UBC Theses and Dissertations
Studies on intermediate moisture beef meat patties Fierheller, Murray Gordon
Recent studies have shown that intermediate moisture foods, while stable to microbial growth, are susceptible to chemical changes resulting in loss of quality. This study observed the effects of different water activities, citric acid contents, fat contents, and pH on lipid oxidation and non-enzymatic browning of a meat product. An intermediate moisture beef patty was produced by equilibrating and cooking the raw meat in various glycerol, water, citric acid and sodium chloride solutions. Experimental results showed that peroxide values increase with increasing water activities between Aw 0.655 and 0.818. Citric acid did not affect the formation of peroxides but prevented peroxide breakdown. There was a loss of the brown colour of the cooked meat patty and an increase in yellowness possibly due to oxidation. The loss of colouring and yellowing was greatest at low pH and high water activities. Non-enzymatic browning was not apparent. Lipid oxidation was the primary cause of the product deterioration. The shelf life was limited to three to four months by the development of rancid odours.