The relation between (bio-)chemical, morphological, and mechanical properties of thermally processed carrots as influenced by high-pressure pretreatment condition

摘要

Thermal texture evolution kinetics (90-110 degC) of nonpretreated and high-pressure pretreated (HP = 400 MPa, 60 degC, 15 min) carrots were determined using a multipa-rameter approach (cutting, compression). Alcohol Insoluble -Residues (AIR) were extracted before and after thermal processing of the samples and the degree of methylation JDM) was estimated. The ft -elimination kinetics of the water soluble pectin extract from the AIR was studied and related to the changes in material properties. Morphological changes and tissue-failure characteristics were monitored. The mechanical properties were strongly dependent on the processing temperature and the DM of the samples. Texture degradation rate constants were independent of the texture measurement method. Increasing temperature accelerated the beta-elimination reaction (k_b) and the thermosoftening (k_x) rates, but pretreatment condition slowed down the rates. Interestingly, a strong correlation (r > 0.99) between k_b> and _kx occurred. Thermal processing resulted in cell-wall thickening accompanied by a transition from cell rapture to cell separation, a process retarded by pretreatment condition.