3.2. Changes in AA, TPI and TA during the production of strawberry
vinegar
3.2.1. Substrate pre-treatments
Three different strawberry purees were employed in this study.
These purees presented similar values for all parameters,
except the high values of TA in the substrate of the 2009 harvest.
After the pretreatments (pectolytic enzymes and SO2 addition),
we observed significant increases in almost all of the measured parameters,
comparing P1 and P2 samples of each harvest (Tables 2e4).
Considering the increases percentage, we observed a good correlation
between the DPPH with TA (r2 ¼ 0.998) and with TPI
(r2 ¼ 0.971) percentages. This could mean that these phenolic
compounds are responsible for a percentage of the increases of AA.
The explanation below was achieved by comparing and contrasting a variety of different theories