Collagen is already used by the food industry as a protein and collagen fibre as a water and fat binder in meat products. But the broader potential of collagen fibre as an emulsifier, obtain from crude collagen and defatted, dried and ground, is a new area of exploration.
Led by Rosiane Cunha, the researchers from the University of Campinas in Brazil were motivated by the demand for natural emulsifiers for use in the food industry instead of synthetic ones. Other natural candidates for food use include casein, whey protein, soybean protein and gelatine.
The team collagen fibre from NovaProm Food Ingredients in Brazil, which extracted it from bovine hides. It then set out to investigate the potential of collagen fibres in oil-in-water emulsions under different pH conditions, in formulations with different protein contents, and using two different emulsification devices, a rotor stator and a high-pressure homogeniser.
The two emulsification devices are used to deliver emulsions with different particle sizes, the former for larger than 1µm and the latter for larger. The stability, the microstructure and the rheology of the emulsions were measured.
They found that at pH 3.5 using the rotor stator phase separation and droplet size decreased with protein concentration and reduction in pH. The resulting emulsions were electromagnetically stable.
At higher pH levels there was a microscopic 3-dimensional network responsible for their stability at protein counts over 1 per cent.
Use of the high-pressure homogenization emulsification method was seen to be problematic, producing less stable and less structured emulsions. This was because the pressure disrupts the collagen fibre structure and the oil droplets. While higher pressure reduced the droplet size, it also reduced the emulsion’s viscosity.
“The results of this work showed that the collagen fibre has a good potential for use an emulsifier in the food industry, mainly in acid products,” concluded the team.
Source
Food Hydrocolloids, published online ahead of print
DOI:
“Emulsifying properties of collagen fibers; effects of pH, protein concentration and homogenization pressure”
Authors: RC Santana, FA Perrechil, ACK Sato, RL Cunha