Modification of potato starch by using superheated steam

Insights into the multiscale structure and pasting properties of ball-milled waxy maize and waxy rice starches

The effects of ball-milling on the pasting properties of waxy maize starch (WMS) and waxy rice starch (WRS) were investigated from a multiscale structural view. The results confirmed that ball-milling significantly destroyed the structures of the two waxy starches (especially WMS). Specifically, ball-milling led to obvious grooves on the surface of starch granules, a decrease in crystallinity and the degree of short-range order, and a reduction in double-helix components. Meanwhile, small-angle X-ray scattering results indicated that the semicrystalline lamellae of starch were disrupted after ball-milling. Ball-milling decreased the pasting temperatures. Furthermore, ball-milled starches exhibited lower peak and breakdown viscosity and weakened tendency to retrogradation. These results implied that ball-milling induced structural changes in starch that significantly affected its pasting properties. Hence, ball-milled starch may serve as food ingredients with low pasting temperature and paste viscosity as well as high paste stability under heating/cooling and shearing.

Modification methods toward the production of porous starch: a review

Starch is a complex carbohydrate formed by the repeating units of glucose structure connected by the alpha-glycosidic linkages. Starch is classified according to their derivatives such as cereals, legumes, tubers, palms, fruits, and stems. For decades, native starch has been widely utilized in various applications such as a thickener, stabilizer, binder, and coating agent. However, starches need to be modified to enhance their properties and to make them more functional in a wide range of applications. Porous starch is a modified starch product which has attracted interest of late. It consists of abundant pores that are distributed on the granule surface without compromising the integrity of its granular structure. Porous starch can be produced either by enzymatic, chemical, and physical methods or a combination thereof. The type of starch and selection of the modification method highly influence the formation of pore structure. By carefully choosing a suitable starch and modification method, the desired morphology of porous starch can be produced and applied accordingly for its intended application. Innovations and technologies related to starch modification methods have evolved over the years in terms of the structure, properties and modification effects of different starch varieties. Therefore, this article reviews recent modification methods in developing porous starch from various origins.

Effects of water-deficit and high-nitrogen treatments on wheat resistant starch crystalline structure and physicochemical properties

This work investigated the effects of water-deficit and high-nitrogen (N) treatments on wheat resistant starch (RS) formation, molecular structure, and physicochemical properties. The results of consecutive 2-year field experiments revealed that water deficit significantly reduced starch granule number and diameter, amylose, RS content, RS particle size distribution, and physicochemical properties, including peak and trough viscosities, oil absorption capacity, and freeze-thaw stability. Water deficit also altered the long- and short-range structures of RS. In contrast, high-N fertilizer application significantly improved the RS content, long- and short-range structures, and physicochemical properties. Pearson correlation analysis revealed that RS content was positively correlated with total starch, amylose, rapidly digesting starch, 90^th percentile of RS particle size, relative crystallinity, infrared 1047/1022 cm^-1 ratio, peak and breakdown viscosities, oil absorption capacity, and freeze-thaw stability, and was negatively correlated with slowly digestible starch content, 1022/995 cm^-1 ratio, and final viscosity.

STUDY OF THE EFFECTIVE VISCOSITY OF GELATINIIZED STARCH DISPERSIONS, BASED ON PHYSICALLY MODIFIED STARCHES, DEPENDING ON TECHNOLOGICAL FACTORS

The aim of the study is to investigate rheological properties of gelatinized starch dispersions, based on physically modified starches, depending on technological factors. Realization of the research aim allows to get products (sauces, creams, fillers for confectionary products and so on), using physically modified starches, able to realize products with given structural-mechanical parameters of quality and safety; and also to provide the rational use of raw material resources, to decrease the labor capacity of the technological process of making culinary products. There were analyzed modern development tendencies of technologies of physically modified starches and their use in food products technologies. Generalization of literary data became a base for using these starches in food products technologies, where the first turn attention is paid to the colloid stability of food systems. Studies of the thermal stability of gelatinized starch dispersions determined that most stable in the cycle “heating-cooling-repeated heating” are gelatinized starch dispersions, based on physically modified starch “Prima”, which effective viscosity doesn’t essentially decrease after repeated heating. In gelatinized starch dispersions, based on physically modified starch «Endura» and «Indulge», repeated heating is also accompanied by the inessential viscosity decrease. Gelatinized starch dispersions, based on corn amylopectin starch, are not thermostable, and their effective viscosity essentially decreases at repeated heating. There are established regularities of the mechanical effect on structural-mechanical properties of gelatinized starch dispersions. It has been determined, that gelatinized starch dispersions, based on physically modified starches «Prima», «Endura» and «Indulge», demonstrate stable characteristics, as opposite to native starches at the mechanical effect. The prospects of further studies in this direction are to investigate an influence of technological factors (change of рН medium, influence of enzymes, pectin substances, mineral salts) on structural-mechanical properties of gelatinized starch dispersions, based on physically modified starches.

A new pre-gelatinized starch preparing by gelatinization and spray drying of rice starch with hydrocolloids

Rice starch with hydrocolloids (pectin, xanthan gum, sodium alginate or ι-carrageenan) was gelatinized and subsequently spray dried to prepare pre-gelatinized rice starch (PRS) with hydrocolloids (PRS-H). The PRS-H displayed concave granular shape with amorphous structure, indicating rice starch in PRS-H was completely gelatinized. Cold paste viscosity of PRS-H was enhanced in comparison with that of PRS. Especially, xanthan and ι-carrageenan increased cold paste viscosity of PRS-H more than pectin and alginate did. Cold paste viscosity of physically mixed PRS and hydrocolloids (PRS+H), and flow behavior of hydrocolloids themselves as well as gelatinized starch-hydrocolloids without spray drying (GRS-H) indicated interactions existed between starch and hydrocolloids during the preparation. Swelling power, water solubility index, and dynamic viscoelastic properties of PRS-H were also adjusted by different hydrocolloids. These results showed that premixing hydrocolloids with starch before gelatinization in method of spray drying would be a suitable methodology for manufacture PRS with altered properties.

Comparison of physicochemical properties of indigenous Ethiopian tuber crop (Coccinia abyssinica) starch with commercially available potato and wheat starches

In this study the chemical composition, morphology, crystallinity, thermal, and pasting properties of Anchote (Coccinia abyssinica) starch were compared with commercial potato and wheat starches. Anchote starch showed lower total starch content than that of potato starch. Their morphological properties were investigated using scanning electron microscopy. The mean granule width of potato starch was four times greater than anchote starch and two times greater than that of wheat starch. The x-ray powder diffraction analysis revealed that anchote starch had a B-type crystallinity pattern. Differential scanning calorimetric (DSC) results showed the significant differences between the gelatinization temperature of anchote, wheat, and potato starches. The onset, peak, and conclusion temperature of anchote starch were 66.58°C, 70.18°C, and 73.98°C, respectively. The gelatinization temperature of potato and wheat starches were 56.53°C and 55.56°C for onset, 61.46°C and 61.14°C for peak, 68.47°C and 67.06°C for conclusion, respectively. These properties of anchote starch make it an attractive candidate for industrial use.