A Comparative Analysis of Cashew Kernel Oil: Physicochemical Characteristics and Yield From Different Extraction Methods
Peter Sarpong, Gustav Komla Mahunu, Newlove Akowuah AfoakwahABSTRACT
This study evaluated the oil yield and physicochemical quality of cashew kernel oil (CKO) extracted using four traditional methods: direct hot‐water flotation with salt (WS), without salt (WOS), fermentation with salt (FWS), and fermentation without salt (FWOS). Significant differences ( p < 0.05) were found among methods. FWS yielded the highest oil content (18.84%), whereas FWOS yielded the lowest (16.23%). The WOS method produced oil with the lowest peroxide value (5.88 meq O 2 /kg), p ‐anisidine value (0.85), and impurity content (0.060%), indicating superior oil purity and oxidative stability. In contrast, oil from FWS had higher peroxide (9.42 meq O 2 /kg) and p ‐anisidine values (3.04), reflecting increased oxidation. Saponification values ranged from 83.94 to 128.05 mg KOH/g, free fatty acids from 0.35% to 2.66%, and iodine values from 38.35 to 54.15 g I 2 /100 g. Principal component analysis revealed distinct quality clusters among methods, with WOS and FWOS oils grouping separately from FWS. Correlation analysis showed strong positive correlations between saponification value and free fatty acids ( r = 0.942) and between impurities and FFA ( r = 0.846), while moisture correlated negatively with peroxide ( r = −0.922). Oil extracted by the WOS method exhibited superior purity and oxidative stability and is ideal for quality‐focused applications. Conversely, FWS produced the highest oil yield, which is beneficial for quantity but requires refinement or antioxidants to manage oxidation.
Practical Applications
The CKO obtained via WOS has superior purity and oxidative stability, making it suitable for direct use in food and cosmetics, without the need for extensive refinement. The FWS method, on the other hand, produces high‐yield oil suitable for industrial‐scale production; however, additional refinement to reduce oxidation is needed. The findings from this study provide small‐scale oil processors with extraction methods to choose from based on the quality requirements of the end product.