Effects of annealing on the physicochemical properties of fermented cassava starch (polvilho azedo)

Mild alkali treatment alters structure and properties of maize starch: The potential role of alkali in starch chemical modification

Normal and waxy maize starches were treated with mild alkali treatment (pH 8.5, 9.9, 11.3) in two temperature-time combinations (25 °C for 1 h and 50 °C for 18 h) to investigate the effect on starch structure and properties. Mild alkali treatment partly removed the starch granule-associated proteins and lipids of normal (from 0.31 % to 0.24 % and from 0.77 % to 0.55 %, respectively) and waxy maize starches (from 0.22 % to 0.18 % and from 0.24 % to 0.15 %, respectively). Gelatinization enthalpy of waxy maize starch increased with alkali treatment from 16.20 J·g-1 to 21.95 J·g-1, indicating that amylopectin (AP) rearrangement and AP-AP double helices formation might occur. But amylose could inhibit these effects by restricting mobility of amylopectin, and no such changes occurred for normal maize starch. Alkali treatment decreased gelatinization temperature and increased peak and final viscosity. Alkali treatment decreased trough viscosity and increased setback of normal maize starch. The hydrothermal treatment promoted the effect of alkali, attributed to the more rapid molecular motion at higher temperature. Normal and waxy starches showed different changes after alkali treatment, indicating that amylose played an important role in controlling the effect of alkali and hydrothermal treatment, primarily as an obstructer of amylopectin rearrangement in mild alkali treatment.

Enhancing Banana Flour Quality through Physical Modifications and Its Application in Gluten-Free Chips Product

The objective of this study was to analyze the effects of different single or dual physical treatments, including pre-gelatinization (PBF), annealing (ANN), PBF+ANN, and ANN+PBF, on banana flour's characteristics and its application in gluten-free chip production. The study involved determining the color, swelling capacity, solubility, oil absorption index, and pasting properties of both the native and modified banana flour samples. The results showed a significant change in color, particularly in the pre-gelatinized samples. There was a noticeable decrease in the values of the pasting parameters in the modified samples. PBF samples exhibited a remarkable reduction in the breakdown value compared to the native and ANN treated samples. Furthermore, PBF-treated banana flour displayed higher oil absorption and swelling power than the other samples, along with lower solubility in the PBF-treated sample. These characteristics appear to be responsible for enabling the pre-gelatinized sample to form the dough required for producing banana chips, resulting in distinct texture profiles. Finally, our research emphasizes the useful application of modified banana flour in the food industry and emphasizes how crucial it is to choose the right modification method to achieve the desired effects on the product.

Starch Modification with Molecular Transformation, Physicochemical Characteristics, and Industrial Usability: A State-of-the-Art Review

Starch is a readily available and abundant source of biological raw materials and is widely used in the food, medical, and textile industries. However, native starch with insufficient functionality limits its utilization in the above applications; therefore, it is modified through various physical, chemical, enzymatic, genetic and multiple modifications. This review summarized the relationship between structural changes and functional properties of starch subjected to different modified methods, including hydrothermal treatment, microwave, pre-gelatinization, ball milling, ultrasonication, radiation, high hydrostatic pressure, supercritical CO₂, oxidation, etherification, esterification, acid hydrolysis, enzymatic modification, genetic modification, and their combined modifications. A better understanding of these features has the potential to lead to starch-based products with targeted structures and optimized properties for specific applications.

Physicochemical, structural, and rheological characteristics of corn starch after thermal-ultrasound processing

Thermal-ultrasound treatment is a green technology that can significantly alter the structural and functional properties of starches. This research extend the effect of at different temperatures (25 °C, 45 °C, and 65 °C) and times (30 and 60 min) on the physicochemical, structural, and rheological properties of corn starch was studied. Amylose content, solubility, swelling power, and the least gelling content increased with increasing temperature and time. Starch treated at 45 °C for 30 min had the lowest syneresis among all treatments. Thermal-ultrasound treatment at 25 °C and 65 °C for 60 min caused increasing paste clarity. Microscopic observations demonstrated that the starch granules were agglomerated at 65 °C. Although the crystallinity of samples decreased from 35.42% to 8.94%, the storage modulus was more than the loss modulus during the frequency sweep test. Pasting properties showed that pasting temperatures shifted to higher values after treatment. Nonetheless, the maximum viscosity decreased, and the final viscosity of the treated samples demonstrated that short-term retrogradation could deteriorate. Results showed that thermal-ultrasound is a viable technique for starch modification compared to conventional thermal and ultrasound treatments.

Modification of the microstructure of tef [Eragrostis tef (Zucc.) Trotter] flour ultrasonicated at different temperatures. Impact on its techno-functional and rheological properties

Tef flour comes from a nutritionally-rich ancient grain gaining increasing interest in gluten-free market. Gluten-free sources are modified by different means to improve their functionality. Ultrasound treatment (US) alters flours' structure and leads to physically modified flours with a wider application range. The aim of the present work was to evaluate the impact of US treatments of moderate treatment time, 10 min, and high concentration of the aqueous flour dispersion, 25%, on the microstructural, starch damage, apparent amylose content, techno-functional, pasting and rheological properties of two tef flour varieties, white and brown. Temperature was varied (20, 40, 45, 50, and 55 °C) to modulate the impact of sonication. US treatments led to general particle fragmentation which markedly increased starch damage and lightness (L*) values. Apparent amylose content was higher after ultrasonication, as consequence of molecular fragmentation due to cavitation. Increased starch granules' exposed area led to enhanced interaction with water, promoting the water absorption index (WAI) and swelling power (SP) of treated flours. Pasting properties showed increased pasting temperatures as well as decreased viscometric profiles with lower breakdown viscosities, indicative of starch rearrangement improved by increasing temperature. Rheological properties indicated higher consistency in gels after US treatments, with improved ability to withstand stress and lower values of tan(δ)1 reflecting a higher solid-like behavior and higher strength of the gel. Temperature was found to be a crucial variable during US treatments, showing an improved degree of modification at higher temperatures in ultrasonicated tef flours, following the same trend in both varieties.

The Influence of Temperature Changes on the Rice Starch Structure and Digestive Characteristics: One and Two-Step Annealing

This study investigated the effects of annealing on the structural and physicochemical properties of rice starch below the onset temperature (To) by 5 °C and 15 °C. The results revealed that annealing improved the gelatinization temperature of rice starch, decreased the swelling power, solubility, and paste viscosity of rice starch, and had no significant effects on the morphological structure and crystal configuration of rice starch. In one-step annealing, the annealing temperature of 60 °C is more conducive to the rearrangement of starch molecules, so its crystallinity, short-range ordered structure, and gelatinization temperature are higher than at 50 °C; however, its RDS, SDS, and RS contents will be increased. During the two-step annealing treatment, the temperature change is not conducive to the molecular chain rearrangement and to the formation of perfect crystalline structure, which increases the sensitivity of enzymes to starch, so the RDS content of starch increases significantly, while the RS content decreases.

Ultrasound-chilling assisted annealing treatment to produce a lower glycemic index of white rice grains with different amylose content

White rice samples, Chai-Nat1 (CN1) and Jasmin rice (KDML105), were treated with the ultrasound-chilling (UC) and combined with annealing treatments (UC + ANN 45, UC + ANN50, and UC + ANN55). Their physicochemical properties and in vitro glycemic index of rice samples were analyzed. UC + ANN treatments presented pasting temperature, gelatinization temperature and crystallinity increased whereas the glycemic index of both rice samples was decreased as compared to its native. Especially, UC + ANN55 treated rice produced the lowest glycemic index and starch hydrolysis. Moreover, UC + ANN treated CN1 rice exhibited delayed gelatinization temperature, increased gelatinization enthalpy, and decreased glycemic index than KDML105 rice. In addition, Pearson's correlation presented that UC + ANN and amylose content had a highly negative correlation with the glycemic index at p < 0.0.1. The result exhibited that UC followed by ANN show an effective way to modify starch granules with delayed starch hydrolysis reduced glycemic index and properties depending on annealing temperature and rice cultivar.

Pressure moisture treatment and hydro-thermal treatment of starch

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.

Removal of starch granule associated proteins alters the physicochemical properties of annealed rice starches

The effect of removal of starch granule associated proteins (SGAPs), annealing and dual-treatment on physicochemical properties of three rice starches with different amylose content (AC) was investigated. SGAPs removal reduced stability of starch granules, thus increasing amylose leaching, swelling power, solubility, and pseudoplasticity of Qiuguang (15.6% AC) and Luhui (22.1% AC) rice starches, decreasing pseudoplasticity of Yangfunuo (1.56% AC) starch, and decreasing T_o, T_p, and T_c, pasting viscosity and storage modulus of all three rice starches. Annealing decreased amylose leaching of the three starches, and pasting properties, pseudoplastic and storage modulus of Yangfunuo starch, but increased swelling power of the three starches, ΔH and T_o of Qiuguang starch, and pasting properties and pseudoplasticity of Qiuguang and Luhui starches. The effect of dual-treatment was generally the sum of effect of SGAPs removal and annealing treatment. But an interaction effect of the dual-treatment was observed for some parameters. The effect of annealing was closely related to the variety and composition of the starch.

Pasting and thermal properties of fermented cassava (Manihotesculenta Crantz)

Cassava (Manihotesculenta Crantz) is used in various applications and recipes worldwide. The natural fermentation of this root flour produces the "puba", a typical food from the north of Brazil. The evaluation of the qualities of the puba flour is little explored, thus, this study aimed to evaluate the pH (of the fermentation liquid), the texture of cassava pieces after a fermentation process, puba flour instrumental color parameters and its thermal and pasting properties. The pH and the force decreased with the incubation time. Puba flour from 3 to 7 days had the highest lightness, being good for food application. "a" and "b" values showed that the roots tended to a light blueish green due to post-harvest degradation and fermentation. The results of DSC analyses demonstrated that there was no significant difference in the gelatinization initial temperature between days 1-7, as well, no significant changes were observed in gelatinization peak temperature, conclusion temperature and gelatinization enthalpy. For the paste properties, the viscosity peak and breakdown slightly increased, and no significant changes as observed in final viscosity, setback and paste temperature on the days of fermentation. Therefore, the fermentation conditions (size of the pieces), the microorganisms (intrinsic of the material), and the time of seven days was not enough to promote drastic changes in the granules of cassava starch.

Assessment of end user traits and physicochemical qualities of cassava flour: a case of Zombo district, Uganda

Cassava breeding programmes in Uganda do not currently select materials based on flour making quality, explaining in part the low adoption rates of many released varieties. In this study, we describe end user trait preferences, processing qualities and physicochemical properties of cassava flour. We found that higher proportion of women than men showed preference for most attributes of cassava flour quality evaluated in this study. Preference for colour was 66% and 52% among women and men, respectively, while that for stickiness of Kwon was 26% (women) and 15% (men). Ease of peeling and stickiness of Kwon were key processing traits. Heap fermented flour had higher pasting temperatures, but lower viscosities than sun-dried flour, and had lower amylose content compared to fresh root starch. The results demonstrate the importance of gender sensitive participatory evaluation of breeding materials, in tandem with physicochemical evaluation during selection of best possible candidate breeding lines.

Clean label starch: production, physicochemical characteristics, and industrial applications

Recently, health-conscious consumers have a tendency to avoid the use of modified starch in their food products because of reluctance regarding food additives or chemical processes. The present paper considers the characteristics and manufacturing methods of clean label starch, which is free from chemical modification. Clean label starch manufacturing is mainly dependent on starch blending, physical and enzymatic modification methods. Physical modifications include ultrasound, hydrothermal (e.g., heat-moisture treatment and annealing), pre-gelatinization (e.g., drum drying, roll drying, spray cooking, and extrusion cooking), high-pressure (high hydrostatic pressure), and pulsed electric field treatments. These physical processes allow variation of starch properties, such as morphological, thermal, rheological, and pasting properties. Enzyme treatment can change the properties of starch more dramatically. Actual use of clean label starch with such altered properties has occurred in industry and is described here. This review may provide useful information on the current status and future direction of clean label starch in the field of food science.

The Comparison of Structural, Physicochemical, and Digestibility Properties of Repeatedly and Continuously Annealed Sweet Potato Starch

In order to investigate the varied effects of repeated annealing treatment (RANN) and continuous annealing treatment (CANN) on the structural, physicochemical, and digestibility properties of the sweet potato. The 75% starch-water suspensions were prepared and incubated at 65 °C for 8 cycles and 96 hr. The results exhibited that RANN and CANN did not influence the starch granules and polarization cross obviously. The crystal type of RANN and CANN starches still maintained A-type, while the relative crystallinity increased. The solubility, swelling power, peak viscosity and breakdown of RANN and CANN starches decreased, but the gelatinization transition temperatures, trough viscosity, final viscosity, setback, and pasting temperatures of starches increased after annealing treatments. Furthermore, RANN and CANN decreased the RS and RS + SDS contents with the increase of annealing cycles and time. The RANN was more effective in modification of the crystallinity, solubility, swelling power, pasting, gelatinization transition temperatures and enthalpy, and digestibility of starch before four times compared with the CANN ones. By and large, RANN may be a potential way for modification of structural, physicochemical and digestibility properties. PRACTICAL APPLICATION: The described RANN and CANN starch provide new ideas for the study of modified starch. Furthermore, this study revealed the mechanism of annealing treatment and it was concluded that the repeated annealing treatment could provide a new potential way for the modification of starch.

Effect of spray-drying and extrusion on physicochemical characteristics of sweet potato starch

This study aimed to understand the physicochemical characteristics of sweet potato starch following spray-drying and extrusion processes for desirable applications. Spray-dried starch showed formation of agglomerates and decreased in average granular size from 16.5 μm of the native starch granules to 14.1 μm. Spray-drying reduced the percentage crystallinity from 25.3 to 22.6% and showed a slight decrease in the molecular weight of amylopectin from 3.1 to 2.6 × 10⁸ g mol^-1. In addition, changes in the pasting and gelatinization properties, higher final viscosity (454.4 RVU), and less enthalpy change (8.73 J g^-1) were reported after spray-drying. Thus, spray-drying resulted in partially gelatinized starch, which can be selected for making more viscous products. Extruded sweet potato starch displayed an amorphous structure, showed total loss of crystallinity, and significant reduction in molecular weight of amylopectin to 0.41 × 10⁸ g mol^-1, reflecting complete gelatinization of starch granules during extrusion. Extruded starch showed significant changes in pasting properties, including a display cold viscosity (9.4 RVU). Therefore, extruded starch was suitable for products that require quick solubility and a low final viscosity. Thus, the spray-drying and extrusion processes produce sweet potato starches with particular characteristics that can be used for different and potential applications in industries.

Study of green nanocomposites based on corn starch and cellulose nanofibrils from Agave tequilana Weber

Global environmental pollution issues caused by synthetic materials and the lack of practical utilization of the local industrial lignocellulosic waste, force Mexican researchers to produce new biobased sustainable materials that use industrial waste as a source of components. Herein, we show the preparation and characterization of environmentally friendly starch-based nanocomposites reinforced with cellulose nanofibrils (CNF) extracted from Agave tequilana Weber. Tensile, bending and impact mechanical properties of dried and hydrated nanocomposites were studied. Moreover, the water absorption capacity of the nanocomposites were measured and evaluated. The mechanical properties improved because of the presence of a small amount of CNF (1 wt%). This work demonstrates the importance of the addition of a natural biomodifier in a starch matrix to achieve better mechanical properties. Most importantly, this study highlights that lignocellulosic waste from the tequila industry can have a practical application, which is being a source of natural nanoreinforcements for preparation of all-biobased sustainable materials.

Impact of heat-moisture and annealing treatments on physicochemical properties and digestibility of starches from different colored sweet potato varieties

The objective of this study is to investigate the change in physicochemical properties and digestibility of starches isolated from colored sweet potato varieties under heat-moisture treatment (HMT) or annealing treatment (ANN). The results showed that morphology and X-ray diffraction patterns of the sweet potato starches remained unchanged after the HMT or ANN. The HMT significantly reduced peak viscosity, breakdown and setback and significantly increased pasting temperature, trough and final viscosities of the sweet potato starches. The swelling powers and solubility of the heat-moisture treated starches were significantly lower than those of the native or annealed starches. The decreased rapid digestible starch and the increased slowly digestible and resistant starch contents of the sweet potato starches after HMT or ANN as compared to those of the native starches were observed. The resistant starch (RS) contents of the heat-moisture treated sweet potato starches were in a range of 30.6-39.3%, significantly higher than those of the annealed starches (28.8-32.0%). The strong impact of the HMT on physicochemical properties and RS formation of the sweet potato starches compared to the ANN might be due to the high stability of the occurred interactions between starch molecules and amylopectin chains during treatment.

The Impact of Heat-Moisture Treatment on Physicochemical Properties and Retrogradation Behavior of Sweet Potato Starch

Starch isolated from sweet potato was subjected to different levels of HMT at 15, 20, 25, 30, and 35 %. HMT showed negligible effect on the swelling power of starch. The swelling power was decreased with the increasing of the initial moisture content of the starch. The apparent amylose contents of HMT starches decreased from 24.11 % to 20.56 % with the initial moisture content increasing from 15 % to 35 %. The pasting temperatures enhanced from 73.1 to 81°C (p < 0.05) with the rapidly digestible starch (RDS) contents decreasing from 86.97 to 70.24 % (p < 0.05). Avrami equation analysis showed that HMT reduced the rate of starch retrogradation. The Avrami exponents of native and HMT-35 starches were 0.70 and 0.98 with the recrystallization rates 0.22 and 0.10, respectively. HMT could restrain the starch retrogradation and these results could provide theoretical guidance on sweet potato starch modification.

Characterization and Prebiotic Effect of the Resistant Starch from Purple Sweet Potato

Purple sweet potato starch is a potential resource for resistant starch production. The effects of heat-moisture treatment (HMT) and enzyme debranching combined heat-moisture treatment (EHMT) on the morphological, crystallinity and thermal properties of PSP starches were investigated. The results indicated that, after HMT or EHMT treatments, native starch granules with smooth surface was destroyed to form a more compact, irregular and sheet-like structure. The crystalline pattern was transformed from C-type to B-type with decreasing relative crystallinity. Due to stronger crystallites formed in modified starches, the swelling power and solubility of HMT and EHMT starch were decreased, while the transition temperatures and gelatinization enthalpy were significantly increased. In addition, HMT and EHMT exhibited greater effects on the proliferation of bifidobacteria compared with either glucose or high amylose maize starch.

Adsorption of lead (II) ions onto novel cassava starch 5-choloromethyl-8-hydroxyquinoline polymer from an aqueous medium

Adsorption of lead (II) ions onto cassava starch 5-choloromethyl-8-hydroxyquinoline polymer (CSCMQ) was investigated with the variation in the parameters of pH, contact time, lead (II) ions concentration, temperature and the adsorbent dose. The Langmuir and Freundlich models have been applied. CSCMQ was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Results showed that the adsorption process was better described by the Langmuir model. Adsorption kinetics data obtained for the metal ions sorption were investigated using pseudo-first-order, pseudo-second-order and intraparticle diffusion model. The maximum adsorption capacities (qm) were 46.512, 43.859 and 42.735 mg/g at 25, 35 and 45 °C, respectively. The dynamical data fit well with the second-order kinetics model. The results indicate that CSCMQ could be employed as low-cost material for the adsorption of Pb(II) ions from aqueous medium.