Annealing of Starch at an Intermediate Water Content

Abstract

The effect of annealing on starch gelatinization behaviour has earlier been described in the literature. The starch: water ratio in these studies have been either very low or very high. In this work the gelatinization behaviour has been studied both with time and temperature at an intermediate starch/water ratio (1:1) by differential scanning calorimetry. Starches from maize, waxy‐maize, wheat and potato have been compared. This investigation shows that annealing causes an increase of To and Tm, a narrowing of the gelatinization temperature interval, and a change of the shape of the endotherm can also be observed. The annealing time has to be more than 6 h to induce these changes.

Impact of annealing and heat-moisture treatment on rapidly digestible, slowly digestible and resistant starch levels in native and gelatinized corn, pea and lentil starches

“…The extent of increase in T o , T p and T c (T o > T p > T c ) at T o À10°C and T o À15°C, followed the order: lentil > pea > corn. ANN has a greater influence on T o , since T o represents melting of the weakest crystallites (Larsson & Eliasson, 1991;Nakazawa & Wang, 2003). These crystallites are more susceptible to crystallite perfection on ANN than crystallites that have a higher stability (represented by T c ) (Jacobs, Eerlingen, Spaepen, Grobet, & Delcour, 1998).…”

Effect of Heat Moisture Treatment Conditions on Swelling Power and Water Soluble Index of Different Cultivars of Sweet Potato (Ipomea batatas (L). Lam) Starch

“…This involves the storage of starch at specific levels of moisture and heat for a specific period of time without causing a significant level of starch gelatinization. Treatment of starch with excess moisture is referred to as "annealing" [4][5][6], and the term "heat-moisture treatment" (HMT) is used when restricted levels of moisture are applied in the literature [7,8]. These two types of physical modifications occur at temperatures above the glass transition temperatures of the relevant starch and often below the gelatinization 2 ISRN Agronomy temperatures which depend on the specific moisture contents used for the treatment.…”

Effect of annealing and pressure on microstructure of cornstarches with different amylose/amylopectin ratios

“…8,10,11 On the other hand, starch annealing is defined as a physical reorganization of starch granules in excess and intermediate water at a temperature above glass transition but below gelatinization temperature. [12][13][14] Previous studies have shown that annealing could increase the initial temperature of gelatinization and narrow the gelatinization temperature range for all starches regardless of their molecular structure and the ratio of amylose and amylopectin. [15][16][17][18][19][20] Mechanisms of the effect of annealing and pressure treatments on starch gelatinization have also been discussed.…”