Effects of Sonication and Edible Coating Containing Rosemary and Tea Extracts on Reduction of Peanut Lipid Oxidative Rancidity
- First Online:
- Cite this article as:
- Wambura, P., Yang, W. & Mwakatage, N.R. Food Bioprocess Technol (2011) 4: 107. doi:10.1007/s11947-008-0150-2
Rancidity due to the lipid oxidation process is a critical factor influencing the quality of roasted peanuts. Sonication in combination with edible coatings added with plant extracts may extend the oxidative stability of peanuts. Peanuts were roasted at 178°C for 15 min, subjected to sonication in hexane for 10 min, and then coated with carboxymethyl cellulose (CMC) solution mixed with rosemary, tea extracts, and α-tocopherol and stored at 35°C for 12 weeks. The oxidative stability of the samples was investigated by measuring the oxidative stability index. Reduction in oxidation of 66.1% and 10.4% was observed for samples roasted and coated with extracts of rosemary and tea, respectively, as compared to uncoated sample. However, the oxidative stability of samples roasted–sonicated and coated with extracts of rosemary and tea was improved by 100.7% and 28.1%, respectively, in relation to the control. Sonication beyond coating improved the oxidative stability of the samples mixed with rosemary, tea extracts, and α-tocopherol by 10.3%, 12.1%, 34.6%, and 17.7%, respectively. The L*, a*, and b* values indicated that the peanut coated with CMC mixed with rosemary, tea extracts, and tocopherol at different concentration levels did not have significant (P < 0.05) color change during the 12-week storage at 35°C.