Porous rice starch produced by combined ultrasound-assisted ice recrystallization and enzymatic hydrolysis

Ultrasound-assisted annealing treatment to improve physicochemical and digestive properties of banana flour

BACKGROUND

Banana flour can provide a solution to people with gluten intolerance, as it is gluten-free. Native banana flour may have limited functionality in certain applications. In this study, banana flour was modified by ultrasonic (US) and annealing (ANN) treatments at four incubation time spans, namely 12, 24, 36 and 72 h, separately or combined sequentially (US-ANN) to enhance the physicochemical and digestive properties.

RESULTS

US led to exposed granular surfaces and damaged non-starch components. Both treatments, at extended incubation time, increased crystallinity, resulting in a narrower starch gelatinization temperature range. The swelling power was significantly lower for ANN and US-ANN compared to US alone, providing a delay of gelatinization temperature. However, none of the treatments affected the gelatinization enthalpy. Furthermore, US increased peak viscosity, breakdown, final viscosity and setback whereas the opposite results were obtained for ANN and US-ANN. Additionally, US prior to ANN significantly increased the resistant starch (RS) content for annealing times over 24 h, especially for the US-ANN treatment for 72 h, which provided the highest RS content (49.3%) compared to ANN treatment for 72 h (44.0%) and native flour (36.3%).

CONCLUSIONS

US prior to ANN treatment offers an alternative method to improve the functional and digestive properties of banana flour, extending the range of applications. © 2024 Society of Chemical Industry.

Micro-encapsulation of garlic oil using esterified-wheat porous starch and whey protein isolate: Physicochemical properties, release behavior during in vitro digestion

The study aimed to inhibit the stimulating impact of garlic oil (GO) on the stomach and attain high release in the intestine during digestion. So, wheat porous starch (WPS) was modified with octenyl succinic acid (OSA) and malic acid (MA) to obtain esterified WPS, OWPS and MWPS, respectively. The differences in physicochemical, encapsulation, and digestive properties of two GO microcapsules, WPI/OWPS/GO and WPI/MWPS/GO microcapsules produced by using OWPS and MWPS as variant carrier materials and whey protein isolate (WPI) as the same coating agent, were compared. The results found that OWPS had greater amphiphilicity, while MWPS had better hydrophobicity and anti-digestive ability than WPS. Encapsulation efficiency of WPI/OWPS/GO (94.67 %) was significantly greater than WPI/MWPS/GO (91.44 %). The digestion inhibition and low GO release (approximately 23 %) of WPI/OWPS/GO and WPI/MWPS/GO microcapsules in the gastric phase resulted from the protective effect of WPI combined with the good adsorption and lipophilicity of OWPS and MWPS. Especially, WPI/OWPS/GO microcapsule was relatively stable in the gastric phase and had sufficient GO release (67.24 %) in the intestinal phase, which was significantly higher than WPI/MWPS/GO microcapsule (56.03 %), benefiting from the adsorption and digestive properties of OWPS, and resulting in a total cumulative GO release rate of 90.86 %.

Effect of different drying methods on the structure and properties of porous starch

In order to investigate the effects of different drying methods on the properties of porous starch. The present study used four drying methods, namely hot air drying (HD), spray drying (SPD), vacuum freeze drying (FD) and supercritical carbon dioxide drying (SCD) to prepare maize and kudzu porous starch. Findings indicated that the physicochemical properties (e.g., morphology, crystallinity, enthalpy value, porosity, surface area and water absorption capacity as well as dye absorption capacity, particle size) of porous starch were significantly affected by the drying method. Compared with other samples, SCD-treated porous starch exhibited the highest surface areas of the starch (2.943 and 3.139 m2/g corresponding to kudzu and maize, respectively), amylose content (22.02 % and 16.85 % corresponding to kudzu and maize, respectively), MB and NR absorption capacity (90.63 %, 100.26 % and 90.63 %, 100.26 %, corresponding to kudzu ad maize, respectively), and thermal stability, whereas HD-treated porous starch showed the highest water-absorption capacity (123.8 % and 131.31 % corresponding to kudzu and maize, respectively). The dye absorption of the maize and kudzu porous starch was positively correlated with surface area, according to Pearson's correlation analysis. Therefore, in this study, our aim was to explore the effects of different drying methods on the Structure and properties of porous starch, and provide reference for selecting the best drying method for its application in different fields.

Investigation of the formation mechanism of the pepper starch-piperine complex

In this study, a new carrier for loading piperine was prepared using pepper starch, and its interaction mechanism was investigated. The porous pepper starch-piperine complex (PPS-PIP) showed higher loading efficiency (76.15 %) compared to the porous corn starch-piperine complex (PCS-PIP (52.34 %)). This may be ascribed to the hemispherical shell structure of porous pepper starch (PPS) compared to the porous structure of porous corn starch (PCS) based on the SEM result. PPS-PIP had smaller particle size (10.53 μm), higher relative crystallinity (38.95 %), and better thermal stability (87.45 °C) than PCS-PIP (17.37 μm, 32.17 %, 74.35 °C). Fourier transform infrared spectroscopy (FTIR) results implied that piperine not only forms a complex with amylose but may also be physically present in porous starch. This was demonstrated by the short-range order and X-ray type. Molecular dynamics simulations confirmed that hydrogen bonding is the primary interaction between amylose and piperine. Besides the formation of the amylose-piperine complex, some of the piperine is also present in physical form.

Physicochemical Characteristics of Porous Starch Obtained by Combined Physical and Enzymatic Methods, Part 1: Structure, Adsorption, and Functional Properties

Porous starch can be applied as an adsorbent and encapsulant for bioactive substances in the food and pharmaceutical industries. By using appropriate modification methods (chemical, physical, enzymatic, or mixed), it is possible to create pores on the surface of the starch granules without disturbing their integrity. This paper aimed to analyze the possibility of obtaining a porous structure for native corn, potato, and pea starches using a combination of ultrasound, enzymatic digestion, and freeze-drying methods. The starch suspensions (30%, w/w) were treated with ultrasound (20 kHz, 30 min, 20 °C), then dried and hydrolyzed with amyloglucosidase (1000 U/g starch, 50 °C, 24 h, 2% starch suspension). After enzyme digestion, the granules were freeze-dried for 72 h. The structure of the native and modified starches were examined using VIS spectroscopy, SEM, ATR-FTIR, and LTNA (low-temperature nitrogen adsorption). Based on the electrophoretic mobility measurements of the starch granules using a laser Doppler velocimeter, zeta potentials were calculated to determine the surface charge level. Additionally, the selected properties such as the water and oil holding capacities, least gelling concentration (LGC), and paste clarity were determined. The results showed that the corn starch was the most susceptible to the combined modification methods and was therefore best suited for the production of porous starch.

Expanded porous-starch matrix as an alternative to porous starch granule: Present status, challenges, and future prospects

Exposing the hydrated-soft-starch matrix of intact grain or reconstituted flour dough to a high-temperature-short-time (HTST) leads to rapid vapor generation that facilitates high-pressure build-up in its elastic matrix linked to large deformation and expansion. The expanded starch matrix at high temperatures dries up quickly by flash vaporization of water, which causes loss of its structural flexibility and imparts a porous and rigid structure of the expanded porous starch matrix (EPSM). EPSM, with abundant pores in its construction, offers adsorptive effectiveness, solubility, swelling ability, mechanical strength, and thermal stability. It can be a sustainable and easy-to-construct alternative to porous starch (PS) in food and pharmaceutical applications. This review is a comparative study of PS and EPSM on their preparation methods, structure, and physicochemical properties, finding compatibility and addressing challenges in recommending EPSM as an alternative to PS in adsorbing, dispersing, stabilizing, and delivering active ingredients in a controlled and efficient way.

Molecular morphology & interactions, functional properties, rheology and in vitro digestibility of ultrasonically modified pearl millet and sorghum starches

The present research investigated to study the effect of ultrasound treatment on isolated pearl millet starch (PMS) and sorghum starch (SS). Ultrasonication was applied to PMS and SS for 10, 15, and 20 min. Ultrasonically modified pearl millet and sorghum starches evaluated for their techno-functionality, pasting profile, morphology, in vitro starch digestibility, XRD, and molecular interactions. Ultrasound treatment increased water and oil absorption capacity, swelling power, and solubility with treatment time. For ultrasonicated PMS and SS, a significant increase (p < 0.05) in paste clarity (PC) (70.05 % and 67.23 %), freeze-thawing stability (FTS), gel consistency (GC) (25.05 mm and 32.95 mm), and in vitro starch digestibility were observed (57.70 g/100 g and 50.29 g/100 g), whereas no significant changes were recorded for the color values after the ultrasound treatment. Variations in pasting property were also observed in ultrasonicated starches with treatment duration. SEM images confirmed ultrasonication mainly forms pores and indentations on starch granule surface. FTIR spectra and X-ray diffractogram for ultrasonicated starches revealed a slight decrease in the peak intensity and A-type X-ray pattern with lower relative crystallinity (RC) than the native starches. G' > G″ value, indicating the elastic behavior and lower tan δ value, depicting viscous behavior and high gel strength.

Synergistic modification of ultrasound and bamboo leaf flavonoid on the rheological properties, multi-scale structure, and in vitro digestibility of pea starch

In this study, the effect of ultrasonic treatment (UT), bamboo leaf flavonoid (BLF), ultrasonic treatment prior to bamboo leaf flavonoid (UT-BLF), and bamboo leaf flavonoid prior to the ultrasonic treatment (BLF-UT) on the rheological properties, multi-scale structure, and digestibility of pea starch (PS) were investigated. The morphology and crystal structure of starch granules were destroyed by UT, thereby promoting starch retrogradation and digestion. The binding between BLF and starch through hydrophobic interactions and hydrogen bonds inhibited the interaction between starch molecular chains and impaired their double helix structure, thus effectively retarding starch retrogradation. The anti-digestibility of starch was enhanced after synergistic treatment. Compared with single treatment, synergistic treatment increased the ordered structure and gelatinization enthalpy of starch. In comparison with the UT-BLF group, the viscoelastic and thermal stability of BLF-UT group were improved with the increase in ordered structure. This study could provide valuable information for PS modification.

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

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

Hydrothermal processes and simultaneous enzymatic hydrolysis in the production of modified cassava starches with porous-surfaces

The amylolytic action of α-amylase and amyloglucosidase has been directly implemented in native cassava starches for the formation of cassava microporous granules with unsatisfactory results, however, its incidence in hydrothermally treated granules has never been evaluated. The effect of hydrothermal processes and simultaneous enzymatic hydrolysis on the physicochemical, morphological and structural properties of native cassava starch was evaluated. Native cassava starch presented a rigid, smooth surface, and was exempt from porosities, whereas hydrothermal processes altered the semicrystalline order and increasing the size and number of pores and increasing the size (4.11 ± 0.09 nm) and volume of pores (0.82 ± 0.00 cm3/g × 10-3). The hydrothermal action followed by enzymatic processes with α-amylase and amyloglucosidase, augmented the processes of internal degradation (endo-erosion) and pore widening (exo-erosion), improving the hydrophilic properties compared to the hydrothermal treatment. Likewise, the hydrothermally process followed by enzymatic hydrolysis for 24 h (HPS + EMS-24) increased the degradation of the amorphous lamellae, consistent with a significant decrease in amylose content. This same dual treatment increased the pore size at 17.68 ± 0.13 nm relative to the native counterpart; therefore, they are considered an effective method in the development of modified cassava starches with porous surfaces.

Effects of high-speed shear and double-enzymatic hydrolysis on the structural and physicochemical properties of rice porous starch

This study aimed to investigate the physicochemical properties of the rice porous starch (HSS-ES) prepared by high-speed shear combined with double-enzymatic (α-amylase and glucoamylase) hydrolysis, and to reveal their mechanism. The analyses of ¹H NMR and amylose content showed that high-speed shear changed the molecular structure of starch and increased the amylose content (up to 20.42 ± 0.04 %). FTIR, XRD and SAXS spectra indicated that high-speed shear did not change the starch crystal configuration but caused a decrease in short-range molecular order and relative crystallinity (24.42 ± 0.06 %), and a loose semi-crystalline lamellar, which were beneficial to the followed double-enzymatic hydrolysis. Therefore, the HSS-ES displayed a superior porous structure and larger specific surface area (2.962 ± 0.002 m²/g) compared with double-enzymatic hydrolyzed porous starch (ES), resulting in the increase of water and oil absorption from 130.79 ± 0.50 % and 109.63 ± 0.71 % to 154.79 ± 1.14 % and 138.40 ± 1.18 %, respectively. In vitro digestion analysis showed that the HSS-ES had good digestive resistance derived from the higher content of slowly digestible and resistant starch. The present study suggested that high-speed shear as an enzymatic hydrolysis pretreatment significantly enhanced the pore formation of rice starch.

Porous corn starch obtained from combined cold plasma and enzymatic hydrolysis: Microstructure and physicochemical properties

The combined effect of cold plasma treatment and enzymatic hydrolysis was investigated on the physicochemical and microstructural properties of porous corn starch. Scanning electron microscopy (SEM) images depicted that the combined treatment led to the creation of deeper pores on the surface of starch granules. The combined treatment indicated the highest swelling power (19.49 g/g), solubility (10.08 %), specific surface area (2.97 m²/g) and total pore volume (10.47 cm³/g). According to the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC), the combined treatment, compared with the enzymatic hydrolysis, decreased the starch crystallinity, the order of the double-helix structure, and the starch gelatinization enthalpy. The rapid visco analyzer (RVA) pasting profile revealed that the combined treatment elevated the breakdown and setback viscosities. This study indicated that cold plasma pretreatment, as a green non-thermal technology, facilitated the performance of enzymes, resulting in the production of a porous starch with a higher absorption capacity.

Effect of ultrasound on the physical properties and processing of major biopolymers-a review

Designing and developing modern techniques to facilitate the extraction and modification of functional properties of biopolymers are key motivations among researchers. As a low-cost, sustainable, non-toxic, and fast process, ultrasound has been considered a method to improve the processing of carbohydrate and protein-based biopolymers such as cellulose, chitin, starch, alginate, carrageenan, gelatine, and guar gum. A better understanding of the complex physicochemical behavior of biopolymers under ultrasonication may fortify the eminence of this technology in advanced-level applications. This review summarizes the recent advances in biopolymer processing and the effect of ultrasound on the physical properties of the selected biopolymers. A major focus will be given to the mechanisms of action and their impact on the properties and extraction. At the end, some possible suggestions are highlighted which need future investigation for amending the physical properties of biopolymers using ultrasonication.

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

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

Properties and digestibility of a novel porous starch from lotus seed prepared via synergistic enzymatic treatment

The objective was to investigate the effect of synergistic enzymatic treatment on the properties and digestibility of a novel C-type lotus seed porous starch (LPS). Scanning electron microscopy showed that the densest and most complete pores were formed on the surface of LPS when the concentration of enzymes added was 1.5% (LS-1.5E). With increases in enzyme addition, the oil and water absorption of the porous starch increased and reached maxima at 1.5% of enzyme. Increased in the specific surface area, total pore volume and average pore diameter of LPS were determined by low-temperature nitrogen adsorption, while when the enzymes exceeded 1.5%, there were no significant changes. Compared to lotus seed starch (LS), the particle size of LPS also decreased. With the increases in enzyme addition, LPS exhibited higher relative crystallinity and ordering structure by XRD and FTIR. The results by SAXS confirmed that LPS had higher ordered semi-crystalline lamellar and denser lamellar structure compared to LS. Low-field ¹H NMR spectroscopy indicated that the proportion of bound water in LPS increased, while the proportion of bulk water decreased. Moreover, the degree of hydrolysis of LPS was lower than that of LS, and the content of rapidly digestible starch decreased, while the content of slowly digestible starch and resistant starch increased with the enzyme addition, which was consistent with the structural properties.

Structural changes of A-, B- and C-type starches of corn, potato and pea as influenced by sonication temperature and their relationships with digestibility

The effect of sonication temperature on the structures and digestion behaviour of corn starch (CS, A-type), potato starch (PtS, B-type), and pea starch (PS, C-type) was investigated. For CS, sonication temperature resulted in a rough surface, decreased apparent amylose content, gelatinization enthalpy and gelatinization degree, increased short-range orders, long-range orders, retrogradation degree and resistant starch content. For PtS, sonication temperature led to a coarser surface with scratches, increased apparent amylose content and gelatinization degree, decreased short-range orders, long-range orders, gelatinization enthalpy, retrogradation degree, and resistant starch content. For PS, sonication temperature showed partial disintegration on surface, increased gelatinization degree, decreased apparent amylose content, short-range orders, long-range orders, gelatinization enthalpy, retrogradation degree and resistant starch content. This study suggested that starch digestion features could be controlled by the crystalline pattern of starch used and the extent of sonication temperature, and thus were of value for rational control of starch digestion features.

The assisting effects of ultrasound on the multiscale characteristics of heat-moisture treated starch from Agriophyllum squarrosum seeds

Present study was aimed to characterize the effects of heat-moisture treatments supported by ultrasound on structural, physicochemical and digestive properties of the starch from Agriophyllum squarrosum seeds. The starch sample was subjected to heat-moisture (120°C, 25% moisture) for different durations with assisting by pre- or post-treatment of ultrasound (20 Hz, 300 W, 20 min). A. squarrosum starch exhibited the original A-type of crystalline structure after all treatments. All modified starches had lower amylose content, amylopectin molecular weight, swelling power and solubility, and higher resistant starch content than the native starch. Heat-moisture treatments and dual modifications of heat-moisture and ultrasound increased the gelatinization temperature of starch granules and significantly (p ≤ 0.05) reduced the viscosity of starch paste. Pretreatment of ultrasound enhanced the effects of heat-moisture on the viscosity properties while post-treatment of ultrasound weakened which on the gelatinization temperature, by regulating the changes of double helix structure and short-range ordered structure in starch granules tested by Fourier-transform infrared spectrometer. Scanning electron microscopy unveiled that A. squarrosum starch pretreated by ultrasound became more susceptible to heat moisture in morphology. This work was very important for the deep excavation of the characteristics of A. squarrosum starch and the effective application of ultrasound in starch modifications.

Impact of ultrasonic treatment on rice starch and grain functional properties: A review

As a green, nonthermal, and innovative technology, ultrasonication generates acoustic cavitation in an aqueous medium, developing physical forces that affect the starch chemistry and rice grain characteristics. This review describes the current information on the effect of ultrasonication on the morphological, textural, and physicochemical properties of rice starch and grain. In a biphasic system, ultrasonication introduced fissures and cracks, which facilitated higher uptake of water and altered the rice starch characteristics impacting textural properties. In wholegrain rice, ultrasonic treatment stimulated the production of health-related metabolites, facilitated the higher uptake of micronutrient fortificants, and enhanced the palatability by softening the rice texture. This review provides insights into the future direction on the utilization of ultrasonication for the applications towards the improvement of rice functional properties.

Pre-treatment of granular rice starch to enhance branching enzyme catalysis

Effects of different pre-treatments of granular rice starch using ethanol (ET) and maltogenic α-amylase (MA), separately or combined sequentially ET→MA, were performed to enable efficient subsequent modification with branching enzyme (BE). The pre-treated samples were characterized with respect to morphology, molecular structure, physicochemical properties and the rate of digestion to amylolytic enzymes. MA produced pores and also eroded the granular surface whereas ET caused coapted granules, noticeable swelling but no pores. Crystallinity and enthalpy of gelatinization dramatically decreased with ET and ET→MA. Subsequent BE catalysis increased the specific surface area, crystallinity, α-1,6-glucosidic linkage ratio and enthalpy. BE catalyzed branching resulted in more intact granules, less swelling capacity, solubility and granular separation as compared to their control. These effects were related to reduced amylolytic susceptibility. Pre-treatment prior to BE catalysis offers an efficient alternative way to modify granular starch with different structure and properties depending on the pre-treatment protocol.

Modification methods toward the production of porous starch: a review

Starch is a complex carbohydrate formed by the repeating units of glucose structure connected by the alpha-glycosidic linkages. Starch is classified according to their derivatives such as cereals, legumes, tubers, palms, fruits, and stems. For decades, native starch has been widely utilized in various applications such as a thickener, stabilizer, binder, and coating agent. However, starches need to be modified to enhance their properties and to make them more functional in a wide range of applications. Porous starch is a modified starch product which has attracted interest of late. It consists of abundant pores that are distributed on the granule surface without compromising the integrity of its granular structure. Porous starch can be produced either by enzymatic, chemical, and physical methods or a combination thereof. The type of starch and selection of the modification method highly influence the formation of pore structure. By carefully choosing a suitable starch and modification method, the desired morphology of porous starch can be produced and applied accordingly for its intended application. Innovations and technologies related to starch modification methods have evolved over the years in terms of the structure, properties and modification effects of different starch varieties. Therefore, this article reviews recent modification methods in developing porous starch from various origins.