Volatile profiling was carried out during heating through vacuum-assisted headspace solid-phase microextraction combined with gas chromatography-mass spectrometry to better understand the flavor forming mechanism of flour products. Ninety-two volatile compounds were detected and identified, including aldehydes (25), ketones (15), alcohols (9), nitrogen- and sulfur-containing compounds (6), benzene derivatives (15), furans (10), and acids and esters (12). The formation temperature of each volatile was also determined. Results showed that temperature played an important role in the formation and content of volatile compounds. In the low-temperature range (60 °C–100 °C), the flavor composition of flour was mainly composed of C6–C10 volatile aldehydes and alcohols. At temperatures exceeding 100 °C, especially at 120 °C, many long carbon chain aldehydes and alcohols, furans, acids, esters, nitrogen- and sulfur-containing compounds were formed. The formation rate of most identified volatile compounds increased during heating, especially from 90 °C to 130 °C.

Vibrio parahaemolyticus (V. parahaemolyticus) is a halophilic gramnegative bacterium which mainly exists in coastal and estuarine waters (DePaola et al., 2003). It is one of the major causes of foodborne infections worldwide. Most human infections have been associated with contaminated aquacultural food products (Mahmud et al., 2010). V. parahaemolyticus has been detected in a variety of fish and shellfish such as tuna, scallops, shrimp, etc (Drake et al., 2007;Su & Liu, 2007). Although V. parahaemolyticus infection has been commonly associated with seafood consumption, its existence in non-seafood products such as freshwater fish and infections caused by contaminated non-seafood products have also been reported (Chao et al., 2009;Liu et al., 2015). Zaher et al. reported a prevalence rate of 24.8% (62/250) for Nile tilapia samples (Zaher et al., 2021) and Li et al. found that 3.67% of 300 miscellaneous ready-to-eat food samples were positive for V. parahaemolyticus (Li et al., 2020). Dong et al. isolated and characterized V. parahaemolyticus strains from crayfish raised in freshwater (Dong et al., 2016) and a V. parahaemolyticus outbreak with 375 infections were attributed to undercooked frozen crayfish in Jiangxi province, China in 2011 (Sun et al., 2012). Human infected with the pathogen will develop a