3.4. Extractability of antioxidative compounds
Extractability factors describing the efficiency of the different
extraction system used in the study are presented in Table 5. Based
on EF values it may be supposed that antiradical and lipid preventing
compounds from control breads possess rather lipophilic
character, and QL supplemented them with hydrophilic active
compounds, a reverse situation was observed for CHEL, while
reductive compounds were more effectively extracted from all
samples using PBS buffer. As expected, LPO from control breads
were most effectively extracted using MeOH:H2O (1:1, v/v)
(FF ¼ 0.38), however QL addition enriched breads with bufferextractable
phytochemicals exhibiting this activity (FF values
about 1). Simulated digestion released multifaceted antioxidant
compounds from all samples much more effectively than chemical
extraction MeOH:H2O (1:1, v/v). The most important differences
were visible in the cases of reductive (EF values from 7.24 to 23.86)
and antiradical (EF values from 3.85 to 5.24) compounds, the lowest
for LPO (EF values from 1.15 to 3.16) and CHEL (1.73e3.75). The
same relationship was observed for AE. Regardless of used
methods, extractability of all antioxidants decreased with QL
addition higher than 3 g/100 g. Obtained data clearly illustrate
essential differences between both used procedures (chemical
extraction and simulated gastrointestinal tract action) and point
the need for standardization and harmonization of procedures for
assessing the activity of newly designed food products.