Abstract:

Polyvinyl pyrrolidone (PVP), a highly effective dispersant, and ultrasonic technique were used for the homogeneous dispersion of nano-titania in corn starch paste to yield a compound coating. The coating was used to treat cherry tomato and the weight loss, the contents of soluble solids, VC and total acid, hardness and percentage of rotten fruits of treated cherry tomato during storage were periodically measured in order to investigate its fresh-keeping effect. The results showed that with increasing amount of added nano-titania, weight loss, soluble solid content and percentage of rotten fruits first decreased and then increased, but hardness and the contents of VC and total acid displayed an opposite change pattern. The compound coating with added nano-titania at 0.025% (m/m, on the basis of the dry weight of corn starch) showed the best fresh-keeping effect on cherry tomato; the weight loss, soluble solid content and percentage of rotten fruits of cherry tomato treated with it after 11 days of storage were reduced by 28.6%, 12.7% and 78.8%, respectively, when compared with untreated cherry tomato, whereas hardness and the contents of VC and total acid exhibited 1.33-, 1.12- and 1.34-fold increases, respectively. Our findings suggest that nano-titania appear to have the potential to be applied for the fresh-keeping of fruits.

Key words: nano-titania, corn starch, cherry tomato, fresh-keeping