. 2018 Jul 25;5:64. doi: 10.3389/fnut.2018.00064

Table 4.

Plasma free amino acid levels.

Amino acid	14% CN diet	10% CN diet (μmol/mL)	5% CN diet
ESSENTIAL
Val	0.253 ± 0.013^a	0.214 ± 0.008^b	0.174 ± 0.009^c
Leu	0.179 ± 0.010^a	0.159 ± 0.009^b	0.143 ± 0.009^c
Ile	0.111 ± 0.006^a	0.098 ± 0.008^b	0.081 ± 0.005^c
Lys	0.399 ± 0.033^a	0.334 ± 0.018^b	0.335 ± 0.019^b
Met	0.055 ± 0.008^a	0.052 ± 0.003^a	0.042 ± 0.002^b
Phe	0.068 ± 0.004^a	0.064 ± 0.003^a	0.056 ± 0.003^b
Trp	0.111 ± 0.006^a	0.096 ± 0.007^b	0.072 ± 0.007^c
His	0.083 ± 0.008^a	0.070 ± 0.001^b	0.078 ± 0.004^a
Thr	0.267 ± 0.032^a	0.276 ± 0.023^a	0.219 ± 0.019^b
NONESSENTIAL
Tyr	0.128 ± 0.011	0.117 ± 0.017	0.115 ± 0.012
Asp	0.008 ± 0.006	0.005 ± 0.005	0.012 ± 0.006
Asn	0.072 ± 0.006^a	0.067 ± 0.003^ab	0.062 ± 0.004^b
Ser	0.234 ± 0.033^c	0.303 ± 0.034^b	0.535 ± 0.044^a
Cys-Cys¹	0.030 ± 0.013	0.035 ± 0.012	0.024 ± 0.011
Glu	0.163 ± 0.062	0.199 ± 0.091	0.158 ± 0.034
Gln	0.769 ± 0.042^a	0.771 ± 0.049^a	0.693 ± 0.044^b
Pro	0.140 ± 0.025	0.129 ± 0.014	0.121 ± 0.019
Gly	0.169 ± 0.022^b	0.189 ± 0.021^b	0.308 ± 0.031^a
Ala	0.686 ± 0.042^b	0.725 ± 0.052^b	0.881 ± 0.106^a
Arg	0.105 ± 0.017	0.100 ± 0.013	0.097 ± 0.009

Three-letter codes are used for all amino acids. Amino acid levels are expressed as means ± SD (n = 6), which were analyzed by one-way ANOVA and Tukey's post hoc test. Values with different superscript letters are significantly different (P < 0.05). CN denotes casein.

¹Cysteine levels were measured as cystine (Cys-Cys).