Dados do Trabalho

Título

VALORIZATION OF CHICKEN DIGESTIVE BY-PRODUCTS: ENZYMATIC PROTEIN HYDROLYSIS AND ANTIOXIDANT POTENTIAL

Introdução

Chicken by-products are generated from the slaughter of animals to obtain meat. These by-products have a varied composition, generally rich in lipids and proteins, and may be valued through enzymatic hydrolysis. Thus, the objective of this study was to evaluate the degree of hydrolysis (DH) and the in vitro antioxidant capacity of protein hydrolysates from different by-products of the chicken digestive system.

Material e Métodos

The ventricle (V), proventriculus (P), and lining (R) were manually cleaned of excess fat, frozen, and crushed. They were characterized for moisture, ash, lipids, protein, and collagen content. Hydrolysis occurred in a jacketed reactor, where 30 g of each by-product, separately, were hydrolyzed (1:2 m/v) using Alcalase© 2.4 L (enzyme/substrate ratio of 5%, by mass) in an aqueous medium under the conditions optimum enzyme levels, maintaining a constant temperature of 60 ºC and pH 8.00, adjusted with 0.5 mol/L NaOH for 4 hours. This resulted in hydrolysates of the ventricle (HV), proventriculus (HP), and lining (HR). DH was determined through base intake. The antioxidant activity was evaluated by the 2,2-azino-bis(3-ethylbezothiazoline)-6-sulfonic acid-(ABTS •+) radical and the ferric reducing antioxidant power (FRAP) methods.

Resultados e Discussão

Sample R presented the highest protein and collagen values, followed by V and P (p<0.05): 98.32 ± 0.84; 87.57 ± 0.65; 80.07 ± 0.27 g/100 g on a dry basis, and 13.83±2.09; 2.45±0.08; 2.36±0.18 g/100 g, respectively. DH is defined as the percentage ratio between the number of broken peptide bonds and the total number of peptide bonds in the studied substrate. HP had the highest HD (22.91%), followed by HV (21.20%) and HR (18.69%). HP showed the highest percentage inhibition of the ABTS radical, followed by HV and HR (57.60±1.92; 65.80±3.51; 37.38±2.95, respectively). For FRAP, HV (66.20%) presented the highest value, followed by HR (44.77%) and HP (29.87%). Pearson's correlation with a high and negative value (r = -1) indicated a strong negative correlation between HD and FRAP (p<0.05 = 0.0046).

Conclusão

The different by-products of the chicken digestive system are relevant sources of animal protein with distinct characteristics, exhibiting in vitro antioxidant activity, making them candidates for use as functional ingredients in processed products.