Influence of Long-Term Storage on the Caking Properties Determined in Punch Test and Fungal Contamination of Potato Starch and Wheat Flour

Abstract

The presented results are an attempt to identify the changes taking place during a punch test experiment and the development of fungal impurities of powdered food materials over long-term storage at 75% RH. The potato starch and wheat flour market has a large share of the global production of bulk materials. The growing interest in powdered food materials requires additional production expenditure. This is associated with an increase in storage time of the discussed product and providing it with the appropriate conditions. The samples of potato starch and wheat flour were stored in perforated containers in a climatic chamber at 75% humidity and 21 °C for five months and then samples were measured by a punch test in a Lloyd LRX materials testing machine. The graphs obtained in the potato starch punch test differed significantly from wheat flour. The thickening of potato starch was observed in the form of layers, while potato starch was uniformly thickened throughout the experiment. The conditions of 75% humidity and 21 °C can be described as the beginning of the caking process. In potato starch, linear sections were observed, which changed the length of their storage time and, additionally, was correlated with the appearance of fungal contamination. These results may suggest the influence of fungi on the phenomenon of bulk material caking.

Determination of the Strength of Consolidated Powder Materials with a Pull-Based Tester

“…The strength of wheat flour is also determined by its morphological structure and particle size [27]. These results are in accordance with the results obtained by Wajs et al [13,14] for the same materials subjected to the penetration test.…”

“…The measuring rods, made of stainless steel and polypropylene, have a height of 93.7 mm and a diameter of 4.82 mm. The rod diameter value was chosen based on similar experiments carried out with bulk materials [13][14][15], where a 5 mm diameter penetrometer was used. The prevalence of rod materials in equipment used in food powder processing dictated the selection of rod materials.…”

“…This method is very useful as an indication of the onset of caking on the surface of the powder layer [11,12]. It is widely used to assess caking in common food powders, such as wheat flour, potato starch [13,14], powdered milk, or powder mixes [15].…”

Knowledge and Behavioral Habits to Reduce Mycotoxin Dietary Exposure at Household Level in a Cohort of German University Students

“…Coton, et al [71] suggest as a rule of thumb that as long as only white mycelium has developed on the cheese surface, trimming can be acceptable, whereas blue mould colour (due to fungal sporulation) is associated with the accumulation of significant amounts of mycotoxins, and the product should be discarded. In wheat flour, the first appearance of fungal contamination occurred on the ninth day, under conditions of high humidity (75% RH) and a temperature of 21 • C, which coincide with the beginning of the caking process (formation of lumps) [72]. However, the skills necessary to decide between trimming and discarding or whether shaking is necessary may not be present among lay persons.…”

Determination of the Influence of Mechanical Properties of Capsules and Seeds on the Susceptibility to Feeding of Mononychus pubctumalbum in Endangered Plant Species Iris aphylla L. and Iris sibirica L.

“…cylindrical penetration probe with a penetration rate of 10 mm/min was used in each test. Similar test parameters are used in many experiments to determine the relationship between the maximum puncture force and other materialspecific parameters [30][31][32][33]. The capsule and the seed were pierced perpendicular to their surface.…”