Antioxidant Activity of Pink-Flesh Guava (Psidium guajava L.): Effect of Extraction Techniques and Solvents

Abstract

The effect of commonly used techniques and solvents in the antioxidant activities of pink-flesh guava fruit were studied. The extraction techniques compared were homogenization, shaking, sonication, magnetic stirring, and maceration for 1, 2, and 3 days. The solvent systems used were methanol, ethanol, and acetone at three different concentrations (50%, 70%, and 100%) and with 100% distilled water. The antioxidant activity of the fruit was evaluated using Folin-Ciocalteu index, ferric-reducing antioxidant power assay, and 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging capacity. Ultrasonic and homogenization were the best techniques to extract the antioxidant from guava fruit. Homogenization technique was found to be the most convenient exhaustive and time-saving extraction technique. Results showed that the extracting solvent significantly (P<0.05) altered the antioxidant property estimations of pink-flesh guava fruit. Pure solvents were inefficient extraction media for antioxidant. Enhanced extraction yields were obtained from solvent containing higher water concentrations and 50% acetone is a recommended solvent for extracting antioxidants compounds from pink-flesh guava fruit. High correlations between phenolic compositions and antioxidant activities of pinkflesh guava extracts were observed. High levels of antioxidant activities were detected in pink-flesh guava, indicating that the fruit may serve as an excellent dietary source of natural antioxidants.

Determination of Antioxidant Capacity, Total Phenolics and Antimicrobial Properties of Spray-Dried Guava Extract for Value-Added Processing

“…The dried guava powder showed good retention of antioxidants when compared with soluble extract through DPPH activity, which confirms that spray drying process does not affect the antioxidant capacity of the fruit powder. Earlier studies on the antioxidant activity of Guava through different extraction procedures found aqueous extraction through simple aqueous homogenization was best procedure [28]. This comparative study between guava powder and guava soluble extract showed higher quality of guava powder was maintained after processing.…”

Bioactive compounds and antioxidant activity during maturation of strawberry guava fruit

“…In contrast, those genotypes that showed the greatest AA for the four stages evaluated were P4, P6 and P7 and were indicated as being the most promising. The different values observed for antioxidant activity are due to the intrinsic characteristics of the fruit, to the method used for obtaining the extract, the extraction solution, the method of determination, and the compounds with an antioxidant action present in the tested material (MUSA et al, 2011). Genovese et al (2008) reported a capacity of 4.4 g mol -1 for guava of the species P. guineensis, of 1.8 g mol -1 in the araçá boi (Eugenia stipitata), of 141.0 g mol -1 in camu-camu and of 9.0 g mol -1 in cambuci.…”

Influence of ripening stages on antioxidant properties of papaya fruit (Carica papaya L.)

“…The determination of antioxidant activity through TPC was carried out according to the method of [10]. About 100 μL papaya extracts was added with 0.4 mL distilled water and 0.5 mL diluted Folin-Ciocalteu reagent.…”

“…The determination of antioxidant activity through FRAP was carried out according to the method of Musa et al [10]. FRAP reagent was prepared fresh as using 300 mM acetatebuffer, pH3.6 (3.1 g sodium acetate trihydrate, plus 16 mL glacial acid made up to 1:1 with distilled water); 10 mM TPTZ (2,4,6-tris (2-pyridyl)-s-triazine), in 40 mMHCLl; and 20 mM FeCl3•6H2O in the ratio of 10:1:1 to give the working reagent.…”

“…The determination of antioxidant activity through DPPH scavenging system was carried out according to the method of Musa et al [10]. Stock solution was prepared by dissolving 40 mg DPPH in 100 mL methanol and kept at -20°C until used.…”