3. Results and discussion
3.1. Extraction
The extraction yield for MJ treated and untreated strawberry
crude extracts were 476.2 and 450.4 (mg/g of dry fruit), respectively.
MJ treated fruits were partioned using liquid–liquid
extraction. The highest extraction yield of the four fractions
was obtained for n-butanol (35.3%) follow by ethyl acetate
(24.1%) and by chloroform (2.5%). The lowest yield was obtained
for hexane (1.3%).
3.2. DPPH assay
In a previous article published in our lab it was reported the
higher ORAC antioxidant activity of the MJ treated strawberry
extract compared to the MJ untreated strawberry (de la Pen˜ a
Moreno et al., 2010b). The use of more than one method is
recommended in the study of antioxidant capacity, because
it is clear that no single method can give a comprehensive
prediction of antioxidant efficacy (Aruoma, 2003). In this
study we consider the DPPH antioxidant activity. Quercetin
was used as positive control. The MJ treated strawberries
showed higher DPPH scavenging activity than the untreated
ones (Table 1). The DPPH scavenging data suggests that
strawberry extracts are capable of scavenging free radicals
at physiological pH; thus preventing the initiation and
propagation of free radical mediated chain reactions which