Page 55 - New additives and ingredients in the formulation of aquafeeds

Figure 3. Antioxidant activity of the chickpea and lupine hydrolysates and
isolates of �-carotene bleaching by oxidation products obtained in plan pilot scale.
Figure 4. Fish growing after 150 days under the challenge conditions in the trial.
Figure 3. Antioxidant activity
of the chickpea and lupin
hydrolysate and isolated
of b-carotene bleaching by
oxidation products obtained
in plan pilot scale
This critical problem can be resolved by adding substances that inhibit
oxidation, synthetic antioxidants usually, and there is a wide variety in the
market. The antioxidant effect may be enhanced by synergistic products
(ascorbic, tartaric and citric acid, phosphates and phospholipids). From the
text mentioned above, we can conclude that it is very important to control
the storage conditions and the expiration dates of food (Castelló, 1993).
In this sense, it was proceeded to evaluate the antioxidant activity of protein
hydrolysates obtained from chickpea and lupin with the aim of using them,
not only because of its nutritional properties but because of its antioxidant
activity. Two methods to measure the antioxidant activity were used for this
purpose. The first one determines the decoloration of β-carotene by the
products of lipid oxidation of linoleic acid. The second test determines the
power of the hydrolysates to reduce metals. As it is shown in Figures 3 and
4, the antioxidative property of protein hydrolysates improves comparing
with the starting isolates as a result of hydrolysis of the native protein. This
could be explained by exposure of peptides with an amino acid composition
with an antioxidant role recognized as in the case of methionine, tyrosine,
histidine, lysine or tryptophan (Elias et al., 2008)
Figure 4. Fish growing
afte 150 days
under the challenge
conditions in the trial
Plant protein isolates and hydrolysates as alternative to the animal protein in aquaculture diets 53
Chickpea Lupin
Absorbance 700 nm Absorbance 700 nm
Control BHT Isolate
10 mg/mL
Isolate
1 mg/mL
Hydrolysate
10 mg/mL
Hydrolysate
1 mg/mL
Control BHT Isolate
10 mg/mL
Isolate
1 mg/mL
Hydrolysate
10 mg/mL
Hydrolysate
1 mg/mL
0
0,1
0,2
0,3
0,4
0,5
0
0,1
0,2
0,3
0,4