Emulsifying and foaming properties of a hydrophobin-based food ingredient from Trichoderma reesei: A phenomenological comparative study
Cristina Alamprese, Manuela Rollini, Alida Musatti, Pasquale Ferranti, Alberto Barbiroli
Abstract
The aim of this study was the production of a hydrophobin-based food ingredient (HFB) from submerged cultures of Trichoderma reesei and the evaluation of its technological properties in comparison with milk whey (WPC) and egg white (EWP) proteins, widely used in foods for their surface-active properties. T. reesei culture medium was formulated without proteins to ease HFB recovery. Culture supernatant after biomass separation was air-bubbled to concentrate HFB at the air-liquid interface, thus reaching a recovery yield of 138 mg/L. HFB, WPC and EWP solutions (1–5 g/L) were used to test the emulsifying activity index (EAI), the creaming stability (CS) and the foaming properties. EAI was almost four times higher than that of WPC and EWP. Also CS was improved in the case of HFB-stabilized emulsions, but only at the lowest concentration. The overrun of the foam obtained with HFB solutions was 1.2–1.9 times higher than that of the foams obtained with the other ingredients; also foam consistency was significantly higher when created with HFB solutions. Overall results indicate that HFB obtained from T. reesei showed interesting and promising technological properties, paving the way to possible applications in aerated foods and foamed emulsions.