2012 Annual Report 1a.Objectives (from AD-416): Optimization of sample preparation procedures for extraction of phenolic compounds from different food and plant matrices. 1b.Approach (from AD-416): The approach will include samples to be extracted by different procedures such as Stirring, Sonication, Shaking and Accelerated Solvent Extractor. Impact of solvent, temperature, and particle size on extraction of phenolic compounds from different food matrices will be evaluated. 3.Progress Report: Potato tubers are eaten worldwide for their nutritional value, but the peels are often disposed of as waste. This study identified the phenolic acids in potato peels and tubers and developed an optimized method for extraction of phenolic acids from potato peels using pressurized liquid extractor (PLE). Caffeoylquinic acid isomers were the predominant phenolic acids present in potato peels as identified by HPLC and LC-MS analysis. The phenolic acid content of the peels was more than ten-fold higher than that of the tubers. A variety of extraction parameters were investigated to optimize the extraction conditions. Altering the solvent composition, particle size, solid-to-solvent ratios, and temperature significantly influenced the phenolic acids extracted from potato peels. The results show that optimization of the extraction parameters is critical for maximum yield and accurate quantification of phytochemicals present in these foods.