Factors influencing the physico-chemical, morphological, thermal and rheological properties of some chemically modified starches for food applications—A review

Effect of plasma-activated water on the supramolecular structure and techno-functional properties of starch: A review

This review discusses the changes in the multi-scale structure and functionality of starch after its hydrothermal modification using plasma-activated water (PAW). PAW contains reactive species that decrease the pH of the water and increase the oxidation-reduction potential, which promotes the oxidation and degradation of the surface of the starch granules to varying extents, depending on the botanical source and treatment conditions. In this article, we compile the information published so far on the effects of using PAW during heat-moisture and annealing treatments and discuss the results of the substitution of water with PAW on the long and short-range crystallinity, helical order, thermal behavior, functional properties, and digestibility. Additionally, we highlighted the possible application of PAW-modified starches. Finally, we provided an overview of future challenges, suggesting several potential directions to understand the mechanisms behind PAW use for developing sustainable modified starches for the food industry.

Recent advances in the impact of gelatinization degree on starch: Structure, properties and applications

During home cooking or industrial food processing operations, starch granules usually undergo a process known as gelatinization. The starch gelatinization degree (DG) influences the structural organization and properties of starch, which in turn alters the physicochemical, organoleptic, and gastrointestinal properties of starchy foods. This review summarizes methods for measuring DG, as well as the impact of DG on the starch structure, properties, and applications. Enzymatic digestion, iodine colorimetry, and differential scanning calorimetry are the most common methods for evaluating the DG. As the DG increases, the structural organization of the molecules within starch granules is progressively disrupted, the particle size of the granules is altered due to swelling and then disruption, the crystallinity is decreased, the molecular weight is reduced, and the starch-lipid complexes are formed. The impact of DG on the starch structure and properties depends on the processing method, operating conditions, and starch source. The starch DG affects the quality of many foods, including baked goods, fried foods, alcoholic beverages, emulsified foods, and edible inks. Thus, a better understanding of the changes in starch structure and function caused by gelatinization could facilitate the development of foods with novel or improved properties.

The effect of cold plasma on starch: Structure and performance

The inherent side effects of the physico-chemical properties of native starches often severely limit their use in food and non-food industries. Plasma is a non-thermal technology that allows rapid improvement of functional properties. This review provides a comprehensive summary of the sources and mechanisms of action of cold plasma and assesses its effects on starch morphology, crystal structure, molecular chain structure and physicochemical properties. The complex relationship between structure and function of plasma-treated starch is also explored. Potential applications of plasma-modified starch are also discussed in detail. The outcome of the modification process is influenced by factors such as starch type and concentration, plasma source, intensity and duration. The properties of starch can be effectively optimised using plasma technology. Plasma-based technologies therefore have the potential to modify starch to create a range of functionalities to meet the growing market demand for clean label ingredients.

Heat moisture treatment and ultrasound-induced hydrothermal wheat starch modification: Techno-functional, microstructural and quality 3D printed characteristics

In this study, the effect of hydrothermal process, ultrasound and combined freezing-ultrasound process on the physical and structural characteristics of wheat starch (Triticum aestivum) was investigated. Two heat-moisture treatments for 2 h (HMT2) and 4 h (HMT4), high-intensity, high-frequency ultrasound under two treatment times (10 to 20 min) (UT10 and UT20) as pre-treatment and sonication after freezing as post-treatment (FUT) on wheat starch suspension was applied. The modifications of starch crystallinity, chemical bonds of starch treated, morphology, thermal, swelling, pasting, and physicochemical characteristics were evaluated. Finally, the starches treated under these conditions were used as ink for a 3D printer, and the characteristics of the printed product were evaluated. The results demonstrate that heat-moisture modified starch increased swelling and size of granules and lowered syneresis values. Sonication promoted molecular depolymerization and reduction of starch swelling and crystallinity. Combined treatment (Sonication and freezing) showed higher peak apparent viscosity during gelatinization and pasting, and the FUT starch-based hydrogels showed the best printability (better ability to stack layers on top of each other and build the desired 3D shape), indicating better reproducibility of this ink. These results showed that FUT is a suitable process for improving the synergy and properties of wheat starch-based hydrogels, which are suitable as inks for use in 3D printers.

The art and science of porous starch: understanding the preparation method and structure-function relationship

Porous starch (PS), a modified form of starch with unique properties, is attracting substantial attention for its diverse advantages and applications. Its intricate porous structure, crystalline and amorphous characteristics, and hydrophilic-hydrophobic properties stem from pore formation via physical, chemical, enzymatic, and combined synergistic methods. Porous starch offers benefits like improved gelatinization temperature, water absorption, increased surface area, tunable crystallinity, and enhanced functional properties, making it appealing for diverse food industry applications. To optimize its properties, determining the parameters governing porous structure formation is crucial. Factors such as processing conditions, starch source, and modification methods substantially impact porosity and the overall characteristics of the material. Understanding and controlling these parameters allows customization for specific applications, from pharmaceutical drug delivery systems to enhancing texture and moisture retention in food products. To date, studies shedding light on how porosity formation can be fine-tuned for specific applications are fewer. This review critically assesses the existing reports on porous starch, focusing on how preparation methods affect porosity formation, thereby influencing the product's crystallinity/hydrophilic-hydrophobic nature and overall applicability.

Synthesis of grafted bromoisobutyryl esterified starch using electron transfer atom transfer radical polymerization method with high-performance adhesion and film properties

Nowadays, few investigations on the process parameters of grafted starch synthesized using electron transfer atom transfer radical polymerization (ARGET ATRP) and its applications in warp sizing and paper-making are presented. Therefore, this study aimed to survey the appropriate process parameters of bromoisobutyryl esterified starch-g-poly(acrylic acid) (BBES-g-PAA) synthesized by the ARGET ATRP, and also aimed to provide a new biobased BBES-g-PAA adhesive. The appropriate synthesis process parameters were 1.2, 0.32, and 0.6 in the molar ratios of vitamin C, CuBr2, and pentamethyldivinyltriamine to BBES, respectively, at 40 °C for 5 h. The BBES-g-PAA samples with a grafting ratio range of 4.63-14.14 % exhibited bonding forces of 57.8-64.6 N to wool fibers [55.5 N (BBES) and 53.8 N (ATS)], and their films showed breaking elongations of 3.29-3.80 % [2.74 % (BBES) and 2.49 % (ATS)] and tensile strengths of 29.1-25.4 MPa [30.4 MPa (BBES) and 34.7 MPa (ATS)]. Compared with BBES, significantly increased bonding forces and film elongations, and decreased film strengths for the BBES-g-PAA samples with grafting ratios ≥10.54 % were displayed (p < 0.05). The time (100-42 s) taken for the BBES-g-PAA films was significantly shorter than that of ATS (246 s) and BBES (196 s) films (p < 0.05), corresponding to better desizability.

Nutritional, physicochemical, and functional properties of Hawaiian taro (Colocasia esculenta) flours: A comparative study

Taro (Colocasia esculenta) flour is a viable carbohydrate alternative and a functional additive for food formulation; however, different taro varieties may possess distinct characteristics that may influence their suitability for food production. This study evaluated the nutritional, physicochemical, and functional properties of flours from five Hawaiian taro varieties: Bun-Long, Mana Ulu, Moi, Kaua'i Lehua, and Tahitian. Tahitian, Bun-long, and Moi had high total starch contents of 40.8, 38.9, and 34.1 g/100 g, respectively. Additionally, Moi had the highest neutral detergent fiber (25.5 g/100 g), lignin (1.39 g/100 g), and cellulose (5.31 g/100 g). In terms of physicochemical properties, Tahitian showed the highest water solubility index (33.3 g/100 g), while Tahitian and Moi exhibited the two highest water absorption indices (5.81 g/g and 5.68 g/g, respectively). Regarding functional properties, Tahitian had the highest water absorption capacity (3.48 g/g), and Tahitian and Moi had the two highest oil absorption capacities (3.15 g/g and 2.68 g/g, respectively). Therefore, the flours from these Hawaiian taro varieties possess promising characteristics that could enhance food quality when used as alternative additives in food processing.

Effects of cooking methods on the physical properties and in vitro digestibility of starch isolated from Chinese yam

The objective of this study was to compare the structural and functional attributes of Chinese yam starches obtained via different domestic cooking methods. Cooking changed the crystalline type from the C type to the CB type, and disrupted the short- and long-range molecular order of Chinese yam starch. The average chain length of amylopectin in BOS (boiling starch) was the smallest at 22.78, while RWS had the longest average chain length, reaching 24.24. These alterations in molecular structure resulted in variations in functional properties such as solubility, swelling power (SP), pasting characteristics, and rheological properties. Among these alterations, boiling was the most effective method for increasing the water-binding capacity and SP of starch. Specifically, its water holding capacity was 2.12 times that of RWS. In vitro digestion experiments indicated that BOS has a higher digestion rate (k = 0.0272 min-1) and lower RDS (rapidly digestible starch), which may be related to its amylopectin chain length distribution. This study can guide us to utilize yam starch through suitable cooking methods, which is relevant for the processing and application of Chinese yam starch.

Starch-Based Polysaccharide Systems with Bioactive Substances: Physicochemical and Wettability Characteristics

Polysaccharide-based systems have very good emulsifying and stabilizing properties, and starch plays a leading role. Their modifications should add new quality features to the product to such an extent that preserves the structure-forming properties of native starch. The aim of this manuscript was to examine the physicochemical characteristics of the combinations of starch with phospholipids or lysozymes and determine the effect of starch modification (surface hydrophobization or biological additives) and preparation temperature (before and after gelatinization). Changes in electrokinetic potential (zeta), effective diameter, and size distribution as a function of time were analyzed using the dynamic light scattering and microelectrophoresis techniques. The wettability of starch-coated glass plates before and after modification was checked by the advancing and receding contact angle measurements, as well as the angle hysteresis, using the settle drop method as a complement to profilometry and FTIR. It can be generalized that starch dispersions are more stable than analogous n-alkane/starch emulsions at room and physiological temperatures. On the other hand, the contact angle hysteresis values usually decrease with temperature increase, pointing to a more homogeneous surface, and the hydrophobization effect decreases vs. the thickness of the substrate. Surface hydrophobization of starch carried out using an n-alkane film does not change its bulk properties and leads to improvement of its mechanical and functional properties. The obtained specific starch-based hybrid systems, characterized in detail by switchable wettability, give the possibility to determine the energetic state of the starch surface and understand the strength and specificity of interactions with substances of different polarities in biological processes and their applicability for multidirectional use.

Structure properties of Canna edulis RS3 (double enzyme hydrolysis) and RS4 (OS-starch and cross-linked starch): Influence on fermentation products and human gut microbiota

This study investigated the in vitro fermentation characteristics of different structural types of Canna edulis resistant starch (RS). RS3 was prepared through a double enzyme hydrolysis method, and RS4 (OS-starch and cross-linked starch) was prepared using octenyl succinic anhydride and sodium trimetaphosphate/sodium tripolyphosphate, respectively. The RS3 and RS4 samples were structurally analyzed using scanning electron microscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction analysis. This was followed by in vitro fermentation experiments. The results revealed microstructure differences in the two groups of starch samples. Compared to native starch, RS3 and RS4 exhibited a lower degree of order and endothermic energy, with lower crystallinity (RS3: 29.59 ± 1.11 %; RS4 [OS-starch]: 28.01 ± 1.32 %; RS4 [cross-linked starch]: 30.44 ± 1.73 %) than that in native starch (36.29 ± 0.89 %). The RS content was higher in RS3 (63.40 ± 2.85 %) and RS4 (OS-starch: 71.21 ± 1.28 %; cross-linked starch: 74.33 ± 0.643 %) than in native starch (57.71 ± 2.95 %). RS3 and RS4 exhibited slow fermentation rates, promoting the production of short-chain fatty acids. RS3 and cross-linked starch significantly increased the production of acetate and butyrate. Moreover, RS3 significantly promoted the abundance of Lactobacillus, while OS-starch and cross-linked starch significantly enhanced the abundance of Dorea and Coprococcus, respectively. Hence, the morphological structure and RS content of the samples greatly influenced the fermentation rate. Moreover, the different varieties of RS induced specific gut microbial regulation. Hence, they show potential applications in functional foods for tailored gut microbiota management.

A review of the effects of fermentation on the structure, properties, and application of cereal starch in foods

Fermentation is one of the oldest food processing techniques known to humans and cereal fermentation is still widely used to create many types of foods and beverages. Starch is a major component of cereals and the changes in its structure and function during fermentation are of great importance for scientific research and industrial applications. This review summarizes the preparation of fermented cereals and the effects of fermentation on the structure, properties, and application of cereal starch in foods. The most important factors influencing cereal fermentation are pretreatment, starter culture, and fermentation conditions. Fermentation preferentially hydrolyzes the amorphous regions of starch and fermented starches have a coarser appearance and a smaller molecular weight. In addition, fermentation increases the starch gelatinization temperature and enthalpy and reduces the setback viscosity. This means that fermentation leads to a more stable and retrogradation-resistant structure, which could expand its application in products prone to staling during storage. Furthermore, fermented cereals have potential health benefits. This review may have important implications for the modulation of the quality and nutritional value of starch-based foods through fermentation.

Flours from fermented lentil and quinoa grains as ingredients with new techno-functional properties

The need to provide novel, nutritious plant-based products requires seeking high-value, sustainable protein sources, like quinoa and lentils, having an increased digestibility and lacking antinutrients. Fungal fermentation has evidenced enhanced nutritional value of flours obtained from these grains. However, research into techno-functional properties, essential to the new product development, is lacking. This study investigated the techno-functional properties of flours made from lentil and quinoa after fermenting them with Pleurotus ostreatus and subjecting them to two drying techniques (lyophilisation and hot air drying). In both cases, the fermentation led to noteworthy improvements in swelling and water holding capacity, especially in those lyophilised than those dried. In contrast, the emulsifying, foaming, thickening, and gelling capacities decreased significantly. The loss of abilities was more severe for dried grains than for lyophilized ones. The thermomechanical analysis of the fermented flours showed lower thickening and gelling potential compared to untreated flours. Microscopy images revealed that the state and structure of starch granules were affected by both fermentation and drying processes. Starch granules in lentils were partly pre-gelatinised and trapped in the cotyledon cell, resulting in limited thickening and gelling abilities. In contrast, in quinoa, starch underwent pre-gelatinisation and retrogradation during the fermentation process, promoting the production of resistant starch and increasing fibre content. This study presents the potential of treated flours as ingredients possessing unique attributes compared to protein and fibre-rich conventional products.

Mechanistic insights into the enhanced texture of potato noodles by incorporation of small granule starches

Potato noodles are a popular food due to their unique texture and taste, but native potato starch often fails to meet consumer demands for precise textural outcomes. The effect of blending small granule (waxy amaranth, non-waxy oat and quinoa) starch with potato starch on the properties of noodles was investigated to enhance quality of noodles. Morphological results demonstrated that small granule starch filled gaps between potato starch granules, some of which gelatinized incompletely. Meanwhile, XRD and FTIR analysis indicated that more ordered structures and hydrogen bonding among starch granules increased with addition of small granule starch. The addition of oat or quinoa starch increased gel elasticity, decreased viscosity of the pastes, and increased the tensile strength of noodles, while addition of 30 % and 45 % waxy amaranth starch did not increase G' value of gel or tensile strength of noodles. These results indicated that amylose molecules played an important role during retrogradation, and may intertwine and interact with each other to enhance the network structure of starch gel in potato starch blended with oat or quinoa starch. This study provides a natural way to modify potato starch for desirable textural properties of noodle product.

Modifications of native lotus (Nelumbo nucifera G.) rhizome starch and its overall characterization: A review

Lotus (Nelumbo nucifera G.) rhizomes are an under-utilized and sustainable starch source that constitutes up to 20 % starch. The review mainly focused on the extraction methods of starch, the chemical composition of LRS, and techno-functional characteristics such as swelling power, solubility, in vitro digestibility, pasting property, and gelatinization is highlighted in LRS review. Lotus rhizome starch (LRS) is also used as a water retention agent, thickening, gelling, stabilizing, and filling in food and non-food applications. Native starch has limited functional characteristics in food applications so by modifying the starch, functional characteristics are enhanced. Single and dual treatment processes are available to enhance microstructural properties, resistant starch, techno-functional, morphological, and, film-forming properties. Compared with other starch sources, there is a lack of systematic information on the LRS. Many industries are interested in developing food products based on starch such as nanoparticles, hydrogels, edible films, and many others. Additionally, there are several recommendations to improve the applications in the food industry. Finally, we provide an outlook on the future possibility of LRS.

Adsorption properties of corn starch modified by malt amylases and crosslinking agents: A comparison between sodium trimetaphosphate and organic acids

In order to investigate the effects of different crosslinking agents on physicochemical properties and adsorption properties of porous starch. Native corn starch was hydrolyzed by maltase and crosslinked with different crosslinking agents. Sodium trimetaphosphate crosslinked porous starch (STMP-MPS), malic acid cross-linked porous starch (MA-MPS) and citric acid cross-linked porous starch (CA-MPS) were prepared. After crosslinking, MA-MPS and CA-MPS showed a new CO stretching absorption peak at 1738 cm-1, and the crosslinking degree was much higher than that of STMP-MPS. The surface area of MA-MPS was 36 % higher than that of STMP-MPS. Compared with the average pore size of 12.43 nm of STMP-MPS, CA-MPS (14.02 nm) and MA-MPS (14.79 nm) were increased more significantly. The degradation temperature of MA-MPS and CA-MPS was increased by the introduction of ester bond, which indicates that the organic acid cross-linking strengthens the starch granules and hence more energy is required for disruption. Compared with STMP-MPS, the water absorption of MA-MPS and CA-MPS increased by 64 % and 32 %, respectively. Furthermore, the adsorption capacity of MA-MPS to essential oil was the strongest, about 4 times that of STMP-MPS. Overall, it is feasible to modify porous starch by crosslinking reaction to improve its heat resistance and adsorption properties.

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.

Selected Physicochemical, Thermal, and Rheological Properties of Barley Starch Depending on the Type of Soil and Fertilization with Ash from Biomass Combustion

The following study analyzed the impact of fertilizing barley with fly ash from biomass combustion grown on two types of soil, Haplic Luvisol (HL) and Gleyic Chernozem (GC), on the properties of starch. The experiment was conducted in 2019 (A) and 2020 (B), and barley was fertilized with ash doses (D1-D6) differing in mineral content. In the tested barley starch samples, the amylose content, the clarity of the paste, and the content of selected minerals were determined. The thermodynamic characteristics of gelatinization and retrogradation were determined using the DSC method. Pasting characteristics, flow curves, and viscoelastic properties of starch pastes were performed. Starches differed in amylose content and paste clarity. The highest gelatinization and retrogradation enthalpy (ΔHG and ΔHR) values were recorded for samples GCD1A and HLD5B. None of the tested factors significantly affected the pasting temperature (PT), but they had a significant impact on the remaining parameters of the pasting characteristics. The average PT value of barley starches was 90.9 °C. However, GCD2A starch had the highest maximum viscosity and the highest rheological stability during heating. GCD2A paste was characterized by the highest apparent viscosity. It was shown that all pastes showed non-Newtonian flow and shear-thinning and had a predominance of elastic features over viscous ones. The resulting gels had the characteristics of weak gels. Ash from burning wood biomass is an innovative alternative to mineral fertilizers. It was shown that the use of such soil fertilization influenced the properties of barley starch.

Starch Assisted the ZnS Buffer Layer in Enhancing the Photoluminescence of ZnSe/ZnS:Mn/ZnS Quantum Dots for Detecting E. Coli and MRSA Bacteria Quickly

In this study, we used a starch paste stabilizer to synthesize ZnSe: Mn/ZnS- Starch and ZnSe/ZnS: Mn/ZnS-starch quantum dot (QDs) in a non-toxic aqueous solvent. The -CH2-OH group of the starch paste promotes dispersibility and improves the compatibility of quantum dots with antibodies, its bonding is observed in the FTIR spectrum. Besides, the Mn-doped ZnS buffer shell with various concentrations (1, 3, 5, 7, and 9%) influence structure, optical, and photoluminescence of QDs properties were investigated in detail. The greatest luminescence intensity is achieved at a molar ratio of 3% Mn2+/Zn2+. Moreover, the ZnS: Mn buffer shell helps to enhance the fluorescence intensity and quantum yield (QY) of the ZnSe/ZnS: Mn/ZnS QDs, which are higher than ZnSe: Mn/ZnS-starch QDs. Through protein A and EDC bridging, ZnSe/ZnS:3%Mn/ZnS- Starch resulted in good signal and sensitivity, with no toxicity to E. coli O157:H7 and MRSA strains.

Starch-based materials for drug delivery in the gastrointestinal tract-A review

Starch is a natural copolymer with unique physicochemical characteristics. Historically, it has been physically, chemically, or enzymatically modified to obtain ad-hoc functional properties for its use in different applications. In this context, the use of starch-based materials in drug delivery systems (DDSs) has gained great attention mainly because it is cheap, biodegradable, biocompatible, and renewable. This paper reviews the state of the art in starch-based materials design for their use in drug-controlled release with internal stimulus responsiveness; i.e., pH, temperature, colonic microbiota, or enzymes; specifically, those orally administered for its release in the gastrointestinal tract (GIT). Physical-chemical principles in the design of these materials taking into account their response to a particular stimulus are discussed. The relationship between the type of DDSs structure, starch modification routes, and the corresponding drug release profiles are systematically analyzed. Furthermore, the challenges and prospects of starch-based materials for their use in stimulus-responsive DDSs are also debated.

Chemically Modified Starches as Food Additives

Starch is a renewable and multifunctional polysaccharide biopolymer that is widely used both in the food industry and other areas of the economy. However, due to a number of undesirable properties in technological processes, it is subjected to various modifications. They improve its functional properties and enable the starch to be widely used in various industries. A modified starch is a natural starch that has been treated in a way that changes one or more of its initial physical and/or chemical properties. Chemical modification consists of the introduction of functional groups into starch molecules, which result in specific changes in the physicochemical and functional properties of starch preparations. The bases of chemical modifications of starch are oxidation, esterification or etherification reactions. In terms of functionality, modified preparations include cross-linked and stabilized starches. These starches have the status of allowed food additives, and their use is strictly regulated by relevant laws. Large-scale scientific research is aimed at developing new methods of starch modification, and the use of innovative technological solutions allows for an increasingly wider use of such preparations. This paper characterizes chemically modified starches used as food additives, including the requirements for such preparations and the directions of their practical application. Health-promoting aspects of the use of chemically modified starches concerning resistant starch type RS4, encapsulation of bioactive ingredients, starch fat substitutes, and carriers of microelements are also described. The topic of new trends in the use of chemically modified starches, including the production of biodegradable films, edible coatings, and nanomaterials, is also addressed.

Glutenin-gliadin ratio changes combining heat-moisture treatment significantly influences the in vitro digestibility of starch in recombinant wheat flours

This study aimed to investigate the effect of heat-moisture treatment (HMT) on the in vitro digestibility of recombinant wheat flours characterizing by gluten proteins differ in glutenin-gliadin ratio. Compared with the untreated flours in our previous study, HMT improved the digestion resistance of starch in flours with different glutenin-gliadin ratios. For the HMT strong-gluten flour, the proportional increase of glutenin led to an excessively strong and fragile gluten network that unstable under HMT, which weakened the wrapping of gluten network around starch granules and reduced the long- and short-range order of starch, resulting in the conversion of resistant starch (RS) and slowly digestible starch (SDS) to rapidly digestible starch (RDS); however, the quantitative increase of gliadin induced the conversion of SDS to RS due to the enhanced protein-starch interactions as well as the improved long- and short-range order of starch during HMT. For the HMT weak-gluten flour, the changes of glutenin-gliadin ratio aggravated the broken of protein network and starch granules during HMT, thus improving the starch digestibility in varying degrees. In conclusion, the relative crystallinity of starch mainly affected the content of resistant starch, while the content of slowly digestible starch was more influenced by protein-starch interactions.

Synthesis and Functions of Resistant Starch

Resistant starch (RS) has become a popular topic of research in recent years. Most scholars believe that there are 5 types of RS. However, accumulating evidence indicates that in addition to starch-lipid complexes, which are the fifth type of RS, complexes containing starch and other substances can also be generated. The physicochemical properties and physiologic functions of these complexes are worth exploring. New physiologic functions of several original RSs are constantly being discovered. Research shows that RS can provide health improvements in many patients with chronic diseases, including diabetes and obesity, and even has potential benefits for kidney disease and colorectal cancer. Moreover, RS can alter the short-chain fatty acids and microorganisms in the gut, positively regulating the body's internal environment. Despite the increase in its market demand, RS production remains limited. Upscaling RS production is thus an urgent requirement. This paper provides detailed insights into the classification, synthesis, and efficacy of RS, serving as a starting point for the future development and applications of RS based on the current status quo.

Customizing Starch Properties: A Review of Starch Modifications and Their Applications

Starch has been a convenient, economically important polymer with substantial applications in the food and processing industry. However, native starches present restricted applications, which hinder their industrial usage. Therefore, modification of starch is carried out to augment the positive characteristics and eliminate the limitations of the native starches. Modifications of starch can result in generating novel polymers with numerous functional and value-added properties that suit the needs of the industry. Here, we summarize the possible starch modifications in planta and outside the plant system (physical, chemical, and enzymatic) and their corresponding applications. In addition, this review will highlight the implications of each starch property adjustment.

Effect of Ball-Milling on Starch Crystalline Structure, Gelatinization Temperature, and Rheological Properties: Towards Enhanced Utilization in Thermosensitive Systems

Starch's crystalline structure and gelatinization temperature might facilitate or hinder its use. Ball milling has frequently been mentioned in the literature as a method for reducing starch size and as a more environmentally friendly way to change starch, such as by increasing surface area and reactivity, which has an impact on other starch properties. In this study, starch samples were milled for varying durations (1, 5, 10, 20, and 30 h) and at different starch-to-ball mass ratios (1:6 and 1:20). Microscopy and XRD revealed that prolonged milling resulted in effective fragmentation and a decrease in crystallinity of the starch granules. Increasing milling times resulted in an increase in amylose content. Rheology and thermal studies revealed that gelatinization temperatures dropped with milling duration and that viscosity and thixotropy were directly influenced. The samples milled for 10, 20, and 30 h at a ratio of 1:20 were the most fragmented and upon drying formed a transparent film at ambient temperature, because of the lower gelatinization temperature. Starch ball milling could lead to the use of this material in thermosensitive systems.

Further insight into the involvement of PII1 in starch granule initiation in Arabidopsis leaf chloroplasts

The control of starch granule initiation in plant leaves is a complex process that requires active enzymes like Starch Synthase 4 and 3 (SS4 or SS3) and several noncatalytic proteins such as Protein Involved in starch Initiation 1 (PII1). In Arabidopsis leaves, SS4 is the main enzyme that control starch granule initiation, but in its absence, SS3 partly fulfills this function. How these proteins collectively act to control the initiation of starch granules remains elusive. PII1 and SS4 physically interact, and PII1 is required for SS4 to be fully active. However, Arabidopsis mutants lacking SS4 or PII1 still accumulate starch granules. Combining pii1 KO mutation with either ss3 or ss4 KO mutations provide new insights of how the remaining starch granules are synthesized. The ss3 pii1 line still accumulates starch, while the phenotype of ss4 pii1 is stronger than that of ss4. Our results indicate first that SS4 initiates starch granule synthesis in the absence of PII1 albeit being limited to one large lenticular granule per plastid. Second, that if in the absence of SS4, SS3 is able to initiate starch granules with low efficiency, this ability is further reduced with the additional absence of PII1.

Synthesis and characterization of sago starch nanocrystal laurate as a food grade particle emulsifier

Starch nanocrystals (SNCs) are tiny particles that possess unique qualities due to their small size, such as increased crystallinity, thin sheet structure, low permeability, and strong resistance to digestion. Although sago starch nanocrystals (SNCs) are naturally hydrophilic, their properties can be modified through chemical modifications to make them more versatile for various applications. In this study, the esterification process was used to modify SNCs using lauroyl chloride (LC) to enhance their surface properties. Three different ratios of LC to SNC were tested to determine the impact on the modified SNC (mSNC). The chemical changes in the mSNC were analyzed using FTIR and ¹H NMR spectroscopy. ##The results showed that as the amount of LC increased, the degree of substitution (DS) also increased, which reduced the crystallinity of the mSNC and its thermal stability. However, the esterification process also improved the hydrophobicity of the SNC, making it more amphiphilic. The emulsification capabilities of the mSNC were investigated using a Pickering emulsion, and the results showed that the emulsion made from mSNC-1.0 had better stability than the one made from pristine SNC. This study highlights the potential of SNC as a particle emulsifier and demonstrates how esterification can improve its emulsification capabilities.

Interpretation of the effects of hydroxypropyl starch and hydroxypropyl distarch phosphate on frozen raw noodles quality during frozen storage: Studies on water state and starch-gluten network properties

The impacts of both structural variations induced by low temperature and physiochemical changes induced by modified starch on the qualities of frozen raw noodles (FRNs) were investigated during long-term freezing storage. The addition of modified starch was a potentially effective method to delay the loss of FRNs qualities during storage. In this study, hydroxypropyl starch (HPS) and hydroxypropyl distarch phosphate (HPDSP) were added to improve the cooking and textural characteristics of FRNs. The cooking loss rate of FRNs with the addition of 12%HPS was consistent with that of the control (4.39 % and 4.37 %, respectively), while after 8 weeks of storage showed the significant decrease effect (5.01 % and 5.78 %, respectively). In addition, adding HPS or HPDSP could change the colour and lustre of FRNs to that preferred by consumers. When 6 % HPS or HPDSP were added, the FRNs showed the lowest of freezable water content during storage. The test results of FTIR showed the secondary structure of FRNs was maintained with the introduction of HPS or HPDSP during refrigeration, and the microstructure was improved during the frozen storage period. Consequently, the results provided a theoretical basis and new insight for the production and transportation of FRNs.

Phosphorylation of Alkali Extracted Mandua Starch by STPP/STMP for Improving Digestion Resistibility

The chemical modifications of starch granules have been adopted to improve the characteristics, viz., paste clarity, resistant starch content, thermal stability, and so forth. The modified starch has been applied as a biopolymer in developing various preparations of food, nutraceutical, and pharmaceutical importance. The present work is focused on phosphorylation of alkali extracted mandua starch for improving digestion resistibility. The phosphorylation of mandua starch extracted from grains of Eleusine coracana (family Poaceae) was carried out by sodium tripolyphosphate/sodium trimetaphosphate at alkaline pH. After chemical treatment of mandua starch, the resistant starch (RS) content was increased significantly. The digestibility of chemically modified starch (CMS) was decreased down after treating by the phosphorylation process. The digestibility of CMS and alkali extracted mandua starch (AMS) in simulated intestinal fluid was found to be 32.64 ± 1.98% w/w and 61.12 ± 2.54% w/w, respectively. After chemical modification of mandua starch, a decrement was observed in amylose content, water-binding capacity, and swelling power. In the three-stage decomposition pattern of CMS studied by thermal gravimetric analysis, the significant changes in decomposition behavior also affirmed the impact of cross-linking in the improvement of stability of internal structure and resistibility of starch. In Fourier transform infrared (FTIR), the formation of the P=O bond was observed in CMS at 1250 cm^-1. The acute and sub-acute toxicity studies in terms of behavioral, haematological, and enzymological parameters for CMS were not different significantly from AMS and control (p > 0.05). The cellular architecture of the liver and the kidney were found normal after consumption of CMS. The results revealed that significant increment in RS fraction occurred after cross-linking of mandua starch. The prepared starch may be applied in developing various formulations of food and pharmaceutical importance.

Starch-based controlled release fertilizers: A review

Starch, as a widely available renewable resource, has the potential to be used in the production of controlled-release fertilizers (CRFs) that support sustainable agriculture. These CRFs can be formed by incorporating nutrients through coating or absorption, or by chemically modifying the starch to enhance its ability to carry and interact with nutrients. This review examines the various methods of creating starch-based CRFs, including coating, chemical modification, and grafting with other polymers. In addition, the mechanisms of controlled release in starch-based CRFs are discussed. Overall, the potential benefits of using starch-based CRFs in terms of resource efficiency and environmental protection are highlighted.

Barley thermoplastic starch nanocomposite films reinforced with nanocellulose

Despite being one of the starch producers, barley has yet to be widely studied for thermoplastic starch applications, including nanocellulose thermoplastic composites, due to its uses in the food and beverage industries. However, only 20% of barley is used in the malting industry to produce both alcoholic and non-alcoholic beverages, and 5% is used as an ingredient in a wide variety of foods. As the fourth most important cereal in the world after wheat, corn, and rice, barley can be considered an interesting biomass source to produce biodegradable thermoplastics, stemming from its starch constitution. Therefore, this review attempts to highlight the barley starch properties and its potential utilization for nanocellulose thermoplastic starch composites. Several studies involving barley-based starch in thermoplastic production and nanocellulose reinforcement for properties enhancement are also reviewed, particularly in the attempt to provide various options to reduce and replace the uses of harmful petroleum-based plastic.

Biopolymers as green-based food packaging materials: A focus on modified and unmodified starch-based films

The ideal food packaging materials are recyclable, biodegradable, and compostable. Starch from plant sources, such as tubers, legumes, cereals, and agro-industrial plant residues, is considered one of the most suitable biopolymers for producing biodegradable films due to its natural abundance and low cost. The chemical modification of starch makes it possible to produce films with better technological properties by changing the functional groups into starch. Using biopolymers extracted from agro-industrial waste can add value to a raw material that would otherwise be discarded. The recent COVID-19 pandemic has driven a rise in demand for single-use plastics, intensifying pressure on this already out-of-control issue. This review provides an overview of biopolymers, with a particular focus on starch, to develop sustainable materials for food packaging. This study summarizes the methods and provides a potential approach to starch modification for improving the mechanical and barrier properties of starch-based films. This review also updates some trends pointed out by the food packaging sector in the last years, considering the impacts of the COVID-19 pandemic. Perspectives to achieve more sustainable food packaging toward a more circular economy are drawn.

Citric acid esterified Glutinous Assam bora rice starch enhances disintegration and dissolution efficiency of model drug

The current work was designed to study the starch's physicochemical attributes, tablet disintegration and dissolution efficiency and its derivatives obtained from the glutinous Assam bora rice (G-ABR) variety of Assam, Northeast India. Starch was isolated by a simple protein denaturation method, and a starch derivative was prepared through citric acid modification. G-ABRS and citrated G-ABRS were characterized through FTIR, DSC, XRD and SEM. The rate of consolidation, consolidation index, angle of internal friction, packing rearrangement and cohesive properties were determined to investigate their applications as functional excipients in pharmaceutical industries. G-ABRS and citrated G-ABRS exhibited better packing rearrangement and cohesive properties than standard corn starch. Furthermore, immediate release of API from the tablet compact was observed when the starch concentration increased from 1 to 5 %, indicating facilitation of the tablet compact disintegration. Therefore, G-ABRS and citrated G-ABRS are potentially functional and sustainable materials for pharmaceutical industries.

Discrimination of Glutopeak Test and Mixograph Parameters for Evaluation of Wheat Flour Supplemented with Hazelnut Skin, Cross-Linked Starch, and Oxidized Starch

Hazelnut skin is a by-product produced from hazelnut processing. It can be used as a nutritional supplement due to its high nutrient values. The purpose of this study was to evaluate the dough properties of refined flour (RF) with the addition of hazelnut skin (HS), cross-linked starch (CS), and oxidized starch (OS). Principal component analysis showed a positive correlation between maximum torque, torque after maximum, and aggregation energy. Usage of 10% HS significantly (p < 0.05) decreased the mixograph MID line peak value indicating a weaker dough. Random forest (RFT) was conducted to classify the samples and to determine the importance levels of the analysis parameters. According to the results, AE and mixograph MID line peak values were the most discriminant parameters to distinguish the samples into groups. High-level HS alone caused undesirable effects on the dough quality, yet the addition of modified starches could be used to compensate for the undesirable effects. When used together, the interaction between hazelnut skin and modified starches should be considered. Glutopeak provides a means for assessing the impacts of additives such as hazelnut skin or modified starches on flour functionality.

High-amylose maize starch: Structure, properties, modifications and industrial applications

High-amylose maize refers to a special type of maize cultivar with a 50 %-90 % amylose content of the total starch. High-amylose maize starch (HAMS) is of interest because it possesses unique functionalities and provides many health benefits for humans. Therefore, many high-amylose maize varieties have been developed via mutation or transgenic breeding approaches. From the literature reviewed, the fine structure of HAMS is different from the waxy and normal corn starches, influencing its gelatinization, retrogradation, solubility, swelling power, freeze-thaw stability, transparency, pasting and rheological properties, and even in vitro digestion. HAMS has undergone physical, chemical, and enzymatical modifications to enhance its characteristics and thereby broaden its possible uses. HAMS has also been used for the benefit of increasing resistant starch levels in food products. This review summarizes the recent developments in our understanding of the extraction and chemical composition, structure, physicochemical properties, digestibility, modifications, and industrial applications of HAMS.

The Flavor Profiles of Highland Barley Fermented with Different Mushroom Mycelium

Highland barley was fermented with Cordyceps militaris, Stropharia rugoso-annulata, Morchella esculenta, Schizophyllum commune and Tremella sanguinea. The flavor profiles were investigated by electronic nose (E-nose), headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and sensory evaluation by train panel. Fermentation with mushroom mycelium was able to change the aroma profile of highland barley. The original strong grassy taste was reduced due to a decrease in hexanal, decanal and 2-pentylfuran, and new aromatic flavors (floral, sweet and mushroom fragrance) were acquired after fermentation. The overall flavor of the fermented highland barley varied with mushroom strains. Schizophyllum commune gave a heavier sour taste to the fermented highland barley. However, fermentation with T. sanguinea increased the content of methyl 4-methoxybenzoate making the sample difficult to accepted. Fermentation with C. militaris, M. esculenta, and S. rugoso-annulata increased the volatile contents. The high levels of 1-octen-3-ol and esters gave a strong mushroom, oily and fruity flavor. Morchella esculenta showed the best performance and the highest acceptance in the fermented highland barley. Our results suggest that fermentation with mushroom mycelium can improve the flavor of highland barley, which provides an innovative utilization of highland barley.

Thermal properties of different types of starch: A review

Starch is present in high amount in various cereals, fruits and roots & tubers which finds major application in industry. Commercially, starch is rarely consumed or processed in its native form, thus modification of starch is widely used method for increasing its application and process stability. Due to the high demand for starch in industrial applications, researchers were driven to hunt for new sources of starch, including modification of starch through green processing. Thermal properties are significant reference parameters for evaluating the quality of starch when it comes to cooking and processing. Modification of starches affects the thermal properties, which are widely studied using Differential scanning calorimeter or Thermogravimetric analysis. It could lead to a better understanding of starch's thermal properties including factors influencing and expand its commercial applications as a thickener, extender, fat replacer, etc. in more depth. Therefore, the review presents the classification of starches, factors influencing the thermal properties, measurement methods and thermal properties of starch in its native and modified form. Further, this review concludes that extensive research on the thermal properties of new sources of starch, as well as modified starch, is required to boost thermal stability and extend industrial applications.

Organocatalytic acetylation of pea starch: Effect of alkanoyl and tartaryl groups on starch acetate performance

Organocatalytic acetylation of pea starch was systematically optimized using tartaric acid as catalyst. The effect of the degree of substitution with alkanoyl (DSacyl) and tartaryl groups (DStar) on thermal and moisture resistivity, and film-forming properties was investigated. Pea starch with DSacyl from 0.03 to 2.8 was successfully developed at more efficient reaction rates than acetylated maize starch. Nevertheless, longer reaction time resulted in granule surface roughness, loss of birefringence, hydrolytic degradation, and a DStar up to 0.5. Solid-state 13C NMR and SEC-MALS-RI suggested that tartaryl groups formed crosslinked di-starch tartrate. Acetylation increased the hydrophobicity, degradation temperature (by ~17 %), and glass transition temperature (by up to ~38 %) of pea starch. The use of organocatalytically-acetylated pea starch with DSacyl ≤ 0.39 generated starch-based biofilms with higher tensile and water barrier properties. Nevertheless, at higher DS, the incompatibility between highly acetylated and native pea starches resulted in a heterogenous/microporous structure that worsened film properties.

Isolation, partial characterization and in vitro digestion of starch from Ariopsis peltata and Lagenandra toxicaria tuber

The starch from two aroid tuber viz. Ariopsis peltata and Lagenandra toxicaria were isolated and evaluated for their morphological, physical and chemical properties. The tubers of these plants are used as food and medicine by the indigenous communities. The starch yield from A. peltata tuber was 25 ± 1.7% with an amylose content of 10 ± 0.9%, while the tuber of L. toxicaria contained 28 ± 6.5% starch with 15 ± 0.5% of apparent amylose in it. The starch isolated from both the tubers was highly pure (99%) starch exhibiting an A-type X-ray diffraction pattern. The starch granules of L. toxicaria were of various shapes and exhibited a smooth surface without any cleft or break. While the starch granules of A. peltata were spherical with smooth surface, as well as rough surface. The breaks and clefts were apparent on the rough-surfaced granules. The gelatinization temperature range for A. peltata and L. toxicaria starch is approximately 23 °C and 19 °C respectively. A. peltata starch showed higher thermal stability compared to L. toxicaria starch and either of the starch was rapidly digestible as evident from in vitro digestion study. The physicochemical properties of both the starches render them stable to withstand extreme processing. Besides they also mimic simple sugar in digestibility. So it can be utilized as a substitute for simple sugars in brewing and pharmaceutical industries.

Effect of chemical treatments on the functional, morphological and rheological properties of starch isolated from pigeon pea (Cajanus cajan)

Different chemical treatments (cross-linking, oxidation, and hydroxypropylation) were used to modify pigeon pea starch, and its effect on physiochemical, pasting and rheological properties were studied. Cross-linking and oxidation decreased while hydroxypropylation increased the swelling power of pigeon pea starch. All starch samples showed a decrease in their paste clarities. FTIR spectra of all starch samples displayed characteristic absorption bands of starch at wave numbers 1076, 1148, 1376, and 1632 cm⁻¹. A significant reduction occurred in peak, cold paste, hot paste, and setback viscosity after chemical modification. Rheological determinations showed that starch pastes had viscoelastic behaviour. G′ and G″ of all starch paste increased after chemical modification. Native and chemically treated starches revealed oval to elliptical-shaped granules and no change was observed after modification when examined in SEM. These results confirmed that the undesirable properties of native pigeon starch can be suitably altered via chemical treatments to make them suitable for several food applications.

•

Chemical modifications significantly (p˂0.05) affect the amylose content, paste clarity, gel hardness, swelling power, and solubility.

•

SEM analysis showed no significant changes after modifications.

•

Pasting properties of starches were significantly reduced (p˂0.05) after the modification, whereas pasting time and peak time were increased.

•

The cross-linked starch structure was more stable than the other modified starches.

Evaluation of the impact of UV radiation on rheological and textural properties of food

Demand for healthy, safe, and high-quality foods and disadvantages of thermal processing methods such as quality losses supported the improvement of the novel, affordable, and quick nonthermal food preservation techniques such as UV light. UV-C light (200-280 nm) radiation is an emerging technology for the disinfection of pathogen microorganisms, increasing the shelf life of foods, and used for pasteurization, surface sterilization, cleaning of equipment and water, and so on. Sensory perceptions of foods are effective on the consumer choice, acceptability, and consumption of foods. Rheology term, which also includes texture and mouthfeel, is primarily important for sensory perception, processing of foods, and shelf stability. Therefore, the determination of the effect of different processing methods on the textural and rheological properties of the food products is important. Rheological and textural changes generally occur in the surface of UV-C-irradiated samples due to the low penetration of UV-C light. The UV light treatment may cause internal disruption of cell membranes, which in turn cause loss of turgidity, weaken the cell walls, and contraction of tissues, which are related to the changes in the textural and rheological properties of foods. The present review focuses on the effect of UV-C radiation on the rheology and textural properties of food products.

Influence of starch with different degrees and order of gelatinization on the microstructural and mechanical properties of pectin cryogels: A potential pore morphology regulator

The applications of cryogels are defined by their porous morphology as well as mechanical properties. To achieve efficient regulation of porous properties for pectin cryogels, we selected starch as a potential polysaccharide regulator. Pectin/starch composite cryogels with different degrees of gelatinization were formulated, and two ways of starch gelatinization were considered: starch gelatinization occurred before or after pectin crosslinking during forming the hydrogel network. The results showed that high gelatinized starch (73.8 %-100.0 %) rendered pectin cryogels with denser pore morphology and higher mechanical strength. The pore diameter transferred from 160-200 μm to 40-60 μm with the degree of gelatinization, while the total porosity decreased by about 15 % and the specific surface area increased by about 100 m²/g. When starch gelatinization occurred before pectin crosslinking, the hydrogen bond interactions between gelatinized starch and pectin were formed to accelerate the gelation rate of the pectin Ca²⁺-dependent network. When gelatinization occurred after pectin crosslinking, the pre-formed pectin network delayed the breakdown of the starch crystalline structure during gelatinization. The qualitative regulation of the pore morphology in pectin cryogels by incorporating starches with varying degrees of gelatinization was confirmed.

Starch-Based Electrochemical Sensors and Biosensors: A Review

Natural green compounds for sensor modification (binders) are challenging in electrochemistry. Starch is a carbohydrate biopolymer that has been used extensively in the development of biomaterials for the food industry due to its ability to impart textural characteristics and provide gelling or film formation. In particular, the excellent film-forming characteristics have been used for the development of new surface modifying architectures for electrodes. Here, we highlight a very comprehensive overview of the properties of interest of various types of starch in conjunction with (bio)materials in the chemical modification of sensors and biosensors. Throughout the review, we first give an introduction to the extraction, applications, and properties of starches followed by an overview of the prospects and their possible applications in electrochemical sensors and biosensors. In this context, we discuss some important characteristics of starches and different strategies of their film formation with an emphasis on their role in the development of electrochemical sensors and biosensors highlighting their main contributions to enhancing the performance of these devices and their applications in environmental and clinical samples.

Effect of pH on the Redox and Sorption Properties of Native and Phosphorylated Starches

Starch is a common biopolymer that can be used for removing heavy metal ions from aqueous solutions. A valuable property of starch is its functional diversity, which can be enhanced by chemical modification. Hydroxyl groups enclosed in the starch and formed during hydrolysis act as reducing agents of Cr(VI). The sorption properties of native starch depend mainly on the presence of carboxyl groups formed during redox processes and basic centers created during acid hydrolysis, while the superiority of phosphorylated starch is related to the presence of phosphate groups binding Cr(III) ions. The effectiveness of starch depends on a series of equilibria established in its aqueous suspension and chromate ions solution, where the pH is the driving force for these processes. In this article, a systematic discussion of pH changes being the consequence of chemical reactions unraveling the extraordinary functionalities of starch was given. It also explained the influence of establishing equilibria and chemical modifications of starch on the efficiency of chromium ion removal. This allowed for the development of a comprehensive mechanism for the interaction of Cr(VI) and Cr(III) ions with native and phosphorylated starch.