Minerals were determined by inductively coupled plasma spectrometry (Optima 5300 DV, Perkin Elmer Inc., Shelton, CT) following the Hardware Guide of the Optima 5000 Series instrument, and amino acids were determined with an Amino Acid Analyzer (S433D, Sykam GmbH, Eresing, Germany) following the Sykam Manual for Amino Acid Analyzer S433.