. 2020 Nov 13;4(4):txaa205. doi: 10.1093/tas/txaa205

Table 3.

Protein oxidation measured by carbonyls in rendered by products for experiment 1 stored at 45 °C over short-term storage

	Carbonyl^*, nmol/mg protein				P-value
Protein source	Control	7 d	14 d	SEM	Time	AOX	Time*AOX
Beef meat and bone meal
No antioxidant	14.7	22.4	17.2	3.1	0.04	0.56	0.24
BHA/BHT	12.8	21.4	15.7
Chicken by-product
No antioxidant	15.0^ab	21.0^a	20.7^a	5.6	0.15	0.07	0.05
BHA/BHT	15.3^ab	18.6^a	10.1^b
Natural antioxidant	16.1^ab	15.1^ab	11.0^b
Low ash chicken by-product meal
No antioxidant	13.6	19.5	16.8	2.5	0.09	0.87	0.40
BHA/BHT	16.5	16.1	14.6
Natural antioxidant	12.8	20.4	13.7
Fish meal
No antioxidant	11.5^c	24.3^a	15.3^bc	3.0	<0.01	0.02	0.01
Ethoxyquin	14.8^bc	21.3^ab	13.8^bc
Natural antioxidant	9.4^c	14.4^bc	8.9^c

AOX, antioxidant; SEM, standard error of the mean for the interaction. The analysis was conducted with five replicates at each time and antioxidant combination (n = 5). The difference in superscripts ^a–b indicates significant interaction between time and antioxidant across antioxidant inclusion and time within a product source.

^*Carbonyls were analyzed as a measure of protein oxidation. Values are reported as nmol of carbonyl/mg of protein and are the average of five replicates.