An In Vitro Digestibility Assay for Prediction of the Metabolizable Energy of Low‐Calorie Dextrose Polymeric Bulking Agents

A method was developed to predict in vivo digestibility and metabolizable energy of dextrose polymers from in vitro enzyme digestibility measurements. A high correlation (r = 0.98) was established between in vivo true digestibility (TD) and in vitro percent dextrose yield (DY) for polymeric compounds representing a wide range of in vivo digestibility (22–96%). The linear regression equation describing this relationship was TD (%) = 1.11 DY + 10.68. The in vivo nitrogen‐corrected true metabolizable energy (TMEn) of four test compounds was predicted from in vivo digestibility data with good accuracy using the linear regression equation TMEn (kcal/g) = 0.038 DY + 0.637 (r = 0.97). The in vitro method is most useful for predicting in vivo digestibility and metabolizable energy of dextrose polymers with in vitro dextrose yields less than 80% and in vivo metabolizable energy values less than 3.6 kcal/gram.