Table 2. Simulation models and formulas in Excel spreadsheet used to calculate the risk of Vibrio parahaemolyticus in sea squirt with @RISK

Input model Unit Variable Formula References
PRODUCT
 Pathogens contamination level PR = RiskBeta (7, 30) This research; Vose (1997)
V. parahaemolyticus concentration CFU/g C = –LN (1–PR) / 25 g Sanaa et al. (2004)
 Initial contamination level Log CFU/g IC = Log (C) This research
TRANSPORTATION TO MARKET
 Transportation
 Transportation time h Timetrans = RiskPert (0, 3.339, 5) Personal communication; This research
 Food temperature during transportation °C Temptrans = RiskWeibull (1.3219, 2.8404, RiskShift (3.1093), Risktruncate (1, 40)) Personal communication; This research
 Growth
h0 = average (growth rate × lag phase duration), Fixed 1.14 This research; Baranyi & Roberts (1994)
Log CFU/g Y0 = average (Y0i), Fixed 3.1 This research; Baranyi & Roberts (1994)
Log CFU/g Yend = average (Yendi), Fixed 5.6 This research; Baranyi & Roberts (1994)
ln(q) = LN (1 / (EXP (h0) – 1)) This research; Baranyi & Roberts (1994)
 Growth rate Log CFU/g/h GRtrans = IF (Temptrans > 4.9515, 0.0330 × (Temptrans–4.9515))2), 0) This research; Baranyi & Roberts (1994)
V. parahaemolyticus growth model Log CFU/g C1 = IC + 1 / (1 + EXP (–ln(q))) × (1 – 10−|Y0–Yend| / LN(10)) × GRtrans × Timetrans This research; Baranyi & Roberts (1994)
MARKET
 Market display
 Display time h TimeMark-dis = RiskUniform(0,48) Personal communication; This research
 Food temperature during display °C TempMark-dis = RiskWeibull (2.2708, 21.394, RiskShift (–8.4157), RiskTruncate (–6, 18.1)) Personal communication; This research
 Growth
h0 = average(growth rate × lag phase duration), Fixed 1.14 This research; Baranyi & Roberts (1994)
Log CFU/g Y0 = average(Y0i), Fixed 3.1 This research; Baranyi & Roberts (1994)
Log CFU/g Yend = average(Yendi), Fixed 5.6 This research; Baranyi & Roberts (1994)
ln(q) = LN (1 / (EXP(h0) – 1)) This research; Baranyi & Roberts (1994)
 Growth rate Log CFU/g/h GRMark-dis = IF(TempMark-dis > 4.9515, 0.0330 × (TempMark-dis – 4.9515))2), 0) This research; Baranyi & Roberts (1994)
V. parahaemolyticus growth model Log CFU/g C2 = C1 + 1 / (1 + EXP (-ln(q))) × (1 – 10−|Y0–Yend| / LN(10)) × GRMark-dis × TimeMark-dis This research; Baranyi & Roberts (1994)
HOME
 Home storage
 Storage time H TimeHome-st = RiskUniform (0, 72) Personal communication; This research
 Food temperature during storage °C TempHome-st = RiskLogLogistic (–29.283, 33.227, 26.666, RiskTruncate (–5, 20)) Lee et al. (2015)
 Growth
h0 = average (growth rate × lag phase duration), Fixed 1.14 This research; Baranyi & Roberts (1994)
Log CFU/g Y0 = average (Y0i), Fixed 3.1 This research; Baranyi & Roberts (1994)
Log CFU/g Yend = average (Yendi), Fixed 5.6 This research; Baranyi & Roberts (1994)
ln(q) = LN (1 / (EXP (h0)–1)) This research; Baranyi & Roberts (1994)
 Growth rate Log CFU/g/h GRHome-st = IF (TempHome-st > 4.9515, 0.0330 × (TempHome-st – 4.9515))2), 0) This research; Baranyi & Roberts (1994)
V. parahaemolyticus growth model Log CFU/g C3 = C2+1 / (1 + EXP (–ln(q))) × (1–10−|Y0–Yend| / LN(10)) GRHome-st × TimeHome-st This research; Baranyi & Roberts (1994)
CONSUMING
 Daily consumption amount g Consump = RiskExpon (60.575, RiskShift (–1.4687), RiskTruncate (0, 348)) KDCA (2016)
 Daily consumption frequency % ConFre Fixed 0.28 KDCA (2016)
CF(0) = 1 – 0.28 / 100 KDCA (2016)
CF(1) = 0.28 / 100 KDCA (2016)
CF = RiskDiscrete ({0, 1}, {CF (0), CF (1)}) KDCA (2016)
Amount = IF (CF = 0, 0, Consump) KDCA (2016)
DOSE-RESPONSE
V. parahaemolyticus amount CFU D = 10C3 × Amount
 Parameter of α α Fixed 0.17 Iwahori et al. (2010); FAO & WHO (2011)
 Parameter of β β Fixed 1.18 × 105 Iwahori et al. (2010); FAO & WHO (2011)
RISK
 Probability of illness/person/day Risk = 1 – (1 + D/β)−α Iwahori et al. (2010); FAO & WHO (2011)