Research on germinated wheat grain, broccoli, alfalfa, radish and hemp seeds microbiological safety

Abstract

For a long time, germinated seeds have been used in food as a healthy product with high nutritional value and as a decor for exquisite dishes today. However, there have been many foodborne outbreaks in Europe, the United States, and other parts of the world associated with pathogens contamination of sprouts. These outbreaks pose a constant challenge to the entire sprouts industry. The aim of this study was to determine the presence of Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., and potentially pathogenic bacteria in germinated grains and seeds intended for industrial food production and ready for use without further processing. In this study, grains of wheat (Triticum aestivum), seeds of broccoli (Brassica oleracea), alfalfa (Medicago sativa), radish (Raphanus sativus) and hemp (Cannabis sativa) were germinated for 72 hours and were evaluated compared with ungerminated grains and seeds. The presence of E.coli was assessed by the inoculation of enrichment broth to Tryptone Bile X-glucuronide (TBX) and Eosin methylene blue (EMB) agars, and colony characterization with MALDI-TOF. E.coli was carried out in accordance with LVS ISO 16649-2:2007. The presence of STEC was determined in accordance with ISO/TS 13136:2012. Salmonella spp. detection was in accordance with ISO 6579-1:2017. As a result, E.coli, Salmonella spp., and STEC were not found in any sample. However, environmental bacteria were detected in TBX dry seeds and 12 h – soaked seeds. The presence of Enterobacteriaceae was found in all samples by colony characterization on EMB by MALDI-TOF. The results show that the sprouts and edible seeds available in Latvia could be included as healthy and relatively safe food.