Data set on the free fatty acid, peroxide value, and moisture contents during thermal degradation of coconut oil

Published: 7 May 2024| Version 1 | DOI: 10.17632/hv5k9fym57.1
Drexel Camacho,


Continuous deep frying of food using oil is a common practice, but the oil undergoes degradation upon thermal treatment making it unfit for consumption. How can we determine when the oil is still safe for use in deep frying? The data set shows the investigation on the thermal degradation of edible coconut oil sans any food matrix by analyzing changes in free fatty acid (FFA), peroxide value (PV), and moisture content (MC) as the oil alone was heated at around deep-frying temperatures (150, 175, and 200 °C) for 1-12 hours. Hourly monitoring reveal that increased temperature and heating time lead to higher FFA, PV, and MC, indicating oil degradation. The data can be used to assess the quality and stability of coconut oil during thermal degradation. These values provide insights into the degree of chemical changes, oxidation, and moisture absorption occurring in the oil under different heating conditions. The values can be compared with industry standards and regulatory guidelines to ensure that the coconut oil meets the required quality thresholds. Monitoring these parameters helps prevent the formation of harmful compounds and ensures the oil is safe for consumption. The data can also be used in optimizing the processing conditions and storage practices for coconut oil to enhance its stability, shelf life, and overall quality.


Steps to reproduce

The heating of coconut oil (Frymax) was carried out using an electric fryer equipped with a thermostat and the oil temperature was monitored using a thermometer. The oil was heated at 150, 175, and 200 ℃, for 12 continuous hours. The sampling schedule was done every hour. All treated samples were packed in ambered bottles and stored at a refrigerated temperature of 4-5 ℃ until analyzed. All data obtained by physicochemical analyses (FFA, peroxide value, and moisture content) were performed in triplicate. Analysis of Free Fatty Acid (FFA) in Heated Coconut Oil The free fatty acids were determined based on the Official Methods of Analysis of AOAC International (2012) using a titrimetric method where 56 g of the oil sample was mixed with 50 ml of 95% ethanol. The solution was heated while thoroughly shaking the flask for complete homogenization. The solution was titrated with aqueous sodium hydroxide (0.1 N) until the color turned to light pink. The amount of FFA was calculated as a percentage for lauric acid. Analysis of Peroxide Value (PV) in Heated Coconut oil The peroxide value of the oil samples was determined by the titration method based on the Association of Official Analytical Chemists (AOAC, 2012). Five (5.0) grams of oil was placed into a 250 ml Erlenmeyer flask. Acetic acid chloroform solution (three parts of glacial acetic acid and two parts of chloroform) was then added, and the solution was swirled vigorously until dissolved. Potassium iodide (KI) solution was added and allowed to stand for 1 minute with occasional shaking. Water (30ml) was added, and the solution is titrated with 0.1M Na2S2O3 (sodium thiosulfate) under vigorous swirling until the yellow color almost disappeared. Starch solution (1%; 0.5ml) was added and the titration was continued until the blue color almost disappeared. The peroxide values of the oil samples were calculated using the following formula: Peroxide value (meq/kg) = [S x N x 1000] / W(g) Where: S = amount of titration sample (ml) N = Normality of the sodium thiosulphate (meq/kg) W= weight of the oil sample (g) Analysis of Moisture Content in Heated Coconut Oil The vacuum oven method was used for the determination of the moisture content of heated coconut oil (AOAC, 2012). This procedure includes weighing oil (3.0g) into tared aluminum moisture dishes, followed by drying in a vacuum oven for 16 hours. The oven temperature was set at 105 ⁰C and a vacuum of <100 millibars. The moisture content was calculated using the equation: %MCwb = [Wt. sample before drying – Wt. sample after drying X 100] / Wt. sample before drying


De la Salle University, Industrial Technology Development Institute


Food Science, Chemical Degradation, Analytical Chemistry in Food Science, Coconut Oil