Modification of multi-scale structure, physicochemical properties, and digestibility of rice starch via microwave and cold plasma treatments

Effect of microwave alone and microwave-assisted modification on the physicochemical properties of starch and its application in food

Native starch has poor stability and usually requires modification to expand its industrial application range. Commonly used methods are physical, chemical, enzymatic and compound modification. Microwave radiation, as a kind of physical method, is promising due to its uniform energy radiation, greenness, safety, non-toxicity. It can meet the demand of consumers for safe food. Microwave-assisted modification with other methods can directly or indirectly affect the structure of starch granules to obtain modified starch with high degree of substitution and low viscosity, and the modification efficiency is greatly improved. This paper reviews the effect of microwave radiation on the physicochemical properties of starch, such as granule morphology, crystallization characteristics, and gelatinization characteristics, as well as the application of microwave radiation in starch modification and starch food processing. It provides theoretical references and suggestions for the research of microwave heating modified starch and the deep processing of starchy foods.

Air and argon cold plasma effects on lipolytic enzymes inactivation, physicochemical properties and volatile profiles of lightly-milled rice

This study investigated the effectiveness of cold-plasma treatment using air and argon as input gas on deactivation of lipolytic enzymes in lightly-milled-rice (LMR). The results showed no significant inactivation in lipase and lipoxygenase using air-plasma. However, using argon as input gas, the residual activities of lipase and lipoxygenase were reduced to 64.51 % and 29.15 % of initial levels, respectively. Argon plasma treatment resulted in more substantial augmentation in peak and breakdown viscosities of LMR starch, suggesting an enhancement in palatability of cooked LMR with increased stickiness and decreased hardness. In contrast to the decrease in volatile compounds in LMR following argon plasma treatment, the concentrations of several prevalent aroma compounds, including 1-hexanol, 1-hexanal, and 2-pentylfuran, exhibited significant increments, reaching 1489.70 ng/g, 3312.10 ng/g, and 58.80 ng/g, respectively. These findings suggest the potential for enhancing various facets of the commercial qualities of LMR by utilizing different input gases during plasma treatment.

Enhancing the nonlinear rheological property and digestibility of mung bean flour gels using controlled microwave treatments: Effect of starch debranching and protein denaturation

In this study, we examined the possibility of using industrial microwave processing to enhance the gelling properties and reduce the starch digestibility of mung bean flour (MBF). MBF (12.6 % moisture) was microwaved at a power of 6 W/g to different final temperatures (100-130 °C), and then its structural and functional properties were characterized. The microwave treatment had little impact on the crystalline structure or amylose content of the starch, but it roughened the starch granule surfaces and decreased the short-range ordered structure and degree of branching. In addition, the extent of mung bean protein denaturation caused by the microwave treatment depended on the final temperature. Slightly denaturing the proteins (100 °C) did not affect the nature of the gels (protein phase dispersed in a starch phase) but the gel network became more compact. Moderately denaturing the proteins (110-120 °C) led to more compact and homogeneous starch-protein double network gels. Excessive protein denaturation (130 °C) caused the gel structure to become more heterogeneous. As a result, the facilitated tangles between starch chains by more linear starch molecules after debranching, and the protein network produced by moderate protein denaturation led to the formation of stronger gel and the improvement of plasticity during large deformation (large amplitude oscillatory shear-LAOS). Starch recrystallization, lipid complexion, and protein network retard starch digestion in the MBF gels. In conclusion, an industrial microwave treatment improved the gelling and digestive properties of MBF, and Lissajous curve has good adaptability in characterizing the viscoelasticity of gels under large deformations.

Effect of atmospheric pressure plasma jet on the structure and physicochemical properties of wheat starch

The effect of atmospheric pressure plasma jet (APPJ) with different discharge power (0, 400, 600, and 800 W) on the structure and physicochemical properties of wheat starch were evaluated in this study. After APPJ treatments, significant declines in peak viscosity, breakdown viscosity, and final viscosity of wheat starch pasting parameters were observed with increase of plasma treatment power. Being treated with discharge power of 800 W, the PV and BD value of wheat starch paste significantly dropped to 2,578 and 331 cP, respectively. Apparently, APPJ could raise the solubility of wheat starch, while reduce the swelling capacity, and also lower the G' and G″ value of wheat starch gel. Roughness and apparent scratch was observed on the surface of the treated wheat starch granules. Although APPJ treatment did not alter wheat starch's crystallization type, it abated the relative crystallinity. APPJ treatment might be useful in producing modified wheat starch with lower viscosity and higher solubility.

Relationships among Structure, Physicochemical Properties and In Vitro Digestibility of Starches from Ethiopian Food Barley Varieties

Studying diversity in local barley varieties can help advance novel uses for the grain. Therefore, starch was isolated from nine Ethiopian food barley varieties to determine starch structural, pasting, thermal, and digestibility characteristics, as well as their inter-relationships. The amylose content in the varieties significantly varied from 24.5 to 30.3%, with a coefficient of variation of 6.1%. The chain length distributions also varied significantly, and fa, fb1, fb2, and fb3 ranged from 26.3 to 29.0, 48.0 to 49.7, 15.0 to 15.9, and 7.5 to 9.5%, respectively. Significant variations were also exhibited in absorbance peak ratios, as well as thermal, pasting, and in vitro digestibility properties, with the latter two parameters showing the greatest diversity. Higher contents of amylose and long amylopectin fractions contributed to higher gelatinization temperatures and viscosities and lower digestibility. Structural characteristics showed strong relationships with viscosity, thermal, and in vitro digestibility properties. Cross 41/98 and Dimtu varieties are more suitable in functional food formulations and for bakery products. These results might inspire further studies to suggest target-based starch modifications and new product development.

Impact of high temperature on microstructural changes and oil absorption of tigernut (Cyperus esculentus L.) starch: Investigations in the starch-oil model system

This study was to explore the internal reasons for the changes in oil absorption performance of tigernut starch (TS) by revealing the high-temperature induced variations of structural and functional properties of TS. The results showed that as the temperature increased from 80 °C to 140 °C, the degree of starch gelatinization increased, while the proportion of double helix structures, the total proportion of B1 and B2 chains, the relative crystallinity and the molecular weight decreased, accompanied by the fragmentation and swelling of TS granules. The oxidation of tigernut oil (TNO) led to a decrease in oil density and an increase in total polar component content. These phenomena could result in an increase of oil absorption capacity of TS and starch-lipid complex index. With further increase in temperature from 170 °C to 200 °C, the disruption of the crystalline structure and chain structure increased, resulting in the melting and disintegration of TS granules. This caused a decrease in the starch-oil contact area and capillary absorption of TNO by the TS granules. The results will contribute to revealing the effect of high-temperature induced changes in the structural and functional properties of TS on its oil absorption properties.

Impact of starch chain length distributions on physicochemical properties and digestibility of starches

Changing starch structure at different levels is a promising approach to promote desirable metabolic responses. Chain length distribution (CLD) is among the starch structural characteristics having a potential to determine properties of starch-based products. Therefore, the objective of the current review is to summarize recent findings on CLD and its impact on physicochemical properties and digestion. Investigations undertaken to enhance understanding of starch structure have shown clearly that CLD is a significant determining factor in modulating starch digestibility. Enzymatic modifications and processing treatments alter the CLD of starch, which in turn affects the rate of digestion, but the underlying molecular mechanisms have yet to be fully elucidated. Even though advances have been made in manipulating CLD using different methods and to correlate the changes with various functional properties, in general the area needs further investigations to open new awareness for enhancing healthiness of starchy foods.

Multi-scale structural disruption induced by radio frequency air cold plasma accelerates enzymatic hydrolysis/ hydroxypropylation of tapioca starch

This study investigated the effects of radio frequency air cold plasma (RFACP) pretreatment on the multi-scale structures, physicochemical properties, enzymatic hydrolysis, and hydroxypropylation of tapioca starch. The results showed that cold plasma (CP) made starch granules rough on the surface and disrupted long- and short-range ordered structures, reducing relative crystallinity from 43.8 % to 37.4 % and R1047/1022 value from 0.992 to 0.934. Meanwhile, the starch molecules were depolymerized and oxidized by CP, reducing weight-average molecular weight from 9.64 × 107 to 2.17 × 107 g/mol, while increasing carbonyl and carboxyl groups by up to 118 % and 53 %. Additionally, CP-treated starches exhibited higher solubility and swelling power, along with lower gelatinization enthalpy. Short-time CP pretreatment (10 min) promoted the hydroxypropylation of starch and increased the molar substitution (0.081-0.112). Also, CP pretreatment accelerated enzymatic hydrolysis of starch, as indicated by the increase in hydrolysis rate (1.846 × 10-3-2.033 × 10-3 min-1) and degree of hydrolysis (51.45 % - 59.92 %). Overall, the multi-scale structural disruption induced by CP treatment facilitated the accessibility of enzymes/chemical reagents into starch granules and glucan chains. This study suggested that RFACP could be used for starch pretreatment to increase production efficiency in modified starch production, as well as in brewing and fermentation industries.

The multi-scale structure changes of γ-ray irradiated potato starch to mitigate pasting/digestion properties

The comprehensive understanding of multi-scale structure of starch and how the structure regulates the pasting/digestion properties remain unclear. This work investigated the effects of γ-ray irradiation with different doses on multi-scale structure and pasting/digestion properties of potato starch. Results indicated that γ-ray at lower doses (<20 kGy) had little effect on micromorphology of starch, increased mainly the amylose content and the thickness of amorphous region while decreased crystallinity, double helix content and lamellar ordering. With the increase of dose, the internal structure of large granules was destroyed, resulting in the depolymerization of starch to form more short-chains and to reduce molecular weight. Meanwhile, amylose content decreased due to the depolymerization of amylose. The enhanced double helix content, crystallinity, lamellar ordering and structural compactness manifested the formation of the thicker and denser starch structure. These structure changes resulted in the decreased viscosity, the increased stability and anti- digestibility of paste.

Understanding the multi-scale structure, physicochemical and digestive properties of extruded yam starch with plasma-activated water

In this study, the synergistic effect of plasma-activated water (PAW) combined with twin-screw extrusion (TSE) on multi-scale structure, physicochemical and digestive properties of yam starch (YS) was studied. PAW-TSE resulted in higher amylose content in YS than TSE alone. Compared with single TSE, the relative crystallinity, short-range ordered degree, and gelatinization enthalpy of YS were increased by PAW-TSE according to the results of X-ray diffraction, Fourier transform infrared, Raman spectroscopy, and differential scanning calorimetry. Furthermore, rapid viscosity and dynamic rheological analysis showed that the peak and breakdown viscosity of PAW-TSE treated YS paste were considerably reduced, and the storage modulus and loss modulus were significantly increased, indicating that the gel strength and thermal stability were improved. In addition, the resistant starch (RS) content of YS treated by PAW-TSE increased from 6.04 % to 21.21 %. Notably, the effect of PAW-TSE on YS enhanced with the preparation time of PAW increased. Finally, correlation analysis indicated that the characteristic indexes of PAW had a significant impact on the long or short-range ordered structure, thermal properties, and in vitro digestibility of YS during extrusion. Therefore, PAW-TSE, as an emerging dual modification technology, will greatly expand the application of extrusion technology.

Starch molecular structure, physicochemical properties and in vitro digestibility of Ethiopian malt barley varieties

Characterization of local varietal barley quality diversity can help boost further development of novel value-added utilization of the grain. Therefore, in this study starch was isolated from 11 Ethiopian malting barley varieties to determine starch structural, pasting, thermal and digestibility characteristics, and their inter-relationships. The varieties showed significant differences in all amylopectin chain length fractions, and the A, B1, B2 and B3 chains ranged from 25.4 to 30.1, 47.4-50.1, 14.3-16.0 and 7.8-9.0 %, respectively. The varieties also exhibited significant variation in amylose content, relative crystallinity, absorbance peak ratios, pasting and thermal properties. Moreover, on average about 83 % raw starch of the varieties was classified as slowly digestible and resistant, whereas after gelatinization this was reduced to 9 %. Molecular and crystalline structures were strongly related to pasting properties, thermal characteristics and in vitro digestibility of the starches. The study provides information on some starch quality characteristics and the inter-relationships among the parameters, and might inspire further studies to suggest possible target-based starch modifications, and future novel utilization of barley. More studies are required to investigate the association of starch quality parameters with malting quality attributes.

Effect of microwave followed by cooling on structural and digestive properties of pinhão starch

To increase its resistant content, native pinhão starch was modified using a microwave (300 W, 90 s) and subsequently cooled at 4 °C for 4, 8, 16, 24, and 72 h. The results demonstrated that all starches exhibited a crystalline structure of type C, with decreased crystallinity after modification. In the modified samples, the ratio of peaks 1047/1022 cm-1 and 995/1022 cm-1, as identified by FTIR, indicated a reduction in the crystalline region and damage to the double helix structure of starch granules. DSC analysis revealed that modified starches had lower gelatinization temperature range values due to the presence of more homogeneous crystals. Rheological analyses showed that starch suspensions obtained exhibited pseudoplastic fluid behavior and gel-like viscoelastic structure formation, with higher storage moduli in samples with longer cooling times. The microwave-modified starch, cooled for 72 h, exhibited higher digestion resistance, resulting in a 43.6 % increase in resistant starch content and a 26.1 % decrease in rapidly digestible starch compared to native starch. The results highlight that the modification of native pinhão starch using a microwave, followed by cooling at 4 °C for 72 h, presents a promising method for increasing the resistant starch content.

Effect of high voltage dielectric barrier discharge (DBD) atmospheric cold plasma treatment on physicochemical and functional properties of taro (Colocasia esculenta) starch

The goal of the proposed study is to investigate the effects of three different power levels (30, 32 and 34 kV) and exposure time (2, 4 and 8 min) of dielectric barrier discharge (DBD) atmospheric cold plasma treatment on the functional and physicochemical characteristics of taro starch. Investigations were done into how different treatments impact the multi-structural, functional and physicochemical attributes of taro starch. The findings showed that cold plasma treatments substantially impacted starch granule shapes (3.60-2.54 μm), such as reduced aggregations and developed fissures on granule surface due to the generation of an etching by plasma species and enhancement in the surface topography and roughness of treated starch as compared with native by SEM and AFM analysis. Besides this, no variations were detected in the functional groups of taro starch using FT-IR analysis after cold plasma treatments. However, the A-type pattern in the XRD did not affect it, while a reduction in relative crystallinity (14.20-11.50 %) was seen as a function of the active plasma species depolymerization. Furthermore, depending on the cold plasma voltage and treatment time, amylose content (20.12-15.98 %), paste clarity (24.48-31.27 %), solubility (0.41-65.53 %), freezing thaw stability (% syneresis) (32.10-42.58 %), color properties (L*, 94.79-97.52), whiteness index (79.37-84.66), molecular weight distribution (Peak 1, 12.79-5.35 × 108 g/mol; Peak 2, 4.20-1.56 × 107 g/mol) and in vitro digestibility (RDS, 64.10-64.08 %) significantly changed. So, based on these excellent properties, this study suggested that cold plasm-treated taro starch can be used in the field of food packaging material, functional food and pharmaceutical products. Therefore, a potential approach for physically altering starch is plasma treatment.

Comprehensive review on single and dual modification of starch: Methods, properties and applications

Starch is a natural, renewable, affordable, and easily available polymer used as gelling agents, thickeners, binders, and potential raw materials in various food products. Due to these techno-functional properties of starch, food and non-food industries are showing interest in developing starch-based food products such as films, hydrogels, starch nanoparticles, and many more. However, the application of native starch is limited due to its shortcomings. To overcome these problems, modification of starch is necessary. Various single and dual modification processes are used to improve techno-functional, morphological, and microstructural properties, film-forming capacity, and resistant starch. This review paper provides a comprehensive and critical understanding of physical, chemical, enzymatic, and dual modifications (combination of any two single modifications), the effects of parameters on modification, and their applications. The sequence of modification plays a key role in the dual modification process. All single modification methods modify the physicochemical properties, crystallinity, and emulsion properties, but some shortcomings such as lower thermal, acidic, and shear stability limit their application in industries. Dual modification has been introduced to overcome these limitations and maximize the effectiveness of single modification.

Recent progress in regulating starch digestibility using natural additives and sustainable processing operations

The development of a healthier and more sustainable food supply is a main concern of consumers, industry, governments, and international institutions. Foods containing high levels of rapidly digestible starches have been linked to a rise in the number of people suffering from diet-related chronic diseases. Consequently, there is interest in reducing the digestibility of starch to improve their healthiness. The ability of natural additives including proteins, dietary fibers, and polyphenols, and sustainable processing technologies such as high-intensity ultrasonic, pulsed electric field, non-thermal plasma, γ-ray irradiation that regulate reduce starch digestibility in foods are reviewed. The potential mechanisms of action, advantages, and disadvantages of each approach at inhibiting starch digestibility is highlighted. The potential for commercializing these technologies is discussed, and areas where further research are required are emphasized. Natural additives and sustainable processing operations can effectively reduce the digestibility of starch and inhibit postprandial sugar "spikes" in the bloodstream by adjusting the structural changes, which can be used to create healthier and more sustainable foods and have broad application prospects.

Effect of radio frequency energy on buckwheat quality: An insight into structure and physicochemical properties of protein and starch

Radio frequency (RF) heating as an emerging technology is widely used to improve cereal-based food quality. To further investigate effects of RF treatment on buckwheat quality, structures and physicochemical properties of protein and starch in buckwheat were evaluated under various temperatures (80, 90, and 100 °C) and holding times (0, 5, and 10 min). Results showed that protein-starch complexes were reaggregated with the increases of RF heating temperature and time, as well as the values of R1047/1022, crystallinity, random coil, and α-helix significantly decreased, and the values of β-sheet obviously increased. Moreover, viscosities and rheological properties of buckwheat were reduced by the raised RF treatment intensity. Besides, the RF processing had a mostly positive effect on swelling power at low temperature of 30 °C, but contrary effect at high temperatures of 60 °C and 90 °C. However, changes of water solubility index, emulsifying capacity, and emulsion stability depended on the RF processing intensity. These results of the study suggested that buckwheat quality was affected by multiple RF treatment conditions, which can be tailored to develop a RF process having the potential to improve the function of buckwheat flour.

Insights into Recent Updates on Factors and Technologies That Modulate the Glycemic Index of Rice and Its Products

Rice is a staple food and energy source for half the world's population. Due to its quick digestion and absorption in the gastrointestinal tract, rice is typically regarded as having a high or medium-high glycemic index (GI); however, this can vary depending on the variety, nutrient compositions, processing, and accompanying factors. This report included a table of the glycemic index for rice and rice products in different countries, which could give an overview and fundamental information on the recent GI of different rice varieties. In addition, latest updates about the mechanism effects of rice nutritional profiles and processing techniques on GI were also provided and discussed. The influence of state-of-the-art GI regulation methods was also evaluated. Furthermore, the effectiveness and efficiency of applied technologies were also given. Furthermore, this review offered some aspects about the potential nutraceutical application of rice that food scientists, producers, or consumers might consider. Diverse types of rice are grown under various conditions that could affect the GI of the product. The instinct nutrients in rice could show different effects on the digestion rate of its product. It also revealed that the rice product's digestibility is process-dependent. The postprandial glucose response of the rice products could be changed by modifying processing techniques, which might produce the new less-digestive compound or the inhibition factor in the starch hydrolysis process. Because of the significant importance of rice, this paper also concluded the challenges, as well as some important aspects for future research.

Efficacy of cold plasma technology on the constituents of plant-based food products: Principles, current applications, and future potentials

Cold plasma (CP) is one of the novel non-thermal food processing technologies, which has the potential to extend the shelf-life of plant-based food products without adversely affecting the nutritional value and sensory characteristics. Besides microbial inactivation, this technology has been explored for food functionality, pesticide control, and allergen removals. Cold plasma technology presents positive results in applications related to food processing at a laboratory scale. This review discusses applications of CP technology and its effect on the constituents of plant-based food products including proteins, lipids, carbohydrates, and polar and non-polar secondary plant metabolites. As proven by the publications in the food field, the influence of CP on the food constituents and sensory quality of various food materials are mainly based on CP-related factors such as processing time, voltage level, power, frequency, type of gas, gas flow rate as well as the amount of sample, type, and content of food constituents. In addition to these, changes in the secondary plant metabolites depend on the action of CP on both cell membrane breakdown and increase/decrease in the scavenging compounds. This technology offers a good alternative to conventional methods by inactivating enzymes and increasing antioxidant levels. With a waterless and chemical-free property, this sustainable and energy-efficient technology presents several advantages in food applications. However, scaling up CP by ensuring uniform plasma treatment is a major challenge. Further investigation is required to provide information regarding the toxicity of plasma-treated food products.

Hierarchical structural modification of starch via non-thermal plasma: A state-of-the-art review

The hierarchical architecture of natural and processed starches with different surface and internal structures determines their final physicochemical properties. However, the oriented control of starch structure presents a significant challenge, and non-thermal plasma (cold plasma, CP) has gradually been used to design and tailor starch macromolecules, though without clear illustration. In this review, the multi-scale structure (i.e., chain-length distribution, crystal structure, lamellar structure, and particle surface) of starch is summarized by CP treatment. The plasma type, mode, medium gas and mechanism are also illustrated, as well as their sustainable food applications, such as in food taste, safety, and packaging. The effects of CP on the chain-length distribution, lamellar structure, amorphous zone, and particle surface/core of starch includes irregularity due to the complex of CP types, action modes, and reactive conditions. CP-induced chain breaks lead to short-chain distributions in starch, but this rule is no longer useful when CP is combined with other physical treatments. The degree but not type of starch crystals is indirectly influenced by CP through attacking the amorphous region. Furthermore, the CP-induced surface corrosion and channel disintegration of starch cause changes in functional properties for starch-related applications.

Structural, rheological, pasting, and digestive properties of wheat A-starch: Effect of outshell removal combined with annealing

Wheat A- starch was subjected to single and combined CaCl₂ and annealing (ANN) treatments. The influence of the treatment on wheat A- starch's structural, rheological, pasting, and digestive characteristics were studied. The results indicated that the application of CaCl₂ treatment caused the removal of the outer layer of wheat A-starch, disrupted the integrity of the growth ring structure, and lowered the molecular weight of amylopectin and relative crystallinity. Meanwhile, the application of outshell removal combined with ANN treatment led to significant damage to the starch granules, resulting in a marked reduction in relative crystallinity, as well as the molecular weight of amylopectin and amylose. However, no changes were found in the non-Newtonian pseudoplastic behavior of starch after single or combined treatments. Furthermore, the combination of outshell removal and annealing treatment resulted in a decreased peak viscosity as well as trough viscosity of starch. Moreover, long-time ANN treatment had the potential to improve the resistant starch (RS) content of deshell starch.

Essential characteristics improvement of metallic nanoparticles loaded carbohydrate polymeric films - A review

Petroleum-based films have contributed immensely to various environmental issues. Developing green-based films from carbohydrate polymers is crucial for addressing the harms encountered. However, some limitations exist on their property, processibility, and applicability that prohibit their processing for further developments. This review discusses the potential carbohydrate polymers and their sources, film preparation methods, such as solvent-casting, tape-casting, extrusion, and thermo-mechanical compressions for green-based films using various biological polymers with their merits and demerits. Research outcomes revealed that the essential characteristics improvement achieved by incorporating different metallic nanoparticles has significantly reformed the properties of biofilms, including crystallization, mechanical stability, thermal stability, barrier function, and antimicrobial activity. The property-enhanced bio-based films made with nanoparticles are potentially interested in replacing fossil-based films in various areas, including food-packaging applications. The review paves a new way for the commercial use of numerous carbohydrate polymers to help maintain a sustainable green environment.

Changes on Techno-Functional, Thermal, Rheological, and Microstructural Properties of Tef Flours Induced by Microwave Radiation-Development of New Improved Gluten-Free Ingredients

Tef [Eragrostis tef (Zucc.) Trotter] flour is a gluten-free cereal rich in fiber, minerals, vitamins, and antioxidants, which offers a promising alternative for new food development. This study investigated the effect of microwave radiation (MW) on the techno-functional, thermal, rheological and microstructural properties of tef flours. White and brown tef grains were milled and microwaved at different moisture contents (MC) (15%, 20% and 25%) for a total irradiation time of 480 s. The morphological structure of tef flours was affected by MW treatment, and its particle size and hydration properties increased after the treatment. Lower peak, breakdown, and setback viscosities, up to 45%, 96%, and 67% below those of the control (untreated) samples, and higher pasting temperature, up to 8 °C in the 25% MC samples, were observed. From FTIR analysis a disruption of short-range molecular order was concluded, while DSC confirmed an increased stability of starch crystallites. Rheological analysis of the gels made from the treated samples revealed that MW had a structuring and stabilizing effect on all samples, leading to higher viscoelastic moduli, G' and G″, and the maximum stress the gels withstood before breaking their structure, τ_max. The MC of the flours during the MWT drove the modification of the techno-functional properties of the tef flours and the gel rheological and thermal characteristics. These results suggest that MW-treated tef flours are potential ingredients for improving the technological, nutritional and sensory quality of food products.

Ultrasound Treatment Enhanced Semidry-Milled Rice Flour Properties and Gluten-Free Rice Bread Quality

The structural and functional properties of physical modified rice flour, including ultrasound treated rice flour (US), microwave treated rice flour (MW) and hydrothermal treated rice flour (HT) were investigated with wet-milled rice flour (WF) used as a positive control. The results showed the presence of small dents and pores on the rice flour granules of US and MW while more fragments and cracks were showed in HT. XRD and FTIR revealed that moderate ultrasonic treatment promoted the orderly arrangement of starch while hydrothermal treatment destroyed the crystalline structure of rice flour. In addition, the significant decrease of gelatinization enthalpy and the narrowing gelatinization temperature were observed in US. Compared to that of SF, adding physical modified rice flour led to a batter with higher viscoelasticity and lower tan δ. However, the batter added HT exhibited highest G' and G″ values and lowest tan δ, which led to a harder texture of bread. Texture analysis demonstrated that physical modified rice flour (except HT) reduced the hardness, cohesion, and gumminess of rice bread. Especially, the specific volume of bread with US increased by 15.6% and the hardness decreased by 17.6%. This study suggested that ultrasound treatment of rice flour could improve texture properties and appearance of rice bread.

Dual Modification of Starch by Physical Methods Based on Corona Electrical Discharge and Ionizing Radiation: Synergistic Impact on Rheological Behavior

The present paper focuses on evaluating the synergistic effects of dual modification with corona electric discharge (CED) and electron beam irradiation (EBI) on the rheological behavior of starch. Combined treatments were applied successively (CED/EBI and EBI/CED) and compared with single treatments. The outcomes showed that the rheological features of starch were altered by the dual modification in correlation with the irradiation dose mainly as a result of radiation-induced degradation. Decreases in apparent viscosity were described by exponential-like-models according to the order of application of the treatment sequences. The mathematical models allowed the estimation of the irradiation doses for which the viscosity decreased by e times for the dual modified starches (3.3 ± 1.3 kGy for CED/EBI and 5.6 ± 0.5 kGy for EBI/CED, respectively) and the fraction (f) of 0.47 ± 0.10 corresponding to starch granule considered to be affected by plasma. Both dual treatments yielded a synergistic effect, regardless of the order of application of the treatment sequences, being more effective in decreasing starch apparent viscosity than single EBI. However, synergism evaluation proved that the use of plasma as a pre-treatment to irradiation processing could provide benefits up to 20 kGy. These findings support the practical goals of technologists with valuable information that may facilitate or simplify the experimental design of starch dual modification with plasma and ionizing radiation.

Cold plasma technologies: Their effect on starch properties and industrial scale-up for starchmodification

Native starches have limited applications in the food industry due to their unreactive and insoluble nature. Cold plasma technology, including plasma-activated water (PAW), has been explored to modify starches to enhance their functional, thermal, molecular, morphological, and physicochemical properties. Atmospheric cold plasma and low-pressure plasma systems have been used to alter starches and have proven successful. This review provides an in-depth analysis of the different cold plasma setups employed for starch modifications. The effect of cold plasma technology application on starch characteristics is summarized. We also discussed the potential of plasma-activated water as a novel alternative for starch modification. This review provides information needed for the industrial scale-up of cold plasma technologies as an eco-friendly method of starch modification.

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Cold plasma technology could be an effective, sustainable alternative for starch modification.

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The extent of modification of starches from different botanical sources depends on the type of cold plasma technology used.

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For mainstream adoption of cold plasma modified starches, research on safety and consumer perception must be conducted.

Effects of Hydrothermal and Microwave Dual Treatment and Zein on the Enzymolysis of High Amylose Corn Starch

Resistant starch (RS) type 2-high-amylose corn starch (HACS) was subjected to simultaneous hydrothermal (25% moisture content, 90 °C for 12 h) and microwave (35% moisture content, 40 W/g microwaving for 4 min) treatment and zein (at a zein to treated starch ratio of 1:5, 50 °C for 1 h) to improve its resistance to enzymolysis. Scanning electron microscopy (SEM) highlighted the aggregation and adhesion of the composite. The average particle size of the composite (27.65 μm) was exceeded that of both the HACS (12.52 μm) and the hydrothermal and microwave treated HACS (hydro-micro-HACS) (12.68 μm). The X-ray diffraction results revealed that the hydro-micro-HACS and composite remained B-type, while their crystallinity significantly decreased to 16.98% and 12.11%, respectively. The viscosity of the hydro-micro-HACS and composite at 50 °C was 25.41% and 35.36% lower than that of HACS. The differential scanning calorimetry (DSC) results demonstrated that the composite displayed a new endothermic peak at 95.79 °C, while the weight loss rate and decomposition temperature were 7.61% and 2.39% lower than HACS, respectively. The RS content in HACS, the hydro-micro-HACS, and composite was 47.12%, 57.28%, and 62.74%, respectively. In conclusion, hydrothermal and microwave treatment combined with zein provide an efficient physical strategy to enhance the RS type 2-HACS.