Extraction and Determination of a Selected Polyphenol from Selected Red and Black Grapes By High Performance Liquid Chromatography.

• Main Author: Niles, Summer Nicole
• Format: Others
• Published: Digital Commons @ East Tennessee State University 2010
• Subjects: Chemistry; Physical Sciences and Mathematics
• Online Access: https://dc.etsu.edu/honors/3; https://dc.etsu.edu/cgi/viewcontent.cgi?article=1006&context=honors

Polyphenols are a group of compounds found naturally in plants and they provide much of the flavor, color, and taste to fruits, vegetables, seeds, and other parts of the plants They also act as antioxidants which provide numerous health benefits by protecting cells against damage caused by free radicals. Their antibacterial, anti-inflammatory and anti-allergenic properties have also contributed to the prevention of degenerative diseases, such as cardiovascular diseases and cancers by slowing the rate of oxidative stress on cells. This study was aimed at the identification and quantitation of a specific polyphenol, quercetin, found in grapes commonly purchased at grocery stores to show their benefits toward human health. Samples of red and black grapes were collected and their polyphenolic compounds were extracted from the pulp using an organic solvent extraction method. High pressure liquid chromatography (hplc) was then used for the determination and quantitation of quercetin in each of samples. Quercetin was identified in both the red and black grape samples at retention times around five minutes. Due to technical problems with the HPLC instrument, only estimates of the amount of quercetin in each of the analyzed samples could be calculated with the highest estimated yield being 8.29 mg/mL of quercetin in black grape extract #4.