Corn, potato, and wrinkled pea starches with heat–moisture treatment: Structure and digestibility

Abstract

Background and objectives Starches from corn, potato, and wrinkled pea were heat treated at 100 and 120°C for 12 hr at a moisture content of 25% to produce slowly digestible starches. The effect of heat–moisture treatment (HMT) on structure and digestibility of those starches was investigated. Findings Changes in morphological aspects could be found in corn and pea starches after HMT treatment, potato starch retained its granular appearance with only some slight breakage of granules. For the HMT‐treated starches, the intensity of birefringence slightly decreased and the polarized cross also still existed. All the HMT starches showed the increasing To, Tp, and Tc and the decreasing enthalpy. The X‐ray diffraction pattern of potato and pea starches was shifted from B‐ or C‐type to A‐type by HMT, and corn starch changed to A + V‐ type. Compared with native starch, the relative crystallinity of starches decreased, and the degree of gelatinization of all starches was greater than that of their counterparts. After HMT, RDS and SDS contents of potato and pea starches (except corn starch) increased compared with their native counterparts, whereas RS content of all three starches was decreased. Compared with native starch, the digestibility of starches after HMT had a certain degree of increase. Conclusions Heat–moisture treatment had different effects on the granules morphology of different starch. The HMT samples exhibited greater To, Tp, and Tc values than those of the native counterparts with regard to the three starch types. The crystal structure and crystal pattern were transformed to the A‐type by HMT. Corn starch was easier to gelatinize than potato starch and pea starch after HMT, which could be the lower amylose content of corn starch and a smaller proportion of long chain. With the increase of HMT temperature, the starch sample RDS and SDS contents increased and RS decreased. Significance and novelty Corn starch was easier to gelatinize than potato starch and pea starch after HMT. With the increase in HMT temperature, the starch sample RDS and SDS contents increased and RS decreased.

Potential beneficial effect of hydrothermal treatment of starches from various sources on in vitro digestion

“…It is important to remember here that major differences would be determined by the structural fragility and short amylopectin proportion, as indicated above. When the various raw starches were tested after thermal processing at 100 °C (GS), there were no significant differences in GI values except for potato GS, which continued to have the lowest GI, owing to the lack of digestibility, as was also observed previously (Shi et al, 2018).…”

“…The gelatinisation enthalpy (ΔH G ) varied from to 12 J/g, except in the case of potato, which had a value of 16 J/g, demonstrating that higher energy was required to disrupt the crystalline structure. The resistance produced by potato may be interpreted as high crystallinity, which could interfere with the accessibility of the enzyme (Shi, Gao & Liu, 2018). Retrogradation parameters were measured after 7 days at 4 °C, and quinoa starch presented the highest resistance to retrogradation of amylopectin (Table 2).…”

Rheological Properties of Wheat Flour Modified by Plasma-Activated Water and Heat Moisture Treatment and in vitro Digestibility of Steamed Bread

“…SDS has a lower rate of complete digestion in the small intestine than rapidly digestible starch (RDS). However, resistant starch (RS) cannot be digested in the small intestine ( 27 , 28 ). Studies have shown that intake of foods rich in RS was beneficial for preventing obesity, controlling blood sugar release and colon health ( 29 ).…”

Effects of plasma‐activated water and heat moisture treatment on the properties of wheat flour and dough

“…Among these, heat moisture treatment (HMT) is relevant to this study, as it is a green modification technology that leaves no residue. HMT is an approach to starch modification that affects WF physicochemical properties including thermal behaviours, in vitro digestibility, starch granule morphology and impact on blood glucose levels (Shi et al ., 2018; Van Hung et al ., 2020).…”