Peter, oxalic acid in the food. But no need to take my word for it! You can easily test by juicing the food (such as vegetables), then adding a little calcium salt (such as calcium chloride). Oxalic acid will immediately react to form white calcium oxalate crystals. Randy Oliver *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html Access BEE-L directly at: http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A0=BEE-L