Page 240 - Natural Antioxidants, Applications in Foods of Animal Origin

Methods and Their Applications for Measuring 219
VetBooks.ir TOTOX = 2PV + p-AV

∈ = (mean of 2 × PV) × (std.dev. of PV) 2
2
2
+ (mean for p-AV) × (std.dev. of p-AV) 2 (6.10)
2
Therefore,
∈ = √∈ 2

For example, the error of uncertainty of TOTOX values can be calculated
by using the data given in the Table 6.3.

TABLE 6.3 TOTOX Data Were Collected to Determine the Error of Uncertainty (the Error
Propagated when Two Measurements are Combined). Calculating the Error of Uncertainty
Assumes the Errors will be Small and the Data Are Normally Distributed. Data from Internal
Study.
TOTOX data
Variable N Mean Std. dev.
2 × PV 7 3.4 1.7
pAV 7 6.5 0.5

Solving for the error of propagation (ϵ) when two factors (PV and p-AV)
are incorporated into Equation 6.10.

2
2
∈ = ((3.4) × (1.7) ) + ((6.5) × (0.5) ))
2
2
2
∈ = √(33.6 + 10.6)
∈= 6.6
The TOTOX value with the calculated error = 14 ± 6.6. If lower values
for the error or uncertainty are needed, measurement methods, processing
procedure, and/or product specifications need to be reviewed.
The application of p-AV, PV, and TOTOX data is shown in Figure 6.10.
Because lard rendering is a lengthy process involving sustained high
processing temperatures, analytical techniques that measure the more vola-
tile secondary oxidation products (2-alkenals, 2, 4 alkadienals for TBARS)
would be lost during processing. In this situation, p-AV data express the
concentration of less volatile secondary oxidation products (less saturated,
higher molecular weight fragments).