Abstract:
Physico - chemical properties like relative
density, moisture and other matter volatile, insoluble
impurities, iodine value and unsaponifiable matter can
be used to evaluate the quality of sesame oil. In this study
ten sesame oil processing centers were selected randomly
from seven divisional secretariats area in Jaffna district
and two fresh samples of sesame oils were collected in
two different time periods from these centers for quality
analysis. All the laboratory analyses for sesame oils were
done according to the Sri Lanka Standard (SLS) 313
procedure and the results were compared with Sri Lanka
Standard 231:2013. According to the SLS 231:2013, the
relative density ranges between 0.915-0.919, moisture
and other matter volatile less than 0.2 percent by mass,
insoluble impurities less than 0.05 percent by mass, iodine
value ranges between 103-115 and unsaponifiable matter
less than 1.5 percent by mass can be an indication for good
quality sesame oil. The results of this study showed that
the mean value of relative density and moisture content
from eight and nine processing centers respectively were
met the required SLS standard. Similarly the mean
of iodine value and unsaponifiable matter of oils from
seven out of ten processing centers were within the SLS
standard value. But for the impurities only two out of
ten processing centers met the SLS specification value.
Samples obtained from five processing centers (50 %)
contained the acceptable values for four out of five quality
parameters. Results of this study show that most of the
sesame oil processing centers available in Jaffna district
need some modification or improvements in processing
methods to meet all quality standards specified for sesame
oil by SLS
