Optimization of fish gelatin drying processes and characterization of its properties

Cleidiane Da Silva Araújo,José De Arimateia Rodrigues Do Rego,Lúcia De Fátima Henriques Lourenço,Enrique Pino-Hernández,Jáira Thayse Souza Batista,Maria Regina Sarkis Peixoto Joele

doi:10.1038/s41598-021-99085-3

Cleidiane Da Silva Araújo, José De Arimateia Rodrigues Do Rego + Show 4 more

Open Access

https://doi.org/10.1038/s41598-021-99085-3

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Abstract

Fish skin is a raw material used for gelatin production. It can satisfy consumers with specific socio-cultural and religious needs. Different technologies have been studied for drying gelatin. Therefore, it is relevant to understand the influence of drying conditions on the final product. This study aims to optimize drying methods such as convection hot air alone and combined with infrared radiation to obtain gelatin from acoupa weakfish skin by using composite central rotational designs 22 and 23 and response surface methodology. The gelatin obtained from the optimized conditions were characterized based on their physical, chemical, technological, and functional properties. The desirability function results show the convection hot air as the most effective method when conducted at 59.14 °C for 12.35 h. Infrared radiation at 70 °C for 2.0 h and convective drying at 70 °C for 3.5 h were the best condition of the combined process. The gelatins obtained had gel strength of 298.00 and 507.33 g and emulsion activity index of 82.46 and 62.77 m2/g in the combined and convective methods, respectively, and protein content above 90%. These results indicate that the processes studied can be used to produce gelatin with suitable technological and functional properties for several applications.

Highlights

Fish skin is a raw material used for gelatin production
The acoupa weakfish skin removed during processing is rich in protein and collagen, which can be used for gelatin extraction, while adding value and reducing the environmental pollution
This study aims to optimize the drying conditions of the convection hot air method applied alone and combined with infrared radiation on fish skin gelatin (Cynoscion acoupa) by using experimental designs via fractional planning and response surface methodology (RSM) with the characterization of the gelatins obtained

Summary

Introduction

Fish skin is a raw material used for gelatin production. It can satisfy consumers with specific sociocultural and religious needs. This study aims to optimize drying methods such as convection hot air alone and combined with infrared radiation to obtain gelatin from acoupa weakfish skin by using composite central rotational designs 22 and 23 and response surface methodology. The gelatins obtained had gel strength of 298.00 and 507.33 g and emulsion activity index of 82.46 and 62.77 m 2/g in the combined and convective methods, respectively, and protein content above 90%. These results indicate that the processes studied can be used to produce gelatin with suitable technological and functional properties for several applications. Functional properties are relatively dependent on the spatial structure of protein molecules being their association status is influenced by the drying process, which leads to physicochemical transformations of their proteins because of the heat and mass transfer[10,11]

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