Metodologia para avaliar eficiência de limpeza para frutas e hortaliças.

Abstract

Cleaning step of a packing line for fresh market tomatoes is divided in three stages: washing, drying and polishing. Washing step is the main one, and it is responsible for removing externai impurities of the firuits. However, it is the necessity to quantify the efficiency of cleaning. The goal of this work was to analyze two methodologies (turbidimeter and colorimeter) verifying which one of those represents better cleaning efficiency. To perform the experiments a synthetic dirt was developed, which was applied in rubber spheres (70 mm) simulating tomatoes. The assay was developed in a packing line prototype developed to UNIMAC* system, with rotation of 100 rpm and water outflow of 800 ml.min-1. For the turbidimeter methodology, the spheres after pass in the prototype were washed with 500 ml of water and then carried through the reading of the turbidez number (NTU). For the colorimeter the spheres were submitted for cleaning in a white fabric piece and later it was carried through the reading of the parameter L*. The results demonstrated that turbidimeter is more efficient, and it represents small differences in the dirt amount. At the colorimeter methodology occurred the saturation of the cloth tissue, with the sphere still dirty, and in some cases the cloth tissue dirtied the spheres, not representing the cleaning efficiency.