Autoclaving and ultrasonication for reducing digestible starch in cassava pulp: modification of cell wall composition, sorption properties, and resistant starch content

STRACK, KAREN NATALY; GARCÍA, MARÍA ALEJANDRA; CABEZAS, DARÍO MARCELINO; VIÑA, SONIA ZULMA; DINI, CECILIA

INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2023 vol. 58 p. 4911 - 4919

0950-5423

Autoclaving (15 min, 121°C, 1 atm overpressure) and high-intensity ultrasound (3 pulses of 1 min,750 W, 20 kHz, 80% amplitude) were evaluated individually or combined in cassava pulp to reduce thedigestible starch and increase the fibre content. Ultrasound alone produced minimal modifications, andthe subsequent autoclaving increased the oil-binding capacity and swelling. Autoclaving alone significantlyincreased total dietary fibre (TDF) from 14.7% to 21.4%, and the ratio of hemicellulose to lignocellulose.It also reduced the extractable starch from 42.7% to 7.5% and the resistant starch from 7.4% to 3.1%.Despite the higher digestibility, the starch digestion rate with pancreaticα-amylase was slower. Starch sol-ubility increased at 25, 68, and 90°C. Ultrasonication after autoclaving reduced the hemicellulose per-centage, but the sorption properties remained unchanged. Resistant starch substantially increased to39.9%, mainly composed of RS1 (inaccessible starch), and starch solubility decreased at the three temperatures assayed.