IMPACT OF ADULTERATION WITH PAWPAW EXTRACT ON THE PHSICOCHEMICAL CHARACTERISTICS OF PALM OIL.

9 Oct
Posted on Author

Authors: Dr. Ugwuoke Malachy Okonkwo, Okozor Petrolina Nkeiruka, Ezea Boniface Chukwuebuka

Abstract: Palm oil is a widely consumed edible oil valued for its nutritional, economic, and industrial importance. However, adulteration with substances such as pawpaw (Carica papaya) extract has become a common malpractice aimed at enhancing color and yield, often at the expense of quality. This study examined the effects of adulteration with pawpaw extract on the physicochemical characteristics of palm oil over an eight-week storage period. Palm oil samples were adulterated at concentrations of 0.05–0.08 g/mL and evaluated for acid value, saponification value, iodine value, peroxide value, free fatty acid content, specific gravity, viscosity, melting point, moisture content, and color using standard AOAC (2019) and Codex (2019) procedures. Results showed that adulteration significantly altered both chemical and physical properties. The acid value increased from 2.41 to 6.38 mgKOH/g, while free fatty acids rose from 1.21% to 3.19%, indicating accelerated hydrolysis and reduced stability. Peroxide value increased sharply from 8.12 to 19.47 meq/kg, confirming enhanced oxidative rancidity. Saponification value increased from 195.1 to 209.3 mgKOH/g, suggesting incorporation of lower-molecular-weight fatty acids, whereas iodine value decreased from 53.6 to 41.2 g I₂/100 g, and indicating reduced unsaturation. Physical changes included increased specific gravity (0.903–0.923), viscosity (43.5–58.2 cP), and moisture content (0.18–0.41%), alongside a reduced melting point (36.4–32.8 °C) and a color shift from dark red to reddish-yellow. Finally, pawpaw extract markedly deteriorated the physicochemical quality of palm oil, promoting oxidation, rancidity, and moisture absorption. These changes compromise its edibility, shelf life, and industrial applicability. The findings underscore the urgent need for stricter monitoring and enforcement of food quality regulations to prevent adulteration and ensure consumer safety.

DOI: http://doi.org/10.5281/zenodo.17301002