Recent outbreaks traced to contaminated flour have created a need in the milling industry for a process that reduces pathogens in wheat while maintaining its functional properties. Vacuum steam treatment is a promising technology for treatment of low moisture foods. Traditional thermal treatment methods can compromise wheat functionality due to high temperatures, thus maintaining the functional quality of the wheat protein was critical for this research. The objective of this study was to evaluate the effect of vacuum steam treatment on hard red spring (HRS) wheat kernels on final flour quality and overall efficacy of vacuum stream treatment to reduce pathogens on HRS wheat kernels. In the first part of the study, HRS wheat samples were treated with steam under vacuum at 65, 70, 75, and 85 Â°C for 4 and 8 min. Significant changes in dough and baked product functionality were observed for treatments â¥70 Â°C. For all of the quality tests performed, treatment time had no significant effect. After determining that vacuum steam treatment at 65 Â°C best preserved product quality, HRS wheat was inoculated with Escherichia coli O121 and Salmonella Enteritidis PT30, and processed at 65 Â°C for 0, 2, 4, 6, or 8 min periods. The treatments achieved a maximum average reduction of 3.57 Â± 0.33 log CFU/g for E. coli O121 and 3.21 Â± 0.27 log CFU/g for Salmonella. Vacuum steam treatment shows potential as an effective pathogen inactivation method for the flour milling industry.
Ochratoxin A (OTA) is a toxin produced by some Penicillium and Aspergillus species around the world in a variety of food and feed, especially cereal grains, before harvest but primarily during storage. Durum and hard red spring (HRS) wheat samples were collected right after harvest as part of the U.S. regional crop quality survey in both 2011 ( n = 560) and 2012 ( n = 654) from the upper Great Plains. All samples were analyzed for OTA contamination using high-performance liquid chromatography with fluorescence detection. Overall, 2.1% of the samples were positive for OTA. In 2011, OTA was detected in 1.0% of the durum wheat samples but was not found in HRS wheat. In 2012, 8.3 and 1.4% of the durum and HRS wheat samples, respectively, were positive for OTA. Of the 25 samples that had detectable OTA, 3 samples (12%), all of which were durum wheat, had OTA that exceeded 5 ng/g.