Biotechnological Preparation of Gelatines from Chicken Feet

Abstract

In the European Union (EU), about five tons of poultry by-product tissues are produced every year. Due to their high collagen content, they represent a significant raw material source for gelatine production. The aim of the paper was the biotechnological preparation of gelatine from chicken feet. The influence of selected process factors on the gelatine yield, gel strength, viscosity, and ash of gelatine was observed; a two-level factor design of experiments with three variable process factors (enzyme addition, enzyme treatment time, and gelatine extraction time) was applied. After grinding and separating soluble proteins and fat, the purified raw material was treated in water at pH 7.5 with the addition of endoprotease at 23 °C and after thorough washing with water at 80 °C, gelatine was extracted. By the suitable choice of process conditions, gelatine with high gel strength (220–320 bloom), low ash content (<2.0%) and viscosity of 3.5–7.3 mPa·s can be prepared. The extraction efficiency was 18–38%. The presented technology is innovative mainly by the enzymatic processing of the source raw material, which is economically, technologically, and environmentally beneficial for manufacturers. Chicken gelatines are a suitable alternative to gelatines made from mammals or fish, and can be used in many food, pharmaceutical, and biomedical applications.

Valorization of a By-Product from the Production of Mechanically Deboned Chicken Meat for Preparation of Gelatins

“…If we compare the yield and properties of gelatins prepared under optimal process conditions with the results of our previous research onto the processing of chicken and hen by-products into gelatins, the following can be stated. The yield of gelatins from MDCM by-product (30–32%) is more or less comparable with the yields of gelatins prepared from chicken paws (18–38%) [ 27 ] and from chicken heads (20–36%) [ 30 ]; depending on the conditions of their preparation. However, compared to the yield of gelatins prepared from hen paws (8–21%) [ 35 ], the yield of gelatins from MDCM by-product is much higher (1.5–4.0 times).…”

“…The results of gelatin yields from MDCM by-product are in certain cases lower; on the other hand, in certain cases higher, depending on the processing conditions, in comparison with the yields of gelatins prepared from chicken paws (18–38%) and from chicken heads (20–36%) using analogous biotechnological approach proposed by the authors [ 27 , 30 ]. From the available literature, it is possible to compare the results of gelatin yields from the same starting material treated with different processing methods as well.…”

“…Biotechnological approach in the preparation of gelatins was already published in the manuscripts by the same group of authors [ 27 , 35 ]. The novelty of the present article is related to the optimization of gelatin extraction process with new raw material—mechanically deboned chicken meat (MDCM) by-product.…”

“…However, the processing of residues from the production of MDCM into gelatins is not currently implemented in industrial practice as there are still a very limited number of studies dealing with this issue; in addition, the procedures for processing the raw material are based on the use of acids or bases, which represents a certain burden on the environment. Our research group has been focusing on development of biotechnological processes for valorization of solid poultry by-products (especially chicken paws, heads, stomachs and skins) rich in proteins, particularly collagen, and the subsequent use of prepared collagen products (gelatins and hydrolysates) in food and cosmetic applications [ 27 , 28 , 29 , 30 ]. The aim of this manuscript is to verify the possibilities of processing MDCM by-product into gelatins with enzymatic treatment of the starting material, which has not been used for these purposes so far.…”

Polymer Biointerfaces

“…which, in contrast to acidic (type A gelatines) or alkaline (type B gelatines) processing, has a variety of economic, technological, and environmental advantages [21].…”