Evaluation of beeswax, candelilla wax, rice bran wax, and sunflower wax as alternative stabilizers for peanut butter

Authors: Moser, Jill; Anderson, Julie; Byars, Jeffrey; Singh, Mukti; Hwang, Hong-Sik

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2019
Publication Date: 8/19/2019
Citation: Winkler-Moser, J.K., Anderson, J.A., Byars, J.A., Singh, M., Hwang, H. 2019. Evaluation of beeswax, candelilla wax, rice bran wax, and sunflower wax as alternative stabilizers for peanut butter. Journal of the American Oil Chemists' Society. 96(11):1235-1248. https://doi.org/10.1002/aocs.12276.
DOI: https://doi.org/10.1002/aocs.12276

Interpretive Summary: Peanut butter and other nut or seed-based spreads are made from roasted or unroasted and ground nuts or seeds. They are a popular and growing category of food products in the U.S. These foods tend to be high in protein as well as fat, but because they are derived from nuts or seeds, the types of fats in these spreads are high in heart-healthy polyunsaturated fatty acids. However, oil separation, where the oil separates from the ground particles and settles at the top, is a problem with these foods. Traditionally, most peanut butter is stabilized to prevent this problem by adding fats with a high melting point, such as hydrogenated or partially hydrogenated vegetable oils, which are high in saturated and trans fatty acids, respectively. Palm oil, which is high in saturated fats, is another oil that is used in some popular nut-based spreads. Since consumption of saturated and trans fats are associated with higher risk for heart disease and atherosclerosis, consumers are encouraged to reduce their consumption, and since hydrogenated fats do not fall in the clean label category, there is interest by the food industry in replacing them with more label friendly ingredients. This study tested natural plant waxes as alternatives to hydrogenated fats for use in stabilizing peanut butter. Beeswax, candelilla wax, sunflower wax, and rice bran wax were added at levels of 0.5 – 2 % to peanut oil, which is similar to levels of hydrogenated oil stabilizers. Sunflower wax and rice bran wax had the best oil binding capacity, followed by candelilla wax and beeswax. Sunflower wax showed the best performance at preventing oil separation over a six month period. The waxes, especially sunflower and rice bran wax, also increased the firmness of the peanut butter. The results indicate that waxes, especially sunflower or rice bran wax, may be useful alternatives to hydrogenated oils or palm oil as stabilizers in peanut butter and other nut- or seed-based spreads.

Technical Abstract: The objective of this study was to evaluate four natural waxes as stabilizers to prevent oil leakage in peanut butter. Beeswax (BW), candelilla wax (CLW), rice bran wax (RBW), sunflower wax (SFW), and a commercial peanut butter stabilizer, hydrogenated cottonseed oil (HCO), were added to three natural peanut butter brands at levels ranging from 0.5 – 2.0 % (w/w). Samples were tested for oil binding capacity, long-term stability, firmness, and rheology. At 0.5 %, all waxes improved oil binding capacity. SFW and HCO had the highest oil binding capacity, followed by RBW, CLW and BW. SFW, HCO, and RBW oil binding capacity leveled off between 1.5 and 2.0 %. All waxes reduced the amount of oil leakage after six months at room temperature compared to no added stabilizer. HCO reduced oil leakage the most at all levels of addition, followed by SFW, then CLW at 1 – 2%. Firmness and yield stress increased in association with higher levels of wax or HCO, with SFW increasing firmness the most, followed by HCO, RBW, and CLW, while BW had the lowest effect on firmness and yield stress values. The results indicate that the waxes may be feasible replacements for HCO as peanut butter stabilizers, and that oil binding capacity, long-term stability, and texture were influenced by wax type and level. Overall, SFW had the best performance at the lowest level of addition (0.5 %) and was most similar to HCO.