Chemical and structural characteristics of frankfurters during in vitro gastric digestion as influenced by cooking method and severity

Cooking processes influence structural properties of foods, and may lead to differences in digestive behavior of food products. In this study, the effects of cooking method, cooking severity and digestion time on moisture, pH, texture (hardness), microstructure and effective diffusivity of frankfurters were investigated. Boiled (3, 6, 9, 12 and 15 mins) and fried (3, 6 and 9 mins) beef frankfurters were cut into cubes and digested in simulated oral and gastric conditions for up to 240 mins. Cooking method, cooking severity, and digestion time significantly influenced the moisture and pH values (p < 0.05). Cooking severity lowered the hardness values of the samples (p < 0.05). SEM images showed that raw and cooked samples were different from each other before and after 240 min of simulated gastric digestion. The estimated effective diffusivity of water into the boiled and fried samples were lower than that of the raw frankfurter. These results can help provide recommendations on cooking protocols of meat products that result in specific digestive outcomes. (C) 2017 Elsevier Ltd. All rights reserved.