Vacuum Steam Pasteurization of Hard Red Spring Wheat

Abstract

Vacuum steam pasteurization (VSP) is a promising technology for pasteurization of low moisture foods. Recent outbreaks traced to wheat flour, a low moisture food, have created demand in the milling industry for a process that reduces pathogens in wheat while maintaining its functional properties. The objective of this study was to evaluate the efficacy of VSP on Hard Red Spring (HRS) wheat. First, HRS wheat samples were pasteurized at 65, 70, 75, and 85°C for 4 and 8 minutes. Significant changes in dough and baked product functionality were observed in treatments ≥70°C suggesting gluten denaturation occurred. After determining that 65°C processing conditions best preserved functionality, HRS wheat was inoculated with Escherichia coli O121, and processed at 65°C for 0, 2, 4, 6, and 8 min periods. The treatments achieved a maximum microbial reduction of ~3.5 log CFU/g. VSP shows potential as an effective pasteurization method for the flour milling industry.