The effect of starch types on extensional, linear and nonlinear rheological properties of starch cracker dough

Cracker is a popular snack, and their quality depends on the rheological properties of the dough during production. This study focused on the impact of different starch types (tapioca, corn, and potato) used in the same amount (30 g) on the rheology of starch cracker dough. Various rheological tests were conducted to assess the dough's properties. Linear viscoelastic properties were determined using oscillatory frequency and temperature sweep tests, while the nonlinear viscoelastic behavior was characterized through stress relaxation and creep recovery tests. Extensional rheological behavior was also examined. Additionally, the textural and thermal properties of the dough were monitored to understand starch gelatinization and its interactions with other components. In the linear viscoelastic region, no significant differences were found between different dough formulations. However, in the nonlinear viscoelastic region, the potato starch-containing formulation exhibited different viscoelastic and textural properties. Biaxial extensional rheological behaviors showed no significant variations between formulations. The temperature sweep test data from differential scanning calorimetry measurements were consistent with temperature sweep data. In summary, this study provides valuable insights into how different starches influence the rheological behavior of starch cracker dough, considering various degrees of deformation and temperature. These findings have implications for cracker production parameters.

Effect of starch and protein on eating quality of japonica rice in Yangtze River Delta

This study examined four types of japonica rice from Yangtze River Delta, categorized based on amylose content (AC) and protein content (PC): high AC with high PC, high AC with low PC, low AC with high PC, and low AC with low PC. It systematically explored the effect of starch, protein and their interactions on eating quality of japonica rice. Rheological analysis revealed that increased amylose, long chains amylopectin or protein levels during cooking strengthen starch-protein interactions (hydrogen bonding), forming a firm gel network. Scanning electron microscopy showed that increased amylose, long chains amylopectin or protein levels made protein and starch more stable in combination during cooking, limiting starch structure cleavage. Therefore, the eating quality of high AC in similar PC japonica rice and high PC in similar AC japonica rice were poor. Further, correlation and random-forest analysis (RFA) identified amylose as the most influential factor in starch-protein interactions affecting rice eating quality, followed by amylopectin and protein. RFA also revealed that in high AC japonica rice, the interactions of Fb3 and albumin with amylose were more conducive to forming good eating quality. In low AC japonica rice, the interactions of Fb2 and prolamin with amylose were more beneficial.

A review of starch swelling behavior: Its mechanism, determination methods, influencing factors, and influence on food quality

Swelling behavior involves the process of starch granules absorbing enough water to swell and increase the viscosity of starch suspension under hydrothermal conditions, making it one of the important aspects in starch research. The changes that starch granules undergo during the swelling process are important factors in predicting their functional properties in food processing. However, the factors that affect starch swelling and how swelling, in turn, affects the texture and digestion characteristics of starch-based foods have not been systematically summarized. Compared to its long chains, the short chains of amylose easily interact with amylopectin chains to inhibit starch swelling. Generally, reducing the swelling of starch could increase the strength of the gel while limiting the accessibility of digestive enzymes to starch chains, resulting in a reduction in starch digestibility. This article aims to conduct a comprehensive review of the mechanism of starch swelling, its influencing factors, and the relationship between swelling and the pasting, gelling, and digestion characteristics of starch. The role of starch swelling in the edible quality and nutritional characteristics of starch-based foods is also discussed, and future research directions for starch swelling are proposed.

Comparisons of rice taste and starch physicochemical properties in superior and inferior grains of rice with different taste value

The difference in grain yield between superior grains (SG) on the upper part and inferior grains (IG) on the lower part of the same panicle was widely reported. To date, variations in rice taste quality between SG and IG and the related starch physicochemical properties remained poorly understood. Here, rice cultivars with different taste quality (NT, normal taste; GT, good taste) were grown to investigate the mechanism underlying taste difference between SG and IG and the correlation between cooked rice taste and starch properties. In this study, the taste value of GT rice was 32.2% higher than that of NT rice across the cultivars. The GT rice comprised a series of typical taste qualities of larger stickiness, smaller hardness, lower apparent amylose content (AAC), and lower protein content (PC). The taste quality differed among rice grains on the same panicle; SG achieved 21.9% and 17.0% higher taste value than IG in GT rice and NT rice, respectively. The higher taste value in SG was owing to the larger stickiness and lower PC. Meanwhile, SG of GT rice achieved the lowest PC (8.2%) and gluten content (5.6%), which might indicate a better health value. Additionally, larger and smoother granules, more fa (DP < 12), lower crystallinity, and larger 1045/1022 cm^-1 ratios were found in SG starch compared to IG starch. These led to a weaker swelling power and lower gelatinization enthalpy in SG starch, while gelatinization temperature and retrogression enthalpy were the opposite. Moreover, SG starch exhibited higher storage modulus, loss modulus, slowly digestible starch contents, and resistant starch contents than IG. Our results revealed a great difference in taste quality between SG and IG in rice. The larger and smoother starch granules and shorter chain length could increase the ordered structure of starch, thus improving swelling power, gelatinization properties, and rheological characteristics and facilitating better taste quality of SG over IG. Besides, the lower PC (especially gluten content), higher slowly digestible starch, and higher resistant starch content indicated a more promising health value of SG in the food industry.

Improving the swelling capacity of granular cold-water rice starch by ultrasound-assisted alcoholic-alkaline treatment

The aim of this study was to determine the ability to improve the capacity of cold swelling and cold-water solubility of rice starch by ultrasonic-assisted alcohol-alkaline and alcohol-alkaline methods. To achieve this, ultrasound powers (U) were varied (30%, 70%, 100%) under the granular cold-water swelling starch (GCWSS) preparation (GCWSS + 30 %U, GCWSS + 70 %U, and GCWSS + 100 %U). The effects of these methods on morphological, pasting properties, amylose content, ratio of 1047/1022 spectra by FTIR, turbidity, freeze-thaw stability, and gel texture were also studied and compared. The results showed that the surface of GCWSS granules presented a honeycomb especially GCWSS + U treatments exhibited more porous on the surface of starch granules. The cold swelling power and solubility of GCWSS + U samples were increased which confirmed by reducing ratio of ordered structure to amorphous structure of starch, and turbidity was also decreased. Moreover, pasting temperature, breakdown, final viscosity, and setback decreased while peak viscosity increased as measured using a Rapid Visco Analyzer. The freeze-thaw stability of GCWSS + U was more resistant to syneresis than GCWSS under repeated freeze-thaw cycles. The reduction of gel hardness and springiness was observed using Texture Analyzer. These changes were enhanced with increasing ultrasound powers. Thus, the results indicate that the different ultrasound-assisted alcohol-alkaline treatments for preparing GCWSS show an effective use in the preparation of GCWSS with improved cold-water swelling and reduced retrogradation of rice starch.

Chemical Modifications of Normal and Waxy Potato Starches Affect Functional Properties of Aerogels

Aerogels are of increasing interest because of their exceptionally large surface area, porous structure, and low weight. Despite the significant increase in interest in the subject of starch-based aerogels, the number of detailed studies is rather scarce, which is especially evident in the case of chemically modified derivatives. Therefore, the study aims to evaluate the physicochemical properties of aerogels from chemically modified potato starch preparations (E 1422 and E 1450) obtained both from normal and waxy starches. Aerogels were prepared through the retrogradation of starch pastes followed by the gradual replacement of water with ethyl alcohol. The obtained preparations were characterized in terms of their bulk density, oil-binding capacity, as well as the texture and rheological properties of the formed pastes. Moreover, their usefulness was evaluated in an emulsion system employing rheological and low-field NMR methods. The obtained aerogels were characterized by a lower bulk density of 0.18-0.59 g/cm³ and 5.4-6.6 times higher oil-binding capacity compared to native potato starch. The chemical modification of starch helped to further alter the functional properties of the obtained aerogels, making them more effective oil binders, emulsifiers, and stabilizers (increasing the stability from 55 to 90%), which was especially evident for E 1450 preparation. Amylose content improved the aerogel properties, as waxy preparations were characterized by worse functional properties with the only exception of improved thickening ability. The most beneficial properties for the preparation of emulsions were observed for the aerogel obtained based on E 1450 normal potato starch.

Effects of Hydroxypropyl and Lactate Esterified Glutinous Rice Starch on Wheat Starch Gel Construction

An investigation was conducted into the impacts of hydroxypropyl glutinous rice starch (HPGRS) and lactate-esterified glutinous rice starch (LAEGRS) on a dilute solution and gel properties of wheat starch (WS) at different proportions (0%, 1%, 3%, 5%, and 10%). The results of dilute solution viscosity showed that hydroxypropyl treatment of glutinous rice starch (GRS) could promote the extension of GRS chains, while lactate esterification led to the hydrophobic association of GRS chains, and the starch chains curled inward. Different HPGRS: WS and LAEGRS: WS ratios, β > 0 and ∆b > 0, showed HPGRS and LAEGRS produced attractive forces with WS and formed a uniform gel structure. Compared with WS gel, HPGRS, and LAEGRS could effectively delay the short-term aging of WS gels, and LAEGRS had a more significant effect. HPGRS increased the pasting viscosity, viscoelasticity, and springiness of WS gels, reduced the free water content, and established a tighter gel network structure, while LAEGRS had an opposite trend on WS. In conclusion, HPGRS was suitable for WS-based foods with stable gel network structure and high water retention requirements, and LAEGRS was suitable for WS-based foods with low viscosity and loose gel structure.

Octenyl succinic anhydride modification alters blending effects of waxy potato and waxy rice starches

This study compared blending effects of native and octenyl succinic anhydride (OSA) modified blends (waxy rice and waxy potato starch). OSA groups were observed to be present primarily in the outer layer of waxy potato starch granule, but throughout the whole waxy rice granule. A high linear correlation with blending ratio was observed for trough viscosity and final viscosity of native blends, but for peak viscosity (PV) and breakdown viscosity (BD) of esterified blends. PV and BD of esterified blends showed weaker non-additive effects than those of native blends. Consistency coefficient in downward curve, flow behavior index in downward curve, and loss tangent mainly showed non-additive effects in native blends, but additive effects in esterified blends. OSA modification affects interaction between molecules on the outer surfaces of two starch granules by altering molecular structures on the outer surfaces, resulting in different blending effects between native and esterified waxy starch blends.