OPTIMIZATION OF THE PRODUCTION OF HYDROLYSATES FROM GRASS CARP (CTENOPHARYNGODON IDELLA) SKIN USING ALCALASE

Abstract

Protein hydrolysate was produced from grass carp skin using Alcalase. Hydrolysis conditions were optimized by using a response surface methodology (RSM). A model equation was proposed with regard to effects of temperature (T), pH, enzyme/substrate (E/S) ratio (%v/w of minced skin) and time (t) on degree of hydrolysis (%DH). The optimum values for T, pH, E/S ratio and t were found to be 59.74C, 8.25, 1.70% and 83.83 min, respectively. Regression coefficients indicated that all linear forms T, pH, t and E/S ratio plus one quadratic form t2 and one cross‐product interaction T · t were significant (α = 0.05). The model showed a good fit in experimental data because 90.7% of the variability within the range of values studied could be explained by it. The freeze‐dried hydrolysate contained high protein content (90.8%). The hydrolysate produced was highly water‐soluble with good water‐holding, oil‐binding and emulsifying properties. Thus, the production of a hydrolysate with desired functional properties is possible from grass carp skin using Alcalase. PRACTICAL APPLICATIONS Considerable amounts of protein‐rich by‐products from seafood processing plants are discarded without any attempt to carry out recovery. The preference in many Western countries for bone‐free fillets necessitates the removal of flesh from fish, and a substantial amount of original weight is considered a waste, of which the skin is inclusive. It would be of great interest to put these by‐products that are high in protein to use in human foods instead of in fish meals for animal feed. Enzymatic hydrolysis of food proteins generally results in profound changes in the functional properties of proteins treated. The choice of substrate, the protease enzyme employed and the degree of hydrolysis can greatly affect the physicochemical properties of the resultant hydrolysate. Through the control of the process parameters such as pH, time and enzyme/substrate ratio, it is possible to produce hydrolysates whose components may present some interesting properties. Fish protein hydrolysates have numerous applications, particularly in the food and pharmaceutical industries.

Optimization of enzymatic hydrolysis conditions for the production of antioxidant peptides from muscles of Nemipterus japonicus and Exocoetus volitans using response surface methodology

“…The range of the degree of hydrolysis for N. japonicus and E. volitans muscle protein was from 29.12 to 42.15% and 21.21 to 43.21%, respectively. In this study the value of degree of (DH) for both fish muscle protein was higher than DH of Grass carp skin, 1.1-15.2% (Wasswa et al 2008) and silver catfish frame, 6.25 to 21.38% (Amiza et al 2011) but lower than degree of hydrolysis of Catla viscera, 34.23-49.65% (Bhaskar et al 2007). The difference in degree of hydrolysis maybe because of the difference in the part of fish used in hydrolysis, difference in fish species and difference in enzyme used (Bhaskar et al 2007).…”

Nutritional and functional properties of Roselle (Hibiscus sabdariffa L.) seed protein hydrolysates

“…Hydrolysis was effective in improving the EC of hydrolysates. Related findings have indicated that enzymatic hydrolysis of tilapia and grass carp skin (Wasswa et al, 2007) produced hydrolysates with higher emulsifying capacity. …”

“…It is proposed that high oil absorption capacity of Roselle seed protein hydrolysates may give an advantage for their consideration in the formulation of food products such as cake, sausages, salad dressings and mayonnaise. Wasswa et al (2007) also produced protein hydrolysates with OHC.…”

Comparative Antibacterial Activity of Tryptic‐Hydrolyzed Palm Kernel Cake Proteins of Different Degrees of Hydrolysis

“…It is important, therefore, to determine the conditions under which to apply enzymatic hydrolysis to produce the best possible response or product (Wasswa et al . ). It is also vital to know which of these factors are critical and the interactions that occur between the factors.…”

“…Additionally, the efficiency of enzymatic hydrolysis is greatly influenced by factors such as the enzyme concentration, reaction temperature and pH. It is important, therefore, to determine the conditions under which to apply enzymatic hydrolysis to produce the best possible response or product (Wasswa et al 2008). It is also vital to know which of these factors are critical and the interactions that occur between the factors.…”