Abstract
Protein-based fat replacers are increasing in popularity due to their low-calorie nature and customers' preference on high protein foods. Nevertheless, their fabrication requires large energy input (75–95 °C, 20–40 min) which limits their food application. In the present study, pea protein isolates (PPI) were hydrolyzed by Alcalase, followed by mild heating (85 °C for 10 min) to form aggregates as fat replacer. Protein aggregates were added to skim milk at various concentrations (0.1, 0.3, 0.5%) to develop fat-free cream cheese. Chemical analysis found incorporation of pea protein hydrolysates aggregates (PPH) into fat-free cream cheese increased the moisture content from ∼63% to ∼70%. Rheological measurements showed the storage modulus (G’) was decreased from 36 kPa in the control cheese to 11 kPa and 25 kPa when at 0.3% PPH and PPI aggregates were added. Apparent viscosity (η) was decreased ∼78% and ∼36% with the addition of 0.3% PPH and PPI, respectively. Creep-recovery test showed under the same stress, the strain (%) and α, λ1, λ2 of cream cheese containing PPH had much larger value than those of PPI. The Confocal and Scanning Electron Microscopy showed a less continuous network with large aggregates in PPH contained cream cheese compared to those of PPI or negative control sample, possibly due to clustering of PPH or PPH-casein complex. The information provided from this study sheds light on the development of desirable plant protein-based fat replacer with higher energy efficiency for potential application of low-fat dairy foods.
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•Aggregates of PPH were produced by heating at 85 °C for 10 min.•Incorporation of PPH aggregates increased the moisture content of cream cheese.•PPH aggregates reduced the viscoelasticity of fat free cream cheese.•PPH aggregates disrupted the continuity of casein network in cream cheese.