EXTRACTION OPTIMIZATION AND ANTIOXIDANT ACTIVITY OF PHENOLIC COMPOUNDS FROM AVOCADO PEEL

2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel

Author(s):  
Naficeh Sadeghi ◽  
Masoomeh Behzad ◽  
Behrooz Jannat ◽  
Mannan Hajimahmoodi ◽  
Mohammad Reza Oveisi ◽  
...  

Tea is the most widely consumed and popular non-alcoholic beverage in the world. Reactive oxygen spices may cause wide range of damages to biological systems. Purpose of this study was to determine the total antioxidant capacity and total phenolic of different black tea samples in Iran. The FRAP (Ferric reducing antioxidant power) assay was used for antioxidant activity. The total phenolic content was measured based on the Folin-Ciocalteu method. The results showed that all samples had substantial antioxidant activity and total phenolic content. Iranian tea samples had significantly the lowest 0.98 ± 0.15, 0.75 ± 0.17 µmoll-1 and Kenya tea samples had significantly the highest 2.67 ± 0.61, 2.10 ± 0.65 µmoll-1 amount of total antioxidant capacity and total phenolic, respectively. A linear positive relationship was observed between the antioxidant activity and total phenolic content of the black tea samples. These findings suggest that black tea can be considered as natural source of antioxidant and total phenolic compounds.


Genetika ◽  
2020 ◽  
Vol 52 (3) ◽  
pp. 825-834
Author(s):  
Emre Sevindik ◽  
Sinem Aydin ◽  
Mehmet Paksoy ◽  
Bahar Sokmen

The genus Inula belongs to family Asteraceae and it is medicinally important because it possesses cytotoxic, anticancer, hepatoprotective, antibacterial and anti-inflammatory properties. The aim of this research was to explore antioxidant and anti-urease activities of fifteen Inula taxa in Turkey. Ethanol extracts of Inula taxa were obtained by Soxhlet extraction. Antioxidant activity was determined through total antioxidant activity, total phenolic content and copper reducing antioxidant capacity (CUPRAC) analyses. The highest total phenolic content and total antioxidant capacity were found in I. orientalis (158.54?0.002 ?g GAE/mL) and I. macrocephala (189.16?0.002 ?g AAE/mL). CUPRAC activity increases with the increasing concentration of the extracts and the standard. Moreover, all the tested plants exhibited better anti-urease activity than standard thiourea except for I. anatolica and I. thapsoides subsp. thapsoides. Results obtained from this study demonstrate that Inula species might be utilized as a probable natural source in the pharmaceutical and food industries but further and more specific studies are needed to determine active antioxidative and anti-urease compounds in the extracts.


Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 2095-2102
Author(s):  
O. Herrera-Calderon ◽  
R. Vega

Waltheria ovata is a medicinal plant belonging to the Sterculiaceae genus. Natural products of Waltheria ovata could be used in the food industry as natural antioxidants due to its high content of polyphenols according to the literature. The main objective in this research was to optimize the extraction of phenolic compounds and the antioxidant activity from Waltheria ovata roots using response surface methodology (RSM). The total phenolic content in different extracts was determined by spectrophotometric method (Folin-Ciocalteu reagent) and the antioxidant activity by using DPPH assay. To optimize the conditions for total phenolic content and antioxidant activity were used three independent variables: solvent/sample ratio (1:10, 1:20 and 1:30 g/mL), temperature (40, 50, and 60°C) and time (40, 50 and 60 mins). The results showed that total phenolic content and antioxidant activity in the experiments ranged from 8.7 to 12.1 mg GAE/g and 76.1% to 96.7%, respectively. The coefficients of determination (R2 values) for phenolic content and antioxidant activity were 0.86 and 0.91, respectively. Under the optimum conditions of 1:20 g/mL, 60°C and 55 mins of extraction, the values for total phenolic content and antioxidant activity were 0.448±0.02 mg GAE/g and 87.00±2.0%, respectively. These data showed that the experimental responses were reasonably close to the predicted responses (0.444 mg GAE/g and 84.67%). Therefore, the results showed that Waltheria ovata can be used as antioxidant in foods.


2021 ◽  
Vol 13 (16) ◽  
pp. 8818
Author(s):  
Georgia-Christina Mitraka ◽  
Konstantinos N. Kontogiannopoulos ◽  
Maria Batsioula ◽  
George F. Banias ◽  
Andreana N. Assimopoulou

The amount of spent coffee grounds (SCGs) created, represents an environmental challenge worldwide. In this context, the aim of the present study was to exploit the potential of SCGs as a source of bioactive compounds that can be utilized in high value-added products. Thus, a cost-effective and environmentally friendly extraction technique was developed to ensure extracts with high total phenolic content and antioxidant activity, as well as significant amounts of caffeine and chlorogenic acid. Response surface methodology was implemented to evaluate the effects of the main extraction parameters (i.e., time, temperature, and ethanol-to-water ratio) and their interactions on the defined responses. The ethanol ratio was found to be the most significant variable. Then, a set of optimum values was determined (i.e., 7 min, 75 °C, and ethanol:water ratio 5:95), where the predicted values for responses were found to be 5.65% for the yield (Y1), 152.68 mg gallic acid equivalents per L for total phenolic content (Y2), 0.797 μmol Trolox equivalent per mL for the antioxidant activity (Y3), 30.5 ppm for caffeine concentration (Y4), and 17.4 ppm for chlorogenic acid concentration (Y5). Furthermore, the corresponding high experimental values from the validation experiment fitted well to these predictions, clearly clarifying the high potential of SCG extracts for use in high value-added applications.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1999
Author(s):  
Mohammad Kaveh ◽  
Yousef Abbaspour-Gilandeh ◽  
Ebrahim Taghinezhad ◽  
Dorota Witrowa-Rajchert ◽  
Małgorzata Nowacka

Most agricultural products are harvested with a moisture content that is not suitable for storage. Therefore, the products are subjected to a drying process to prevent spoilage. This study evaluates an infrared rotary dryer (IRRD) with three levels of infrared power (250, 500, and 750 W) and three levels of rotation speed (5, 10, and 15 rpm) to dry terebinth. Response surface methodology (RSM) was used to illustrate and optimize the interaction between the independent variables (infrared power and rotation speed) and the response variables (drying time, moisture diffusivity, shrinkage, color change, rehydration rate, total phenolic content, and antioxidant activity). As infrared power and rotation speed increased, drying time, rehydration rate, antioxidant activity, and total phenolic content decreased, while the other parameters were increased. According to the results, the optimum drying conditions of terebinth were determined in the IRRD at an infrared power of 250 W and drum rotation speed of 5 rpm. The optimum values of the response variables were 49.5 min for drying time, 8.27 × 10−9 m2/s for effective moisture diffusivity, 2.26 for lightness, 21.60 for total color changes, 34.75% for shrinkage, 2.4 for rehydration rate, 124.76 mg GAE/g d.m. for total phenolic content and 81% for antioxidant activity.


Author(s):  
Milica Stojanović ◽  
Vuk Maksimović ◽  
Dragosav Mutavdžić ◽  
Ivana Petrović ◽  
Zorica Jovanović ◽  
...  

Lettuce is a worldwide grown leafy vegetable rich in phytochemicals which are essential in human diet. The aim of this study was to examine the effect of genotype, microbiological fertilisers and season on the rosette fresh weight and components of antioxidant activity. Six cultivars (green ‘Kiribati’, ‘Aleppo’, ‘Aquino’ and red ‘Murai’, ‘Carmesi’, ‘Gaugin’) were grown in a greenhouse experiment during three consecutive seasons (autumn, winter and spring) with application of microbiological fertilisers (EM Aktiv, Vital Tricho and their combination). Green cultivars showed higher fresh weight than red in spring and winter. Green cultivar ‘Aleppo’ showed the highest fresh weight in control during spring. Microbiological fertilisers led to increased fresh weight in autumn. Mainly, red cultivars showed higher quality parameters compared to green (total antioxidant capacity, total phenolic content, total carotenoids and POD activity). Red cultivar ‘Carmesi’ showed the highest total antioxidant capacity, total carotenoids, and total phenolic content in winter with combination of fertilisers, Vital Tricho, and in control. In spring, ‘Carmesi’ and ‘Gaugin’ showed the highest POD activity with Vital Tricho, and combination of fertilisers. The present study suggested that genotype, fertilisers and season jointly influenced quantity and quality parameters with emphasis on Vital Tricho, and/or combination of fertilisers.


2014 ◽  
Vol 23 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Zhichun Xie ◽  
Jinshuan Fan ◽  
Denis Charlebois ◽  
Dominique Roussel ◽  
Claudine Dubé ◽  
...  

Eleven advanced strawberry lines (‘SJ011‑10’, ‘SJ0440‑2’, ‘SJ061‑8’, ‘SJ066‑3’, ‘SJ069‑3’, ‘SJ069‑12’, ‘SJ0814‑37’, ‘SJ8518‑11’, ‘K04‑12’, ‘LL0220‑10’ and ‘V151’) were evaluated for their yield, fruit quality, total phenolic content, total antioxidant capacity, and phenolic composition, and were compared with a commercial cultivar (‘Wendy’). The results showed that ‘SJ069‑3’ had excellent soluble solids content, mid-level titratable acidity, low weight loss, and the best firmness among all the cultivars. Higher total antioxidant capacity was found in ‘SJ069‑3’, according to ferric reducing antioxidant power and oxygen radical absorbance capacity assays, an indication that ‘SJ069‑3’ is a promising new cultivar for the fresh market. In addition to rich individual phenolics, ‘SJ061‑8’ had the highest total antioxidant capacity, which was significantly different from the other genotypes, suggesting the potential use of this line as parent material in breeding or as a functional food ingredient. There was a strong relationship between total antioxidant capacity and total phenolic content, according to Folin–Ciocalteu, ferric reducing antioxidant power, and oxygen radical absorbance capacity assays. This study confirms that anthocyanins are major phenolic compounds contributing to the main antioxidant power of strawberries.


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