Abstract Thus, the objective of this work was to evaluate the performance of industrial drying and the quality of soybean grains using a direct-fire furnace automatically fed by wood chips. To represent the grains before drying, four samples were collected together with the sampling of the loads in the trucks carried out to classify the product in the storage unit. At drying, performance evaluations and specific energy consumption were carried out. The grains were evaluated for moisture content, germination, electrical conductivity, apparent specific mass, color, acidity index, and PAHs. Drying showed an average efficiency of 75.50%. The average chip consumption was 0.4403 kg of chip/kg of evaporated water. The specific energy consumption was 8,099.50 kJ/kg of evaporated water. The grains showed differences after drying in the characteristics of germination, electrical conductivity, and chroma. Six PAHs were detected in the samples before drying: (B(a)A, Chr, 5 MC, B(j)F, Dib(ai)P, and IcdP). After drying, in addition to the PAHs obtained before drying, five more were detected (B(b)F, B(k)F, B(a)P, Dib(al)P, and Dib(ah)A). Mean PAH concentrations were higher than the maximum values allowed by European Union legislation.

ABSTRACT Bugs are pest insects that, when not adequately controlled, may cause significant losses in the soybean crop. Their damage to grains compromises delivery in the storage unit and storage success. Thus, the objective of this study was to evaluate, during storage, the effect of temperature and moisture content on soybean grain quality with high damage caused by bugs in the crop. The experiment was set in a completely randomized design with a 2 x 4 x 5 factorial design, with two moisture contents (11.75 and 13.84% (w.b.)), four storage temperatures (20, 25, 30 and 35 °C), and five evaluation periods (0, 2, 4, 6 and 8 months). The percentage of damaged/fermented, damaged, fermented, broken grains, and electrical conductivity were analyzed. It can be inferred that bug-damaged soybean grains have reduced quality when stored at higher temperatures and for more extended periods. It is not recommended to store bug-damaged grains in moisture contents of 13.84% (w.b.) at temperatures above 30 °C for longer than four months. Grains stored at 35 °C when not damaged by bugs, ferment after six months of storage. Bug-damaged grains evolve to fermented grains during storage.