Effect of annealing on the structural and physicochemical properties of waxy rice starch nanoparticles

A review on research advances in efficient approaches to augment hydrothermal techniques for starch functionalization: Mechanisms, properties and potential food applications

The applications of hydrothermally modified starches in conventional water media, such as distilled water (DW), are limited due to their poor performance. Therefore, researchers are introducing innovative techniques in various environments, including ethanol solutions, salt solutions, acidic or alkaline conditions, plasma-activated water (PAW), and hydrogen-infused water (HW), to enhance the efficiency of annealing (ANN) and heat moisture treatment (HMT). The present review discusses these new approaches aimed at improving the performance of ANN and HMT, their potential mechanisms for starch modification, the resulting changes in the functional properties of starch, and their role in various food applications. Additionally, it systematically elucidates the challenges, opportunities, and future directions in this field. Unlike classical water-based ANN or HMT, innovative and sustainable approaches adopted for hydrothermal methods drastically enhance the structural stability, resistance to digestive enzymes, and low-temperature storage stability of starch. However, these changes depend on controlled parameters, such as the concentration of ethanol or salt, pH of the medium, incubation time, moisture level, treatment temperature, and starch properties (e.g., amylose/amylopectin ratio) during treatment. This consolidated report on cutting-edge techniques designed to enhance the effectiveness of hydrothermal modifications seeks to expand the potential applications of ANN and HMT in food-grade products.

Effect of Debranching Enzymes on Self-Assembly Kinetics and Physicochemical Characteristics of Short-Chain Glucan Aggregates (SCGAs)

Characteristics of short-chain glucan aggregates (SCGAs) prepared with two different debranching enzymes, isoamylase (I-SCGA) and pullulanase (P-SCGA), were investigated. In terms of self-assembly and crystallization kinetics, I-SCGA exhibited a faster SCGA formation rate, while P-SCGA demonstrated a rapid crystallization rate. P-SCGA had a higher amount of glucan chains with DP ≤ 12, whereas I-SCGA showed a significantly higher amount of B1 chains (13 ≤ DP ≤ 24). Both SCGAs formed aggregates with average sizes of 990 nm (P-SCGA) and 810 nm (I-SCGA), respectively. P-SCGA displayed a wider double-helical melting transition temperature range and higher melting enthalpy than I-SCGA. Although both SCGAs revealed similar amounts of RDS content, P-SCGA showed significantly higher RS and lower SDS contents than I-SCGA. These results highlight the potential of using specific debranching enzymes to develop SCGA with targeted nutritional and functional properties, supporting the creation of customized starch ingredients for health-oriented food products.

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

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

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.

Effects of Continuous and Cycled Annealing on the Physicochemical Properties and Digestibility of Water Caltrop Starch

The effects of treatment time of continuous annealing (ANN) and cycle numbers of cycled ANN on the structural, physicochemical, and digestive properties of water caltrop starch were studied under 70% moisture at 65 °C. It was found that continuous and cycled ANN have no significant effects on the morphology of starch granules. However, the relative crystallinity and content of resistant starch increased pronouncedly, possibly due to crystalline perfection, which also led to the rise in gelatinization temperature and the narrowed gelatinization temperature range of starch. The treatment time in continuous ANN generally showed a pronounced effect on the rheological properties of water caltrop starch. During pasting, the breakdown viscosity and setback viscosity of all treatment decreased, implying that ANN modified starch was less susceptible to the condition in heating and continuous shearing, and less likely to cause short-term retrogradation. In contrast, peak viscosity decreased with increasing treatment time of continuous ANN, indicating crystalline perfection restricted the swelling of starch granules and viscosity development during pasting process, which was consistent with the results of steady and dynamic rheological evaluation. All ANN-modified samples showed pseudoplastic behavior with weak gel viscoelastic characteristic. Under a total annealing time of 96 h, the pasting and rheological properties of water caltrop starch were essentially less affected by annealing cycle numbers. However, multistage ANN showed stronger resistance to enzyme hydrolysis.

Size-controlled synthesis of xylan micro / nanoparticles by self-assembly of alkali-extracted xylan

Valorization of underutilized biobased feedstocks like hetero-polysaccharides is critical for the development of the biorefinery concept. Towards this goal, highly uniform xylan micro/nanoparticles with a particle size ranging from 400 nm to 2.5 μm in diameter were synthesized by a facile self-assembly method in aqueous solutions. Initial concentration of the insoluble xylan suspension was utilized to control the particle size. The method utilized supersaturated aqueous suspensions formed at standard autoclaving conditions without any other chemical treatments to create the resulting particles as solutions cooled to room temperature. Processing parameters of the xylan micro/nanoparticles were systematically studied and correlated with both the morphology and size of xylan particles. By adjusting the crowding of the supersaturated solutions, highly uniform dispersions of xylan particles were synthesized of defined size. The xylan micro/nanoparticles prepared by self-assembly have a quasi-hexagonal shape, like a tile, and depending upon solution concentrations xylan nanoparticles with a thickness of <100 nm were achieved at high concentrations. Based on the usefulness of polysaccharide nanoparticles, like cellulose nanocrystals, these particles have potential for unique structures for hydrogels, aerogels, drug delivery, and photonic materials. This study highlights the formation of a diffraction grating film for visible light with these size-controlled particles.

Sonochemical effect on the degree of substitution of octenyl-succinic anhydride into waxy rice starch nanoparticles and study of gastro-intestinal hydrolysis using INFOGEST in vitro digestion method

Octenyl succinylation of starch nanoparticles has been proven to be effective in a variety of food industry applications such as fat replacement, thickening agents, emulsion formation, and delivery of bioactive compounds. In this study, waxy rice starch was debranched with pullulanase to obtain short glucans, which were then modified with octenyl succinic anhydride (OSA) to obtain amphiphilic short glucans (ASG) using high (400 W) and low (200 W) ultrasonic power intensity at 30 and 60 cycles. Developed ASG were characterized by nanoparticle size (ca. < 50 nm), surface hydrophobicity and gastro-intestinal stability. Ultrasonic intervention progressively increased the degree of substitution (DS) of OSA into hydrolysed starch. A significant molecular exchange between starch and OSA was confirmed with shoulder peak at 1.07 ppm by ¹H NMR, and 1560 and 1727 cm^-1 peaks in FTIR spectral image, and broad band at 1260 cm^-1 by Raman spectroscopy. The XRD analysis confirmed the change in crystalline structure, and the emergence of new peaks at 2θ angles of around 5.81° which represent the development of B-type structure following pullulanasehydrolysis, and minor peaks at 13.92° and 19.83°, which imply the production of V_h type structures in ASG. Gastro-intestinal hydrolysis of starch after modification was analyzed in a sequential digestion process using INFOGEST method. The gastro-kinetic studies unveiled the reduction in the digestibility constant in the oral-gastric phase, with significantly enhanced value of kinetic constants in the intestinal phase, proving a sustained gastro-intestinal stability. The OSA-modified starches with greater DS havemore rigid and compact surface structure, which provides superior protection against biochemical conditions in the stomach fluid.

Recent advances of antibacterial starch-based materials

Starch has attracted a lot of attention because it is biodegradable, renewable, nontoxic and low cost. By adding antibacterial substances to starch, starch-based materials have antibacterial properties. The composite with other materials can improve the comprehensive performance of starch-based materials, thus broadening the application field of the material. In this paper, we focus on antibacterial starch-based materials and review their preparation and applications. It was found that antibacterial starch-based materials were most widely used in packaging, followed by medicine, and the research on smart starch-based materials was relatively less. This review may provide some reference value for subsequent studies of starch-based materials.

Active Food Packaging Made of Biopolymer-Based Composites

Food packaging plays a vital role in protecting food products from environmental damage and preventing contamination from microorganisms. Conventional food packaging made of plastics produced from unrenewable fossil resources is hard to degrade and poses a negative impact on environmental sustainability. Natural biopolymers are attracting interest for reducing environmental problems to achieve a sustainable society, because of their abundance, biocompatibility, biodegradability, chemical stability, and non-toxicity. Active packaging systems composed of these biopolymers and biopolymer-based composites go beyond simply acting as a barrier to maintain food quality. This review provides a comprehensive overview of natural biopolymer materials used as matrices for food packaging. The antioxidant, water barrier, and oxygen barrier properties of these composites are compared and discussed. Furthermore, biopolymer-based composites integrated with antimicrobial agents-such as inorganic nanostructures and natural products-are reviewed, and the related mechanisms are discussed in terms of antimicrobial function. In summary, composites used for active food packaging systems can inhibit microbial growth and maintain food quality.

A Mini Review of Physicochemical Properties of Starch and Flour by Using Hydrothermal Treatment

Starch and flour from various plants have been widely used for sundry applications, especially in the food and chemical industries. However, native starch and flour have several weaknesses, especially in functional, pasting, and physicochemical properties. The quality of native starch and flour can be improved by a modification process. The type of modification that is safe, easy, and efficient is physical modification using hydrothermal treatment techniques, including heat moisture treatment (HMT) and annealing (ANN). This review discusses the hydrothermal modifications of starch and flour, especially from various tubers and cereals. The discussion is mainly on its effect on five parameters, namely functional properties, morphology, pasting properties, crystallinity, and thermal properties. Modification of HMT and ANN, in general, can improve the functional properties, causing cracking of the granule surface, stable viscosity to heat, increasing crystallinity, and increasing gelatinization temperature. However, some modifications of starch and flour by HMT and ANN had no effect on several parameters or even had the opposite effect. The summary of the various studies reviewed can be a reference for the development of hydrothermal-modified starch and flour applications for various industries.

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

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

Chemical modification of waxy maize starch by esterification with saturated fatty acid chlorides: Synthesis, physicochemical and emulsifying properties

In the current study, the physicochemical and emulsifying properties of modified waxy maize starch obtained through a new environmentally friendly method of esterification were evaluated. The starch modification was carried out in NaOH solution with different levels of octanoyl, myristoyl, and stearoyl chlorides. Increasing the fatty acid chlorides concentration led to the degree of substitution increment, while reaction efficiency and yield decreased. Based on fourier transform infrared spectroscopy results, the presence of two new bands of carbonyl (1740-1750 cm^-1) and carboxyl (1570 cm^-1) groups in the ester bond confirmed the successful starch esterification process. The level of 0.1 mL fatty acid chlorides/g of starch demonstrated the highest emulsifying properties. Upon esterification, the crystalline structure of amylopectin was destroyed, indicating no gelatinization features. Therefore, using the fatty acid chlorides in an alkaline condition could be suggested as a feasible way to modify waxy maize starch toward hydrophobicity increment with desirable properties.

Physical modification of starch by heat-moisture treatment and annealing and their applications: A review

Heat-moisture treatment (HMT) and annealing are hydrothermal starch modifications. HMT is performed using high temperature and low moisture content range, whereas annealing uses excess of water, a long period of time, and temperature above the glass transition and below the gelatinization temperature. This review focuses on: research advances; the effect of HMT and annealing on starch structure and most important properties; combined modifications; and HMT-starch and annealed-starch applications. Annealing and HMT can be performed together or combined with other modifications. These combinations contribute to new applications in different areas. The annealed and HMT-starches can be used for pasta, candy, bakery products, films, nanocrystals, and nanoparticles. HMT has been studied on starch digestibility and promising data have been reported, due to increased content of slowly digestible and resistant starches. The starch industry is in constant expansion, and modification processes increase its versatility, adapting it for different purposes in food industries.

Pharmaceutical applications of starch nanoparticles: A scoping review

Starch nanoparticles (SNPs) have been applied to different areas of material sciences, especially in pharmaceuticals due to their characteristics such as small particle size, high surface ratio-volume, and biological compatibility. However, in pharmaceutical sciences, there are no records of a scoping review that had extensively mapped all available information about SNPs. A scoping review was performed here by searching electronic databases (Pubmed and Science Direct) to identify studies published previous to June 2020. From 699 total records, 37 matched the criteria for inclusion. The findings showed that SNPs have been used, not only for the development of different active pharmaceutical ingredient delivery systems, but also as an enzyme inhibitor, adsorption, and DNA precipitation agent. In conclusion, by combining different starch sources and methods SNPs show a remarkable diversity in pharmaceutical applications. Future studies should explore SNPs safety and provide information about variables that may affect important properties for this kind of application.

Infrared heating under optimized conditions enhanced the pasting and swelling behaviour of cowpea starch

Native starches are not suitable for industrial use and must be modified for improved functionality. In this study, the effect of moisture preconditioning and infrared heating time on physicochemical properties of cowpea starch was investigated using a two-factor central composite rotatable design. Factors (moisture levels:10-40 g/100 g starch and infrared heating time:10-60 min) with their corresponding α mid-point values resulted in 13 experimental runs. Selected functional and pasting properties were determined as response variables. Starch samples produced under optimized conditions were compared with corn starch and their physicochemical properties determined. Except for pasting temperature, cowpea starch prepared using the optimal conditions (moisture: 46.21 g/100 g starch, dry basis and heating time of 32.88 min) had higher functional and pasting properties compared with the native cowpea starch. Infrared heating significantly reduced the gelatinization temperatures of cowpea starch but did not significantly change that of the corn starch. The crystallinity and double-helical order structure of moisture conditioned cowpea starch also reduced after modification. Cowpea starch showed a bigger granule size, higher swelling power but lower water absorption capacities and pasting properties compared with the control. The infrared heating process is a novel and promising modification method for improving the swelling properties of starch.

Starch nanoparticles prepared by enzymatic hydrolysis and self-assembly of short-chain glucans

Enzymatic hydrolysis and self-assembly are considered promising methods for preparation of starch nanoparticles (SNPs) because they are environmentally friendly, and time- and cost-effective. These methods are based on the self-assembly of short-chain glucans released from the α-1,6 bonds in amylopectin. Since their discovery, many studies have described the structural and physicochemical properties of self-assembled SNPs. Self-assembled SNPs can be prepared by two methods: using only the soluble portion containing the short-chain glucans, or using the whole hydrolyzate including both insoluble and soluble fractions. Although the structural and physical properties of self-assembled SNPs can be attributed to the composition of the hydrolyzates that participate in self-assembly, this aspect has not yet been discussed. This review focuses on SNPs self-assembled with only soluble short-chain glucans and addresses their characteristics, including formation mechanisms as well as structural and physicochemical properties, compared with SNPs prepared with total hydrolyzates.

Effect of repeated heat-moisture treatments on the structural characteristics of nanocrystals from waxy maize starch

The effect of repeated heat-moisture treatment (RHMT) on the structural characteristics of waxy maize starch nanocrystals was investigated. Compared with native waxy maize starch (WMS), waxy maize starch nanocrystals (WMSNs) changed the crystalline pattern from A-type to B-type, and displayed the lower crystallinity (RC), molecular order (MO), enthalpy (∆H) and double-helix (DH) content, indicating a reduction in the long- and short-range orders of starch molecules. Single heat-moisture treatment significantly increased values, including RC, MO, α (power law exponent obtained by SAXS), ∆H, DH, and the melting temperatures (To, Tp and Tc), while repeated heat-moisture treatment further increased values of these parameters except ∆H, indicating the reinforcement of the long- and short-range orders of WMSNs. In addition, repeated heat-moisture treatment also caused a gradual conversion from B-type to "A + B"-type (Cb, Cc to Ca polymorphs in sequence) and finally to A-type crystallites.

Chitosan coating of zein-carboxymethylated short-chain amylose nanocomposites improves oral bioavailability of insulin in vitro and in vivo

Non-invasive means of insulin administration circumvent some of the inconveniences of injections. Oral administration in particular is convenient, pain-free, and allows favorable glucose homeostasis, but is subject to chemical instability, enzymatic degradation, and poor gastrointestinal absorption. Natural polymeric nanoparticles have emerged as a promising oral delivery system for peptide therapeutics due their safety, biocompatibility, and stability. In this study, self-assembled nanocomposites from chitosan (CS) and insulin-loaded, zein-carboxymethylated short-chain amylose (IN-Z-CSA) nanocomposites were synthesized to improve oral bioavailability of insulin. The optimized IN-Z-CSA/CS_0.2% nanocomposites exhibited an average size of 311.32±6.98 nm, a low polydispersity index (0.227±0.01), a negative zeta potential (43.77±1.36 mV), an encapsulation efficiency of 89.6±0.9%, and a loading capacity of 6.8±0.4%. The IN-Z-CSA/CS_0.2% nanocomposites were stable in storage conditions. The transepithelial permeability of the N-Z-CSA/CS_0.2% nanocomposites was 12-fold higher than that of insulin. Cellular uptake studies revealed that the IN-Z-CSA/CS_0.2% nanocomposites were internalized into Caco-2 cells by both endocytosis and a paracellular route. Additionally, in pharmacological studies, orally administered IN-Z-CSA/CS_0.2% nanocomposites had a stronger hypoglycemic effect with a relative bioavailability of 15.19% compared with that of IN-Z-CSA_1.0% nanocomposites. Furthermore, cell toxicity and in vivo tests revealed that the IN-Z-CSA/CS_0.2% nanocomposites were biocompatible. Overall, these results indicate that the IN-Z-CSA/CS_0.2% nanocomposites can improve oral bioavailability of insulin and are a promising delivery system for insulin or other peptide/protein drugs.