Commercial canning increases the digestibility of beans in vitro and postprandial metabolic responses to them in vivo

Abstract

Six weight-stable subjects consumed three test meals containing 50 g carbohydrate in random order after a 12-h fast: D-glucose, canned baked beans, or home-cooked (boiled) baked beans. Postprandial glucose and insulin responses were greatest to glucose, lowest to home-cooked baked beans, and intermediate to canned baked beans. Profiles of glucose and insulin responses to home-cooked beans were flatter and more attenuated than responses to canned beans or glucose, which correlates with the in vitro data showing a six-to-eight times higher rate of starch hydrolysis in canned beans relative to boiled beans. Increases in temperature (pressure) and duration of pressure-cooking resulted in increased starch digestibility, whereas even mildly acidic conditions (pH 5.0) markedly reduced it. None of the processes studied affected the total amount of available carbohydrate.