The grain temperature and moisture content and their differences or gradients are the two significant factors influencing movement and distribution of insects in grain bulks. The temperature response of adult Cryptolestes ferrugineus (Stephens) in stored wheat has been well-reported in the literature. However, the adult response toward nonlinear moisture differences or gradients is not yet been researched in detail. This study focuses on determining the sensitivity of adults to moisture differences in grain bulks. The moisture response of the adults was determined in 1 and 2 m grain columns with 3 and 5 percentage points difference in the wheat moisture content (12% and 15 or 17%) at 25°C in 24 and 48 h. Results showed that adults could readily detect high moisture wheat in 24 h with positive hygrotactic response. More than 88% of adults remained in the high moisture sections when introduced at damp wheat (3 or 5 percentage points higher than the surrounding grain). The adults tend to move away from dry wheat (12%) in search of high-moisture wheat sections. The moisture response of the adults was significantly influenced by the movement distance and was effective until 0.25 m. However, the movement was not influenced by increased movement period from 24 to 48 h. There were many aggregations near damp wheat demonstrating a uniform biased movement under bidirectional conditions in 1 and 2 m grain columns. Thus, the findings of the present study and data from literatures are useful in developing mathematical model of insect movement.

Triboelectrostatic separation (TES) is a green separation method. It is commercially used in the mineral and recycling industries. Its dry fractionation capabilities have immense potential for agro-particle separation technology. Unfortunately, the complexities of tribocharging pulse flours make it difficult to upscale this technology. In this research, we have attempted to understand separation characteristics such as protein enrichment, protein separation yield, and mass yield for three different factors: wall material (Stainless Steel, Copper, and Polyethylene (PE)), air velocity (Q) (2.1m3/h to 4.7m3/h), and electric field strength (EFS) (100 kV/m to 300 kV/m). The charge ability of pea protein concentrate (PP55), pea starch, and their mixtures ( mass ratio 1:1) were compared using two different techniques of tribocharging: Vibratory Feeder and Solid Particle Dispenser (SPD). The superior results of SPD steered its use for separation experiments. Separation results indicated that plate voltage and tribocharger material play a crucial role. Increasing the airflow rate in the turbulent regime does not benefit separation. However, higher electric field strength resulted in lower protein content but a relatively higher yield. Tribocharger material must be carefully selected as it pre-determines the charging of particles and their interaction with the electric field. A maximum of 58% protein content was obtained with a PTFE tribocharger, Q = 2.1 m3/h, and EFS = 100kV/m. Agglomeration and improper disentanglement of protein-starch mix need a thorough investigation for an efficacious TES.

Three varieties (AAC Starbuck, Faller, and AAC Brandon) of Canada Western Red Spring (CWRS) wheat class were stored for five weeks at 17% moisture content (wb). Grains were analyzed for structural changes using synchrotron phase contrast micro-computed tomography (SRP-µCT) at the Canadian Light Source (CLS), Saskatoon, SK. Imaging parameters: photon energy of 20 keV, propagation distance of 5 cm, 3.6 µm resolution and CT stage speed of 0.06° step were used to achieve better contrast in acquired projections. Total 13 scans were collected in 45 min for each variety with 3000 projections in one scan. The high-resolution SRP-µCT data were analyzed for structural information and showed structural differences in seed features among the three varieties, which played a role in the safe storage time differences among the three varieties. Edge enhancement of phase contrast in imaging made it possible to visualize and characterize changes due to spoilage and moisture in stored grains. The image processing pipeline was developed using ImageJ and Avizo, which can be used in future grain storage studies.