The following standards were purchased: sinapic acid, hippuric acid, caffeic acid, quercetin 3-glucoside (all ≥98% purity, Sigma, St. Louis, MO), chlorogenic acid (primary standard grade, ≥98% purity, Chromadex, Irvine, CA), and cyanidin 3-O-β-glucopyranoside (≥97% purity, Polyphenols, Norway). BeadBug™ Microtube Homogenizer and 3.0 mm zirconium beads were purchased from Benchmark Scientific (Edison, NJ).
RSL looseleaf variety NFR, was provided by Shamrock Seed Co. (Salinas, CA) and green leaf lettuce (GL) variety Crispa (Andy Boy, Salinas, CA) were purchased from the grocery store (Stop and Shop, Highland Park, NJ). NFR plant and seed vouchers were made and deposited at the Chrysler Herbarium and ATCC [4 (link),12 (link)]. Outer leaves and tops of RSL lettuce heads were used as they have the highest levels of phenolics. Lettuce leaves were rinsed, lyophilized and homogenized in a Vitamix Professional 500 Blender (Cleveland, OH) to a fine powder. Dried RSL and GL powders were used for phytochemical extraction, nutritional analyses, and rodent diet formulations.
RSL looseleaf variety NFR, was provided by Shamrock Seed Co. (Salinas, CA) and green leaf lettuce (GL) variety Crispa (Andy Boy, Salinas, CA) were purchased from the grocery store (Stop and Shop, Highland Park, NJ). NFR plant and seed vouchers were made and deposited at the Chrysler Herbarium and ATCC [4 (link),12 (link)]. Outer leaves and tops of RSL lettuce heads were used as they have the highest levels of phenolics. Lettuce leaves were rinsed, lyophilized and homogenized in a Vitamix Professional 500 Blender (Cleveland, OH) to a fine powder. Dried RSL and GL powders were used for phytochemical extraction, nutritional analyses, and rodent diet formulations.
