Temperature-Controlled Pulsed Light Treatment: Impact on Aflatoxin Level and Quality Parameters of Peanut Oil

Abstract

Peanuts are an economically significant crop that is commonly used for edible oil production; however, they are prone to contamination by aflatoxin (AFT)-producing fungi. Common methods to treat edible oils for AFTs often utilize high temperatures (> 100 °C) to thermally degrade the toxins. However, high temperatures often negatively impact product quality. In this study, pulsed light (PL) was assessed as a possible method to degrade AFTs in peanut oil. A pilot-scale PL applicator was used to treat 5-mL samples of peanut oil of 10 mm thick. Samples were treated for 1 to 10 min with or without temperature reduction (TR). The sample containers were placed in an ice water bath to mitigate increases in oil temperatures for the TR samples. The physical, color, and chemical quality parameters (peroxide value, free fatty acid, acidity value, and oxidative stability index (OSI)) of the oil were assessed in comparison to controls. Results show that significant AFT destruction was achieved using PL. There was a significant difference between reduction achieved when TR was employed, likely due to the combined effect of photochemical and thermal treatment. TR samples treated for 400 s experienced an AFT reduction of 48.4%, while those treated 600 and 800 s achieved 55.6 and 78%, respectively. The samples treated with TR showed lower quality degradation when compared to peanut oil samples treated without TR for equivalent treatment times. Using TR, PL resulted in a significant reduction of AFT, without losses in quality typically associated with thermal methods. At industrial scale, PL may offer an economical treatment of AFT-contaminated oil.