DPPH Antiradical Activity Research Articles

Research of the properties of protein hydrolysates obtained from the broiler chicken gizzards as a potential component of bioactive film coatings

Protein hydrolysates are a promising active component in the production of bioactive film coatings for food products. Some biopolymers can exert the biological activity. More often, however, it is necessary to select biologically active substances to impart these properties to films. On the other hand, not all components allow forming films with the required properties, and therefore there is a need to study the individual technological characteristics of the components used. The purpose of the research is to establish the antioxidant and technological properties of protein hydrolysates obtained by microbial fermenta- tion of poultry by-products in whey with bifidobacteria, propionic acid bacteria and acidophilic bacteria as a potential basis for bioactive film coatings of food products. The hydrolysate obtained by fermentation without the addition of the specified bacterial species was used as a control sample. The functional properties of protein hydrolysates were assessed: antioxidant capacity by coulometric titration on an Expert-006 coulometer using ascorbic acid as a standard, antiradical activity by the DPPH method on a Jenway 6405 UV/Vis spectrophotometer with determination of the IC50 value. The technological proper- ties, solubility, water-holding, fat-holding and fat-emulsifying capacities were also determined by the gravimetric method. In addition, the average hydrodynamic diameter of particles in protein hydrolysates was determined using a Microtrac FLEX particle size analyzer. The results of studies of the antioxidant properties showed that the DPPH antiradical activity was 14.7% higher in the experimental samples of hydrolysates obtained by fermentation with bifidobacteria compared to the control; samples of hydrolysates obtained by fermentation with propionic acid bacteria showed an antioxidant capacity 29.6% higher than that of the control sample. The IC50 value turned out to be the highest in the control hydrolysate sample (2.994 mg/ml), which was 45.5–53.3% higher than that in the experimental hydrolysate samples. The results of determining the technologi- cal properties showed that they differ significantly for protein hydrolysates obtained by fermentation with different types of bacteria. For example, the highest values of fat-holding and fat-emulsifying capacities were found in the hydrolysate obtained by fermentation with bifidobacteria (351.1% and 61%, respectively), which shows its potential for incorporation into the bio- composite in the form of a protein-oil emulsion. The high solubility of the experimental samples of hydrolysates (from 90.1 to 91.4%) suggests their uniform distribution in the aqueous phase when composing the biocomposite of the film. Thus, the research results have shown the prospects of using protein hydrolysates from the gizzards of broiler chickens in whey as an active component of bioactive film coatings. The antioxidant properties of protein hydrolysates allow slowing down oxidative processes in the main food nutrients, which will contribute to an increase in the shelf life of food products packaged in bioac- tive films with this component.

Effect of microwave, ultraviolet and pulsed electric field treatments on ochratoxin A level and physicochemical quality attributes of paprika powder

Ochratoxin A (OTA) is a highly toxic and thermally stable food toxin, which commonly contaminate paprika spices and OTA detoxification from paprika is highly significant. This study investigated the impacts of microwave (MW), ultraviolet (UV–C), and pulsed electric field (PEF) treatments on the OTA level in paprika powder. OTA level of 51.36 μg/kg were found in paprika powder. PEF, UV, and MW treatments exhibited 42.31%, 39.19%, and 37.05% detoxification of OTA, respectively. These treatments affected the physicochemical quality attributes of paprika powder in different manners (p ≤ 0.05). MW treatment enhanced minerals, ash, total phenolic content (TPC), L*, b*, ΔE, and chroma, and PEF treatment improved the detoxification percentage, a*, and DPPH antiradical activity of paprika powder (p ≤ 0.05). UV-C treatment increased the protein content, DPPH, phosphorous, copper, zinc, L*, b*, and hue angle compared to control (p ≤ 0.05). Untreated paprika powder has the highest OTA, browning index (BI) and moisture content (p ≤ 0.05). In conclusion, PEF treatment exhibited the highest (p ≤ 0.05) detoxification level of OTA with less effect on the physicochemical quality attributes of paprika powder.

Antioxidant and antimicrobial activities and GC/MS-based phytochemical analysis of two traditional Lichen species Trypethellium virens and Phaeographis dendritica

BackgroundLichens are complex plants living in symbiotic relationship between fungi and algae. They are used for human and animal nutrition and are used in folk medicine in many countries over a considerable period of time. In the present study, various solvent extracts of Trypethelslium virens and Phaeographis dendritica were tested for their antioxidant and antimicrobial activity. ResultsThe phytochemical analysis by GC/MS revealed phenolics (1.273%), terpene (0.963%), hydrocarbons (2.081%), benzofurans (2.081%), quinone (1.273%), alkanes (0.963%), and aliphatic aldehydes (0.963%) as the predominant compounds in Trypethellium virens SPTV02, whereas secondary alcohol (1.184%), alkaloids (1.184%), and fatty acids (4.466) were the major constituents in Phaeographis dendritica. The antioxidant property of methanolic extract of T. virens and P. dendritica revealed the presence of total phenolic and terpenoids. The methanolic extracts of both the lichens exhibited encouraging DPPH antiradical activity, with the IC50 of 62.4 ± 0.76 µg/ml for T. virens and 68.48 ± 0.45 µg/ml for P. dendritica. Similarly, ferric reducing power assay result exhibited higher reducing activity. Further, the lichen extracts (methanolic) indicated promising antimicrobial activities against pathogens showing MIC from 62.5 to 500 µg/ml. ConclusionThe study results concludes that both the lichens could be used as new natural source of antioxidants and antimicrobial agents which can be exploited for pharmaceutical applications.

Bioactive Compounds Extracted from Saudi Dates Using Green Methods and Utilization of These Extracts in Functional Yogurt

The bioactive compounds of four Saudi date flesh extracts (Ambara (AF), Majdool (MF), Sagai (SF), and Sukkari (SKF)) prepared using different extraction methods-namely, supercritical fluid extraction (SFE), subcritical CO2 extraction (SCE), and Soxhlet extraction (SXE)-were evaluated. A total of 19 bioactive compounds were detected in extracts prepared using SFE and SCE methods, whereas less than 12 compounds were detected in extracts obtained using the SXE method. Both the date variety and extraction method affected the phenolic profile of date flesh extract (p ≤ 0.05). The apparent viscosity, surface color, and bioactive properties of yogurt were affected by both date flesh extracts and storage duration in varied magnitudes (p ≤ 0.05). The incorporation of date flesh extracts into yogurt formulations increased the total phenolic content (TPC), DPPH antiradical activity, viscosity, and redness (a*) and decreased the lightness (L*) and yellowness (b*) of the developed product (p ≤ 0.05). The elongation of storage time progressively (p ≤ 0.05) reduced the pH, TPC, DPPH antiradical activity, bacterial counts, and L* and b* values and increased the acidity, syneresis, viscosity, and a* values with few exceptions. Date flesh extracts can improve the health quality of yogurt without major influence on the sensory attributes while stored at 4 °C.

Pulsed Electric Field as a Novel Technology for Fresh Barhi Date Shelf-Life Extension: Process Optimization Using Response Surface Methodology

Fresh dates of the Barhi cultivar at the Khalal maturity stage are well known for their pleasant taste, crispy texture, and bright yellow color. One of the primary technical challenges is preserving the initial high-quality fresh Khalal Barhi dates and extending their shelf life for the longest possible period after harvesting and during the marketing process. Resolving this problem would permit the export of high-quality fresh Saudi dates to international markets. Therefore, the main aim of this study is to evaluate the feasibility of utilizing a pulsed electric field as a novel non-thermal postharvest processing technology for preserving the nutritional, microbiological, and physical quality of Barhi dates during storage at different temperatures and durations. To accomplish this goal, a five-factor mixed-level central composite rotating design (CCRD) with a response surface methodology (RSM) model was used to define the best PEF processing conditions and subsequent storage environments. The influence of independent factors, PEF intensity (10, 20, 30, and 40 kV/cm), PEF exposure time (40, 80, 120, and 160 ms), PEF numbers (50, 100, 150, and 200 pulses), storage temperature (1 °C, 5 °C, 15 °C, and 25 °C), and storage time (1 day, 6 days, 11 days, 16 days, and 21 days), on the total soluble solids, firmness, total color changes, total viable count, total phenolic content, DPPH antiradical activity, fructose, and glucose were assessed. The results indicated the optimal conditions of PEF treatment and subsequently storage conditions for conserving the quality and elongating the storability of fresh Barhi dates were: 10.3 kV/cm PEF intensity; 46.73 ms PEF duration; number of PEF, is 169.9 pulses; 18.7 °C storage temperature; and 21 days’ storage time. At the aforementioned optimal conditions, the values of total soluble solids (TSS), firmness, ΔE, total viable count (TVC), total phenolic content (TPC), DPPH antiradical activity, glucose, and fructose were 41.44%, 62.47 newton, 0.1, 0.098 log CFU/g, 1.29 mg GAE/g, 65.95%, 3.45, and 3.44, respectively. These values were comparable to the predicted values (Desirability value = 1), indicating that the applied RSM models were ideal for optimizing the PEF and storage conditions for preserving the quality and prolonging the fresh Barhi dates’ shelf life. Overall, the ideal PEF treatment and storage conditions for sustaining the quality characteristics of Barhi dates during an extended storage time were identified in this study.

Rich in Phenolics-Strong Antioxidant Fruit? Comparative Study of 25 Strawberry Cultivars.

Phenolic compounds of 25 newly introduced strawberry cultivars were profiled using spectrophotometry, electron paramagnetic resonance (EPR) spectroscopy, and high-performance liquid chromatography-mass spectrometry. Total phenolic and anthocyanin content (TPC and TACY, respectively), as well as vitamin C, and concentrations of individual phenolic compounds in fruits were evaluated to identify the most promising cultivars according to their phenolic profile. The highest values of TPC, TACY, and vitamin C were recorded in 'Premy' (1.53 mg eq GA g-1 FW), 'Sandra' (30.60 mg eq Pg-3-g 100 g-1 FW), and 'Laetitia' (56.32 mg 100 g-1 FW), respectively. The DPPH and •OH radicals scavenging activity of fruit methanolic extracts was estimated using EPR spectroscopy. All cultivars are almost uniformly effective in the scavenging of •OH radical, while 'Tea', 'Premy', and 'Joly' were marked as highly potent cultivars (over 70%) in terms of DPPH-antiradical activity. Specific peroxidase activities were the highest in 'Garda', 'Federica', and 'Rumba' (0.11, 0.08, and 0.06 U mg-1 prot, respectively). 'Laetitia', 'Joly', 'Arianna', 'Tea', and 'Mila' cultivars were distinguished from others as the richest concerning almost all flavonoids and phenolic acids, including some other parameters of bioactivity. These cultivars could be recommended to consumers as functional fruit foods.

Quality Characteristics of Novel Pasta Enriched with Non-Extruded and Extruded Blackcurrant Pomace.

Fruit pomace is a valuable by-product in terms of its chemical composition, which potential might be used through transformation of the pomace into food ingredients. The aim of this work was to assess the effect of partial (5% and 10%) substitution of powdered non-extruded or extruded blackcurrant pomace for semolina in pasta formula on nutritional and technological properties of the final product. The pasta was assessed for chemical composition, DPPH antiradical activity, color, cooking and textural properties. Presence of the by-products in the pasta resulted in increased total dietary fiber content (from 1.89 ± 0.06 up to 10.03 ± 0.15 g/100 g, dwb), fat content (from 1.29 ± 0.01 up to 2.70 ± 0.05 g/100 g, dwb) and DPPH antiradical activity (from 253 ± 15 up to 1037 ± 7 µmol TE/g, dwb), as well as in significantly different color (p < 0.05) as compared to the semolina-only pasta. The optimal cooking time was shortened by 1.0−1.5 min and by 2.0 min in the case of the lower and higher, respectively, level of pasta supplementation. The water absorption decreased by up to 32% in the enriched pasta. In general, the cooking loss remained unchanged. The uncooked product containing the extruded fruit pomace was characterized by significantly higher breaking strength (p < 0.05) as compared to the standard pasta. Presence of the pomace also affected texture of the cooked pasta, increasing its firmness and hardness and, when using the non-extruded pomace, the tensile strength. In our research, we have shown that durum wheat pasta enriched with 5 or 10% of powdered blackcurrant pomace or their extrudates constitute a food product of improved nutritional value and of appropriate textural characteristics, while maintaining culinary properties that meet pasta industry requirements.

Micro‐encapsulation of gurum (Citrullus lanatus Var. Colocynthoide) seed oil maintains functional quality characteristics during accelerated storage

SummaryIn this study, microencapsulation was used on gurum seed oil (GSO) to evaluate quality characteristics during accelerated storage at 60°C for 28 days. Accelerated storage altered the levels of all fatty acids of GSO (31.36–95.65%), whereas, those of microencapsulated GSO showed reduced changes (0.13–38.46%). At the beginning of storage, the tocopherol and phytosterol content of GSO (563.61 and 149.86 mg/100 g oil, respectively) was significantly higher than that of MGSO (425.30 and 132.21 mg/100 g oil, respectively), while the polyphenol contents of GSO and MGSO were 20.21 mg GAE/kg oil and 19.45 mg GAE/kg oil, respectively. The IC50% DPPH antiradical activity of GSO and MGSO was 20.89 and 19.31 mg/mL, respectively, which was increased for GSO and remained constant for MGSO during accelerated storage. In conclusion, microencapsulation effectively preserved the quality of GSO during accelerated storage at 60°C for up to 28 days.

Antioxidant and antiradical activities depend on adrenal tumor type.

The aim of the study was to assess the total antioxidant/oxidant status in the plasma and urine of patients with adrenal tumors. The study group consisted of 60 patients (31 women and 29 men) with adrenal masses, classified into three subgroups: non-functional incidentaloma, pheochromocytoma and Cushing’s/Conn’s adenoma. The number of patients was set a priori based on our previous experiment (α = 0.05, test power = 0.9). Antioxidant activity (Total Antioxidant Capacity (TAC), Total Oxidant Status (TOS), Oxidative Stress Index (OSI)) and antiradical activity (Radical-Scavenging Activity Assay (DPPH), Ferric-Reducing Antioxidant Power (FRAP)) were measured using colorimetric methods. FRAP level was decreased in plasma and urine incidentaloma (p<0.0001), pheochromocytoma (p<0.0001) and Cushing’s/Conn’s adenoma (p<0.0001), while DPPH antiradical activity only in plasma of patients with adrenal masses (p<0.0001). Plasma TAC was increased in incidentaloma patients (p=0.0192), whereas in pheochromocytoma group (p=0.0343) was decreased. Plasma and urine TOS (p<0.0001) and OSI (p<0.01) were significantly higher in patients with adrenal tumors. In pheochromocytoma patients, plasma and urine TAC (p=0.001; p=0.002), as well as plasma plasma DPPH (p=0.007) and urine FRAP (p=0.017) correlated positively with normethanephrine. We are the first who showed reduced radical scavenging capacity in the plasma/urine of patients with adrenal masses. Nevertheless, plasma TAC was significantly higher in the incidentaloma group compared to controls. Therefore, plasma and urinary antioxidant and antiradical activities depend on the presence of the tumor. Lower levels of TAC, DPPH and FRAP clearly indicate a reduced ability to scavenge free radicals and thus a lack of effective protection against oxidative stress in patients with adrenal tumors. Both plasma and urine redox biomarkers can be used to assess systemic antioxidant status in adrenal tumor patients.

Response Surface Methodology (RSM) Optimization of the Physicochemical Quality Attributes of Ultraviolet (UV-C)-Treated Barhi Dates.

Barhi date fruit is one of the most important fruits that has high consumer preference and market value at the Khalal maturity stage. However, this stage is very short and the fruit is vulnerable to decay and the ripening process under improper handling and storage conditions. Thus, the purpose of this study was to evaluate the feasibility of utilizing ultraviolet (UV-C) as a method to preserve the qualitative features of Barhi dates under various storage circumstances. The core of this study was defining the best conditions for UV-C treatment of Barhi dates, which was accomplished using a response surface methodology (RSM) model with a central composite, rotating four-factors-mixed-levels design (CCRD). The impacts of independent variables [UV-C exposure time (1, 2, 3, 4 min), UV-C dose (1, 3, 5, 7 kJ/m2), storage time (1, 6, 11, 16, 21 days) and storage temperature (1, 5, 15, 25 °C)] on the moisture content (MC), total soluble solids (TSS), total color changes (E), firmness, total phenolic content (TPC), total viable count (TVC), DPPH antiradical activity, fructose and glucose were investigated. The results revealed that the optimum UV-C treatment and storage settings for keeping the quality features of the dates were the UV-C exposure period and dosage of 1 min and 2.07 kJ/m2, and the storage time and temperature of 18 days and 12.36 °C, respectively. At the optimum conditions, the values of 59.66% moisture content, 38.24% TSS, 60.24 N firmness value, 48.83 ΔE, 0.07 log CFU/g TVC, 5.29 mg GAE/g TPC, 56.32% DPPH antiradical activity, 6.87 g/100 g fructose and 14.02 g/100 g glucose were comparable predicted values demonstrating the suitability of the used RSM models. Overall, the perfect UV-C treatment and storage circumstances for extending the storability and shelf life and maintaining the quality features of Barhi dates were identified in this study.

Extending the Shelf Life of Fresh Khalal Barhi Dates via an Optimized Postharvest Ultrasonic Treatment.

The Barhi date is a high-quality date cultivar whose fruits (dates) are plucked and eaten fresh when they reach the Khalal maturity stage due to their sweetness, crispiness, and yellow skin color. After harvesting, Khalal Barhi fruits rapidly matured to the Rutab stage, where their tissues become soft and their skin color browner. This results in a decrease in their market value and customer demand. This study aims at investigating the effectiveness of the postharvest ultrasonic treatment in conserving the physical, microbial, and nutritional quality of Barhi fruits and extending their shelf life. To achieve the goals of the present work, the response surface methodology (RSM) was used for the optimization of the ultrasonic intensity (50, 100, 150, and 200 W/cm2) and application time (5, 10, 15, and 20 min) to preserve the Barhi dates high quality features for varied storage temperatures (1, 5, 15, and 25 °C) and duration (1, 6, 16, and 21 days). In RSM, a four-factors-mixed-levels central composite rotatable design (CCRD) was applied to optimize the ultrasound treatment and storage environments for better-quality physical [total soluble solids (TSS), firmness, and total color changes (ΔE)], microbial [total viable count (TVC)], nutritional [total phenolic content (TPC), DPPH antiradical activity, glucose, and fructose] features of Barhi dates. The outcomes showed that ultrasound intensity and its application time, storage temperature, and storage period influence the physical, microbial, and nutritional quality attributes in different magnitudes. The ideal settings for lessening the changes in the physical attributes, eliminating the microbial growth, and improving the nutritional quality attributes were 140 W/cm2, 5.2 min, 20.9 °C, and 21 days for ultrasound intensity, ultrasound exposure duration, storage temperature, and storage duration, respectively. In conclusion, this study proved the potential application of ultrasound for persevering the excellence aspects of Barhi dates and identified the ideal ultrasound environments for maintaining the physical, microbial, and nutritional quality features of Barhi dates during extended storing.

Influence of Different Coffee Brewing Methods on the Biochemical Composition of Fruit Juice and Coffee Drink

Abstract A fruit juice and coffee drink is an interesting combination that provides the necessary bioactive compounds and caffeine for the whole day. The coffee brewing method changes not only the amount of caffeine but also the taste of fruit juice and coffee drink. The least bitter taste is felt in cold brewed coffee, making it an ideal ingredient for a fruit juice and coffee drink. The aim of this study was to evaluate the influence of preparing technologies for creating an innovative fruit juice and coffee drink with a high content of bioactive compounds. Four different types of medium-roasted “Lofbergs” coffee beans were compared, as well as two brewing techniques: French press (hot coffee) and cold-brew. Concentration of vitamin C, pH, soluble solids content, titratable acids, total phenol content, DPPH antiradical activity, and sensory analyses were determined for all prepared samples. Concentration of vitamin C in juice with coffee was from 10.36 to 22.60 mg·100 g−1, and the highest vitamin C concentration was preserved in the pasteurised juice and coffee drink with cold-brew coffee preparation technique. Concentration of soluble solids was from 12.3 to 12.6%, titratable acids from 0.79 to 0.87%, pH from 2.68 to 2.88, total phenols from 54.31 to 129.26 mg·100 g−1, and the highest total phenol concentration was obtained in the pasteurised fruit and coffee drink with smooth and sweet coffee beans prepared using the cold-brew technique. DPPH antiradical activity was from 126.24 to 177.89 mg·100 g−1 in the tested samples, and the highest DPPH antiradical activity was detected in the pasteurised fruit and coffee drink with sweet and nutty coffee beans prepared with cold-brew technique. The best sensory profile was for coffee and juice drinks with “Lofbergs” Medium roast Fruity and Velvety Rwanda coffee beans and “Lofbergs” Medium roast prepared with cold-brew technology.

DPPH antiradical activity and total phenolic content of methanol and ethanol extracts from macroalgae (Ulva rigida) and microalgae (Chlorella)

Introduction: Algae are widely popular as dietary supplement. Furthermore, they can be a great source of antioxidants (pigments, alkaloids, carotenoids, phenolic acids, sulfated polysaccharides and long-chain polyunsaturated fatty acids etc.) and can be used instead of synthetic ones. The different nutrient compositions of algae depend on class, species, habitats, maturity, and environmental conditions. Aim: The present study aims to investigate the differences in the antioxidant activity (AOA) and total phenolic content (TPC) of macroalgae Ulva rigida from the Black Sea and microalgae Chlorella . In addition, the obtained results will show their potential as natural sources of antioxidants. Materials and Methods: The marine macroalgae Ulva rigida and the microalgae Chlorella were used to perform different solvent extracts, which were analyzed for antiradical activity and total phenol content. Results and Discussion: All analyzed extracts (methanol and ethanol) showed positive results of the DPPH test and TPC. Both methanol extracts of microalgae Chlorella and macroalgae Ulva rigida had higher scavenging effect on used radicals for antioxidant activity compared to both ethanol extracts of the same plant material. The results show high potential as natural source of antioxidants of both algae species due perhaps to the phenolic content and other compounds having antioxidant activity. Conclusion: Both Ulva rigida and Chlorella can be used as a source of antioxidants and phenolic acids, which can be added to new functional foods and supplements, as well as be the basis of pharmaceutical and cosmetic products.

Antimicrobial and antioxidant properties of Saturn peach subjected to ultrasound-assisted osmotic dehydration

This study was performed to investigate the effectiveness of ultrasound-assisted osmotic dehydration on reducing foodborne pathogens (Escherichia coli, Enterococcus faecalis, Salmonella Typhi and Shigella sonnei), as well as its impact on moisture content and antioxidant properties of Saturn peach. Peach samples were inoculated and underwent ultrasonic waves (50 and 75% amplitudes). Afterwards, the osmotic dehydration was performed by immersing the samples in 70% sucrose solution (for 4, 8 and 12 h). Results indicated that ultrasound pre-treatment markedly diminished the microbial count and the reduction levels of pathogens enhanced with the increase of ultrasound amplitude. The greatest reduction in pathogens was observed at 75% amplitude after 12 h storage in osmotic solution, in which the mean number of E. coli, E. faecalis, S. Typhi and S. sonnei was reduced to 0.1, 4.2, 3.7 and 0.1 log CFU/g, respectively. Additionally, osmotic dehydration treatment significantly reduced the amount of moisture content, total phenolics and DPPH antiradical activity of samples. It should be added that increasing the ultrasound amplitude led to a further decrease in the mentioned parameters.

Extraction and Estimation of Pectins from Unripe, Ripe and Overripe Banana (&lt;I&gt;Musa Acuminata L.&lt;/I&gt;) and Plantain (&lt;I&gt;Musa Paradisiaca L.&lt;/I&gt;) Peels and their Antioxidant Activities

Background: Pectin has several unique properties that enabled it to be use as a matrix for entrapment and/or delivery of a variety of drugs, proteins and cells. They are used in pharmaceutical as carriers in drug delivery, and in the treatment of various disease conditions.Objectives: This study aimed at determining percentage yield of pectin, extracted from unripe, ripe, and overripe Banana (Musa acuminata L. Musaceae) and Plantain (Musa paradisiaca L. Musaceae) peels and to evaluate their antioxidant activities.Materials and Method: Pectins were extracted from the stated samples using conventional extraction method involving alcohol precipitation, and the percentage yields were calculated. The DPPH antiradical activity and reducing capacity was assayed, using Ascorbic acid as standard.Results: The percentage yield of pectin were obtained as 3.04±0.97%, 5.84±0.49%, 3.70±0.68% for banana and 4.65±0.70%, 6.61±0.21%, 6.91±0.86% for plantain corresponding to unripe, ripe, and overripe respectively. The extracted pectin of all the samples were observed to be statistically inferior to when compared to the standard used Ascorbic acid at all concentrations of samples prepared for both DPPH antiradical activity assay and Reducing capacity assay (p ≤ 0.005), at 95% confidence interval.Conclusion: The yield of banana peel pectin have an initial increase with ripening followed by a decrease in yield, while plantain peel pectin can be said to increase from its unripe stage through to its overripe stage; with plantain pectin yield greater than banana across all stages. All data showed statistical inferiority to Ascorbic acid in reducing capacity and against DPPH.&#x0D; Keywords: Pectin, Banana, Plantain, DPPH, Ripening, Antioxidant

Isolation and Identification of DPPH Radical (2,2-diphenyl-1-pikrylhidrazyl) Scavenging Active Compound in Ethyl acetat fraction of Piper acre Blume

Piper acre Blume, known as Black Betel (local name), is a plant that is widely used by the people of East Kalimantan, especially in Samarinda, for the treatment of illness. Leaves (3-4 months old) are collected from Samarinda, extracted, fractionated, and monitored by DPPH antiradical activity. The isolation of the Piper acre Blume is performed on the active fraction, and the structure identification is based on spectroscopic data of the compound. The leaves were dried, pulverized, and macerated with MeOH. Dried MeOH extract was obtained upon evaporation of the solvent. The extract was then fractionated by vacuum liquid chromatography (vlc), eluted gradually by solvents having different polarities (n-hexane, ethyl acetate and methanol). The fractions obtained were monitored using TLC [n-hexane: ethyl acetate (3: 1 v/v)] that was visualized by UV254 nm, UV366 nm and DPPH. The isolation was performed by preparative TLC [SiO2, n-hexane: ethyl acetate (3: 1)] on ethyl acetate fraction that showed the highest DPPH antiradical value. A single compound was obtained, and it appeared as a round spot and pure according to TLC performances at 3 different solvent systems. The isolated Piper acre Blume compound displayed the IC50 value on the anti-radical DPPH (measured at λ 520 nm) as 10.41µg/mL. The IR spectrum (KBr) showed –OH band (3450 cm-1), aliphatic bands [alkene, 3010 cm-1; alkana 2900 cm-1), an aromatic overtone bands (1900-200 cm-1) and a strong C=O band (1725 cm-1). The NMR (1H- and 13C-) (mono and 2D) indicated the present of a p-di-substituted aromatic signals (δ, 7.54 and 7.52, d, J =6 Hz, 1 H each), 2 methyl (δ, 0.96, d, J = 7.0 Hz, 6 Hs), a triplet signal (δ, 4.22 ppm). Other signals of CH- and CH2 were shown as m signals at δ, 1.64 and 1.34 ppm. Based on those data, the compound was identified as isoamyl p-OH benzoate that is grouped as parabens used as a preservative in the pharmaceutical preparations. In conclusion, the anti-radical (DPPH) active compound present in the leaves of Piper acre Blume is identified as isoamyl p-OH benzoate, having IC50 value anti-radical DPPH 10,41µg/mL.

Chemical characterization of essential oils and antioxidant activity of Dictyota dichotoma and Dictyopteris membranacea

The work focuses on the study of two brown algae Dictyota dichotoma and Dictyopteris membranacea. Extracts obtained by different organic solvents (dichloromethane, hexane, acetone, methanol, chloroform) were screened for their DPPH antiradical activity, whereas essential oils obtained by steam distillation were chemically characterized by GC-MS. Steam distillation yielded 0.07 and 0.095% of the essential oils for Dictyota dichotoma and Dictyopteris membranacea, respectively. The chemical screening of the essential oils of Dictyopteris membranacea and Dictyota dichotoma showed similar chemical profiles. Namely, trans-anethole showed to be the main component in both studied oils, yielding 12.28% and 10.70% for Dictyopteris membranacea and Dictyota dichotoma, respectively. Antioxidant activity of extracts was expressed by IC50 values and was in the range 0.375-1.72 mg/ml.

DPPH antiradical scavenging, anthelmintic and phytochemical studies of Cissus poulnea rhizomes

Objective: To investigate the phytochemical constituents, antioxidant and anthelmintic activities of the crude methanol extract of Cissus populnea (C. populnea) rhizomes. Methods: Phytochemical screening was performed using standard protocols, and column chromatography of silica gel was used for the compounds isolation. DPPH antiradical scavenging assay was performed in order to evaluate the antioxidant activity. Total phenolic content was evaluated using the Folin–Ciocalteu assay. The anthelmintic activity was screened on the bovine adult male forms of parasitic nematode Onchocerca ochengi, by the in vitro evaluation of the inhibition of adult worm motility and mortality. Worms were incubated in the presence of different concentrations of the plant extract and effects on survival were monitored after 24 and 48 h. Results: The preliminary phytochemical screening revealed the presence of phenolic compounds, saponins, steroids, tannins, and terpenoids. Bergenin and a mixture of phytosterol, β -sitosterol and stigmasterol were isolated from this extract and were identified by nuclear magnetic resonance, mass spectrometry and by comparison with published data. The crude methanol extract of C. populnea rhizomes showed a strong DPPH antiradical activity with a good amount of total phenolic content ((20.69±2.13) g gallic acid equivalent/100 g of extract) and significant anthelmintic activity comparable to the standard drug ivermectin. Bergenin was found to be inactive even after 72 h of incubation. Conclusions: This study constitutes the first report on the anthelmintic activity of this plant and supports the traditional use of C. populnea as a natural antioxidant and anthelmintic.

A Palladium Catalyst System for the Efficient Cross-Coupling Reaction of Aryl Bromides and Chlorides with Phenylboronic Acid: Synthesis and Biological Activity Evaluation.

New benzimidazolium salts 1a–c and their palladium bis-N-heterocyclic carbene complexes 2a–c and palladium PEPPSI-type complexes 3a–c were designed, synthesized and structurally characterized by NMR (1H and 13C), IR, DART-TOF mass spectrometry and elemental analysis. Then these complexes 2–3 were employed in the Suzuki-Miyaura cross-coupling reaction of substituted arenes with phenylboronic acid under mild conditions in toluene and DMF/H2O (1/1) to afford functionalized biaryl derivatives in good to excellent yields. The antibacterial activity of palladium bis-N-heterocyclic carbene complexes 2a–c and palladium PEPPSI-type complexes 3a–c was measured by disc diffusion method against Gram positive and Gram negative bacteria. Compounds 2a, 2c and 3a–c exhibited potential antibacterial activity against four bacterial species among the five used indicator cells. The product 2b inhibits the growth of the all five tested microorganisms. Moreover, the antioxidant activity determination of these complexes 2–3, using 2.2-diphenyl-1-picrylhydrazyl (DPPH) as a reagent, showed that compounds 2a–c and 3b possess DPPH antiradical activity. The higher antioxidant activity was obtained from the product 2b which has radical scavenging activity comparable to that of the two used positive controls (gallic acid “GA“ and tutylatedhydroxytoluene “BHT“). Investigation of the anti-acetylcholinesterase activity of the studied complexes showed that compounds 2b, 3a, and 3b exhibited moderate activity at 100 μg/mL and product 2b is the most active.

Kinetic study of the DPPH antiradical activity of lipophilic tomato waste extracts

In this study, lipophilic tomato waste extracts (obtained from the Knjaz, Backa, Saint Pierre, Rutgers and Novosadski niski genotypes) were analyzed to determine their lycopene and ?-carotene content, as well as their kinetics of antiradical activity. The kinetic behaviour of lipophilic tomato waste extracts and standard antioxidant compound (BHA) were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical test. In addition, correlations between the contents of lycopene and ?-carotene content and antiradical activity of lipophilic tomato waste extracts were also sought. The content of lycopene in tomato waste extracts ranged from 4.29 ? 0.14 mg/g for Rutgers waste exract to 22.64 ? 0.86 mg/g for Knjaz waste extract, while the content of ?-carotene varied from 2.48 ? 0.09 mg/g for Novosadski niski waste exract to 15.93 ? 0.56 mg/g for Knjaz waste extract. Based on the time required for the DPPH radical-extract reaction to reach steady state, the investigated lipophilic extracts, as well as BHA can be classified as the antioxidants with slow (steady state ? 150 min) antiradical behaviour. A comparison of the efficient concentrations at different kinetic times (EC50,t) for the lipophilic tomato waste extracts and BHA showed that the DPPH antiradical activity decreased in the order of BHA &gt; Knjaz &gt; Backa &gt; Saint Pierre &gt; Rutgers &gt; Novosadski niski. The results of the correlation analysis suggest that lycopene is the main individual carotenoid responsible for the EC50,t values of the tomato waste extracts towards the stable DPPH radical.