaves polyphenols and its application in yogurt

Polycaprolactone (PCL)was used via double emulsion/solvent evaporation technique for the encapsulation of polyphenols olive leaves (OLs) extracts. In this study, the PCL-microcapsules loaded with OLs polyphenols extract powder were characterized by scanning electron microscopy and fourier transform infrared spectrometry analysis. Their total phenolic (TPC), total flavonoid (TFC) contents, and antioxidant activities (DPPH, FRAP, and ABTS), and polyphenols stability were measured after oral, gastric, and intestinal steps of in vitro digestion. PCL-microcapsules were utilized in formulating novel functional yogurt containing 0, 25, 50, and 75mg of TPC estimated as mg GAE (added as PCL-microcapsules) per 100gyogurt. All yogurt samples were evaluated for their pH, acidity, syneresis, viscosity, and color during storage. In vitro digestion significantly affected the phenolic composition in non-encapsulated extract whereas it had a lower impact on encapsulated phenolics. Higher protection was provided for encapsulated OLs extract and their higher release was observed at the intestinal phase. Unlike the undigested OLs extract, which had a TPC of 490mg GAE/100 g,lower values of TPC (136 and 289mg GAE/100 g)were obtained for non-encapsulated and encapsulated OLs extract, respectively, in the intestinal fluids. Yogurt with PCL-microcapsules had lower viscosity, syneresis, and color parameters, compared to control yogurt. Thus, OLs represent a valuable and cheap source of polyphenols that can be successfully applied in microencapsulated form, in formulating functional yogurt.

Influence of Brewer's Spent Grain Compounds on Glucose Metabolism Enzymes.

With a yearly production of about 39 million tons, brewer’s spent grain (BSG) is the most abundant brewing industry byproduct. Because it is rich in fiber and protein, it is commonly used as cattle feed but could also be used within the human diet. Additionally, it contains many bioactive substances such as hydroxycinnamic acids that are known to be antioxidants and potent inhibitors of enzymes of glucose metabolism. Therefore, our study aim was to prepare different extracts—A1-A7 (solid-liquid extraction with 60% acetone); HE1-HE6 (alkaline hydrolysis followed by ethyl acetate extraction) and HA1-HA3 (60% acetone extraction of alkaline residue)—from various BSGs which were characterized for their total phenolic (TPC) and total flavonoid (TFC) contents, before conducting in vitro studies on their effects on the glucose metabolism enzymes α-amylase, α-glucosidase, dipeptidyl peptidase IV (DPP IV), and glycogen phosphorylase α (GPα). Depending on the extraction procedures, TPCs ranged from 20–350 µg gallic acid equivalents/mg extract and TFCs were as high as 94 µg catechin equivalents/mg extract. Strong inhibition of glucose metabolism enzymes was also observed: the IC50 values for α-glucosidase inhibition ranged from 67.4 ± 8.1 µg/mL to 268.1 ± 29.4 µg/mL, for DPP IV inhibition they ranged from 290.6 ± 97.4 to 778.4 ± 95.5 µg/mL and for GPα enzyme inhibition from 12.6 ± 1.1 to 261 ± 6 µg/mL. However, the extracts did not strongly inhibit α-amylase. In general, the A extracts from solid-liquid extraction with 60% acetone showed stronger inhibitory potential towards a-glucosidase and GPα than other extracts whereby no correlation with TPC or TFC were observed. Additionally, DPP IV was mainly inhibited by HE extracts but the effect was not of biological relevance. Our results show that BSG is a potent source of α-glucosidase and GPα inhibitors, but further research is needed to identify these bioactive compounds within BSG extracts focusing on extracts from solid-liquid extraction with 60% acetone.

Activity Guided Isolation of Phenolic Compositions from Anneslea fragrans Wall. and Their Cytoprotective Effect against Hydrogen Peroxide Induced Oxidative Stress in HepG2 Cells.

Anneslea fragrans Wall., commonly known as “Pangpo Tea”, is traditionally used as a folk medicine and healthy tea for the treatment of liver and intestine diseases. The aim of this study was to purify the antioxidative and cytoprotective polyphenols from A. fragrans leaves. After fractionation with polar and nonpolar organic solvents, the fractions of aqueous ethanol extract were evaluated for their total phenolic (TPC) and flavonoid contents (TFC) and antioxidant activities (DPPH, ABTS, and FRAP assays). The n-butanol fraction (BF) showed the highest TPC and TFC with the strongest antioxidant activity. The bio-guided chromatography of BF led to the purification of six flavonoids (1–6) and one benzoquinolethanoid (7). The structures of these compounds were determined by NMR and MS techniques. Compound 6 had the strongest antioxidant capacity, which was followed by 5 and 2. The protective effect of the isolated compounds on hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells revealed that the compounds 5 and 6 exhibited better protective effects by inhibiting ROS productions, having no significant difference with vitamin C (p > 0.05), whereas 6 showed the best anti-apoptosis activity. The results suggest that A. fragrans could serve as a valuable antioxidant phytochemical source for developing functional food and health nutraceutical products.

Development of Herbal Green Tea Bags with <em>Osbeckia octandra</em> L.(DC.) (Heen bovitiya) and Evaluation of the Effect of InfusionTime and Temperature on Extracted Phytochemicals

Herbal tea or a tisane is a mixture of dried plant parts used for medicinal purposes. Present study was aimed to develop herbal green tea bags with Osbeckia octandra (Heen bovitiya) leaves predominantly and evaluate the effect of infusion time and temperature on their total phenolic (TP), total flavonoid (TF) contents and in vitro antioxidant activity. Six different tea bags (T1 to T6) were prepared by incorporating dried O. octandra (leaves), Camellia sinensis (leaves), Zingiber officinale (rhizomes), Vanilla planifolia (pods) and Allium sativum (bulbs) in different proportions. Each herbal tea bag was infused at a constant infusion temperature of 100 ⁰C for 3, 5 and 7 minutes and for a constant infusion time of 7 minutes at different temperatures; 100, 90 and 80 ⁰C. TP, TF contents, in vitro radical scavenging activity and ferric reducing antioxidant power of all tea extracts were determined by spectroscopic analysis. Data were analyzed with one sample t-test. All infusions were rich in phytochemicals; phenols, flavonoids, tannins, terpenes, triterpenoids, phytosterols, saponins, alkaloids, amino acids and carbohydrates. TP, TF contents and in vitro antioxidant activity of the formulated tea bags were significantly higher after the addition of O. octandra leaves and the values were different at different infusion conditions (p<0.05). At constant infusion time of 7 minutes, TP, TF contents and antioxidant activity of O. octandra incorporated green tea bags were higher when infused at 80 ⁰C compared to 90 ⁰C and 100 ⁰C. At constant infusion temperature of 100 ⁰C, the values were higher for the formulated green tea bags when infused for 7 minutes compared to 3 and 5 minutes. Hence, it was concluded that the formulated tea bags with O. octandra leaves were rich with antioxidants and that they should be brewed for a long time period (7 minutes) at a low temperature (80 ⁰C).

Phytochemical Constituents and Antioxidant Activity ofOudneya Africana L. Leaves Extracts: Evaluation Effects on Fatty Acids and Proteins Oxidation of Beef Burger during Refrigerated Storage.

Five Oudneya Africana (OA) leaves extracts were screened for their total phenolic (TPC), total flavonoid (TFC), condensed tannins (CTC) content, as well as their antioxidant capacity. The highest amount of TPC (661.66 ± 0.08 mg GAE/g), TFC (344.68 ± 0.44 mg QE/g) and TCT (90.18 ± 0.49 mg CE/g) was recorded to ethanol, acetone, and dichloromethane extracts, respectively. For 2,2-diphenyl-1-picrylhydrazyl (DPPH) (22.00 ± 0.03 µg/mL) and Reducing Power Assay (FRAP) (269.00 ± 0.01µg/mL) assays, ethanol extract showed the potent activity, while with ABTS test, acetone extract was the most active (761.15 ± 0.09 µg/mL). HPLC-MS analysis of acetonic and ethanolic extracts reveals the predominance of quinic acid, chlorogenic acid, 4-O-caffeoylquinic acid, and rutin compounds. The addition effect evaluation of OA extracts in beef burger preservation demonstrates the powerful effect (p < 0.05) of acetonic and ethanolic ones (0.03%) to inhibit lipids oxidation during storage for 10 days, given by the lowest increase in Thiobarbituric Acid-reactive Substances (TBARS) values as compared to the (−) control with a significant difference between free thiols values. In addition, these two extracts appear to be effective (p < 0.05) for pH stability, color, and sensory parameters as compared to (+) and (−) controls and aqueous extract. Hamburger odour was considered as a dependent variable in multiple linear regression analysis, where the models results showed that physicochemical parameters determine more burger odour than sensorial ones.

Determination of Vitamin B2 Content in Black, Green, Sage, and Rosemary Tea Infusions by Capillary Electrophoresis with Laser-Induced Fluorescence Detection

Vitamin B2, also known as riboflavin (RF) is an essential micronutrient for human health and must be obtained from dietary sources. Plants biosynthesize riboflavin and are important dietary sources of vitamin B2 for humans. Our present study reports sensitive detection of vitamin B2 in widely consumed tea infusions, namely black, green, sage and rosemary tea infusions, by a capillary electrophoresis method combined with laser induced fluorescence detection. Moreover, the correlation between the vitamin B2 content of tea plants with their total phenolics (TPs) and antioxidant capacity are evaluated in this study. Whereas green teas have the highest TPs and antioxidant capacity, the highest RF content is in sage infusions. The RF content ranged between 0.34 and 10.36 µg/g for all tea samples studied. Comparing the RF content of tea samples found in this study to the RF content of known RF sources, tea infusions are proposed as important dietary sources of vitamin B2.

Total Phenolics and Antioxidant Capacity of Vegetables Grown in the Southwestern Andes Region of South America

The antioxidant richness of 69 species and/or varieties of vegetables grown in the southwestern Andes region of South America, including some endemic varieties, was evaluated in terms of their total phenolics (TP) and oxygen radical absorbance capacity (ORAC). Parsley, basil and coriander rank notably higher among those species that are commonly consumed in their raw state, exhibiting TP and ORAC values that are comparable to those reported earlier by us for various antioxidant-rich indigenous berries. For a given species, major differences were also seen among its varieties; in the case of tomatoes and lettuce, the maximal-to-minimal differences in ORAC values reached 16- and 28-fold, respectively. For those vegetables that are not consumed raw, the boil-cooking process affected differentially the antioxidant richness; for instance, while in the case of asparagus, chard, and lima beans boil-cooking induced major drops in ORAC (40-60%), in the case of artichoke bottoms a marked increase (35%) in ORAC was seen. Within the frame of building rankings of antioxidant richness, in the present work substantial data are also presented to highlight the concept that when assessing the antioxidant supply potential of any vegetable, besides quantifying its antioxidant richness per 100 g, considering its actual portion of consumption is also fundamental. On such basis, among the 29 vegetables analyzed in their cooked state, the endemic and regionally-grown Michune, Cabrita, and purple varieties of potatoes emerge as the top 3 antioxidant-rich plant foods.

Isolation of bioactive compounds from spruce bark waste using sub- and supercritical fluids

The aim of this study was to investigate the possibility of isolating bioactive phenolics compounds from spruce bark (Picea abies), using sub- and supercritical fluids. In order to improve the yields and to assure a higher recovery of the phenolic compounds, in the first part of this study, extraction of lipophilic compounds was performed using only supercritical (SC) CO2 as solvent. Amount of obtained lipophilic compounds was quantified. In the second step, to the SCCO2 a cosolvent was added, namely 70% (v/v) aqueous ethanol, in order to isolate the bioactive phenolic compounds more efficiently. Effect of temperature, pressure and cosolvent flow rate on the yield of phenolic compounds was observed, at 40–60°C, 100–200bar and at 1.2mL/min and 2.5mL/min, respectively. Obtained extracts were analysed for their total phenolics (TPC), tannins (TTC) and flavonoids (TFC) content, as well as their antioxidant activity using UV–vis spectrophotometric methods. The maximum extraction yield of phenolic compounds (30.46±1.20)% was achieved at 100bar pressure and 40°C and the determined total phenolics content was 314.49mg/g dry extract, the total flavonoids content was 100.67mg/g dry extract and the total tannins content was 26.38mg/g dry extract. Additionally, the content of different phenolic compounds, typically found in woody biomass was assessed using high pressure liquid chromatography, ferulic acid and p-coumaric acid being the two major quantifiable phenolic compounds identified. Lastly, the consumption of solvents for production of kg of product with highest possible purity was determined and discussed.

Comparison of Phenolics and Phenolic Acid Profiles in Conjunction with Oxygen Radical Absorbing Capacity (ORAC) in Berries of Vaccinium arctostaphylos L. and V. myrtillus L.

1. THE STUDY OF PHENOLIC COMPOUNDS OF THE BERRIES OF THREE SPECIES OF PLANTS OF THE GENUS VACCINIUM, GROWING IN THE KHANTY-MANSI AUTONOMOUS AREA Yekaterina Belova, Vladislav Tritek, Zarina Shul'gau, Aleksandr Gulyayev, Elena Krivykh, Lyudmila Kovalenko, Aleksey Drenin, Erkin Botirov chemistry of plant raw material CrossRef

Home-Processed Red Beetroot (Beta vulgaris L.) Products: Changes in Antioxidant Properties and Bioaccessibility

In this study, the effects of home-processing on the antioxidant properties and in vitro bioaccessibility of red beetroot bioactives were investigated. For this purpose, fresh red beetroot and six different home-processed red beetroot products—including boiled, oven-dried, pickled, pureed, juice-processed, and jam-processed—were analyzed and compared for their total phenolic (TP) and total flavonoid (TF) contents, total antioxidant capacities (TAC), and individual anthocyanin contents. In addition, bioaccessibility of red beetroot antioxidants was determined using an in vitro simulated gastrointestinal digestion method. Dried, pureed, and fresh red beetroot samples had the highest TP, TF, and TAC values, which were 347 ± 23 mg gallic acid equivalent (GAE)/100 g, 289 ± 53 mg rutin equivalent (RE)/100 g, 3889 ± 982 mg trolox equivalent antioxidant capacity (TEAC)/100 g, respectively. The in vitro digestion method revealed the highest recovery for TP (16%) and TAC (1.3%) in jam. This study provides comparative data to evaluate the effects of various home-processing techniques on antioxidant potential of red beetroot products.

Chemical profiling and antioxidant activity of Bolivian propolis.

Propolis is a relevant research subject worldwide. However, there is no information so far on Bolivian propolis. Ten propolis samples were collected from regions with high biodiversity in the main honey production places in Bolivia and were analyzed for their total phenolics (TP), flavonoids (TF) and antioxidant activity. The chemical profiles of the samples were assessed by TLC, HPLC-DAD, HPLC-DAD-MS/MS(n) and NMR analysis. TP, TF, TLC and NMR analysis showed significant chemical differences between the samples. Isolation of the main constituents by chromatography and identification by HPLC-DAD-MS/MS(n) achieved more than 35 constituents. According to their profiles, the Bolivian propolis can be classified into phenolic-rich and triterpene-rich samples. Propolis from the valleys (Cochabamba, Chuquisaca and Tarija) contained mainly prenylated phenylpropanoids, while samples from La Paz and Santa Cruz contained cycloartane and pentacyclic triterpenes. Phenolic-rich samples presented moderate to strong antioxidant activity while the triterpene-rich propolis were weakly active. High chemical diversity and differential antioxidant effects were found in Bolivian propolis. Our results provide additional evidence on the chemical composition and bioactivity of South American propolis.

Assessment of antibacterial and antioxidant properties of chitosan edible films incorporated with maqui berry (Aristotelia chilensis)

The purpose of this work was to evaluate chitosan edible films (CH) incorporated with maqui berry extracts (MB) for (i) the inhibition growth of some bacterial strains (ii) their total phenolic (TPC) and total flavonoid content and (iii) their antioxidant activity to define if the chitosan edible films incorporated with maqui berry extract (CH + MB) could be used as natural active films for food use. The antioxidant activity was determined with three different analytical assays: DPPH radical scavenging ability assay, Ferrous chelating capacity (FIC) and ferric reducing activity power (FRAP). The agar disc diffusion method was used to determine the antibacterial activity against Listeria innocua, Serratia marcescens, Aeromonas hydrophila, Achromobacter denitrificans, Alcaligenes faecalis, Pseudomonas fluorescens, Citrobacter freundii and Shewanella putrefaciens. CH + MB showed higher antioxidant activity, at all concentrations (0.5 and 1%) and with all methods assayed than CH. Furthermore, the antioxidant activity of CH + MB occurs in a concentration-dependent manner. Regarding the antimicrobial activity, CH + MB were effective against seven of the eight tested bacteria. This antibacterial activity takes place in a concentration-dependent manner. CH were not active, against six of the eight bacteria strain tested. CH + MB could improve the quality of foods due to delay the oxidation and the microbial growth.

Enzyme-assisted supercritical fluid extraction of phenolic antioxidants from pomegranate peel

This study presents a comprehensive enzyme-assisted supercritical fluid extraction (EASCFE) process developed to extract antioxidant phenolics from pomegranate peel (PP). Pomegranate peel collected from local agro-processing units was treated with various commercial and feed enzyme preparations. The morphological changes in the ultrastructure of PP cell wall after enzyme treatment were visualized by field emission scanning electron microscopy (FESEM). Extraction of antioxidant phenolics from enzyme pretreated PP was carried out by supercritical carbon dioxide (SC-CO2) with ethanol as a co-solvent. The extracts produced were investigated for their total phenolics (TP), antioxidant activity and phenolic acids profile using HPLC-DAD-ESI–MS. The observed results showed that EASCFE doubled the recovery of crude extracts with increased level of phenolic constituents (TPs), and improved radical scavenging capacity (RSC), trolox equivalent antioxidant capacity (TEAC) and inhibition of linoleic acid peroxidation. HPLC-DAD-ESI–MS characterization of the extracts authenticated the presence of vanillic (108.36μg/g of extract), ferulic (75.19μg/g of extract) and syringic (88.24μg/g of extract) as potent phenolic acids. The results of this study support that EASCFE can be explored as a state-of-the-art green technological process for recovering optimum amounts of antioxidant phenolics from under-utilized pomegranate peel or other such materials. In addition, retention of appreciable level of naturally occurring vanillic, ferulic, and syringic acids in the enzyme-extracted components advocates that EASCFE is a good choice for preparation of PP extracts for food preservation as well as for the development of nutraceuticals and chemo-preventive phytomedicine.

Physical, Chemical, and Sensory Properties of Antioxidant‐Enriched Raw and Cooked Rice by Vacuum‐Drying Impregnation in a Semidry State

ABSTRACTVacuum drying was employed with a vacuum impregnation technique in a semidry state to enrich rice with antioxidants of beetroot juice. The properties of the vacuum‐dried raw and cooked rice grains were characterized. The various raw rice grains (three varieties and two storage time periods) exhibited a significant absorption of beetroot juice, which was evident from the red‐violet beetroot color of the rice, as distinguished from the white color of the control. The color increase (ΔE= 20−40) was linear with the juice content (R2 = 0.96−0.99). Their total phenolic (TP) contents and 2,2‐diphenyl‐2‐picrylhydrazyl radical (DPPH) scavenging activities were enhanced (ΔTP = 21−260 mg of gallic acid equivalents/100 g of rice db and ΔDPPH = 22−64 mg of vitamin C equivalents/100 g of rice db). Their grain integrity was reduced (Δforce = −1 to −63), which was potentially associated with the formation of grain surface cracks (linear relationship of %crack and %juice with R2 = 0.94−0.98). After cooking, the enriched rice grains were linearly elongated with added juice (R2 = 0.88−0.97, up to 1.6‐, 2.0‐, and 2.0‐fold for Sanpatong 1, Khao Dawk Mali 105, and Chainart 1 rice samples, respectively), and the overall volume of the cooked rice was increased (likely not linear, up to 3.2‐, 4.3‐, and 4.8‐fold for Sanpatong 1, Khao Dawk Mali 105, and Chainart 1 rice samples, respectively). Such improvements in cooking qualities were obtained by this simple vacuum‐drying technique, in comparison to existing rice‐aging processes that are more time consuming. The sensorial scores of the resultant rice products were excellent. Vacuum drying is an effective tool to improve the antioxidant value of rice as well as its cooking quality, and the raw quality remains appreciable. It is a simple and rapid process that could be practical for manufacturing healthy rice products.

Antioxidant and nitrite-scavenging capacities of phenolic compounds from sugarcane (Saccharum officinarum L.) tops.

Sugarcane tops were extracted with 50% ethanol and fractionated by petroleum ether, ethyl acetate (EtOAc), and n-butyl alcohol successively. Eight phenolic compounds in EtOAc extracts were purified through silica gel and Sephadex LH-20 column chromatographies, and then identified by nuclear magnetic resonance and electrospray ionization mass spectra. The results showed that eight phenolic compounds from EtOAc extracts were identified as caffeic acid, cis-p-hydroxycinnamic acid, quercetin, apigenin, albanin A, australone A, moracin M, and 5'-geranyl-5,7,2',4'-tetrahydroxyflavone. The antioxidant and nitrite-scavenging capacities of different solvent extracts correlated positively with their total phenolic (TP) contents. Amongst various extracts, EtOAc extracts possessed the highest TP content and presented the strongest oxygen radical absorbance capacity (ORAC), 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging capacity, 2,2'-azobis-3-ethylbenthiaazoline-6-sulfonic acid (ABTS) radical-scavenging capacity, ferric reducing antioxidant power (FRAP) and nitrite-scavenging capacity. Thus, sugarcane tops could be promoted as a source of natural antioxidant.

Phytochemicals and Antioxidative Properties of Borneo Indigenous Liposu (Baccaurea lanceolata) and Tampoi (Baccaurea macrocarpa) Fruits.

Two underutilized indigenous fruits of Borneo, Liposu (Baccaurea lanceolata) and Tampoi (Baccaurea macrocarpa) were investigated for their total phenolic (TPC), flavonoid (TFC), anthocyanin (TAC) and carotenoid (TCC) contents as well as antioxidant properties in vitro. The fruits were separated into three different parts (i.e., pericarp, flesh and seed) and extracted using 80% methanol. Antioxidant activity was determined using DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging, ABTS decolorization and FRAP (Ferric Reducing Antioxidant Power) assays. The results showed that B. macrocarpa pericarp contained the highest amount of total phenolics, total flavonoid, total anthocyanin and total carotenoid with the values of 60.04 ± 0.53 mg GAE/g, 44.68 ± 0.67 mg CE/g, 1.23 ± 0.20 mg c-3-gE/100 g and 0.81 ± 0.14 mg BCE/g. Results from DPPH, ABTS and FRAP assays also showed that the pericarp of B. macrocarpa displayed the highest antioxidant capacity. The antioxidant activity of the extract was significantly correlated with the total phenolic and flavonoid contents, but not with the carotenoid contents. In conclusion, B. macrocarpa displayed high potential as natural source of phytochemicals with antioxidant properties.