In the canning industry, thermal preservation processes typically are designed based on Clostridium botulinum thermal destruction kinetics. However, some bacteria can still survive, necessitating implementation of stricter timetemperature regimen for sterilization process. The aim of this study was to compare processing effectiveness at F₀ (sterilization value) 8 ±1 min from the perspective of the vegetable-based product canning facility, while analyzing the inactivation, viability, and recovery of thermophilic bacteria. Four commercial products [tomato soup and rassolnik soup - acidified food (AF), and mushroom soup and pea porridge - low-acid food (LACF)] with different heat transfer characteristics (convection and conduction) were inoculated with 6.6 log₁₀ spores/ml Geobacillus stearothermophilus LMKK 244 (reported as DSM 6790 and ATCC 10149 in other collections) and 4.8₁₀ log spores/ml Thermoanaerobacterium thermosaccharolyticum DSM 571 spore suspensions. Food samples contaminated with bacterial spores were processed in a steam-air retort at 118 °C for 75 min. G. stearothermophilus and T. thermosaccharolyticum growth was not detected in AF samples (pH = 4.4 and 4.5), but was observed in LACF samples (pH = 5.1 and 5.8). Practical evaluation showed that T. thermosaccharolyticum did not survive thermal processing, which was verified using a presence/absence test after incubation at 55 °C. G. stearothermophilus did not survive thermal processing, but recovered in pea porridge (pH = 5.8) during incubation. Our observations showed that food pH is a crucial factor determining microorganism survival during heat treatment and may be used by the vegetable-based product canning facilities to improve the food sterilization conditions.

Bumblebee activity interaction with solar irradiation, solar irradiation and HPS lighting irradiation, the HPS effect of photoperiod, day temperature and hive density were assessed with tomato fruit weights in a commercial tomato glass greenhouse in 2020–2021. Pollination activity was measured by observing ten randomly chosen cv. ‘Be orange’ tomato plants and by counting bumblebee bruised tomato flowers. MANOVA was conducted between factors and bee activity, followed by Pearson’s correlation. A Mann-Whitney U test was calculated to determine the significance between tomato flower bruising levels and fruit weights, followed by Cliff’s delta (d). Pollination activity decreased mainly in December and January when solar irradiation decreased to below 110 J cmE−2 dayE−1. Bumblebee activity was significantly affected by solar irradiation with HPS lighting (p is less than 0.001; p is less than 0.01). There was a significant correlation between bumblebee activity and solar irradiation (r= 0.75; p is less than 0.05), and solar irradiation with HPS lighting (r= 0.70; p is less than 0.05). There was no correlation between bumblebee activity and fruit weights (r= −0.20; p is less than 0.05). Bruised flowers had significantly greater fruit weight increases (165.7 g) compared to unbruised flowers (123.4 g) (d= 0.12; p is less than 0.05). Bee activity rates between 60% and 80% can be concluded as an effective rate for tomato growers. Bumblebees need at least 110–154 J cmE−2 dayE−1 of solar irradiation to achieve a high pollination activity rate in temperate climate zones during the winter season.