Biotechnological Processing of Laying Hen Paw Collagen into Gelatins

Robert Gál,Ngo Thi Hong Linh,Jana Pavlačková,Pavel Mokrejš,Jiří Mlček

doi:10.3390/pr8111415

Abstract

By-products of laying hens represent a promising raw material source with a high collagen content, which is currently not adequately used. The aim of the paper is to prepare gelatins from laying hen paws. The purified collagen raw material was processed by a biotechnological process using the food endoprotease Protamex®. After cleavage of the cross-links in the collagen structure, the gelatin was extracted by a batch process with a stirrer in two extraction steps. The influence of the extraction process on the yield of gelatins and on selected qualitative parameters of gelatins was monitored by two-level factor experiments with three selected process factors. The studied factors were: enzyme dosage (0.2–0.8%), enzyme processing time (24–72 h) and gelatin extraction time (30–120 min). After the first extraction step at 75 °C, gelatin was extracted with a yield of 8.2–21.4% and a gel strength of 275–380 Bloom. In the second extraction step at 80–100 °C, it is possible to obtain another portion (3.3–7.7%) of gelatin with a gel strength of 185–273 Bloom. Total extraction efficiency of gelatins prepared from laying hen collagen is almost 30%. The prepared gelatins are of high quality and, under proper extraction conditions, gelatins with a gel strength above 300 Bloom can be prepared, thus equaling commercial beef and pork gelatins of the highest quality. Biotechnological processing of laying hen collagen into gelatins is environmentally friendly.

Highlights

In 2019, worldwide poultry meat production was 128.4 million metric tons, the highest by type of meat; pork production was 115.6 million metric tons, followed by beef (71.6) and lamb (15.3)
By removing the accompanying components, purified collagen can be obtained from hen paws, which is an excellent source of raw material for the preparation of gelatins
The aim of this study was to verify the possibilities of processing laying hen collagen into gelatin using an innovative biotechnological process of conditioning the raw material

Summary

Introduction

In 2019, worldwide poultry meat production was 128.4 million metric tons, the highest by type of meat; pork production was 115.6 million metric tons, followed by beef (71.6) and lamb (15.3). If we compare only the production of poultry meat in the last 15 years, it has increased by about 44 million metric tons [1]. Compared to 2019, by 2028 it is estimated that the production of poultry meat will increase by about 10% [2]. The amount of by-products produced during the processing of animals into meat may vary, depending on whether the by-products are subsequently used, e.g., in the food, feed or technical fields. Their amount represents approximately 1/3 of the live weight of the animals, but in some cases, it can be up to 55% [3,4]

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