Changes in peroxide value (PV)
Shelf life of oily fish species is limited due to the oxidation of
lipid. Initially, PV was absent in themackerel, and it increased from
1st month onward and reached a maximum of 18.26 and 17.07
meq O2/kg fat for plate and air blast frozen samples on 2nd month
(Figure 3). Subsequently, it decreased (P < 0.05) in both the frozen
methods. Awad and others (1969) observed that the peroxide values
increased to a maximum and subsequently declined to aminimum
when frozen fish were stored near −10 ◦C. This indicates that they
are not stable compounds and are decomposed faster than they are
being formed.