Comparative Analysis of Enzymatically Hydrolysed and Fermented Protein Hydrolysed Ghee Residue Powder for Techno-functional Properties

Abstract

Background: Ghee residue (GR) protein hydrolysate was prepared to utilise the protein component of this dairy-industry by-product. For sustainable utilisation, it needs to be incorporated into various food products, as direct consumption is challenging because of the bitter taste of the hydrolysed product and the unsuitability of the unhydrolysed product. Aim: This study compared the techno-functional properties of enzymatically hydrolysed and fermented freeze-dried GR powders with unhydrolysed defatted GR powder as the control. Study Design: A comparative analysis was conducted using freeze-dried enzymatically hydrolysed and fermented powders, with unhydrolysed defatted GR as the control. The samples were evaluated for various techno-functional properties. Methodology: Parameters such as solubility, emulsifying properties and foaming properties were studied in the Livestock Product Technology Division of ICAR-IVRI, Izzatnagar, Bareilly. Comparative analysis was performed to assess the effect of protein breakdown on these parameters and the differing effects of enzymatic hydrolysis and fermentation on these properties. Result: Both processed powders showed significant improvements (p<0.01) in several measured techno-functional properties relative to the unhydrolysed control. The enzymatically hydrolysed powder showed the highest water solubility index (77.033±1.123%), foaming capacity (21.620±0.517%), foaming stability (16.687±0.684%), and water absorption capacity (3.966±0.125 g H₂O/g). The fermented powder also showed improvement, with corresponding values of 39.497±1.068%, 19.163±0.853%, 12.617±0.729%, and 3.641±0.078 g H₂O/g, respectively. Emulsifying activity and stability were also higher in the processed samples than in the control, with the enzymatically hydrolysed powder showing the greater response. Water activity was 0.273±0.014 for the enzymatically hydrolysed powder and 0.291±0.012 for the fermented powder. Conclusion: Under the conditions evaluated, enzymatic hydrolysis generally produced greater changes in techno-functional performance than fermentation, although both processing approaches improved the functional characteristics of GR powder and may support its selection according to the requirements of the intended food application.