Impact of food structure on the compatibility of heated WPI-pectin-complexes in meat dispersions.

Process-stable complexes composed of whey protein isolate (WPI) and sugar beet pectin have great potential as structuring agents or fat replacers in foods. The current study investigates the compatibility of heated WPI : pectin complexes in different meat matrices. Spreadable raw-fermented sausages and sliceable emulsion-type sausages were therefore manufactured containing biopolymer complexes with various WPI : pectin ratios r (2 : 1, 8 : 1). Macro- and microstructural properties of the meat dispersions were analyzed in terms of colour, texture, rheometry, sensory, and confocal laser scanning microscopy (CLSM) measurements. Textural and sensorial results demonstrated that the meat products became increasingly soft and yellowish as the biopolymer ratio r was increased regardless of the meat matrix, whereas pH and water activity values were not affected. CLSM images revealed that the meat protein network became disrupted and loose in the presence of pectin, which was attributed to a thermodynamic incompatibility effect. The results obtained from this study highlight that biopolymer complexes might be suitable fat mimetics, particularly for spreadable meat products.