Avaliação de variáveis que influenciam a hidrólise enzimática da caseína do leite de cabra Moxotó

Abstract

Resumo − O objetivo deste trabalho foi avaliar os efeitos da temperatura, pH, relação enzima:substrato (E:S) e tempo de reação sobre a hidrólise enzimática da caseína do leite de cabra Moxotó, com uso de diferentes enzimas proteolíticas. A hidrólise enzimática da caseína caprina foi realizada com uso de tripsina, pepsina e papaína. Para cada enzima, foram utilizados dois níveis de cada variável, na avaliação de seus efeitos sobre a hidrólise da caseína, em um fatorial completo 2 4 . Os produtos da hidrólise foram visualizados em eletroforese SDS-PAGE. O melhor valor do grau de hidrólise com a enzima papaína foi obtido em pH 6,5, E:S de 1:150 e 5 horas de hidrólise a 50ºC (28,17%); com a tripsina, em pH 8,5, E:S de 1:150 e 5 horas a 40ºC (29,55%); e com a pepsina, em pH 3,0, E:S de 1:100 e 5 horas a 40ºC (38,27%). A hidrólise da caseína caprina é influenciada positivamente pelo pH e tempo de hidrólise, com o uso da pepsina. Foram observadas interações significativas antagônicas entre pH e relação E:S, com o uso da tripsina; e entre pH, temperatura e tempo de hidrólise, com o uso da papaína. A pepsina apresenta elevada eficiência na hidrólise de α s1 , β e κ-caseína, evidenciada por hidrolisados com massa molar abaixo de 14,4 kDa.Termos para indexação: Capra hircus, leite de cabra, papaína, pepsina, proteólise, tripsina. Evaluation of the variables that influence the enzymatic hydrolysis of Moxotó goat's milk caseinAbstract -The aim of this work was to evaluate the effects of temperature, pH, enzyme:substrate ratio (E:S), and reaction time on the enzymatic hydrolysis of Moxotó breed goat's milk casein, using different proteolytic enzymes. Enzymatic hydrolysis of the capric casein was performed using trypsin, pepsin and papain. For each enzyme, two levels of the variables were used to assess their effects on the hydrolysis of casein, using a full factorial design (2 4 ). The hydrolysis products were visualized on SDS-PAGE. The best hydrolysis degree using papain were at pH 6.5, E:S of 1:150 and 5 hours of hydrolysis at 50°C (28.17%); for trypsin, at pH 8.5, E:S of 1:150 and 5 hours at 40°C (29.55%); and for pepsin, at pH 3.0, E:S of 1:100 and 5 hours at 40°C (38.27%). Capric casein hydrolysis is affected positively by pH and reaction time, using pepsin. Significant antagonistic interactions were observed between pH and E:S, with trypsine; and between pH, temperature and reaction time, with papain. Pepsin has high α s1 , β e κ-casein hydrolysis efficiency, evidenced by the molar masses below 14.4 kDa of its products.

Biotechnological richness of the northeastern semi-arid region: antioxidant activity of casein hydrolysates from Moxotó goat milk (Capra hircus Linnaeus, 1758) obtained by papain action

“…The best DH degree of hydrolysis value, obtained in assay 10, was 28.5%, using 1:150 E:S ratio for 5 hours. Our results confirm those of Lira et al (2010), who obtained 28.18% DH by goat casein hydrolysis with papain, using the same conditions tested in our study. From another standpoint, Zhang, Li and Zho (2009) obtained 10.2% for DH when used papain enzyme to hydrolyze bovine casein (pH 7.0; 1:100 E:S ratio; 55 °C; 24 hours), which was statistically different from our results.…”

“…However, E: S (Q) ratio had a significant negative effect on DH under tested conditions, which indicates that the decrease in E: S ratio from 1:100 to 1:200 favored DH. Our results corroborate Lira et al (2010), who demonstrated the influence of kinetic parameters in casein hydrolysis of Moxotó goat milk, by utilization of papain use, as well as the negative influence of E:S on goat casein DH. On the other hand, this situation was different when the E: S ratio decreased from 1:150 to 1:200, showing that intermediate levels were responsible for the greatest DH.…”

“…This study was carried out using a 50 °C reaction temperature and pH 6.5, as established by Lira et al (2010). The analyzed variables and their levels (obtained from the factorial design), which were used to obtain casein DH degree of hydrolysis as well as its antioxidant activity by papain enzyme utilization, are shown in Table 1.…”

Enzymatic hydrolysis of camel milk casein and its antioxidant properties

“…Similar results were also reported by Graszkiewicz et al (2010) in egg-white protein precipitate hydrolysis in which chymotrypsin caused a higher DH in 1-h hydrolysates than trypsin and elastase. Lira et al (2010) also reported 28.17% DH of goat milk casein obtained with the use of papain. In the current study, the DH after 6 h of hydrolysis had not increased significantly (data not shown).…”

Queijo de coalho artesanal: fonte alternativa de peptídeos antimicrobianos

“…Eles têm sido isolados de produtos lácteos incluindo queijos, iogurtes e leites fermentados. Os peptídeos antimicrobianos provenientes da caseína têm mostrado capacidade de eliminar células-alvo rapidamente e com um amplo espectro de atividade (LIRA et al, 2010;LÓPEZ-EXPÓSITO;.…”