For cysteine and methionine determination, the acid
hydrolysis was preceded by overnight cold performic acid oxidation
(Method 982.30 E(b)) (Horwitz & Latimer, 2007). However,
tryptophan determination involved alkaline (NaOH) hydrolysis at
110 C for 22 h (Method 982.30 E(c)) (Horwitz & Latimer, 2007).
The amino acid results are expressed in milligram amino acid per
100 g edible portion on fresh weight basis of the samples.