Effects of high-speed homogenization and high-pressure homogenization on structure of tomato residue fibers

- Effects of HSH, HPH and HSH-HPH processing on tomato fiber structure were investigated.
- HSH, HPH and HSH-HPH processing could produce different morphologies and structures to fibers.
- Microfibrils and elementary fibrils were released and their structure were observed by TEM.
- Both HSH and HPH processing could convert insoluble fibers to soluble fibers by 8%
- Effect of acidic degradation could be promoted by high shearing or high pressure.

Tomato residue fibers obtained after derosination and deproteinization were processed by high-speed homogenization (HSH) and high-pressure homogenization (HPH), and their effects on fiber structure was investigated, respectively. Characterizations including particle size distribution, SEM, TEM and XRD were performed. HSH could break raw fibers to small particles of around 60 μm, while HPH could reshape fibers to build network structure. Microfibrils were released and their nanostructure consisting of elementary fibrils was observed by TEM. XRD patterns indicated both HSH and HPH could hardly alter the nanostructure of the fibers. Physicochemical properties including expansibility, WHC and OHC were determined. Both HSH and HPH could increase the soluble fiber content by about 8%, but HSH-HPH combined processing did not show better result. Acid (4 mol/L HCl) was used in replacement of water medium and the acidic degradation of fibers could be promoted by high speed shearing or high pressure processing.