Hidden treasure of the nature: PAs. The effects of grape seeds on free formaldehyde of leather

Grape seeds are increasingly on demand as a side product of wine industry. Having oligomeric proanthocyanides (PAs) in their structure, grape seeds can be used as antioxidising agents in a wide area of applications. In the present study, a variety of grape seeds (powder, grape seed extract and modified extract) have been tested for their effects on free formaldehyde readily found on leather. Formaldehyde was quantified with two methods; AATCC test method 112 was employed to measure free formaldehyde and that of hydrolysed form obtained at 49 °C for 20 h. By IUC 19 (ISO TS 17226) method, free formaldehyde and a little formaldehyde from the hydrolysis was obtained at 40 °C for 1 h. The results indicated that the grape seeds in all forms used at the step of retanning process lowered free formaldehyde at appreciable levels.

► A variety of grape seeds have been tested for their effects on free formaldehyde readily found on leather.
► Formaldehyde was quantified with two methods.
► The grape seeds in all forms used at the step of retanning process lowered free formaldehyde.