Abstract:
The purpose of the present study was to explore the influence of different
heat pretreatments on the chemical composition of honeydew seed oil and to extend
our knowledge concerning on its oxidative stability. The honeydew seeds were
treated with different heat pretreatments namely roasting (R) (20min at 200
C),
steaming (S) (20min at 100
°
C), and microwave (M) (15min at 2450MHz). The
honeydew seed oils from respective treated seeds were extracted by using a Bligh and
Dyer method and the yields were found to be in the range of 17.22-21.59%. Fatty
acid composition of the honeydew seed oils was examined by using gas
chromatography and no significant difference was found among different
pretreatments. Four types of major fatty acids of honeydew seed oils were palmitic
acid (7.21 -7.31%), stearic acid (4.14 -4.33%), oleic (13.38 -13.90%) and linoleic
acid (73.83 -74.47%). Meanwhile, the iodine value and free fatty acid content were
determined by AOAC standard methods. The iodine values were found in the range
of 133-135 g h/ 100 g. The free fatty acid content was in the range of 0.8 -1.4%
and it was found that among the different pretreatments, roasted seed oil showed the
lowest value. Oxidative stability was determined by Schaal oven method in a
condition of 60
°
°
C for duration of 12 days by monitoring the changes in peroxide value
(PY) and para-anisidine value (AV). The roasted honeydew seed oil was found to
demonstrate the best oxidative stability among the pretreatments applied.
