Inactivation of murine norovirus by thermal treatment and grape seed extract

Human norovirus is the leading cause of foodborne gastroenteritis outbreaks worldwide. This study evaluates the thermal inactivation behavior of MNV-1 with and without the addition of grape seed extract (GSE) in a model juice system. The antioxidant activity of GSE was measured using the DPPH assay. The antioxidant and virucidal activities of GSE were reduced when suspended in an acidic buffer (citrate buffer, pH 2.3). Thermal treatment at 56, 60, and 65C resulted in tD values of 8.24 0.07, 2.39 1.10, and 0.59 0.38 min, respectively. When 500 ppm GSE suspended in citrate buffer (pH 4.0) was included with thermal treatment, tD values of 6.19 3.73, 6.41 5.46, and 0.45 0.28 min were found for the same temperatures. Although results suggest there may be no synergism of treatments for improved viral inactivation, the efficacy of thermal treatment alone and GSE alone was established.