a-Amylase action on starch in chickpea flour following hydrothermal processing and different drying, cooling and storage conditions

Edwards C,Veerabahu AS,Mason AJ,Butterworth PJ,Ellis PR. (2021)

Carbohydrate Polymers

Starch is present in many prepared ready-meals that have undergone processing and/or storage in frozen or chilled state. Hydrothermal processing greatly increases starch digestibility and postprandial glycaemia. Effects of different heating/drying and cooling regimes on amylolysis have received little attention. Hence, we examined the effects of different processing treatments on in vitro digestibility of starch in chickpea flour. Solid-state ¹³C NMR was used to estimate ordered double-helical structure in the starch. Native starch with 25 % double-helical content was the most resistant to digestion but hydrothermal processing (gelatinisation) resulted in >95 % loss of order and a large increase in starch digestibility. Air-drying of pre-treated flour produced slowly-digestible starch (C₈, 55.9 %). Refrigeration of gelatinised samples decreased ease of amylolysis coincident with increase in double-helical content. Freezing maintained the same degree of digestibility as freshly gelatinised material and produced negligible retrogradation. Chilling may be exploited to produce ready-meals with a lower glycaemic response.

Carbohydrate Polymers

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