Pecan kernels from six cultivars were analyzed for phenolic content and
antioxidant properties. In addition, kernels from two cultivars were irradiated with 0, 1.5
and 3.0 kGy using E-Beam irradiation and stored in accelerated conditions (40 °C and
55% R.H.). Changes in phytochemical profile and antioxidant properties were monitored
for 134 days.
Cultivars differed greatly in their phytochemical content. Total extractable
phenolic content (TP) ranged from 62 to 106 milligrams of chlorogenic acid equivalents
per gram of defatted kernel. Antioxidant capacity (AC) measured by the DPPH free
radical had a strong correlation with TP. Shells from each cultivar were 6, 4.5 and 18
times greater for TP, AC and condensed tannin content (CT). Gallic and ellagic acids,
epicatechin and catechin were identified in hydrolyzed extracts of all cultivars. Prior to
hydrolysis, no compounds were positively identified. Fatty acid profile of kernel oil had
a strong inverse correlation between oleic and linoleic oil. Kernels from the same
cultivar but different location differed in their fatty acid composition but had similar TP.
Irradiation of â Kanzaâ and â Desirableâ kernels with 1.5 and 3.0 kGy had no
detrimental effects on AC and TP by the end of experiments. Phenolic profile was
similar for all treatments. Tocopherol content decreased with irradiation treatments, but
no further degradation was observed throughout storage. Peroxide values increased
slightly after 98 and 134 days of storage for â Desirableâ kernels, with slight differences
between controls and irradiated samples. Color of kernels decreased in lightness and yellowness and increased in redness with no differences between irradiated samples and
controls.
For the first time the effect of pecan cultivar and E-Beam irradiation was
assessed in phytochemical and antioxidant attributes of pecan kernels. Additionally,
irradiation with E-Beam had no significant detrimental effects in phytochemical
composition and only a slight increase in peroxide value, indicating potential as pecan
kernel sanitization.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-1015 |
| Date | 15 May 2009 |
| Creators | Villarreal Lozoya, Jose Emilio |
| Contributors | Cisneros-Zevallos, Luis, Lombardini, Leonardo |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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