Thermal degradation kinetics of thiamine in periwinkle based formulated low acidity foods

The kinetics of the thermal degradation of thiamine in periwinkle-in-brine (PIB), periwinkle-in-sauce (PIS) and periwinkle-in-egusi soup (PES) were investigated in the temperature range 104-121.1 degrees C (5-40 min). Thiamine degradation could be modeled as a first order rate reaction with the rates being higher in the brine than the formulated food systems. The temperature dependence of the rates of destruction gave highly significant correlations when analyzed by the thermal resistance, Arrhenius and absolute reaction rate methods. E-a-values ranged from 107.2 kJ mol(-1) in PES to 111.5 KJ mol(-1) in PIB. The Delta H-# and Delta S-# values ranged from 103.9 kJ mol(-1) and 52.4 J deg(-1) mol(-1) respectively in PES to 108.3 kJ mol(-1) and -40.5 J deg(-1) mol(-1) respectively in PIB while the z-values were 26.3, 25.5 and 25.3 degrees C for PES, PIS and PIB respectively.