Potentially High Value Conjugated Linolenic Acids (CLnA) in Melon Seed Waste

Conjugated linolenic acids (CLnAs) are natural phytochemicals with known and potential bioactivities in mammals. Established CLnA sources are limited to a few common fruit seeds, notably pomegranate seeds and cherry pits, and the search for alternatives is impeded in part by cumbersome methods for reliable measurement. We investigated CLnA contents in lower value fruit seeds with a recently available facile mass spectrometry method, solvent-mediated chemical ionization, enabling and quantitative analysis. We report for the first time the detection of CLnAs in cantaloupe and honeydew seeds at levels of 2 mg CLnA/g seed kernel. Based on the combined waste stream for these muskmelons of about 1.4 billion pounds in the USA annually, we estimate that the available CLnAs amount to 37.5 tons, similar to cherry pits. Our results suggest the potentially enhanced economic value of a specific class of bioactives that may be extracted from discarded food processing waste.