High Hydrostatic Pressure in Astringent and Non-Astringent Persimmons to Obtain Fiber-Enriched Ingredients with Improved Functionality

This study examined the effects of high hydrostatic pressure (HHP) processing on dietary fiber, cell wall sugars, cell wall-modifying enzymes, and techno-functional properties of astringent and non-astringent persimmon flesh. The fruits were subjected to 200 and 400 MPa for 1, 3, and 6 min, at 25 °C. Dietary fiber and alcohol insoluble residue (AIR) were affected significantly (p ≤ 0.05). Soluble fraction of fiber (SDF) decreased, and AIR content increased up to 46% after application of high pressure. HHP reduced total sugar content of AIRs and promoted changes in the contribution of uronic acids (UA) and glucose, obtaining pectin-enriched materials (from 45 to 61% UA) in astringent persimmons treated by pressure. Pectinmethylesterase (PME) activity increased independently of the astringency level of persimmons (from 1.7- to 2.0-fold), while polygalacturonase (PG) activity was highly dependent on pressure and time conditions of HHP treatments. The application of HHP enhanced techno-functional properties of persimmon AIRs. Great water-absorption (21–31 mL/g AIR) and oil-holding (10–14 mL/g AIR) capacities were obtained for HHP-treated astringent and non-astringent persimmons, respectively, which showed the potential of HHP technology to add value to persimmons.