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Subject: search.filters.subject.Antioxidant activities

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    Evaluation of antioxidant activities, total phenolic content (TPC), and total catechin content (TCC) of 10 sugar apple (Annona squamosa L.) cultivar peels grown in Thailand
    (2018-12-01)
    Manochai, Benya
    ;
    Ingkasupart, Pajaree
    ;
    Lee, Sang Hyun
    ;
    Hong, Jeong Hwa
    Antioxidant activities, total phenolic content (TPC), and total catechin content were analyzed in the ethanol extracts of 10 sugar apple (Annona squamosa L.) cultivar peels grown in Thailand. Antioxidant activity assays carried out in the this study were the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing antioxidant power (FRAP), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity, and oxygen radical absorbance activity (ORAC). ‘Nhur Thong’, ‘Nung Keaw’, and ‘Fai Keaw’ showed high percentage fruit peel (over 38.0%). ‘Nhur Thong’, ‘Nung Keaw’, and ‘Fai Keaw’ ethanol extracts possessed high antioxidant capacities in the majority of methods used, and thus could be potential candidate of natural antioxidants. ‘Fai Keaw’ showed the best activity in the ABTS (1.57 mmol of trolox/g dry sample), FRAP (0.43 mmol of trolox/g dry sample), and ORAC assays (2.84 mmol of trolox/g dry sample), as well as the highest content of TPC (140.4 mg) per gram dry sugar apple peel among the 10 cultivars. TPC showed a positive correlation compared with all antioxidant activity assays. In conclusion, ‘Fai Keaw’ could be utilized as an excellent phenolic compound source for functional food products.
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    In vitro antioxidant activities and volatile compounds from karanda (Carissa carandas L.) fruit wine
    (2018-12-01)
    Rumjuankiat, K.
    ;
    Sonhom, N.
    ;
    Showpanish, K.
    ;
    Somsri, A.
    ;
    Pilasombut, K.
    Carissa carandas L. or karanda (in Thai called namdaeng or manaao ho) is widely used as a medicinal plant. Karanda juice was fermented for 22 days to produce alcohol using Saccharomyces cerevisiae TISTR5918. Total soluble solids or TSS of karanda juice (approximately 1.0°Brix) was adjusted to 24°Brix and samples were collected every 2 days for analysis of total soluble solids (TSS), pH and alcohol content. Yield of alcohol was measured at 12.50±0.35% in the final fermentation. TSS dropped gradually from 24°Brix to 9.17±0.58°Brix, whereas pH increased slightly from 2.47±0.06 to 2.80±0.00 (Day 0-22). Volatile compounds in karanda wine (KW) were examined and analyzed using gas chromatography-mass spectrometry (GC-MS). Volatile compounds detected in KW included 3-methyl-1-butanol, butanoic acid, butyrolactone, phenylethyl alcohol, butanedioic acid, benzene ethanol and 2-propenyl ester as a common flavor and aroma in wine. Heavy metals (Pb, As, Cu and Cd) determined by atomic absorption spectroscopy (AAS) were present in lower than their maximum allowed concentrations. Methanol was detected at only 0.005% in KW analyzed by gas chromatography equipped with a flame ionization detector (GC-FID). Antioxidant activities were determined by three methods comprising diphenyl picrylhydrazyl radical scavenging assay (DPPH), radical cation decolorization assay (ABTS) and reducing power. The IC <inf>50</inf> values of DPPH and ABTS were 0.84±0.03% and 3.28±0.03%, respectively, and the EC <inf>50</inf> of reducing power was 11.03±0.11%. Total phenolic content, measured according to the Folin-Ciocalteu procedure, was determined as 746.64±3.10 mg GAE/100 ml sample.