EFFECT OF SOAKING BY OUTER EPIDERMIAL LAYER OF COCONUT MEAT (COCOS NUCIFERA) ON QUALITY OF WASTE COOKING OIL

• Main Author: Christina, Merry
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/35276
• Institution: Institut Teknologi Bandung

Cooking oil is a staple food product. Their components and structure may change due to prolong high temperature heating, for example the formation of short-chain fatty acids, double bond destruction, and formation newly compound that might be harmful to human health. Preliminary research showed that outer epidermial layer of coconut meat can improve the visual quality of the used cooking oil. To study this, the present study on some chemical parameters such as wavelength shift in UV-Vis region, iodine number, IR spectra, and GC- MS analysis of fresh cooking oil, used cooking oil, and used cooking oil that was soaked with sterilize outer epidermial layer of coconut meat were determined. In this experiment, two type of sterilization method was applied to outer epidermial layer of coconut meat which were autoclave method (as a control experiment) and bleaching method. Three types of samples were used in this experiment, which were a controlled twicely used cooking oil (sample A), fried chicken cooking oil (sample B), and fried stuffed tofu cooking oil (sample C). Absorption wavelength shift was observed especially to that of sample A which was shift from 228 nm to 242 nm due to heating, and shifted back to 230 nm after outer epidermial layer of coconut meat treatment. Iodine number of treated sample B and treated sample C showed an increasing number compared to that of controlled experiment (as much as 7,78 g iod/100 g samples for sample B and 2,33 g iod/100 g samples for sample C). This data showed that the treatment with outer epidermial layer of coconut meat involved enzyme activities. The most significant increase in iodine number found in those sample after treatment with outer epidermial layer of coconut meat for 9 days for sample A and 10 days for sample B and C respectively. Functional group analysis using IR spectroscopy didn’t give some significant change for all used cooking oil samples compared to that of fresh cooking oil, but there was some different on its peak intensity. The intensity of alkanes, cis –C=C-, and esters functional group of sample A were higher compared to that of fresh cooking oil. These values were reduced close to the original number of fresh cooking oil by the treatment of outer epidermial layer of coconut meat. GC-MS chromatograms revealed that the amount of compound were decreased by frying (A sample) especially for the peak that has retention time of 5,75 minutes which substituted by the formation of a new peak at retention time of 5,42 minutes. After soaking by outer epidermial layer of coconut meat, the amount of the compounds didn’t change significantly, however the intensity of peak 5,42 minutes decrease and 5,75 minutes-peak were increased. All those data showed that a better quality change in used cooking oil after the treatment of outer epidermial layer of coconut meat.