The influence of the sequential extractions on the structure and the properties of single cell materials from apples

In order to evaluate the influence of disintegration on the structure and the properties of single cell wall materials from apples, parenchymatic single cells (MM) were extracted step by step with water (BM), chelating agents (CH), sodium chlorite/acetic acid mixture (CO) and sodium hydroxide/NaBH4 (CA). The composition and the structure parameters of the dried materials obtained showed enhanced cell wall disintegration in the order MM, BM, CH, CO and CA. This disintegration was proved by decreasing yields and increasing glucose contents indicating a lower share of amorphous matrix and a higher share of cellulose-xyloglucan network with rising steps of the sequential extraction. However, systematic alterations of galacturonan content, bulk density, solid density and porosity with increasing cell wall disintegration were not found. The hydration properties, determined as swelling and water retention capacities, decreased in the order BM, MM≈CO, CH and CA. Also, the structure-viscous and viscoelastic properties of the rehydrated CWM in the decreasing order CH, CO, BM, MM and CA were not in agreement with the order of the cell wall disintegration as well as with the order of the hydration properties. The results show a complex and multivariate correlation between structure, physical state and properties.