Effect of different degumming methods on the chemical composition and physicochemical properties of tiger nut (Cyperus esculentus L.) oil

Objectives Tiger nut (Cyperus esculentus L.) oil is a promising edible oil that is rich in oleic acid. This study aimed to clarify the impact of different degumming methods on the chemical composition and physicochemical properties of crude tiger nut oil (CTO).Materials and Methods Five degummed tiger nut oils were prepared by high-temperature water (HWDO), medium-temperature water (MWDO), sodium chloride solution (SDO), acidic solution (ADO), and enzymatic method (EDO), respectively.Results Compared to that of CTO, the phospholipid contents of HWDO, MWDO, SDO, ADO, and EDO were reduced by 99.39%, 97.18%, 69.95%, 63.77%, and 65.60%, respectively. For CTO and all degummed oils, the fatty acid and endogenous antioxidant (i.e. tocopherols, sterols, flavonoids, total phenolics, and carotenoids) contents showed only small differences, but showed significant differences in quality parameters. Both the oxidative stability index and ferric ion-reducing antioxidant power decreased significantly after degumming; the former decreased from 52.26 to 15.55-19.80 h, and the latter decreased from 5818.91 to 4348.73-4524.34 mu mol Trolox (TE)/kg.Conclusions These changes are highly related to the removal of hydratable phospholipids. In short, EDO exhibited the lowest turbidity, whereas MWDO showed the best oxidative stability (19.80 h) and highest smoke point (230.0 degrees C). This information can be utilized to improve the industrial production of tiger nut oil.