The distribution of total phenolics, antioxidant capacity, monomeric
anthocyanin, and ascorbic acid contents in the peel and flesh of Red Delicious,
Granny Smith, and Fuji apples during a six-month storage period were determined.
In addition, the effect of 1-MCP (1-Methyl cyclopropene) on these parameters of
the edible portion of apples during storage was also investigated. Two different
assays were employed to determine antioxidant activities: the spectrofluorometric-based
Oxygen Radical absorbing Capacity (ORAC) and the spectrophotometric-based
Ferric Reducing Antioxidant Power (FRAP). Total phenolics were measured
using the Folin-Ciocalteau method. A determination of monomeric anthocyanin
content was also performed using the pH-differential method for Red Delicious
and Fuji apples.
Antioxidant activity was predominantly observed in the aqueous fraction
and was attributed to polyphenolics. Antioxidant activities were highest in the peel,
with Red Delicious peel having the highest values, presumably due to anthocyanin
pigments. At zero time month storage, the ORAC, FRAP, total phenolics, and total
monomeric anthocyanin contents of Red Delicious peel were: 37.7 μmol T.E./g,
62.7 μmol T.E./g, 6.63 mg/g GAE, and 26.4 mg/100g, respectively. The three
tested cultivars were significantly different with respect to ORAC, FRAP, total
phenolics, and monomeric anthocyanin contents. 1-MCP treatment did not have a significant influence on antioxidant activities and monomeric anthocyanin contents
of the three cultivars during storage. Storage did not have significant influence on
ORAC values of the edible portion of apple, however it had significant influence
on the FRAP values. The contribution of ascorbic acid to the total antioxidant
capacity was small. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28171 |
| Date | 14 June 2002 |
| Creators | Widyasari, Maria Angela Artania |
| Contributors | Wrolstad, Ronald E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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