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

Abstract

Summary 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 °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. Ea‐values ranged from 107.2 kJ mol–1 in PES to 111.5 KJ mol–1 in PIB. The ΔH# and ΔS# 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 °C for PES, PIS and PIB respectively.

Investigations into the thiamine and riboflavin content of malt and the effects of malting and roasting on their final content

“…The small increase in riboflavin during the second half of the roasting process might be due to the disintegration of FMN, resulting in a transient increase in free riboflavin. Thiamine vitamers have been noted to be heat liable (Ariahu and Ogunsua, 2000;Arnold, 1972, 1973;Farrer, 1948) at neutral pH conditions but at a low pH (2.0e4.0) the stability of thiamine is increased to withstand typical autoclave conditions while the phosphorylated forms are quickly lost. This explains why the thiamine is rapidly lost during the roasting process.…”

Production and Stability of Protease from Candida buinensis

“…The related enthalpy (ΔH*) and entropy (ΔS*) of activation were estimated by regression analysis of ln(k/T) versus 1/T [26], according to the equation of Eyring [27] derived from the transition state theory:…”

Thermal degradation kinetics of nutrients in orange juice heated by electromagnetic and conventional methods

“…Enthalpy (DH) and entropy (DS) of activation were obtained by the regression analysis of ln(k) on 1/T from the equation derived from transition state theory (Ariahu & Ogunsua, 2000) …”