Influence of storage under unfavourable conditions on the caking properties and fungal contamination of potato starch and wheat flour

Abstract

In recent years, there has been growing interest in the elimination of undesirable phenomena in the processing of bulk materials. In this study, the relationship between the mechanical properties of caking, as analysed with FTIR structural measurements, and the phenomena connected with fungal growth were investigated in wheat flour and potato starch. The materials were stored in high humidity conditions at room temperature (20 ± 2oC) in order to rapidly cause caking. The results showed changes in cake strength, for which the maximum force recorded by the sensor during storage was assumed. For the potato starch, the maximum strength occurred on the 8th day of storage and amounted to 29.4 N. From that day, the level of strength in this powder started to decrease, however, an increase in fungal contamination was also observed. Day 8 also marked the beginning of structural changes in the potato starch, which were observed in the FTIR spectra. The results obtained suggest that the strength of the agglomerates correlates with structural changes and fungal contamination.