Effect of high pressure processing on selected physicochemical and functional properties of yellow lentil protein concentrate
Creators: name: Navare, Sawali Suhas
Publisher: name: No Publisher Supplied
Year: 2019

description: There is a growing interest in utilizing plant proteins as functional ingredients in foods, in an effort to address the consumer demand for ‘clean label’ or only natural ingredients in foods. Plant proteins can be used as emulsifiers, foaming agents and fat binding agents in order to replace synthetic food surfactants such as Sodium Tri-polyphosphate. High Pressure Processing (HPP) can bring about structural modifications in the plant proteins and increase their functionality. The aim of this project was to study the effect of High Pressure Processing parameters on selected physicochemical and functional properties of yellow lentil protein concentrate.Yellow lentil protein concentrate (YLPC) solutions (10% w/w) were subjected to high pressure processing, followed by freeze drying. Experiments based on Box- Behnken (BBD) design were carried out, with Pressure (MPa), time (min), and pH of the protein solution as the three independent factors. The freeze dried samples were then analysed for emulsification capacity, foaming ability, solubility, fat binding capacity, surface hydrophobicity, and surface zeta potential. These analyses were carried out in two different pH systems, namely, pH = 3 and pH = 7. Unprocessed yellow lentil protein concentrate was used as the control It was observed that lower pressures and intermediate treatment times at neutral pH (=7) protein solutions were most effective in improving the functional properties of the protein. The solubility of the protein in a pH 7 system increased from 40% ± 3% for unprocessed control to 50% ± 5% for the sample processed at 150 MPa. The emulsifying ability of the protein decreased at higher pressures of 350 MPa and 550 MPa. In the pH 3 system, the droplet size of the dispersed phase of the emulsion stabilized by the protein sample processed at 550 MPa increased to 24 µm ± 0.2 µm from 16 µm ± 0.5 µm for the unprocessed control. Similarly, in the pH 7 system, the droplet size increased from 8 µm ± 1.5 µm for the emulsion stabilized by the unprocessed control to about 11 µm ± 2 µm for emulsion stabilized by the protein sample treated at 550 MPa. However, samples processed at these pressures imparted higher stability to the emulsions- around 89% ± 2% compared to 82% ± 3% for the emulsions stabilized by the unprocessed control. Foaming ability was not significantly affected by the HPP treatment in both systems: pH 3 and pH 7. The surface hydrophobicity increased from H0 = 2800 ± 228 for unprocessed control to H0 = 6400± 51 for the sample processed at 350 MPa Surface zeta potential was not significantly affected by the three independent factors studied. Different factors or combination of factors played a significant role in the changes in each of these functional properties.In conclusion, pressure treatments at lower pressures (150 MPa, 10 min) at neutral pH were found to be better at improving the functional properties compared to higher pressures and longer times at lower or neutral pH values.