78 The effects of guar gum and other select gums and gelling carbohydrates on appearance, texture, and heating characteristics of wet pet foods

Abstract

Abstract Many wet pet foods include carbohydrate ingredients that enhance viscosity for container filling or provide structure after processing. These gums and gels can cause differences in commercial sterilization as well as visible changes in product quality. Therefore, the objective was to determine the effect of different gums and gelling carbohydrates on the appearance, texture, and thermal processing metrics of wet pet foods. Treatments were added to a chicken-based formula as 1% dextrose (NH), 0.5% guar gum and 0.5% dextrose (GG), 0.5% guar gum and 0.5% kappa carrageenan (KCGG), 0.5% guar gum and 0.5% locust bean gum (LBGGG), or 0.5% guar gum and 0.5% xanthan gum (XGGG). Batters were analyzed for pH, water activity, and consistency with a Bostwick consistometer as a crude indication of viscosity. Thermocouples were placed in cans to measure cold-spot temperatures for Fo and cook-value calculations. Replicate batches (n = 3) included each treatment and were commercially sterilized in a still retort at 121 ℃ and 144.79 kPa. Can vacuum and product color (colorimetry) were measured after cans cooled to ambient temperatures. Treatments were analyzed as a 1-way ANOVA with batch as a blocking factor. Means were separated by Fisher’s LSD using statistical analysis software (GLIMMIX; SAS 9.4). Batter consistency thickened (P < 0.05) with increasing levels of gums and gelling carbohydrates. Batter pH, batter water activity, and can vacuum were not different (P > 0.05) among treatments (averaging 5.94, 0.990, and -12.9 kPa, respectively). The NH treatment accumulated the greatest (P < 0.05) Fo and cook values during the cook cycle compared to all other treatments. The NH and GG treatments were more (P < 0.05) red and yellow than KCGG, LBGGG, and XGGG. Gums and gelling carbohydrates influenced the rate of heat penetration of the foods, likely due to the differences in batter consistency, and affected product color and physical characteristics.