Physicochemical properties, structural transformation, and relaxation time in strength analysis for honey powder models
2019
Fan, Fanghui | Roos, Yrjö H.
Present study developed a strength analysis for relaxation time (τ) in characterizing physicochemical properties and structural transformation of freeze-dried honey/whey protein isolate (H/WPI) and honey/maltodextrin (H/MD) models based on water sorption, time-dependent crystallization, glass transition, and α-relaxation at various water activities (0.11aw to 0.76aw) and 25 °C. Water sorption data of two models explained WPI was a more effectiveness drying stabilizer than MD as H/WPI model owned higher monolayer water content. Crystallization was observed in prepared models with drying-aids content below 50% of mass ratios at water activity above 0.44aw and 25 °C, whereas the extent of crystallization and structural collapse were inhibited by WPI and MD addition based on sorption isotherms. Glass transition temperature, α-relaxation temperature, and τ for two models were composition-dependent and altered by water, WPI, and MD at water activity below 0.44aw. According to strength analysis of τ, the S for H/WPI and H/MD models was affected by drying-aids and could give a quantitative measure to estimate compositional effects on τ. Moreover, a S-involved state diagram was established to determine the critical parameters (water content and S) for controlling structural transformation of honey powder models during production and storage, i.e., collapse and stickiness.
显示更多 [+] 显示较少 [-]