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The Phenolic Content and Antioxidant Capacity of Pumpkin, Rosehip and Pomegranate Seeds
2024
Sena Bakır
Food waste is a significant problem worldwide. These food wastes, often discarded without any preliminary processing, can be rich in bioactive substances. In this study, the aim was to identify the phenolic compounds in pumpkin, rosehip and pomegranate seeds, which are frequently consumed in winter. For this purpose, ultrasonically assisted methanolic extracts were prepared from seeds separated from other waste parts (such as shells, stems, and leaves). The results indicated that pomegranate seeds had the highest total phenolic content, with 45.6±3.1 mg GAE/g sample (P<0.05). Similarly, pomegranate seeds also showed the highest total antioxidant capacity in both CUPRAC (114.7±2.6 mg torolox/g sample) and DPPH (71.2±3.8 mg torolox/g sample) analyses (P<0.05). In phenolic profiling analysis using HPLC-PDA, syringic acid was the most abundant compound in pumpkin seeds, (-)-catechin in rosehip seeds, and punicalagin derivatives in pomegranate seeds.
Show more [+] Less [-]Quality Parameters and Antioxidant Activity, Phenolic Compounds, Sensory Properties of Functional Yogurt with Melon (Cucumis melo L.) Peel Powder
2024
Zuhal Okcu | Filiz Yangılar
In the current study, four different types of yogurt were produced as control samples (no MPP added) and 1, 2, and 3% melon peel powder (MPP1, MPP2, and MPP3). These yogurts were determined by physicochemical, microbiological, sensory, total phenolic, and antioxidant activity weekly for 21 days. While ash, moisture, titratable acidity (TA), viscosity, water holding capacity (WHC), a* and b* values, total phenolic content (TPC), and antioxidant capacity of melon peel powder samples increased, L*, pH, and syneresis values decreased. In concentrations of 1, 2, and 3%, the mean antioxidant activity of powdered yogurt was found to have average values during storage of 30.09%, 32.32%, and 36.26%, respectively. All yogurts continued to contain more than 107 cfu/g of live lactic acid bacteria during fermentation. As the storage time increased, the sample’s pH and syneresis decreased, while titration acidity and texture increased. No yeast or mold (2 log cfu/g) was determined in the samples. The panelists preferred MPP1 and MPP2 samples. According to the findings of the study, melon rind powder, which is a by-product, can be recommended as a functional food additive in yogurts.
Show more [+] Less [-]The Effects of Seed Infestation by Fusarium proliferatum on Root and Crown Rot, Plant Growth and Phenolic Compounds in Roots of Some Pumpkin (Cucurbita pepo L.) Cultivars
2023
Ebru Sevinç | Nuray Özer
This study investigates the reactions of four summer pumpkin cultivars (cvs. Çağlayan, Mert Bey, Sena Hanım, TG38) to root and crown rot caused by Fusarium proliferatum by taking into account criteria such as disease severity, plant growth (number of leaves, height, dry and fresh weight of shoot) and the accumulation of phenolic compounds in the roots. Seeds of each cultivar were inoculated with the pathogen and left to develop for 1 month at 25oC in a controlled climate room. The content of phenolic compounds in ethanolic root extracts was determined using high-performance liquid chromatography (HPLC). Cv. Sena Hanım had the lowest disease severity (4.40%) among the cultivars, followed by cvs. Çağlayan (10.62%) and Mert Bey (11.07%). Plants developed from inoculated seeds of cvs. Çağlayan and Sena Hanım had no decrease in the number of leaves and in length, fresh and dry weight of shoots in comparison to the control (plants from non-inoculated seeds), while cv. Mert Bey demonstrated a decrease at very low rates in shoot fresh and dry weight (2.24% and 0.77%, respectively). The phenolic compound that exhibited the highest increase in root extracts of cv. Sena Hanım compared to the control among the cultivars was p-coumaric acid (6.57-fold). This study demonstrates that p-coumaric acid can play an important role in the resistance of pumpkin to seed infestation by F. proliferatum.
Show more [+] Less [-]Studies of Phenolic Compounds Coupled to Minerals in Cocoa Beans of the “Mercedes” and “Forastero” Varieties from the Divo and Abengourou Regions (Côte d’Ivoire)
2022
Jean Constant Kouablan Karim | Suomion Justin Saki | Tehi Bernard Sea | Kouassi Aboutou Severin Kra | Guillaume Arthur Kouassi Loh Yoboue
The aim of this study is to contribute to the valorization of the cocoa bean varieties “Mercedes” and “Forastero” grown in Côte d’Ivoire. A comparative characterisation of phenolic compounds and minerals in the beans of the “Mercedes” and “Forastero” varieties from two major cocoa production areas of Côte d’Ivoire were determined. The phenolic compounds of cocoa beans were determined by high performance liquid chromatography (HPLC) and the minerals by atomic absorption spectrophotometer. The study showed that a significant difference at the 5% level was observed in the averages of minerals, cinnamic acid, protocatechic acid, quercetin, coumaric acid, rutin, ellagic acid, veratric acid, epicatechin, ferulic acid and naringenin. On the other hand, no significant difference at the 5% level was observed in the averages of arbutin, catechin, vanillic acid and caffeic acid in the bean kernels analysed in the Divo and Abengourou regions. The proportion of cinnamic acid is (6.18±0.63 mg/100g “Mercedes” Divo), that of ellagic acid is (18.48±0.44 mg/100g “Mercedes” Divo) and that of naringenin is (5.95±0.35 mg/100g “Mercedes” Divo). The amount of potassium is (7569.97±1.51 mg/kg “Forastero” of Abengourou) and that of iron is (179.9 ± 0.70 mg/Kg “Forastero” of Divo). The phenolic compounds and minerals in the cocoa bean samples analysed are highly correlated and rich in antioxidants. They would be beneficial for many biological functions. They can be recommended in pharmacology and cosmetics to fight against oxidative stress and cardiovascular diseases.
Show more [+] Less [-]The Bifunctional Catalase-Phenol Oxidase of Mycothermus Thermophilum (MtCATPO) Increases the Antioxidant Capacities of its Ortho-Diphenolic Substrates and of Green and Black Tea Extracts
2021
Betül Söyler | Zümrüt Begüm Ögel
Catalase from the thermophilic fungus Mycothermus thermophilus is a bifunctional enzyme with a secondary phenol oxidase activity (CATPO). MtCATPO catalyses the oxidation of catechol, chlorogenic acid, caffeic acid and (+)-catechin to yield mainly dimers, and higher molecular weight oligomers and polymers. The role of this phenol oxidase activity is not known. Here, the antioxidant capacities (AC) of the phenolic substrates in the absence and presence of MtCATPO were compared. The oxidized products displayed enhanced AC reaching a maximum of 2.4-fold with catechol. Other phenol oxidases (laccase and tyrosinase) did not yield AC enhancement to the same extent. MtCATPO-treatment increased AC of green and black tea infusions, as well as water extracts of samples collected from a black tea production line up to 28%. The bifunctional MtCATPO appears to be an important antioxidant enzyme with a wide range of potential applications in the food, neutraceuticals and pharmaceuticals industry.
Show more [+] Less [-]Phenolic compound and antioxidant activity of two slightly consumed wild mushrooms (Lentinus squarrosulus and Auricularia politrich) in three regions from center Ivory Coast
2021
Hermann Fourier Atta Anno | Hyacinthe Attoh Anon | Koffi Amoin Gisèle | Appolinaire Kouamé Kouassi | Jean Parfait Eugène Kouadio
Mushrooms contain a variety of secondary metabolites, including various phenolic compounds, which have been shown to act as excellent antioxidants. In this study, the contents of total phenolic, flavonoids and tannins of mushrooms methanolic extracts were evaluated by colorimetric assays to ranges of 277.36±0.66 to 420.86±0.90 mg (GAE)/100g DW; 31.99±0.90 to 90.90±0.07mg (QE)/100g DW and 150.61±0.16 to 220.47±1.01mg (TAE)/100g DW respectively. HPLC-profiles of methanolic extracts indicated that the individual phenolic compounds found to the samples of the species of mushrooms that are Lentinus squarrosulus and Auricularia politrich revealed us that gallic acid, catechin, acid ρ-hydroxybenzoїc, acid ellagique and naringerin were presented to the level of the two species. With respect to organic acids, the results showed that citric acid and fumaric acid was the major organic acid in all the samples of both mushrooms species. The methanolic extracts of the two mushrooms exhibited the high DPPH radical scavenging activities ranging from 34.10±1.12 to 58.95±0.52%. These data indicated that these mushrooms could constitute a potential good source of natural antioxidant for the local population.
Show more [+] Less [-]UV-B Radiations and Secondary Metabolites
2020
İlkay Yavaş | Aydın Ünay | Shafaqat Ali | Zohaib Abbas
Ultraviolet-B (UV-B: 280 to 320 nm) radiations have appeared to be detrimental to plants, due to their damaging effects on proteins, lipids, membranes and DNA. UV-B radiations are a significant regulator of plants’ secondary metabolites. High intensity of ultraviolet radiations may interfere with growth and productivity of crops. But low levels of UV-B radiations give rise to changes in the plants’ secondary metabolites such as phenolic compounds, carotenoids and glucoseinolates. Therefore, low intensity of UV-B radiations may be used to generate plants, enriched with secondary metabolites, having improved reproductive ability, early ripening and tolerance against fungi, bacteria and herbivores.
Show more [+] Less [-]Phenolic Compounds and Antioxidant Activity of Local Cultivar of Apple (Malus domestica Borkh) in East of Turkey
2020
Gülden Gökşen | Fevzi Keleş
Apples, rich in phenolic compounds, are widely grown in abundance and consumed as fruit which reduces the risk of many illnesses. In this study, physico-chemical properties old apple cultivars from east of Turkey were investigated. Identification and quantification of phenolic compounds of freeze dried fresh apple varieties (fruit, pulp and peel) were analysed by using the HPLC method. Total phenolic content and antioxidant capacity of samples was also found in 25.00-11.63 mg GAE/g DW and 49.86-86.12 µmol TE/g DW. The highest antioxidant activity was identified in the peel of the Kara Sakı apple whereas the lowest was identified in the pulp of Ak Sakı. Varieties of apple differ significantly in terms of ferulic acid and hidroxycinnamic acid. (-)-Epicatechin was found in the peel of Kara Sakı apple at the very most and p- coumaric acid was found in the pulp of Kara Sakı at the very least. Hidroxycinnamic acid was identified only in the peel. It is approved to these cultivars show unique long shelf life (unusual for apples) without any storage condition due to the significantly presence of ferulic acid.
Show more [+] Less [-]Properties of Antioxidant and Anti-Inflammatory Activity and Phenolic Profiles of Şevketi Bostan (Cnicus benedictus L.) Cultivated in Aegean Region from Turkey
2017
Zehra Can | Nimet Baltaş | Saban Keskin | Oktay Yıldız | Sevgi Kolaylı
The aim of this work was to evaluate the phenolic profiles and anti-inflammatory, antioxidant and gastro-protective activities of Cnicus benedictus L., a type of milk thistle cultivated in Turkey. The total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity was measured to determine antioxidant capacity. The anti-urease and anti-xanthine oxidase activities were used to determine the gastro-protective and anti-inflammatory potential of the plant extracts, respectively. The TPC was 337.40 and 635.10 mg of gallic acid equivalents (GAE)/100 g and TFC was 41.05 -119.12 mg of quercetin equivalents (QE)/100 g in the root and leaf extracts, respectively. The root and leaf extracts of Cnicus benedictus L., were exhibited different inhibition values against both of the enzymes. The inhibition effect of the both enzymes were calculated as IC50 (mg/mL) in terms of 50% inhibition of the enzymes. The xanthine oxidase activity of the leaf and root was 18.53 and 19.75 mg/mL and the urease activity were 2.29 mg/mL and 11.53 mg/mL, respectively. Fifteen phenolic compounds were determined by high-performance liquid chromatography (HPLC-UV). Vanillic, silibinin B, ferulic acid and rutin were found major amount of the plant. In conclusion, the plant have high potential beneficial nutraceuticals and consumption of the together with its roots and leafs will be beneficial in terms of nutrition.
Show more [+] Less [-]Comparison of Extraction Techniques for Determining Bioactive Compounds and Antioxidant Activity of Spirulina platensis
2024
Türkan Uzlaşır | Hatice Kübra Şaşmaz | Haşim Kelebek
Spirulina platensis (S. platensis) is a high-nutrient blue-green algae that has been used as a food supplement for a long time. It contains carbohydrates, lipids, proteins, vitamins, minerals, and bioactive compounds essential for basic human nutrition. It is known to have anti-cancer, antioxidant, anti-inflammatory, neuroprotective, hepatoprotective, and hypocholesterolemic properties due to the bioactive compounds it contains. In this study, the effects of freeze-thawing, a rapid freezing (-20°C) and thawing (4°C) process, and ultrasonically assisted extraction techniques on the color, antioxidant capacity, total phenolic content, and phenolic composition of Spirulina platensis extracts were investigated. The antioxidant capacity of the extracts obtained was determined by two different methods, DPPH (2,2-diphenyl-1-picryl hydrazyl) and ABTS (2,2-azinobis (3-ethylbenzothiazollin-6-sulfonic acid)). The sugar profile was determined by HPLC-RID and phenolic composition was determined by HPLC-ESI-DAD-MS/MS. The antioxidant activity and total phenolic content of samples prepared by the freeze-thawing were higher than those prepared by ultrasonic-assisted conventional extraction technique. In addition to ferulic acid 4-O-glucuronide and brevifolin carboxylate, an isocoumarin derivative, as the dominant phenolic compound in S. platensis extracts, a total of 10 phenolic compounds including catechin isomer, resveratrol C-hexoside, myricetin, ferulic acid, gallic acid, phloroglucinol, and lutein were detected. Glucose was the predominant sugar in both samples. The total sugar content was higher in the freeze-thawed samples (217.92 mg/100 g DW) than in the ultrasonic-assisted conventional extraction technique (182.91 mg/100 g DW). S. platensis has a significant amount of antioxidants, valuable secondary metabolites, and potential commercial applications and medicinal properties, but releasing these compounds is difficult due to the cell wall. This study was carried out to determine how different extraction techniques alter the release of bioactive compounds.
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