The level of TBA increased in all butter samples until the 30th
day of storage, and thereafter decreased at the end of storage. No
significant differences were observed between the butter samples
for TBA content during storage (P > 0.05; Table 2). During
storage, TBA values exhibited irregular changes, different to the
trends for PV (Table 2). Variations of TBA and PV can be
explained by the formation of peroxides as, a result of primary
oxidation, that quickly change to secondary oxidation products
that are unstable. TBA values were lower than those reported by
Dagdemir et al. (2009) for butter produced with the addition of
Origanum acutidens and T. haussknechtii, and values reported by
Simsek (2011) for butters stored at a different temperature, but
in these two studies, the TBA values increased in all samples
during storage.