Colonic fermentation of potato starch after a freeze-thaw cycle.

To estimate colonic carbohydrate fermentation following a potato meal, 13 healthy volunteers consumed 375 g potatoes containing 60 g starch on three different occasions in random order: (A) potatoes boiled and consumed fresh at 60 degrees C; (B) potatoes boiled, frozen, thawed and consumed at 20 degrees C; and (C) potatoes boiled, frozen, thawed, reheated to 90 degrees C, and consumed at 60 degrees C. End-expiratory breath hydrogen (H2) was measured every 15 min for 10-14 hr with a selective electrochemical cell. The extent of colonic carbohydrate fermentation (AUC = area under the breath H2 concentration vs time curve) in experiment B was significantly higher (+186%, P less than 0.002) than in experiment A. The breath hydrogen AUC in experiment C was higher than in experiment A (+48%, P less than 0.04) but lower than in experiment B (-94%, P less than 0.003). It is suggested that structural alterations of the starch molecule occur during freezing, thawing, and reheating and alter the availability of carbohydrates for fermentation by colonic anaerobes.

RCT Entities:   Population Interventions Outcomes