ELLAGIC ACID CONTENT OF RED RASPBERRY JUICE AS INFLUENCED BY CULTIVAR, PROCESSING, AND ENVIRONMENTAL-FACTORS

Ellagic acid and its derivatives present in pilot-plant-processed rasp berry juices and commercial juice concentrates were characterized and concentrations estimated using HPLC/diode array spectral techniques. E xperimental juice samples (n = 45) contained a mean concentration of 1 0 ppm of ellagic acid and less-than-or-equal-to 16 derivatives of ella gic acid with individual mean concentrations of up to 3 ppm. Commercia l juices (n = 7) contained more ellagic acid and derivatives than expe rimental juices, with a mean concentration of 30 ppm of ellagic acid a nd up to 6.7 ppm for individual ellagic acid derivatives. The mean tot al concentration of ellagic acid and its derivatives in experimental j uices was 28 ppm and in commercial juices 52 ppm. Qualitatively, the c hromatographic profiles were very similar for the juices studied, but quantitatively, there were great differences due to cultivar (n = 10) and processing method. Williamette and Meeker cultivars contained the most ellagic acid and its forms. Juices made by diffusion extraction a nd a standard process had by far the highest concentrations of ellagic acid and its forms. High-speed centrifugation reduced total ellagic a cid forms by half compared to diffusion extraction; depectinization an d concentration decreased total forms even further.