UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Thiamine degradation in a luncheon-type ham product thermally processed in retort pouches and cans Young, Kirsten Emily


Thiamine is an essential nutrient and meat products can serve as an important source of this vitamin. It is thermally labile and thus significant destruction can occur during the commercial sterilization of foods. This study investigated the thermal degradation kinetics of thiamine in a luncheon-type ham product. In addition, thiamine retention following processing of the product in retort pouches and metal cans at two retort temperatures was evaluated. Degradation of thiamine in the luncheon-type ham product was described by first order reaction kinetics for temperatures between 100 and 140°C, and temperature dependence of the reaction followed the Arrhenius equation. The activation energy was 105 kJ/mol and the reaction rate constant at a reference temperature of 121°C was 2.03x10⁻² min⁻¹. Thiamine retention was determined following processing of 397 g quantities of the luncheon-type ham product in 300x407 cans and 159 mm by 229 mm retort pouches restrained to 19 mm thickness. Retort temperatures of 115.6°C (240°F) and 126.7°C (260°F) were used to obtain minimum process lethalities of 6.0 min. As well, for a control, 184 g of product was processed at 115.6°C in the 307x111.5 cans used commercially. All cans were sterilized in pure steam whereas a 75/25 steam/ air mixture was used for the retort pouch processes. Analysis of variance indicated significant differences in thiamine retention among the package and processing temperature combinations (p ≤ 0.001). Student-Newman-Keuls multiple comparisons procedure showed that all treatments were significantly different from one another (p ≤ 0.05). The luncheon-type ham product processed in retort pouches required process times 61 and 75% shorter than processes of equivalent center-point lethality for cans at 115.6 and 126.7°C. As a consequence, the products in retort pouches retained 16 and 26% more thiamine than their canned counterparts at the two retort temperatures. The higher retort temperature for cans resulted in a k% decrease in thiamine retention compared to the lower temperature, while for retort pouches there was a 6% increase in thiamine retained. The product processed in the smaller control cans at 115.6°C had a level of thiamine retention intermediate between that processed in retort pouches and the larger cans.

Item Media

Item Citations and Data


For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.