Total polyphenolic compounds extracted by methy1 alcohol from pomeqranate
peel and Oavedo layer of sour orange peel were found to be 23.251 and 3.562 (mg/g
dry weight), respectively. GC profiles 01 the two methyl extracts showed that Ihe
highest peak for pomegranate extrncl was recorded al retention time of 0.556 min,
whereas the highest peaks for sour orange extract were recorded al relention urnes 01
0.548,0.606,1.053,1.44 and 11.271 min. The presence of aflaglc acid, tertgalUc acid.
gallic acid, caffeic, p-coumarle, Ierullc acJd, slnaplnlc acid In polMgranate pool extract
and ferolle acid, slnapielc acid, neoeriocitrta, narirutJn, naringln, haspertdln, caffeic
acid and p-cournaric in sour orange extract have been reported. Oven storage test (at
100 ·C up to 72 hrs) was carried out to evaluate antioxidant activity of the two extracts
011 the stability of cotton seed oil at three concentrations (200,400,600 ppm) compared
with synthetic antioxidants (BHA. 8HT, 200ppm). lootoe vatue for atl oil sarnptes was
decreased and the highest d ecrease was recorded for (he control sample (wit/lout
addition of any antioxidant). A5 a result o( accelerated storage, all off samples showed
gradual Incre-ases in peroxide value, acIdity. thiobarbiturlc acld, and absoroances at
400 and 450 nm vs time. Addltlon of pomegranate extract, BOUT' orange extract, BHA
or BHT ratarceo lhasa changes, wnereas pomegranate extract recorded the best
results. On the other skle, as a result of accelerated storage, the unsaturated fatty
acids were decreased whilst saturated ones were Increased. Thus, the ratio ostween
total unsatured fatty acids and total ssturated ones (TulTs) decreased, especially for
tbe control 011 sample. The overall results showed that both pomegranate peel anc
Mavedo layer of sour orange peel extracts have anUoxJdant property. and may be
exploite~ as otopreservauve !n food appllcatloos,