Characterization of Physicochemical Properties of Cooking Oils Sold in Phnom Penh, Cambodia

Author(s): Manit Say, Punlork Heng, Sela Kong, Chin Ping Tan, Sivchheng Phal, Yukleav Nat, Reasmey Tan.

Cooking oils are prone to degradation through oxidation, leading to a loss of nutritional value and the development of off-flavors causing by the formation of oxidative by-products. The process, marked by reactivity and toxicity, can potentially contribute to health risks such as cancer and inflammation. In the context of Cambodia, cooking oils are currently imported from various countries without a comprehensive assessment of their quality. To address this gap, the present study aimed to assess the physicochemical characteristics of cooking oils available in Phnom Penh’s supermarkets. A total of 48 oil samples, sourced from different raw materials and brands, were subjected to extensive analysis to determine their physicochemical attributes. The results revealed a range of findings: peroxide value between 1.69 and 14.55 meq O2/kg, acid value between 0.11 and 1.62 mg KOH/g, iodine value ranging from 54.12 to 140.00 g I2/100 g, anisidine value from 19.90 to 138.13, and specific UV extinction at 233 nm and 269 nm varying between 2.30 to 10.82 and 0.32 to 4.36, respectively. Significantly, one sunflower oil sample exhibited a peroxide value exceeding the FAO’s Codex Alimentarius Standards, while five oils samples displayed acid value surpassing the recommended FAO limit. Furthermore, the color attributes (L*, a*, and b*) of the cooking oils were measured within ranges of 32.28 to 34.84, -1.75 to -0.15, and 0.93 to 6.83, respectively. These findings underscore the concern that certain cooking oils available in Phnom Penh’s supermarkets do not meet the established FAO standards, potentially attributable to factors such as expiration dates, inappropriate transportation, and improper storage conditions.