Abstract
Gelatinization of starch content in pet foods can be impacted by several factors including moisture, retention time, and ingredients used. Starch gelatinization has been associated with digestibility but isn’t well studied using ingredients common in non-traditional canine diets. The objective of this research was to examine the impacts of dietary ingredient profile (traditional vs non-traditional) and assess impacts to total starch content and starch gelatinization. Traditional diets (n = 10) utilizing meat-based ingredients including chicken, chicken by-product meal, meat and bone meal and plant-based ingredients including rice, barley, oats, and corn were examined in comparison with non-traditional diets (n = 10) utilizing meat-based ingredients including alligator, buffalo, venison, kangaroo, squid, quail, rabbit, rabbit and salmon along with plant-based ingredients including tapioca, peas, chickpeas, lentils, potato, and pumpkin. Representative samples were collected via grab sample technique (5 samples/diet) and were assessed for total starch content as well as percent starch gelatinization. Difference between ingredient type was assessed using a Students t-test in SAS 9.4. Significance was set at P < 0.05. Distribution of total starch content based on ingredient type (traditional vs non-traditional) revealed that mean total starch content was higher in traditional diets as compared to non-traditional diets (P <0.0001). Conversely, starch gelatinization was found to be higher in non-traditional diets (P < 0.0001). Total starch content and total gelatinized starch had a strong negative correlation (P < 0.01) in traditional diets, though no correlation was observed in non-traditional diets. This negative correlation indicates a decrease in total gelatinized starch associated with increased total starch content. These novel data reveal important differences between starch content and gelatinization and could impact manufacturing processes for ingredient types as well as feeding recommendations. Unpredicted variation between ingredient formulations could potentially lead to decreased digestibility and absorption and may result in nutrient deficiencies.