. 2022 Sep;60(3):293–307. doi: 10.17113/ftb.60.03.22.7104

Table 1. The total polyphenols, total flavonoids, total phenolic acids, oxalic acid and nitrate mass fractions on dry mass basis in predigested (original sample) and digested (initial phase, salivary phase, gastric phase and intestinal phase) spinach (S) and lemon juice (L) formulations.

Sample	Original sample	Initial phase	Salivary phase	Gastric phase	Intestinal phase
w(total phenols as GAE)/(mg/g)
S	(8.6±0.3)^bC	(10.4±0.7)^bABC	(11.6±0.6)^bA	(10.9±2.1)^bcAB	(9.6±0.8)^bBC
S+L₂	(8.5±0.5)^bC	(10.8±0.8)^abAB	(12.2±1.6)^bA	(9.6±1.2)^cBC	(9.3±1.1)^bBC
S+L₅	(8.8±0.6)^abC	(11.0±1.0)^abAB	(12.3±1.2)^bA	(11.8±1.4)^bcA	(9.9±0.8)^abBC
S+L₁₀	(8.8±0.7)^abB	(12.4±1.1)^aA	(13.3±0.8)^abA	(13.6±2.9)^abA	(9.4±2.1)^bB
S+L₂₀	(9.6±0.7)^aC	(11.3±1.7)^abB	(14.9±1.6)^aA	(15.7±0.8)^aA	(11.9±1.4)^aB
Mean	(8.9±0.7)^D	(11.3±1.2)^B	(12.9±1.6)^A	(12.2±2.7)^AB	(10.0±1.6)^C
w(total flavonoids as QE)/(mg/g)
S	(6.3±2.3)^bB	(8.8±0.1)^aA	(7.96±0.09)^bAB	(6.8±0.1)^bcB	(7.5±0.3)^aAB
S+L₂	(8.85±0.09)^aA	(7.9±0.1)^bB	(8.02±0.03)^bB	(6.7±0.1)^cC	(6.76±0.07)^bcC
S+L₅	(9.1±0.3)^aA	(7.7±0.1)^bB	(7.8±0.4)^bB	(6.97±0.09)^bcC	(6.5±0.1)^cC
S+L₁₀	(9.1±0.2)^aA	(8.3±0.7)^aA	(8.07±0.05)^bB	(7.1±0.4)^bC	(6.7±0.4)^bcC
S+L₂₀	(8.92±0.08)^aA	(8.6±0.4)^aA	(9.2±1.1)^aA	(7.63±0.08)^aB	(7.1±0.4)^abB
Mean	(8.5±1.4)^A	(8.4±0.6)^A	(8.2±0.7)^A	(7.0±0.4)^B	(6.9±0.4)^B
w(total phenolic acids as CAE)/(mg/g)
S	(1.8±0.1)^dE	(3.55±0.06)^dB	(3.8±0.1)^dA	(2.9±0.1)^cD	(3.2±0.2)^cC
S+L₂	(2.20±0.06)^bD	(4.1±0.3)^bcA	(3.9±0.1)^cdA	(3.0±0.2)^cC	(3.5±0.2)^cB
S+L₅	(2.09±0.03)^cD	(3.9±0.1)^cA	(4.0±0.1)^bcA	(3.1±0.1)^bcC	(3.44±0.08)^cB
S+L₁₀	(2.12±0.03)^bcD	(4.3±0.3)^abA	(4.2±0.1)^bA	(3.3±0.3)^bC	(3.8±0.2)^bB
S+L₂₀	(2.30±0.04)^aC	(4.5±0.3)^aA	(4.5±0.2)^aA	(3.8±0.2)^aB	(4.4±0.2)^aA
Mean	(2.1±0.2)^D	(4.1±0.4)^A	(4.1±0.3)^A	(3.2±0.4)^C	(3.7±0.4)^B
w(oxalic acid as OAE)/(mg/g)
S	(7.5±1.00)^dB	(9.30±0.01)^dA	(9.22±0.06)^eA	(7.98±0.01)^eB	(6.02±0.07)^eC
S+L₂	(9.2±0.2)^cB	(9.47±0.01)^cdA	(9.4±0.1)^dAB	(8.11±0.03)^dC	(6.31±0.04)^dC
S+L₅	(8.4±1.1)^cdB	(9.5±0.3)^cA	(9.63±0.03)^cA	(8.34±0.01)^cB	(6.53±0.02)^cC
S L₁₀	(10.4±0.6)^bA	(10.23±0.01)^bA	(10.19±0.05)^bA	(8.80±0.01)^bB	(6.90±0.06)^bC
S+L₂₀	(12.24±0.01)^aA	(11.54±0.02)^aB	(11.53±0.01)^aB	(9.91±0.01)^aC	(7.71±0.06)^aD
Mean	(9.5±1.8)^A	(10.0±0.9)^A	(10.0±0.9)^A	(8.6±0.7)^B	(6.7±0.6)^B
w(nitrate as KNO₃E)/(mg/g)
S	(7.4±0.2)^cE	(19.67±0.09)^abA	(16.1±1.1)^bB	(13.1±0.3)^cC	(10.2±0.5)^bD
S+L₂	(8.2±0.2)^bcE	(19.3±0.3)^bA	(16.7±0.9)^abB	(13.5±0.5)^bcC	(10.0±0.4)^bD
S+L₅	(9.21±0.06)^abD	(19.5±0.3)^bA	(17.2±1.2)^abB	(13.5±0.2)^abcC	(10.6±0.3)^bD
S+L₁₀	(9.9±1.2)^aC	(20.2±0.3)^abA	(16.8±1.3)^abB	(14.4±0.2)^aB	(10.5±1.1)^bC
S+L₂₀	(10.4±0.2)^aE	(20.5±0.5)^aA	(19.0±0.4)^aB	(14.4±0.5)^abC	(12.3±0.3)^aD
Mean	(9.0±1.2)^E	(19.8±0.5)^A	(17.2±1.3)^B	(13.8±0.618)^C	(10.7±1.0)^D

Data are presented as mean value±S.D, N=4. Different lower case letters indicate significant difference at p≤0.05 within each phase separately. Capital letters indicate significant difference at p≤0.05 among phases. φ(lemon juice)=2 (L₂), 5 (L₅), 10 (L₁₀) and 20 (L₂₀) %. GAE=gallic acid equivalents, QE=quercetin equivalent, CAE=caffeic acid equivalents, OAE=oxalic acid equivalents, KNO₃E=KNO₃ equivalents