Canarium ovatum oil Engl. (pili nut oil) was extracted by using cold press method and then the
physico-chemical properties of the oil samples, roasted pili nut oil (RPNO) and unroasted pili
nut oil (UPNO) such as iodine value (IV), peroxide value (PV), acid value (% FFA), solid fat
content (SFC), fatty acid composition and triacylglycerol (TAG) composition were determined.
The percentage of oil yield and iodine value for RPNO and UPNO were showed no significant
different, wheareas there were significantly different for the peroxide value and percentage of
free fatty acid. The solid fat content for RPNO and UPNO were similar to the palm olein oil
and both completely melt at 25°C. Both samples, RPNO and UPNO were contained 50.70%
and 52.59% of oleic acid and were found not contain the trisaturated TAGs.
Some vegetable oils contain natural antioxidants such as beta carotene and vitamin E namely alpha tocopherol. The objective of this study was to screening the value of α-tocopherol, β-carotene, antioxidant capacity, antimicrobial activity and toxicological properties of roasted pili nut oil (RPNO) and unroasted pili nut oil (UPNO). The result showed that RPNO contained higher amount of vitamin E and less amount of beta carotene compared to UPNO. RPNO and UPNO scavenged DPPH radicals by 24.66% and 9.52% at concentration of 140 μg/ml. The total phenolic compound (TPC) in UPNO and RPNO were about 19.96 ± 0.52 mg/kg and 12.43 ± 0.69 mg/kg respectively. It was observed that bacteria species exhibited different sensitivities towards RPNO, UPNO, Gentamycin, Ampicillin and Chloramphenicol. Bacillus cereus 14570 was the most sensitive bacterium and all strains of Staphylococcus aureus tested were resistant against both samples RPNO and UPNO. An in vitro toxicological study based on the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) cytotoxicity assay was also performed. In vitro cytotoxicity indicated that both RPNO and UPNO had no effect against HeLa (cervical cancer cell), MCF-7 (breast cancer cell) and HT-29 (human colon adenocarcinoma cell) cell lines tested.
Honey is a sweet liquid food of high nutritional value and it provides immense health benefits. It is highly concentrated with sugar and contains mostly glucose and fructose, which will crystallize over a period of time. Crystallisation of honey will affect its quality, as well as consumers’ acceptability. Storage condition is one of the factors that influence the crystallisation of honey. Different types of honey may need different storage conditions to retain the quality. This research was conducted with the aims to study the crystallisation behaviour of the selected Malaysian honeys and to determine the storage conditions that influence the formation of crystal. The crystallisation of Malaysian honeys (Hutan, Kelulut, Acacia, Gelam) stored at 25, 4 and -20oC for different storage times of 0, 5, 14, 30, 60 and 180 days was analyzed by a differential scanning calorimeter (DSC), and sugar composition was analyzed using a high performance liquid chromatography (HPLC). The results showed that Hutan honey had the greatest crystal formation at the storage temperature of 4oC even after 14 days of storage. Glucose compositions in Hutan and Gelam honeys were also high which were 33.49 ± 0.53% and 33.93 ± 0.15 %, respectively. The enthalpy value for the storage temperature of 25oC, which represents the amount of heat needed to melt crystals present in honey, was the lowest (0.37 ± 0.1 – 2.56 ± 0.5 J/g) compared to other storage temperatures, which showed only a small amount of crystals was formed at this temperature. Thus, this study suggested that the crystallisation behaviour of Malaysian honeys is influenced by the storage condition and will be different for each type of honey.