Design of Model Apple Cells Suspensions: Rheological Properties and Impact of the Continuous Phase

Abstract : The objective of this work is twofold: to develop a relevant model system to study plant cells suspensions’ rheology and to evaluate the impact of the continuous phase composition and viscosity on the rheological behaviour of apple cells suspensions. Model suspensions of individual or clustered apple cells were developed. Rheological behaviours of both type of suspensions were observed separately, suspending from 0.145 g/100mL to 3.48 g/100mL of particles in five model media and in the original apple serum. Our results show that model suspensions successfully reproduce the rheological behaviour of apple purees, following three concentration domains. In particular, cell clusters greatly reproduce the behaviour of bimodal apple purees, suggesting that clusters dominate the rheological behaviour of the whole puree. One of our main result is that continuous phase does not affect elastic properties of suspensions in the concentrated domain since they are essentially governed by particle interactions: G’ values are similar whatever the continuous phase. If the continuous phase has the main impact on diluted suspensions’ viscosity, its effect becomes smaller as particle concentration increases. A lubricating effect was observed in the concentrated domain for continuous phases containing polymers. Presence of polymers may help in structuring the network in the intermediate domain.