Functional Properties of Grass Carp (Ctenopharyngodon Idella), Nile Perch (Lates Niloticus) and Nile Tilapia (Oreochromis Niloticus) Skin Hydrolysates

Abstract

The influence of using an endo-peptidase (alcalase) on the functional properties of hydrolysis products from Nile perch, Grass carp, and Nile tilapia skin was studied. Reaction conditions were controlled at pH 8.25, 60°C, and the enzyme was added on the basis of standard activity units at an enzyme to substrate ratio of 1.7 g/100 g protein. The reaction was allowed to proceed for 85 min and enzyme was inactivated by heat. The soluble protein fractions were recovered and lyophilized. All freeze-dried fish skin hydrolysates powders had a light yellow color and contained up to 90% protein. Nitrogen solubility varied from 95.93 to 98.72% and was not significantly different at 5% probability level. The water and oil holding capacities of the skin hydrolysates were good in the range of 2.8 to 3.2 mL/g and 3.4 to 3.8 mL/g, respectively. Emulsification capacity varied from 11.3 to 21 mL/0.5 g with Nile perch skin hydrolysate having the highest score while Nile tilapia skin hydrolysate was the lowest. Grass carp skin hydrolysate was not able to form stable foam, unlike the Nile perch and Nile tilapia skin hydrolysate. Alcalase treated freshwater fish skin exhibited satisfactory functional properties hence may play an important role as an ingredient in the food and pharmaceutical industry.

Comparison between thermal hydrolysis and enzymatic proteolysis processes for the preparation of tilapia skin collagen hydrolysates

“…And the hydrolysates produced by double 15-min hydrolysis had a greater DPPH radical scavenging effect than those produced by double 30-min hydrolysis. Tables 1 and 2 demonstrate that the molecular mass distribution was not correlated with the antioxidant activity of tilapia skin collagen hydrolysate, which is comparable with the results reported by Yang et al (2009) Wasswa et al (2008 hydrolysed tilapia skin collagen with Alcalase (1.7 g enzyme/100 g ground dried skin) at 60°C for 85 min and obtained hydrolysates, of which 77% of the molecular mass distribution was below 1000 Da. The process in pH 4 3000 ± 500 13 94 ± 4 74 ± 6 pH 9 7000 ± 1000 14 89 ± 3 71 ± 3 pH 6.5 6000 ± 500 11 90 ± 5 54 ± 5 this study is more concise and economical (60 mg enzyme/100 g wet skin, 50°C, less than 70 min) with a similar average molecular weight of the product.…”

“…Chances are that hydrolysed collagen coming from fish can improve bone metabolism (Guillerminet et al 2010) and prevent skin aging (Tanaka et al 2009 optimised the process for the production of tilapia retorted skin collagen hydrolysates with antioxidant properties. Wasswa et al (2008) prepared protein hydrolysates from the skin of Nile tilapia hydrolysed with protease, which exhibited satisfactory functional properties required in food processes.…”

Storage Stability of Protein Hydrolysate from Yellow Stripe Trevally (Selaroides leptolepis)

“…Protein hydrolysates generally exhibited the improved functional properties associated with the increased solubility. Protein hydrolysates from many sources, such as fish, [1,2] soy, [3] ram horn, [4] and banana peel [5] have been used as functional ingredients and microbial media and their performances were comparable to that of commercial peptone. [1,4] As microbial media, protein hydrolysate should be clear or only slightly colored and free from precipitates.…”

Emulsifying and Foaming Properties of Defatted Soy Meal Extracts Obtained by Subcritical Water Treatment

“…[12] However, functional properties of the extracts have not been reported in the literature. Since protein products are frequently determined for their emulsifying and foaming properties, [13][14][15] therefore, these properties of the extracts obtained by subcritical water treatment at different temperatures were evaluated in this study.…”