Effects And Mechanism Of Mixtures Of Small Peptides And/or Oligopeptides From Enzymic Hydrolysates Of Chicken Egg White On Immune Functions Of Mice

Effects and mechanism of the mixtures of small peptides and/or oligopeptides from enzymic hydrolysates of chicken egg white (MSEE and/or MOEE) on immune functions of mice were investigated. After the enzymic hydrolytical parameters were optimized, 5 MSEE and 5 MOEE products were prepared under the optimum conditions. The most effective MSEE or MOEE was selected based on the in vitro study on immune functions of mice. The effects and mechanism of the selected MSEE or MOEE on immune functions of mice with normal or sub-normal immunity were evaluated. The whole study consisted of four experimental parts.Part. 1 Study on the Optimum Parameters of Proteases to Hydrolyze Chicken Egg White in vitroExp. 1 Study on the Optimum Parameters of Seven Single ProteasesIt's well known that the main factors influencing hydrolytical efficacy of proteases are reactive temperature, pH, enzyme levels, concentration of substrate and reaction time.In this experiment, according to nitrogen solution index (NSI), degree of hydrolysis (DH, including DH₁ and DH₂) and bitter taste values, the optimum parameters of reactive temperature (T, ℃) , pH vaule, enzyme levels ([E]/[S], w/w) , substrate concentration ([S], w/v) and reaction time (t, min) were studied individually for Alcalase (AL), acidic protease (AP), Flavourzyme (FL), As. 1398 neutal protease (NP), papain (PA), pepsin (PE), and Trypsin (TR) to hydrolize chicken egg white. The results showed that:1) The hydrolytical efficacy of each protease on egg white was significantly influenced by the temperature, pH value, enzyme levels, substrate concentration and reaction time in the reaction system.2) Different protease had significantly different effect on egg white. The most effective enzyme was FL, while NP and AP were the worst.Exp. 2 Study on the Optimum Parameters of Ten Combinations of Two EnzymesL₉ (3⁴) orthogonal design was employed to determine the optimum enzymic hydrolytical parameters of 10 combinations of two enzymes, which included 5 "PE+X" combinations and 5 " AP +X" combinations ( X representing any one of AL, FL, NP, PA and TR). Three factors were reaction time, PE or AP level and X enzyme level. The specific level of each factor was based on the results of Exp.1. DH(DHl) and bitter taste values were used as indicators.The results showed that:1) Reaction time and PE or AP level were the key factors affecting the enzymolysis effect of 10...