A systematic comparative study on morphological, crystallinity, pasting, thermal and functional characteristics of starches resources utilized in China

High pressure processing of glutinous Rice starch complexed with Buddleja officinalis maxim. Extract: Structural stability and digestibility improvements

This study investigated the impact of high pressure processing (HPP) on yellow glutinous rice starch (Y-GRS) formed by glutinous rice starch (GRS) complexed with Buddleja officinalis Maxim. extract (BOME). Y-GRS at 500 MPa achieved the highest complex index (0.506), indicating stronger starch-BOME interactions. Particle size analysis revealed that Y-GRS exhibited superior resistance to swelling, with D (Song et al., 2021; Leone et al., 2018 [3,4]) increasing by 18.97 μm for Y-GRS and 31.64 μm for GRS as the pressure increased from 400 to 600 MPa. Y-GRS retained higher thermal stability, with an enthalpy change of 1.55 J/g at 500 MPa, compared with 0.83 J/g for GRS. The relative crystallinity of Y-GRS was 8.81 % higher than that of GRS. Structural analyses confirmed BOME mitigated higher pressure-induced damage to starch granule, preserving double helix and crystal structure. Rheologically, Y-GRS exhibited stable peak viscosity, weaker shear thinning behavior, and greater resistance to deformation than GRS. Following HPP, Y-GRS contained lower levels of rapidly digestible starch (RDS) and higher levels of resistant starch (RS) than GRS. In conclusion, these findings highlight HPP as a promising strategy for enhancing the functional properties of Y-GRS, offering improved stability and digestibility for starch-based food applications.

Understanding key component factors influencing the processing performance of extruded foxtail millet

This study elucidated the relationship among physicochemical properties of native/extruded foxtail millet, rheological properties, and processing performance of dough made from extruded millet through an in-depth exploration utilizing Pearson correlation, principal component, and K-means cluster analysis. Results showed that crude protein (8.21 %-9.27 %) and lipid content (1.47 %-5.19 %), peak time (4.6-5.3 min), and starch short-range order (R995/1016) of native millet (1.564-1.901) were pivotal in shaping the molecular dynamics, degradation and reorganization processes during extrusion. Notably, heightened levels of crude protein and lipid content, alongside increased short-range order of starch in native millet, hindered the disorder and reorganization of starch, resulting in decreased expansion ratio, degree of gelatinization, water solubility index, and R995/1016 value. These factors significantly impacted dough properties, leading to increased hardness and elasticity while concurrently reducing viscosity. K-means cluster analysis classified 11 foxtail millet varieties into three groups: those exhibiting high hardness (9.26 % protein, 3.77 % lipid and R995/1016 = 1.87) (1), exceptional springiness (8.58 % protein, 1.77 % lipid and R995/1016 = 1.75) (2), and advantageous viscosity (8.46 % protein, 1.82 % lipid and R995/1016 = 1.71) (3).

Integrating the modified amphiphilic Eleocharis tuberosa starch to stabilize curcuminoid-enriched Pickering emulsions for enhanced bioavailability, thermal stability, and retention of the hydrophobic bioactive compound

The study involves the modification of a non-conventional starch isolated from the under-utilized variety of Chinese water chestnut (CWC (Eleocharis tuberosa) and integrating it to fabricate stabilized and curcumin-enriched Pickering emulsions with enhanced bioavailability, thermal stability, and retention of encapsulated curcumin. A time-efficient, semi-dried esterification method was used to prepare modified amphiphilic starches using 3, 6, or 9 % (w/v) octenyl succinic anhydride (OSA) and characterized through degree of substitution (DS), contact angle, particle size, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and in-vitro digestibility. Moreover, Pickering emulsions were formulated using CWCS-OSA at 3 %, 6 %, or 9 % concentrations to serve as a carrier for curcumin to improve its water solubility and storage stability. The research investigated Pickering emulsions' encapsulation efficiency, curcumin retention, emulsifying properties, micromorphology, temperature stability, and bioaccessibility. Results showed that CWCS-OSA, with an OSA concentration between 3 % and 9 %, exhibited a degree of substitution (DS) ranging from 0.017 to 0.031 and an expansion in contact angle from 68.36o to 85.45o. CWCS-9%OSA showed the highest encapsulation efficiency at 89.4 % and maintained an emulsification index above 80 % during a 10-day storage period. A significantly higher bio-accessibility (41.26 ± 1.34 %) of curcumin in Pickering emulsions stabilized with CWCS-9%OSA than in the bulk oil system (19.53 ± 1.62 %). This study highlights the potential of chemically modified amphiphilic starch from an underutilized variety of CWCS (Eleocharis tuberosa) to produce the stabilized Pickering emulsion gels as a stable and effective carrier for unstable hydrophobic polyphenolic compounds by enhancing their bioavailability in the foods and pharmaceutics.

Effects of yeast β-glucan on gelatinization, structure and digestibility of potato starch

BACKGROUND

Potato starch (PS) is widely used in food, but its application is limited because of its poor heat resistance and easy aging. Therefore, it is necessary to adopt some modification methods to improve its performance and expand its application range.

RESULTS

To improve these shortcomings of PS, the effect of yeast β-glucan (YG) at different concentrations (0%, 1%, 2% and 3%, w/v) on the gelatinization, structure and in vitro digestive properties of PS were investigated. The interaction of YG with PS was different because of different molecular weights. The addition of YG reduced the peak viscosity and increased the final viscosity of PS. YG made the texture of PS gel softer, and the effect of low molecular weight YG was more obvious. YG enhanced the thermal stability of PS. Fourier transform infrared spectroscopy showed that YG and PS interacted through hydrogen bonds. In addition, YG reduced the digestibility of PS in vitro.

CONCLUSION

Collectively, the addition of β-glucan to PS can serve as a new approach to enhance the technological properties of PS in food applications. These results will provide theoretical basis for PS to develop into functional food. © 2024 Society of Chemical Industry.

High-Throughput Phenotyping for Agronomic Traits in Cassava Using Aerial Imaging

Large-scale phenotyping using unmanned aerial vehicles (UAVs) has been considered an important tool for plant selection. This study aimed to estimate the correlations between agronomic data and vegetation indices (VIs) obtained at different flight heights and to select prediction models to evaluate the potential use of aerial imaging in cassava breeding programs. Various VIs were obtained and analyzed using mixed models to derive the best linear unbiased predictors, heritability parameters, and correlations with various agronomic traits. The VIs were also used to build prediction models for agronomic traits. Aerial imaging showed high potential for estimating plant height, regardless of flight height (r = 0.99), although lower-altitude flights (20 m) resulted in less biased estimates of this trait. Multispectral sensors showed higher correlations compared to RGB, especially for vigor, shoot yield, and fresh root yield (-0.40 ≤ r ≤ 0.50). The heritability of VIs at different flight heights ranged from moderate to high (0.51 ≤ HCullis2 ≤ 0.94), regardless of the sensor used. The best prediction models were observed for the traits of plant vigor and dry matter content, using the Generalized Linear Model with Stepwise Feature Selection (GLMSS) and the K-Nearest Neighbor (KNN) model. The predictive ability for dry matter content increased with flight height for the GLMSS model (R2 = 0.26 at 20 m and R2 = 0.44 at 60 m), while plant vigor ranged from R2 = 0.50 at 20 m to R2 = 0.47 at 40 m in the KNN model. Our results indicate the practical potential of implementing high-throughput phenotyping via aerial imaging for rapid and efficient selection in breeding programs.

Understanding starch biosynthesis in potatoes for metabolic engineering to improve starch quality: A detailed review

Potato tubers accumulate substantial quantities of starch, which serves as their primary energy reserve. As the predominant component of potato tubers, starch strongly influences tuber yield, processing quality, and nutritional attributes. Potato starch is distinguished from other food starches by its unique granule morphology and compositional attributes. It possesses large, oval granules with amylose content ranging from 20 to 33 % and high phosphorus levels, which collectively determine the unique physicochemical characteristics. These physicochemical properties direct the utility of potato starch across diverse food and industrial applications. This review synthesizes current knowledge on the molecular factors controlling potato starch biosynthesis and structure-function relationships. Key topics covered are starch granule morphology, the roles and regulation of major biosynthetic enzymes, transcriptional and hormonal control, genetic engineering strategies, and opportunities to tailor starch functionality. Elucidating the contributions of different enzymes in starch biosynthesis has enabled targeted modification of potato starch composition and properties. However, realizing the full potential of this knowledge faces challenges in optimizing starch quality without compromising plant vigor and yield. Overall, integrating multi-omics datasets with advanced genetic and metabolic engineering tools can facilitate the development of elite cultivars with enhanced starch yield and tailored functionalities.

Variability of amylose content and its correlation with the paste properties of cassava starch

The amylose content can significantly impact the diverse industrial applications of cassava starch. This study aimed to assess the variability of cassava germplasm concerning amylose content and other attributes pertinent to root quality, alongside its correlation with paste properties. Starch extracted from 281 genotypes, obtained in germplasm evaluation trials, was evaluated for amylose content, with additional analysis of parameters such as pasting temperature, time to peak viscosity (TPV), viscosity breakdown (BrD), retrogradation tendency, and maximum, minimum, and final viscosities. The genotypes exhibited considerable variation in dry matter content (ranging from 27.06% to 41.02%), starch content (from 14.61% to 25.67%), cyanogenic compounds (1.77 to 7.81), and amylose content (0.05% to 33.23%). High phenotypic variability in paste properties was observed, alongside a low residual effect for most traits, resulting in high broad-sense heritabilities (>0.95). Strong correlations of significant magnitude (>0.80) were found between parameters such as peak viscosity × viscosity breakdown, minimum viscosity × final viscosity, and final viscosity × retrogradation tendency. Moderate correlations were also identified, such as between dry matter content × starch content (0.56). While positive, correlations between amylose content and paste properties were of low magnitude (ranging from 0.13 to 0.35), except for TPV and BrD. Principal component discriminant analysis clustered the germplasm into six distinct groups based on root quality and paste properties, with most improved genotypes falling into two clusters characterized by high starch and dry matter contents. This study underscores the necessity of simultaneous evaluation of amylose content and paste properties in the breeding pipeline. Additionally, clustering cassava genotypes proves beneficial in identifying those that fulfill specific requirements in industrial and breeding applications.

The structural properties of "Huilou" yam starch fermented with five microbial species

In this study, we employed two lactic acid bacterial species, two yeast species, and Bacillus amyloliquefaciens to ferment "Huilou" yam starch. The aim was to explore the effects of fermentation time and microbial species on the structural properties of yam starch. The results showed that fermentation caused an increase in relative crystallinity (29.23 %-37.98 %) compared with native starch (25.69 %). The fermentation process altered the thermal properties of yam starch, leading to higher enthalpy of gelatinization values compared with unfermented starch. Notably, an absorption peak of native starch shifted from 992 cm-1 to 1015 cm-1 upon 2-day fermentation by Bacillus amyloliquefaciens and 5-day fermentation by Lactobacillus plantarum or Pediococcus pentococcus, associated with an increase in the presence of amorphous structures in yam starch. "Huilou" yam starch obtained through lactic acid bacterial fermentation exhibited a significant presence of organic acids, whereas samples derived from Bacillus amyloliquefaciens fermentation were primarily affected by amylase activity. Following yeast fermentation, organic acids and amylase were observed, albeit with relatively low influence. This research reveals that microbial fermentation can potentially alter the structural characteristics of yam starch, which can improve the quality of yam starch-based foods.

Polysaccharides from fruit and vegetable wastes and their food applications: A review

Fruit and vegetables are a great source of nutrients and have numerous health benefits. The fruit and vegetable industry produces enormous amounts of waste such as peels, seeds, and stems. The amount of this waste production has increased, causing economic and environmental problems. Fruit and vegetable wastes (FVWs) have the potential to be recovered and used to produce high-value goods. Furthermore, FVWs have a large variety and quantity of polysaccharides, which makes them interesting to study for potential industrial use. Currently, the investigations on extracting polysaccharides from FVWs and examining how they affect human health are increasing. The present review focuses on polysaccharides from FVWs such as starch, pectin, cellulose, and inulin, and their various biological activities such as anti-inflammatory, anti-tumor, anti-diabetic, antioxidant, and antimicrobial. Additionally, applications as packaging material, gelling agent, emulsifier, prebiotic, and fat replacer of polysaccharides from FVWs in the food industry have been viewed in detail. As a result, FVWs can be reused as the source of polysaccharides, reducing environmental pollution and enabling sustainable green development. Further investigation of the biological activities of polysaccharides from FVWs on human health is of great importance for using these polysaccharides in food applications.

Effects of Premna microphylla turcz polysaccharide on rheological, gelling, and structural properties of mung bean starch and their interactions

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.

Starch exploration in Nelumbo nucifera and Trapa natans: Understanding physicochemical and functional variations for future perspectives

The current research emphasis on identifying unconventional starch sources with varied properties to broaden industrial applications. The focus of this research is on the search for alternative sources of starch with different properties in order to expand their potential use in the industrial sector. Starch was extracted from Trapa natans and Nelumbo nucifera and analyzed for their physicochemical and functional properties. They had similar protein (0.35 %) and ash contents, but the nitrogen-free extract was slightly higher in Nelumbo starch (87.58 %) than in Trapa starch (85.09 %). The amylose and amylopectin contents were 23.89 % and 76.11 % in Trapa starch and 15.70 % and 84.30 % in Nelumbo starch, respectively. Fourier-transform infrared spectroscopy identified both as polysaccharides. The characteristic absorption bands assigned to the stretching of OH groups (3324 cm-1; 3280 cm-1), the asymmetric and symmetric stretching of aliphatic chain groups (2925 cm-1; 2854 cm-1), the bending vibration of CHO groups (1149 cm-1; 1144 cm-1) were present in both the starch samples, with the exception of CH3 which could not be detected in Trapa natans starch. X-ray diffraction confirmed hexagonal and orthorhombic crystal structures in Nelumbo nucifera and Trapa natans starch. Scanning electron microscopy revealed a smooth oval and a rough cuboidal shape for lotus and chestnut starch, respectively. Rheological analysis showed that both starch solutions exhibited gel behavior, with Trapa showing stronger gel behavior after the crossover point. These results suggest potential applications in various industries, including the food industry and beyond.

Resistant starch from yam: Preparation, nutrition, properties and applications in the food sector

Yam is a significant staple food and starch source, particularly in tropical and subtropical regions, holding the fourth position among the world's top ten tuber crops. Yam tubers are rich in essential nutrients and a diverse range of beneficial plant compounds, which contribute to their multifaceted beneficial functions. Furthermore, the abundant starch and resistant starch (RS) content in yam can fulfil the market demand for RS. The inherent and modified properties of yam starch and RS make them versatile ingredients for a wide range of food products, with the potential to become one of the most cost-effective raw materials in the food industry. In recent years, research on yam RS has experienced progressive expansion. This article provides a comprehensive summary of the latest research findings on yam starch and its RS, elucidating the feasibility of commercial RS production and the technology's impact on the physical and chemical properties of starch. Yam has emerged as a promising reservoir of tuber starch for sustainable RS production, with thermal, chemical, enzymatic and combination treatments proving to be effective manufacturing procedures for RS. The adaptability of yam RS allows for a wide range of food applications.

Elucidating effects of Epiphyllum oxypetalum (DC.) Haw polysaccharide on the physicochemical and digestive properties of tapioca starch

Effects of Epiphyllum oxypetalum (DC.) Haw polysaccharide (EP) on physicochemical/digestive properties of tapioca starch (TS) were investigated, and its effects on final quality of TS-based foods were further determined. Results showed EP significantly decreased gelatinization enthalpy (3.92 to 2.11 J/g) and increased breakdown (302 to 382 cp), thereby inducing the gelatinization of TS. Meanwhile, EP decreased setback viscosity (324 to 258 cp), suggesting the retrogradation of TS paste was inhibited. Rheological determination results suggested EP had an impact on the viscoelasticity of TS paste. Moreover, particle size distribution showed EP increased size of TS by cross-linking. Additionally, the suitable addition of EP ameliorated the microstructure and decreased the crystal diffraction peak area of TS gel. Infrared spectroscopy results revealed EP modified the above properties of TS by hydrogen bonds and non-covalent forces. Furthermore, EP inhibited the in vitro digestion of TS paste. Using taro balls as TS-based food model, appropriate addition of EP (0.10 %) improved texture properties, frozen storage stability and color of samples. The present results can not only facilitate the understanding of the modification mechanism of EP on the properties of TS, but also induce the burgeoning of starchy products and the possible application of EP in foods.

Jicama (Pachyrhizus spp.) a nonconventional starch: A review on isolation, composition, structure, properties, modifications and its application

Starch attracts food industries due to their availability in nature, cheapness, biodegradability and possibilities of endless applications. The starch properties and their modification affect food quality. Compared to other cereals, tuber and root starches, more systematic information is needed on the jicama starches (JS). This review article summarizes the isolation, composition, morphology, rheological, thermal and digestibility properties of JS. The modifications and its current and potential applications are also discussed. The chemical composition and structure of JS are different from other starches, influencing its properties. JS has been modified by physical and chemical methods to improve the properties of starch. However, there are very few studies on the modification of JS as compared with other commercial starch although it has been used in food formulation as a stabilizer and to improve the texture of food products. It is also applied as an edible coating to preserve the quality of food products and use as a raw material for making edible and bioplastic packaging. However, large-scale utilization of JS is unexplored compared to commercial starches. Therefore, this review would provide useful information and suggestions for more research on Jicama starch and its industrial applications.

Characterization of the physicochemical properties of Lipu Colocasia esculenta (L.) Schott starch: A potential new food ingredient

The physicochemical properties of Lipu taro starch (LTS), cassava starch (CS) and wheat starch (WS) were analyzed. These starches exhibited a comparable starch content (86 %). However, LTS had a significantly lower amylose content (15.93 %) compared to CS (26.62 %) and WS (33.53 %). Moreover, LTS demonstrated an irregular polygonal cubic morphology with a smaller particle size of 2.55 μm while possessed an A-type crystal structure with high crystallinity at 25.07 %. In contrast, CS and WS had larger particle sizes of 13.33 μm and 16.68 μm, respectively, with lower crystallinities of 22.52 % and 20.33 %. Due to these physicochemical properties, LTS exhibited superior emulsification properties with a higher emulsifying activity index of 8.63 m2/g and an emulsion stability index of 69.18 min, whereas CS and WS had values of 2.35 m2/g and 25.15 min, and 0.37 m2/g and 11.48 min, respectively. LTS also demonstrated enhanced thermal stability, characterized by higher gelatinization temperature (indicated by To, Tp, Tc, and ΔT) and reduced paste viscosity (indicated by PV, TV, FV, SBV, and BDV) compared to CS. However, the mechanical strength of the gel made from LTS (indicated by hardness, adhesiveness, springiness, gumminess, and chewiness) was comparatively inferior to those from CS and WS.

Comparison of structures and properties of gels formed by corn starch with fresh or dried Mesona chinensis polysaccharide

Starch is a major dietary carbohydrate, but its digestion properties need to be improved. Mesona chinensis polysaccharides (MCPs) had a unique function in improving the flocculation performance of starch. This study investigated the effects of adding Mesona chinensis polysaccharide extracted from wet fresh and dry plants with one-year storage, namely WMCP and DMCP, on the physicochemical properties and digestion kinetics of corn starch(CS). The composition analysis showed both WMCP and DMCP were an acidic heteropolysaccharide rich in galacturonic acid and galactose, whereas showed different average main fraction molecular weights (Mw) of 47.36 kDa and 42.98 kDa, respectively. In addition, WMCP showed higher yield, purity and better physicochemical properties to CS than DWCP. Thermal analysis showed WMCP decreased more gelatinization temperatures and enthalpy of CS, and increased more freeze-thaw stability, water holding capacity, and textural parameters of CS gels than DMCP. Structural analysis revealed WMCP induced more changes in crystallinity, short-range order, and microstructure of CS, which inhibited retrogradation than DMCP. In vitro digestion assays demonstrated WMCP addition significantly increased higher resistant starch content by altering starch-starch and starch-MCP interactions than DWCP. Overall, MCPs addition beneficially modulated CS properties and digestion kinetics, providing a novel way to improve starch functionalities. Moreover, WMCP had more advantages to be chosen to form hydrocolloid with CS than DMCP.

Physicochemical Properties of Granular and Gelatinized Lotus Rhizome Starch with Varied Proximate Compositions and Structural Characteristics

As a traditional and popular dietary supplement, lotus rhizome starch (LRS) has health benefits for its many nutritional components and is especially suitable for teenagers and seniors. In this paper, the approximate composition, apparent amylose content (AAC), and structural characteristics of five LRS samples from different regions were investigated, and their correlations with the physicochemical properties of granular and gelatinized LRS were revealed. LRS exhibited rod-shaped and ellipsoidal starch granules, with AAC ranging from 26.6% to 31.7%. LRS-3, from Fuzhou, Jiangxi Province, exhibited a deeper hydrogel color and contained more ash, with 302.6 mg/kg iron, and it could reach the pasting temperature of 62.6 °C. In comparison, LRS-5, from Baoshan, Yunnan Province, exhibited smoother granule surface, less fragmentation, and higher AAC, resulting in better swelling power and freeze-thaw stability. The resistant starch contents of LRS-3 and LRS-5 were the lowest (15.3%) and highest (69.7%), respectively. The enzymatic digestion performance of LRS was positively correlated with ash content and short- and long-term ordered structures but negatively correlated with AAC. Furthermore, the color and network firmness of gelatinized LRS was negatively correlated with its ash content, and the retrograde trend and freeze-thaw stability were more closely correlated with AAC and structural characteristics. These results revealed the physicochemical properties of LRS from different regions and suggested their advantages in appropriate applications as a hydrogel matrix.

Effects of taro [Colocasia esculenta (L.) Schott] slices on nutritional quality, sensory quality, and shelf life of Chinese pickled and steamed pork belly

This study aimed to investigate the influence of different ratios of taro slices (TS) on the nutritional quality, sensory quality, and shelf life of Chinese pickled and steamed pork belly (CPSPB). The study examined various aspects of CPSPB, including its proximate components, fat oxidation, fatty acid composition, protein hydrolysis, oxidation reaction, and induction period (IP). Additionally, the sensory quality and texture analysis were compared simultaneously. The results showed that the addition of TS to CPSPB significantly improved water and lipid loss (p < 0.05), increased the unsaturated/saturated ratio of fatty acids, and reduced lipid and protein oxidation. Additionally, the incorporation of TS extended the IP and enhanced the shelf life of CPSPB. Particularly, the addition of a specific amount of TS (60%) to CPSPB resulted in the highest organoleptic quality. Therefore, these results emphasize the positive impact of TS on the overall quality of CPSPB, highlighting its potential to enhance the nutritional value, sensory attributes, and shelf life.

Hydrogel properties of non-conventional starches from guabiju, pinhão, and uvaia seeds

The physicochemical properties of starch vary depending on the botanical sources, thereby influencing the gelatinisation/retrogradation properties and subsequently affecting the hydrogels characteristics. This study aimed to assess the influence of botanical sources influence on starch and hydrogel properties using non-conventional starch derived from guabiju, pinhão, and uvaia seeds. Hydrogels were prepared by starch gelatinisation followed by 6 h ageing period at room temperature (20 ± 2 °C) and subjected to five freeze-thaw cycles. Pinhão starch exhibited a higher viscosity peak and breakdown, along with a lower final viscosity and setback, compared to guabiju and uvaia starches. The significantly different pasting properties influenced the porous microstructure, water absorption (p-value: 0.01), and resistance of the hydrogels (p-value: 0.01). The guabiju starch hydrogels showed a uniform pore structure without cavities, whereas pinhão and uvaia starch hydrogels exhibited agglomerated and spongy pore structures. Furthermore, the guabiju starch hydrogel demonstrated the lowest water absorption (4.56 g/g) and the highest compression resistance (1448.50 g) among all the studied starch hydrogels. In contrast, the pinhão starch hydrogel showed the highest water absorption (7.43 g/; p-value: 0.01) among all studied starch hydrogels. The hardness of uvaia starch hydrogel did not differ significantly from the guabiju and pinhão starch hydrogel. The different non-conventional starches reveal important variations in the hydrogels characteristics. This provides insights into how amylose and amylopectin interact and present alternatives for using these unique starch-based hydrogels in diverse applications.

Research progress and application of ultrasonic- and microwave-assisted food processing technology

Microwaves are electromagnetic waves of specific frequencies (300 MHz-3000 GHz), whereas ultrasonic is mechanical waves of specific frequencies. Microwave and ultrasonic technology as a new processing method has been widely used in food processing fields. Combined ultrasonic and microwave technology is exploited by researchers as an improvement technique and has been successfully applied in food processing such as thawing, drying, frying, extraction, and sterilization. This paper overviews the principle and characteristics of ultrasonic- and microwave-assisted food processing techniques, particularly their combinations, design of equipment, and their applications in the processing of agricultural products such as thawing, drying, frying, extraction, and sterilization. The combination of ultrasonic and microwave is applied in food processing, where microwave enhances the heating rate, and ultrasonic improves the efficiency of heat and mass transfer. The synergy of the heating effect of microwave and the cavitation effect of ultrasonic improves processing efficiency and damages the cell structure of the material. The degradation of nutrient composition and energy consumption due to the short processing time of combined ultrasonic and microwave technology is decreased. Ultrasonic technology, as an auxiliary means of efficient microwave heating, is pollution-free, highly efficient, and has a wide range of applications in food processing.

Characterization of arrowroot (Maranta arundinacea) starch as a potential starch source for the food industry

Arrowroot is an underutilized tuber crop in Sri Lanka and the characterization of starch was done to identify its nutritional, physicochemical, and functional properties to evaluate its potential for use in the food industry. This study distinctly advances the field of arrowroot starch characterization by providing more characterization techniques for starch samples from Sri Lanka. Arrowroot starch colour was closely similar to colour of wheat flour indicating that the effect of colour is minimum when replacing wheat flour. Oval, spherical, and irregular globular shapes were the predominant starch granule shapes for arrowroot. The average length of starch granules was 44.99 ± 1.27 μm while the width of granules was 31.44 ± 0.58 μm. The least gelation concentration was 8.0% indicating its better gel-forming ability. The nutritional composition of arrowroot starch consisted of low crude protein (0.72 ± 0.02%), crude fat (0.26 ± 0.19%), and crude fiber (1.00 ± 0.09%) contents indicating the purity of starch. Sodium, Potassium, Calcium, Iron, and Zinc contents were 52.6 mg/kg, 4312.95 mg/kg, 382.67 mg/kg, 9.07 mg/kg, and 2.59 mg/kg, respectively. Results of flour densities demonstrated the potential of arrowroot starch to be used in the pharmaceutical industry. Arrowroot starch had high viscosity defining its potential as a thickener. The starch also had high swelling power and solubility indices while solubility was positively correlated with viscosity (0.679; P > 0.05). The low moisture absorbance indicates a longer shelf life of stored arrowroot starch. Onset temperature (To) of 75.02 °C, peak temperature (Tp) of 77.95 °C, and conclusion temperature (Tc) of 82.43 °C were resulted from DSC thermogram. Arrowroot was identified as an A-type starch from x-ray diffractometry and the FT-IR spectrum of arrowroot was identical to starch and presented the carbohydrate nature of starch. Thus, arrowroot starch has a high potential to be used in the food industry based on its functional properties.

Insights into the modification of physicochemical properties and digestibility of pea starch gels with barley β-glucan

The influences of barley β-glucan (BBG) on the physicochemical properties and in vitro digestibility of pea starch were investigated. BBG was found to decrease pasting viscosity in a concentration dependent manner and inhibited the aggregation of pea starch. After the presence of BBG, the gelatinization enthalpy of pea starch was decreased (from 7.83 ± 0.03 to 5.55 ± 0.22 J/g), whereas the gelatinization temperature was enhanced (from 62.64 ± 0.01 to 64.52 ± 0.14°C) according to the differential scanning calorimeter results. In addition, BBG inhibited the swelling of pea starch and amylose leaching. When amylose leached out from pea starch to form a BBG-amylose barrier, starch gelatinization was inhibited. The starch gels exhibited weak gels and shear thinning behaviors by rheological tests results. The interaction between BBG and amylose led to lower viscoelasticity and texture parameters in pea starch gels. The structure analysis results unveiled that the force between BBG and amylose was mainly hydrogen bonds. Pea starch hydrolysis was inhibited when BBG was present in the system, which was connected with the restricted starch gelatinization. These results obtained in the study would supply insights into incorporating BBG into various food systems.

Preparation of Neohesperidin-Taro Starch Complex as a Novel Approach to Modulate the Physicochemical Properties, Structure and In Vitro Digestibility

Neohesperidin (NH), a natural flavonoid, exerts multiple actions, such as antioxidant, antiviral, antiallergic, vasoprotective, anticarcinogenic and anti-inflammatory effects, as well as inhibition of tumor progression. In this study, the NH-taro starch complex is prepared, and the effects of NH complexation on the physicochemical properties, structure and in vitro digestibility of taro starch (TS) are investigated. Results showed that NH complexation significantly affected starch gelatinization temperatures and reduced its enthalpy value (ΔH). The addition of NH increased the viscosity and thickening of taro starch, facilitating shearing and thinning. NH binds to TS via hydrogen bonds and promotes the formation of certain crystalline regions in taro starch. SEM images revealed that the surface of NH-TS complexes became looser with the increasing addition of NH. The digestibility results demonstrated that the increase in NH (from 0.1% to 1.1%, weight based on starch) could raise RS (resistant starch) from 21.66% to 27.75% and reduce RDS (rapidly digestible starch) from 33.51% to 26.76% in taro starch. Our work provided a theoretical reference for the NH-taro starch complex's modification of physicochemical properties and in vitro digestibility with potential in food and non-food applications.

Physicochemical properties and molecular structure of lotus seed starch

Current understanding of physicochemical properties of lotus seed starch (LS) is scarce partly due to its largely unknown molecular structure. This study compared the physicochemical and molecular characteristics of LSs of a wide collection to those of conventional starches (potato (PS) and maize starches (MS)). Variations were found in the chemical composition, physicochemical properties, and molecular structure of LSs. Amylose content and weight-based ratio of short to long chains of amylopectin (APS:APL) were principal factors affecting the physicochemical properties of LSs from different origins. Compared with PS and MS, LSs had higher gelatinization temperatures, lower amylose leaching, and faster retrogradation. These unique properties of LSs were related to their molecular structure and chemical composition. LSs had higher amylose contents than PS and MS as evaluated by various methods. A majority of amylose chains in LS were longer than those in MS but were shorter than those in PS. The APS:APL of LSs were higher than that of MS but lower than that of PS. The results provided a structural basis for understanding the properties of LS and suggested that this unconventional starch may be complementary to conventional starches for industrial applications.

Development of flaxseed gum/konjac glucomannan with agar as gelling agents with enhanced elastic properties

In this study, a natural-based gelling agent comprised of blended flax seed gum (FSG), konjac glucomannan (KG), and agar gel (AG) was developed for application to control the textural properties of foods. The compound gels, including FSG, KG, and AG, were investigated to determine their moisture affinity, including minimum gelling concentration, water binding capacity, water soluble index, and swelling power. In addition, we analyzed the rheological properties of the compound gel through texture analysis, frequency sweep, and creep and recovery. The microstructure of the compound gel was identified and compared with the viscoelastic properties of the gel. Overall, these results showed that the F4K6 (4:6:2 of FSG:KG:AG) could serve as an excellent gelling agent, which endowed food gel with the promoted elastic properties, water capacity, and rigid surface morphology. This work suggests that novel gelling agents, including FSG, KGM, and AG, successfully prepared food gels with improved physicochemical properties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01179-9.

Effect of heat-moisture treatment (HMT) on thermal stability of starch gel and the surface adhesiveness of vermicelli

The molecular structure has an important influence on the surface adhesion of starch gel. In the present study, the surface adhesiveness of vermicelli after cooking was reduced by heat-moisture treatment (HMT), and the mechanism underlying the increased thermal stability was explored by measuring the changes in short-range order, crystallinity, the thickness of the crystalline layer, and the length of the double helix in the dry starch gel. The surface adhesiveness decreased by 72.12 % when the moisture content was 26 %. HMT increased the crystallinity, and the thickness of the crystalline layer of the starch gel increased from 14.61 nm to 14.83-17.30 nm at 20-26 % moisture content. The molecular rearrangement and destruction of unstable short double helixes increased the proportion of long double helixes, resulting in an increased crystallinity and layer thickness.

Resistant starch from sweet potatoes: Recent advancements and applications in the food sector

In tropical and subtropical areas, tuber and root crops are staple foods and a key source of energy. Sweet potato (SP) is currently regarded as one of the world's top ten foods because of its diverse sizes, shapes, color, and health benefits. The resistant starch (RS) content of SP is substantial. It is predicted to become the cheapest item in the food industry due to its extensive variety, food stability, emulsifier and fat substitution capabilities, and as filler. As a result, interest in SP-sourced RS has recently increased. Due to their unique nutritional and functional qualities, novelty has become a popular research focus in recent years. This review will summarize the current understanding of SP starch components and their impact on the technological and physicochemical properties of produced starch for commercial viability. The importance of sweet potato RS in addressing future RS demand sustainability is emphasized. SPs are a viable alternative to tubers as a sustainable raw material for RS production. It has an advantage over tubers because of its intrinsic nutritional value and climatic endurance. Thermal, chemical, and enzymatic treatments are effective RS manufacturing procedures. The adaptability of sweet potato RS allows for a wide range of food applications.

Characterization of Biodegradable Films Made from Taro Peel (Colocasia esculenta) Starch

Studies of renewable polymers have highlighted starch’s role to replace petroleum-based components to produce biodegradable films with plastic-like qualities. In this study, the novelty of taro peel starch (TPS) to produce such films using the casting technique is reported for the first time. A response surface method (RSM) approach was employed to optimize different concentrations of TPS (2.5−3.5%, w/w) and glycerol (25−35%, w/w) and investigate their effects on the physico-mechanical and water barrier properties of TPS films. TPS films showed a positive linear effect (p < 0.05) for thickness (0.058−0.088 mm), opacity (1.95−2.67), water vapor permeability (0.06−0.09 g∙m/m2∙kPa∙h), and cubic effect (p < 0.05) for moisture content (0.58−1.57%), which were linked to high starch concentrations when plasticized with glycerol. X-ray diffraction analysis of TPS films depicted “amorphous”-type crystalline structure peaks at 19.88°, while the thermogravimetric analysis of the film samples exhibited 75−80% of the weight loss of TPS film in the second phase between temperatures of 300 °C to 400 °C. All films exhibited homogenous, transparent surfaces with flexibility, and completely degraded in 5 days in simulated river water and composting soil environments, which confirmed TPS as a promising film polymer in food packaging.

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.

In-situ compatibilized starch/polyacylonitrile composite fiber fabricated via dry-wet spinning technique

An in-situ compatibilized starch (St) and polyacrylonitrile (PAN) composite spinning solution was designed by preparing starch-graft-polyacrylonitrile (St-g-PAN) through graft copolymerizing acrylonitrile from soluble starch and using ammonium cerium nitrate (CAN) as initiator. As dimethyl sulfoxide (DMSO) was used as the solvent, St/St-g-PAN/PAN/DMSO spinning solution was prepared and St/St-g-PAN/PAN composite fibers were obtained by dry-wet spinning technique. The effects of air gap, coagulation bath, hot drawing and stretching, and thermal-setting process were studied in detail. Fourier transform infrared spectroscopy (FT-IR), solid state nuclear magnetic resonance (¹³C NMR), thermogravimetric analysis (TGA), X-ray diffraction analysis (XRD), and scanning electron microscopy (SEM) were used to characterize the structure and morphology of the copolymer and the fibers. Single fiber strength tester and sonic orientation instrument were performed to measure the fiber mechanical properties and orientation degrees. The results showed that as the grafting ratio ~150.0% and the reacting mixture containing St ~9.8%, St-g-PAN ~81.6%, and homo-PAN ~8.6% in DMSO solution with 6.0 wt% in concentration were used, the spinning parameters such as air gap ~35 mm, coagulation bath concentration ~70%, temperature ~25 °C, and positive stretching ~48%, hot drawing and stretching 6 times at 80 °C, thermal-setting at 90 °C for 3 h under constant length mode were met, composite fibers with breaking strength 3.41 cN·dtex^-1, breaking elongation 14.41%, sonic orientation factor 0.625, moisture recovery ratio 10.53% under standard condition (1 atm, 22 °C, and relative humidity 65%), and boiling water shrinkage ratio 9.60% were obtained. The as prepared composite fiber was better than common viscose fiber 2.11 cN·dtex^-1 and cotton fiber ~3.24 cN·dtex^-1 and expected to be used in the fields of medical gauze, bandage, protective clothing, et al. besides of common textiles. The in-situ compatibilization method can be applied in preparation of other composite polymer materials.

Separation of principal component dihydromyricetin from Ampelopsis grossedentata by high-speed counter-current chromatography and its interaction with corn starch

Ampelopsis grossedentata (AG) is an industrial crop in the grape family, which has been used as a dual-purpose plant for medicine and tea with high medicinal values. However, little is reported on the separation technology of active components from AG and processing technology of AG products. High-speed counter-current chromatography (HSCCC) was applied to separate the principal component dihydromyricetin (DMY) from AG. DMY is added to starch-based products to improve food quality. The interaction between corn starch (CS) and DMY was investigated to predict and control the structure and function of starch-based foods. Results show that DMY with 97.13% purity was successfully obtained by HSCCC using a solvent system composed of light petroleum-ethyl acetate-methanol-water-trichloroacetic acid (1:3:1:3:0.01, v/v/v/v/v). Fourier-transform infrared spectroscopy (FT-IR) exhibits that the interactions between CS and DMY included hydrogen bond and noncovalent bond. X-ray diffraction (XRD) shows that DMY could increase the relative crystallinity of CS. Low-field nuclear magnetic resonance results (LF-NMR) imply that DMY decreased the spin relaxation time (T₂ ) and inhibited the mobility of free water. Atomic force microscopy (AFM) results suggest that DMY changed the surface morphology of CS through hydrogen bond interaction. Moreover, the results of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) indicate that DMY could enlarge the pores and change the microstructure of CS-DMY complexes. The findings promote the development of industrial CS-based products and utilization of corn crop.

Separation of gallic acid from Cornus officinalis and its interactions with corn starch

D101 macroporous resin combined with high speed counter-current chromatography (D101 MR-HSCCC) was used to separate gallic acid (GA) from Cornus officinalis, and GA was added to starch-based products to improve food quality. The interaction and action mechanism of corn starch (CS) with GA were investigated for prediction and thereby controlling the structure and functions of starch-based foods. Results show that GA with 98.72% purity was successfully obtained using the D101 MR-HSCCC technique. HSCCC solvent system was composed of n-hexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v). GA inhibited CS dissolution and improved CS swelling. Based on the particle size distribution, GA could enlarge the size of CS-GA complexes. FT-IR spectra exhibit that the interactions between CS and GA may comprise the intermolecular hydrogen bond and non-covalent bond. The results of XRD, LF-NMR and AFM show that the presence of GA could increase the relative crystallinity of CS, decrease the spin relaxation time (T₂)_, and change the surface morphology of CS via the modification of hydrogen bonds distribution. Finally, SEM analysis indicates that GA could change the microstructure of CS-GA complexes. These findings facilitate the development of CS-based products and utilization of CS.

Dry heat treatment induced the gelatinization, rheology and gel properties changes of chestnut starch

The effects of continuous dry heat treatment (CT) and repeated dry heat treatment (RT) on gel and structural properties of chestnut starch (CS) were investigated. CT and RT both reduced the swelling degree of starch and showed significant variations in pasting viscosity, viscoelasticity, gel strength and hardness varying from high to low after dry heat treatment, and CT was lower than that of RT. Neither dry heat treatment nor gelatinization produced new functional groups, and both reduced short-range ordered degree. There were significant decrease in spin-spin relaxation time (T₂) with dry heat treatment (CT and RT), which made the starch in the samples closely combine with water. These results are helpful to better understand the changes of physicochemical properties of starch gel products during dry heat treatment and provide some theoretical references for the application of CS in food industry.

Insights into the correlations between the size of starch at nano- to microscale and its functional properties based on asymmetrical flow field-flow fractionation

In this study, the starches were isolated from three botanical sources (i.e., rice, sweet potato, and lotus seed). The size distributions of starch granules and molecules were determined by asymmetrical flow field-flow fractionation (AF4), and compared with those measured from optical microscopy (OM) and dynamic light scattering (DLS). Furthermore, the starches were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). AF4 coupled online with UV-visible, multiangle light scattering (MALS), and differential refractive index (dRI) detectors (AF4-UV-MALS-dRI) was employed for the investigation of the digestion and retrogradation properties of starches. Meanwhile, the relationships between the size of starch at nano- to microscale and its functional properties (i.e., digestibility, retrogradation, and thermal properties) were studied by Pearson correlation analysis. AF4-UV-MALS-dRI was proved to be a rapid and gentle method for the separation and size characterization of starches at both micro- and nano-molecule levels. Moreover, it was demonstrated that AF4-UV-MALS-dRI is a useful tool for the monitoring of the digestion and retrogradation properties of starches. The results suggested that the sizes of starch granules and molecules were to some extent correlated with their thermal properties and digestibility, but not with retrogradation property.

Effect of inulin on pasting, thermal, rheological properties and in vitro digestibility of pea starch gel

The influence of inulin (IN) on pasting, thermal, rheological properties, and in vitro digestibility of pea starch gel was investigated. Results showed that as the concentration of IN in PS increased, the pasting temperature of PS gradually increased, while the value of peak viscosity, breakdown, and setback decreased. Rheological test suggested that all PS-IN gels were typical non-Newtonian fluids and exhibited a solid-like behavior. With the increased concentration of IN, hardness, chewiness, and gumminess of PS-IN gels significantly declined, in which the minimum value was at addition level of 20%. The presence of IN increased the gelatinization temperatures of PS-IN gels, while decreased the gelatinization enthalpy. Fourier-transform infrared spectroscopy (FT-IR) results indicated that no covalent bonding but intermolecular hydrogen bonding occurred between PS and IN. No influence of IN on the diffraction peak of PS after pasting was confirmed by X-ray diffraction analysis. In addition, IN decreased the content of rapidly and slowly digestible starch of PS, while increasing the content of resistant starch. These results will expand the application range of PS, and also provide a theoretical basis for the development of inulin-starch based products.

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.