The effects of heat moisture treatment (HMT) times on the physicochemical properties of three bean flours and their starch were analyzed. The colors of L*, b* and ΔE values increased significantly with time. The adzuki bean and pea flours showed better WAI and SP, and better gelation of starch at 2 h. The rheological properties of mixed HMT dough (3:7) exhibited the typical solid-like weak gel behavior. HMT had a significantly decreased on the pasting viscosity of bean flour starch with treated time. HMT caused the starch granules damage, but did not radically change the crystal type. FTIR results showed more proteins attached to the surface of starch granules, and the short-range molecular order decreased the DO at 2 h. In vitro digestibility inferred that RDS converted into SDS and RS. These results indicated that HMT significantly affected the digestibility and physicochemical properties of bean flours.

The effect of osmotic pressure treatment (OPT), heat moisture treatment (HMT), and their dual combination as HMT-OPT and OPT-HMT on functional and pasting properties, gel texture, crystallinity, thermal, morphological, and rheological properties, and in vitro digestibility of modified starches were investigated. HMT was done with 29 % moisture at 111 °C for 45 min while OPT was performed at 117 °C for 35 min with saturated sodium sulphate solution. All modifications increased amylose content, improved pasting stability, and reduced swelling power and solubility. Dual modifications caused higher morphological changes than single modified starches. HMT and OPT increased pasting temperature, setback and final viscosity while decreased peak viscosity and breakdown, whereas HMT-OPT and OPT-HMT reduced all pasting parameters except pasting temperature. 1047/1022 and 995/1022 ratios and relative crystallinity decreased. V-type polymorphs were formed, and gelatinization temperature range increased with lower gelatinization enthalpy. Starch gel elasticity, RS and SDS content were enhanced to a greater extent after HMT-OPT and OPT-HMT. HMT as a single and dual form with OPT showed prominent effect on pasting, thermal, crystalline, and rheological properties. Application of HMT, OPT and dual modified starches with improved functionalities may be targeted for suitable food applications such as noodles.

The set aim of present work was to investigate the effects of acetylation, oxidation and heat moisture treatment on physicochemical, pasting, gel texture, structural, thermal and morphological properties of common buckwheat starch. Swelling power and solubility of starches reduced after modification except acetylation. Color of buckwheat starch improved after oxidation and acetylation. Paste clarity increased while syneresis reduced following modification with the exception of oxidation. Pasting properties of buckwheat starch revealed increased peak viscosity and breakdown viscosity following modification treatments. Gel texture analysis depicted increased hardness and reduced springiness, chewiness and cohesiveness for modified starches of buckwheat. Diffractograms of starches showed variation in intensity of some bands. Heat moisture treatment increased agglomeration and oxidation caused slight depression on surface of some granules. Relative crystallinity reduced following oxidation and hydrothermal treatment of starch. The gelatinization temperatures were increased in hydrothermal treated starch samples while oxidation and acetylation reduced the gelatinization temperature. The findings of this work would favor the new applications of modified starch from common buckwheat.

This study explores a new strategy for manipulating the digestibility of high-amylose maize starch (HAMS) through combinative modifications, namely depolymerization via electron beam irradiation (EBI) followed by reorganizing glucan chains via heat moisture treatment (HMT). The results show that semi-crystalline structure, morphological features and thermal properties of HAMS remained similar. However, EBI increased branching degree of the starch at high irradiation dosage (20 kGy), resulting in more readily leached amylose during heating. HMT increased the relative crystallinity (3.9-5.4% increase) and V-type fraction (0.6-1.9% increase), without significant changes (p > 0.05) in gelatinization onset temperature, peak temperature and enthalpy. Under simulated gastrointestinal conditions, the combination of EBI and HMT either had no effect or negative effect on starch enzymatic resistance, depending on the irradiation dosage. These results suggest that the depolymerization by EBI predominantly affects the changes in enzyme resistance, rather than the growth and perfection of crystallites induced by HMT.

Starch-based biodegradable films have been studied for a long time. To improve starch properties and to increase film characteristics, starch is commonly modified. Amongst different types of starch modifications, oxidation and heat moisture treatment are interesting to explore. Unfortunately, review on these modifications for film application is rarely found, although these starch modifications provide interesting results regarding the starch and film properties. This paper aims to discuss the progress of research on oxidized and heat moisture-treated-starch for edible film application. In general, both HMT and oxidation modification on starch lead to an increase in film\'s tensile strength and Young\'s modulus, suggesting an improvement in film mechanical properties. The elongation, however, tends to decrease in oxidized starch-based film, hence more brittle film. Meanwhile, HMT tends to result in a more ductile film. The drawback of HMT film is its lower transparency, while the opposite is observed in oxidized films. The observation on WVP (water vapor permeability) of HMT starch-based film shows that the trend of WVP is not consistent. Similarly, an inconsistent trend of WVP is also found in oxidized starch films. This suggests that the WVP parameter is very sensitive to intrinsic and extrinsic factors. Starch source and its concentration in film, film thickness, RH (relative humidity) of film storage, oxidation method and its severity, plasticizer type and its concentration in film, and crystallinity value may partly play roles in determining film properties.

Microwave-assisted heat moisture treatment (MWT) was applied to quinoa grains, a nutritious gluten-free pseudocereal of great interest in food product development, to achieve the physical modification of the quinoa flour. The effect of treating quinoa grains at different initial water contents (WC; 10%, 20%, and 30%) in two operational systems was compared: one open at atmospheric pressure and variable WC (V system), and the other in hermetic containers at constant WC (C system). The morphological structure of the obtained flours and their techno-functional, rheological, and thermal properties were evaluated. MWT proved to be effective in modifying these properties, the main effects probably being caused by protein denaturation and aggregation, and intragranular molecular rearrangements of starch, with disruption of short-range molecular order and even the partial collapse of starch granules in the samples treated at the highest WC. The greatest differences were observed for the 20 and 30% WC treated-samples, particularly when using C system, which increased their water absorption capacity and decreased their foaming, emulsion, and gel-forming capacities. Based on these results, the control of WC and its evolution during MWT of quinoa grains appears to be a viable and effective approach to adapt flour functionality to the needs of food production, allowing a wider range of flour properties depending on the MWT conditions.

Starch and flour from various plants have been widely used for sundry applications, especially in the food and chemical industries. However, native starch and flour have several weaknesses, especially in functional, pasting, and physicochemical properties. The quality of native starch and flour can be improved by a modification process. The type of modification that is safe, easy, and efficient is physical modification using hydrothermal treatment techniques, including heat moisture treatment (HMT) and annealing (ANN). This review discusses the hydrothermal modifications of starch and flour, especially from various tubers and cereals. The discussion is mainly on its effect on five parameters, namely functional properties, morphology, pasting properties, crystallinity, and thermal properties. Modification of HMT and ANN, in general, can improve the functional properties, causing cracking of the granule surface, stable viscosity to heat, increasing crystallinity, and increasing gelatinization temperature. However, some modifications of starch and flour by HMT and ANN had no effect on several parameters or even had the opposite effect. The summary of the various studies reviewed can be a reference for the development of hydrothermal-modified starch and flour applications for various industries.

Nowadays，It is difficult for the polysaccharide-starch system to meet demand of practical production owing to the poor gel properties. Therefore, aiming to further improve the practical application of polysaccharide-starch gel, the effects of gallic acid (GA) and heat moisture treatment (HMT) on the gel properties and microstructure of yam starch/chitosan (YS/CS) composite gels were investigated. Swell power (SP) results showed that GA and HMT treatment respectively reduced the SP of YS gel by 3.24 g/g and 6.03 g/g, given that GA and HMT decrease the rheology of the water phase inhibiting the entry of water into the swollen starch. In the pasting process, HMT reduced pasting viscosity of the HMT/YS system because only little amylose was leached in the medium for elevating its viscosity after HMT. The rheological properties suggested that high temperature treatment of HMT facilitated the disruption and disintegration of starch granules resulting dynamic modulus had a decline trend. The elastic properties of GA/YS gels were enhanced with the addition of GA, which could be supported by the thicken lamellar observed in its microstructure. In general, GA and HMT effectively alter the gel properties of YS/CS gel system, and facilitate its practical application in food industry.

To elucidate the pretreatment of a heat moisture treatment that could increase the DS and hydrophobicity of OSA starch, the effect of the moisture level of the HMT process on the physicochemical properties was investigated. The higher moisture content (MC) in the HMT process led to a decreasing degree of crystallinity and gelatinization enthalpy and also produced surface damage and cracking of the granules. HMT pretreatment with the right moisture content resulted in OSA starch with the maximum DS value and reaction efficiency. Pre-treatment HMT at 25% MC (HMT-25) followed by OSA esterification exhibited the highest DS value (0.0086) and reaction efficiency (35.86%). H25-OSA starch has been shown to have good water resistance (OAC 1.03%, WVP 4.92 × 10-5 g/s m Pa, water contact angle 88.43°), and conversely, has a high cold water solubility (8.44%). Based on FTIR, there were two new peaks at 1729 and 1568 cm-1 of the HMT-OSA starch, which proved that the hydroxyl group of the HMT starch molecule had been substituted with the carbonyl and carboxyl ester groups of OSA.

Starch is often subjected to denaturation treatment to improve its useful properties and eliminate its shortcomings. Various methods have been developed to produce modified starches with different properties and for a variety of uses. Because physically modified starch can be produced without chemical substances or biological agents, the modification method is very simple and inexpensive, and the resulting material can be used as clean label starch. Among these physical modification technologies, heat moisture treatment (HMT) is a universally valid technology, but little is known about pressure moisture treatment (PMT)-related technology. Physical modification of starch using PMT results in new functions and value-added characteristics required by industry, and PMT has the potential to produce starch with new functions. In this paper, PMT-related technologies for physically modified starch, the difference between PMT and the hydro-thermal treatment, and clean label starch manufacturing using HMT and PMT were investigated.