Effect of Waxes on Oil Separation and Texture Properties of Peanut Butter

Abstract

Peanuts have a nutrient-dense profile and are considered a great source of protein. They are largely consumed as commercially produced peanut butter. Currently, to avoid oil separation, hydrogenated and palm oils are added as a stabilizer, which increases the saturated fat percentages in peanut butter. This study aims to understand the impact of waxes and wax-oleogels on the oil separation and texture properties of peanut butter, and consequently, reduce the saturated fat content. In a preliminary test, three waxes (rice bran, beeswax, and carnauba) were added to natural peanut butter in different amounts (1%, 1.5%, and 2%). As a result, carnauba and rice bran waxes improved the rheological properties and decreased significatively (p >0.05) the oil separation after four weeks, with no significant difference (p >0.05) between the percentage of waxes. Thus, for the final test were chosen 1% of rice bran and carnauba waxes. Two types of peanut butter were produced, one natural peanut butter from roasted groundnuts and a second using peanut defatted flour and wax-based oleogel (containing 1% rice bran or carnauba waxes). The peanut butters were evaluated by their texture properties (firmness, spreadability, and adhesivity), oil content and oil separation. The both peanut butter were standardized to have approximately the same amount of oil and wax. The results showed that the spreadability was improved using 1% of both waxes (1218.0±92.1 for carnauba and 1999.1±72.0 for rice bran) compared to their control (340.7±11). The wax-oleogels added to the peanut flour also improved the spreadability (11730.8±248.7 for carnauba oleogel and 4787.4.1±101.8 for rice bran) compared to the control (2009.2±137.7). Rice bran and carnauba wax, significantly improve the texture properties and oil separation of butter from groundnut. This behavior was also observed with the addition of wax-based oleogel to peanut flour.