To conform to the trend of whole-food diets in recent years, whole potato powder has been used for the processing of extruded vermicelli. The effects of different additives, such as NaCl, citric acid and ethanol, on the cooking quality and sensory quality of whole potato vermicelli obtained via twin-screw extrusion were investigated. The colour, gelatinisation properties, water absorption, cooking loss, texture profile analysis, scanning electron microscopy analysis and correlation analysis of the whole potato vermicelli were determined and discussed. The brightness of the whole potato vermicelli increased from 52.0 to 55.4 at 1% NaCl addition and increased from 52.0 to 54.9 at 0.8% citric acid addition, and the water absorption of the whole potato vermicelli increased from 83.1% to 159.1% at 0.4% citric acid addition and increased from 83.1% to 258.9% at 8% ethanol addition. The cooking loss of the whole potato vermicelli decreased from 5.3% to 5.1% at 8% ethanol addition, indicating that ethanol could improve the cooking quality of whole potato vermicelli. The texture properties of the whole potato vermicelli decreased with the addition of ethanol, and the Delta H of the whole potato vermicelli decreased from 3.7 to 1.8 J g(-1) at 0.8% citric acid addition and decreased from 3.7 to 1.5 J g(-1) at 8% ethanol addition, respectively. Moreover, the addition of ethanol was negatively correlated with the max force, break distance, stretching work, hardness, adhesiveness and chewiness of the whole potato vermicelli. The addition of NaCl was positively correlated with the peak gelatinisation temperature. All three additives affected the microstructure of the whole potato vermicelli, including roughening the cross section and increasing the number of pores. In this study, NaCl improved the gelatinisation properties of whole potato vermicelli, citric acid and ethanol improved the water absorption of the whole potato vermicelli, and citric acid improved the anti-browning effects of the whole potato vermicelli.

To develop natural complex materials as starch-dominated emulsifiers, pregelatinization was conducted on potato flour. The effects of gelatinization degrees (GDs, 0 %-50 %) on the structural characteristics, physicochemical properties, and emulsifying potentials of potato flour were investigated. Increasing GD of potato flour promoted protein aggregation on starch granules surfaces and transformed starch semicrystalline structures into melted networks. The emulsion stabilized with 50 % GD potato flour exhibited excellent storage stability (7 d) and gel-like behavior. With increasing GD from 0 to 50 %, the respective apparent viscosities and elastic moduli of emulsion increased from 21.4 Pa to 1126.7 Pa, and from 0.133 Pa & sdot;s to 1176.6 Pa & sdot;s, promoting the formation of a stable network structure in the emulsion. Fourier transform infrared spectra from emulsions with a continuous phase of >20 % GD displayed a new peak around 1740 cm(-1), suggesting improved covalent interactions between droplets, thereby facilitating emulsion stability. Confocal laser scanning microscopy images indicated that droplets could be anchored in the melted networks and broken starch granules, inhibiting droplets coalescence. These results suggest that pregelatinization is a viable strategy for customizing natural starch-dominated emulsions.

This study aimed to evaluate the effects of enzymatic hydrolysis on the chewing and swallowing properties of potato cubes using a freeze-thaw impregnation technique. The texture properties, microstructure, rheological properties, and suitability as a dysphagia diet of the potato cubes after enzymatic hydrolysis were studied. The results indicated that pectinase reduced the texture of the potato cubes more than cellulase and alpha-amylase. Pectinase hydrolysis could improve the safety of potato cubes as food for the elderly. Pectinase improved the stability of the mashed potatoes by increasing their viscosity and elastic modulus after chewing, thus improving their swallowing properties. The concentration at 200 U/mL and the hydrolysis time at 60 min were the best hydrolysis condition for pectinase to make dysphagia-suitable potato cubes. This study provides insights into the development of potato-based foods that can be used as dysphagia diet for the elderly.

Repeated freeze-thaw (FT) cycles damage the quality of frozen starch-based foods and accelerate the digestion rate of starch. This study investigated how potato soluble dietary fiber (PSDF) affects the physicochemical characteristics and digestibility of potato starch (PS) after repeated FT cycles. Results indicated that repeated FT cycles of potato starch resulted in the enlargement of gel pores, an increase in hardness (from 322.5 g to 579.5 g), and a decrease in gel porosity, leading to reduced water-holding capacity (from 94.2 % to 85.4 %). However, the addition of PSDF stabilized the 3D structure of the PS/PSDF gel, with minimal fluctuations in hardness (413.0-447.5 g) and water-holding capacity (94.4-93.6 %). Meanwhile, PSDF enhanced intramolecular hydrogen bonding within starch molecules and promoted molecular interactions, increasing the PS/PSDF gel's helix structure; therefore, PSDF effectively addressed the increase in rapidly digestible starch caused by repeated FT cycles. Furthermore, PSDF might attach to the surface of starch particles, so limiting starch granule expansion and decreasing the peak viscosity increase caused by repeated FT cycles. The findings suggest that PSDF could be an effective component for improving the quality of potato starch-based frozen food.

The shear-thickening phenomenon in waxy starch dispersions has been reported; however, the influence of starch properties on it remains unclear. Herein, the shear-thickening behavior of five waxy starch dispersions at different concentrations is investigated, and two shear-thickening areas are identified for the first time. Waxy potato and cassava starch dispersions present two shear-thickening areas, waxy maize and wheat starch dispersions exhibit one shear-thickening area, and waxy rice starch dispersion exhibits no shear-thickening behavior. Starches with high degree of polymerization (DP > 12 and > 37 chains), short-range order, relative crystallinity, melting enthalpy (Delta H), and low molecular weight easily form large particle fragments and strong intermolecular forces, thereby resulting in double shear-thickening areas. Starches with relatively high DP > 12 chains, short-range order, relative crystallinity, and Delta H form one shear-thickening area. Starches with no shearthickening area have high molecular weight, degree of branching, and DP < 12 chains, and low short-range order, relative crystallinity, and Delta H. It can be speculated that the first shear-thickening area (2-5 s(-1)) is due to the presence of large particle fragments, whereas the second (10-15 s(-1)) is due to the interaction between the side chains of the starch molecule.

In order to explore the influence of pressure on dough texture properties during hand kneading and mechanical bionic kneading, the pressure distribution of dough was characterized by numerical simulation, the changes of dough moisture distribution, protein secondary structures, gluten network development, microstructure and texture properties with development of resting time were investigated. For mechanical-bionic-kneaded dough, pressure level and compression ratio were greater than those of hand-kneaded dough. The increase in pressure level was beneficial for the unfolding and orientation of protein molecules in the dough, allowing more sites to form hydrogen bonds, and thus improve the content of 13-sheet and alpha-helix structures. The maximum values of 13-sheet and alpha-helix contents in mechanical-bionic-kneaded dough were about 10 % higher than that in handkneaded dough. This made continuity and uniformity of gluten network structure, combination degree of gluten network and starch granules, and resilience of mechanical-bionic-kneaded dough were better than those of hand-kneaded dough. The best conditions of mechanical-bionic-kneaded and hand-kneaded dough occurred at 30 min and 45 min of resting time, respectively. High pressure during kneading could promote the formation of gluten network, the dough resilience and shortened the resting time required for dough to reach a stable state.

Twin-screw extrusion pretreatment has great potential for the development of three-dimensional (3D) printed food as dysphagia diets. This study aimed to investigate the effect of twin-screw extrusion pretreatment on starch structure, rheological properties and 3D printing accuracy of whole potato flour and its application in dysphagia diets. The results indicated that twin-screw extrusion pretreatment was found to change chain length distributions, short-range ordered structure and relative crystallinity of whole potato flour (WPF), thereby improving its 3D printing performance. With the increasing proportion of long linear chains (DP > 12), the intensity of hydrogen bonds, linear viscoelastic region, storage modulus (G'), loss modulus (G″), viscosity and n of whole potato flour paste were increased, enhancing high printing accuracy and shape retention of 3D printed samples with a denser microstructure and smaller pore diameter distribution. The whole potato flour paste extruded with a peristaltic pump speed at 5.25 mL/min (WPF-4) displayed the highest printing accuracy with excellent rheological properties, good water distribution state and dense network structure, which classified as class 5 level dysphagia diets. This research provides an effective guidance for the modification of whole potato flour using twin-screw extrusion pretreatment as 3D printed food inks for dysphagia patients.

Due to their prebiotic effects, lactulose and maltulose have garnered increasing interest from the food and pharmaceutical industries. Pulsed electric field (PEF) technology can enhance energy use efficiency, particularly in electroactivation, offering a potential means to convert reducing sugars. A specialized PEF-treated design has been developed to facilitate alternative catalyst-driven production of lactulose and maltulose by manipulating the morphology and oxidation states of copper catalysts. Under optimal conditions (4 kV/cm, 50 Hz, and 10 mu s for 30 min), remarkable yields of lactulose (55.75%) and maltulose (43.27%) were achieved. Higher conversion rates were observed with an increased PEF treatment electric field strength and pulse width. The yields and selectivities of lactulose and maltulose were not significantly influenced by the frequency. Intriguingly, structural monosaccharides, including glucose, galactose, xylose, and arabinose, were also detected in the isomerization reaction. These findings suggest that PEF, utilizing CuO plates, induces glycoside bond hydrolysis and the conversion of aldose to pentose. Microscopic measurements (high-resolution transmission electron microscopy (HRTEM), high-energy X-ray diffraction (XRD), in situ Raman, and X-ray photoelectron spectroscopy (XPS)) revealed that transient Lewis acid-base pairs formed by the Cu+/Cu2+ shuttle could serve as active sites for reducing sugar isomerization, and DFT simulation further confirmed that the presence of active Cu species could promote the isomerization of lactose and maltose via a lower energy barrier. The PEF process proves to be an economical method for transforming low-value sugars into high-value carbon materials.

Summary Improving the edible quality and nutrition of gluten‐free (GF) products is vital for patients to improve their coeliac disease (CD). This study explored the effect of the addition of soybean protein isolate (SPI), ovalbumin (OVA), and whey protein (WP) on the cooking characteristics of rice‐maize‐potato (RMP) GF pasta and made a comprehensive evaluation of the quality of GF pasta. The addition of SPI at higher concentrations would seriously increase the cooking loss of GF pasta. In contrast, the addition of OVA and WP could improve the cooking stability of GF pasta. The amount of OVA and WP powder in GF flour was positively correlated with gelatinization and gel stability, and negatively correlated with cooking loss. Moreover, the addition of OVA to GF flour improved the chewiness, hardness, elasticity and tensile properties of GF pasta based on texture profile analysis. Furthermore, 13 GF pasta with different additions of protein powder were studied based on principal component analysis to evaluate the comprehensive quality of GF pasta. The consistent results of GF pasta cooking characteristics and their ranking in comprehensive quality evaluation verified the reliability of this method. This study provides a reasonable instruction for quality improvement of GF pasta and a theoretical basis for the comprehensive quality evaluation of GF pasta, which could facilitate the development of foods with high cooking characteristics and nutrition suitable for patients with CD.

The interest in incorporating potatoes into wheat dough is increasing. However, potatoes exhibit significant viscosity during thermal processing, affecting product processing and quality. This study aims to find an effective method to reduce the viscosity of mashed potatoes. We aimed to compare the effects of different enzymes (α‐amylase, β‐amylase, and flavourzyme) and concentrations (0.01%, 0.05%, and 0.1%) on the micromorphology and rheological properties of mashed potatoes and potato–wheat dough. The impact of flavourzyme was the most significant (p<0.05). When enzyme concentration increased, viscosity decreased, and the degree of structural damage, indicated by increased porosity. Notably, the addition of flavourzyme can increase the content of sweet and umami free amino acids, improving the flavor of mashed potatoes. The scanning electron microscopy and confocal laser scanning microscopy images of potato–wheat dough revealed that enzyme‐hydrolyzed mashed potatoes had improved homogeneity, reestablished the dough continuity, and strengthened the three‐dimensional structure comprising proteins and starch. Notably, flavourzyme demonstrated the most significant effect on enhancing the protein–starch network structure. This was attributed to the exposure of functional groups resulting from protein hydrolysis, facilitating interaction with starch molecules. Our findings indicate that the addition of 0.1% flavourzyme (500 LAPU/g, pH 5.5, 55 ± 2°C, 30 min treated) was the most effective in reducing viscosity and reconstructing the gluten network. Enzymatic hydrolysis plays a vital role in the production of high‐quality potato products, with particular importance in the baking industry, where flavourzyme exhibits significant potential.Practical ApplicationEnzymatic hydrolysis plays a vital role in the production of high‐quality potato products, with particular importance in the baking industry, where flavourzyme exhibits significant potential.

In this study, the physicochemical properties of potato starch from different varieties were investigated. Furthermore, the relationships among gelatinization, retrogradation behavior, and impedance characteristics of potato starch gels were evaluated by texture analysis, low-field nuclear magnetic resonance spectroscopy, and electrical impedance spectroscopy. The results indicated amylose content was positively correlated with setback viscosity, and negatively correlated with To and ΔH. In addition, impedance values of potato starch gels differed in a frequency-dependent manner. Notably, higher frequencies resulted in low diffusion of ions in prepared gels, which combined with the concentration of mobile ions in free water, led to a gradual decrease in impedance module. Compared with phase values, impedance module showed high correlation with gelatinization parameters (To, Tp, and Tc) and viscosity parameters (peak temperature and setback viscosity), more notably at frequencies below 100 Hz. In this context, the electric current flowed through mobile ions that interacted with bound water attached to the starch molecules at lower voltage frequencies, and were repressed by the formation of an ordered and compact gel network during retrogradation. Collectively, these results indicate that impedance spectroscopy can be potentially used as an efficient and reliable method to predict gelatinization and retrogradation behavior of potato starch.

In this study, we aimed to use electrical impedance spectroscopy (EIS) to assess the freeze-damage level of starches from potato tubers treated with multiple freezing-thawing (FT) cycles. The results showed that the relationship between the physicochemical properties of starches and the impedance characteristics of starch paste is temperature-dependent. As the temperature rises to 70-90 °C, the impedance modules show a significant correlation with the amylose and mineral contents, gelatinization and pasting properties, short-range ordered structure, relative crystallinity, and damage level within the range of 10-1 MHz (p < 0.01). This could be because FT leads to a reduction in amylose and ion content. Compared to a high level of freeze-damaged starch (FDS), a low level of FDS has less amylopectin and more amylose. Additionally, the ions could be typically evenly distributed throughout the unbranched linear amylose structure in starch paste. At the peak gelatinization temperature, the starch paste made from a low level of FDS exhibits a weakened network structure, allowing more unbound water for ion movement and enhancing electric conduction. In conclusion, EIS can predict the damage level and properties of FDS, which can benefit the frozen starchy food industry.

In order to reveal the flavor characteristics of Chinese pancakes, the aroma and taste compounds of seven traditional Chinese pancakes were identified. The results showed that electronic nose (E-nose) analysis with PCA could successfully distinguish the aroma profiles of seven Chinese pancakes; the principal components PC1 and PC2 represented 75.74% and 23.2% of the total variance (98.94%) respectively. Meanwhile, the discrimination index of taste profiles of seven Chinese pancakes based on electronic tongue (E-tongue) analysis with LDA was 99.32%; the discriminant factors DF1 and DF2 represented 94.99% and 4.33% of the total variance respectively. Furthermore, GC-MS results demonstrated that thirty-three flavor compounds were identified in seven Chinese pancakes, including aldehydes, alcohols, alkanes, acids, and aromatics. Among the flavor components, aldehydes with ROAVs higher than 1 contributed most significantly to the overall aroma, such as (E,E)-2,4-nonadienal present the largest contribution in Qingzhou pancake, Jinan and Yishui pancake; hexanal present the largest contribution in Shenxian and Gaomi pancake; nonanal and benzeneacetaldehyde present the largest contribution in Linqu and Tai'an pancake, respectively. The umami and sweet taste amino acids were the most abundant in all the Chinese pancake samples, and Qingzhou pancake had relatively high amino acid content. The content of glucose was higher than maltose in Gaomi, Shenxian, and Tai'an pancakes, whereas the content of maltose was higher than glucose in Linqu, Qingzhou, Jinan, and Yishui pancakes. These results indicated that the aroma and taste profiles of Chinese pancakes differed significantly in terms of their flavor compound composition. The presented results could be beneficial for providing a comprehensive method for flavor profile identification of traditional whole-grain-based staples such as Chinese pancakes.

Type 2 diabetes mellitus (T2DM) is the most common type of diabetes globally and poses a major concern for human health. This study aimed to investigate the effects on T2DM of low-glycemic index (GI) potato biscuits with oat bran and inulin as functional additives. T2DM was induced in rats by streptozotocin (STZ) and a high-sugar and high-fat diet. The alleviation of T2DM by low-GI potato biscuits at different doses was evaluated based on the analysis of glycolipid levels, histological observations, inflammatory markers, and gut microbiota structure. Compared to wheat biscuits, low-GI potato biscuits resulted in lower postprandial blood glucose levels. After 8 weeks of intervention, fasting blood sugar levels were 16.9% lower in T2DM rats fed high-dose low-GI potato biscuits than in untreated T2DM rats. Moreover, the intervention with low-GI potato biscuits significantly alleviated T2DM-induced pathological damage, glucose and lipid metabolic disorders, and inflammation by reversing the levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, transforming growth factor-β, interleukin-1β, interleukin-6 and tumor necrosis factor-α. Moreover, the levels of short-chain fatty acids and gut microbiota structure in T2DM rats were significantly reversed. The abundance of beneficial bacteria (e.g., Bifidobacterium, Lachnoclostridium, Roseburia) in the gut of T2DM rats was significantly increased whereas the abundance of Escherichia-Shigella and Desulfovibrio decreased. The present study revealed that low-GI potato biscuits alleviated damages caused by high-sugar and high-fat diet- and STZ-induced T2DM in rats, as well as reversed disturbances in the gut microbiota. Thus, low-GI potato biscuits are potentially beneficial to T2DM patients.

The study aimed to investigate the effect of high intensity ultrasonic (HIU) treatment at different times (0, 10, 20, and 30 min) on the structure and gel properties of water-soluble potato protein isolate (WPPI) and to further investigate the improvement of gel properties of ultrasonicated WPPI (UWPPI) by the addition of egg white protein (EWP). HIU reduced the particle size of WPPI, whose structure became loose and disordered, which improved gelling properties of UWPPI. Fourier transform infrared results indicated that α-helix content decreased, whereas the proportion of irregular curl increased with the increase in ultrasonication time (0-20 min), indicating that the initially ordered structure of UWPPI became disordered. After HIU treatment, the free sulfhydryl groups of UWPPI and surface hydrophobicity decreased and fluorescence intensity increased. These results demonstrated that the HIU loosened the structure of UWPPI, exposing more chromogenic groups while embedding more hydrophilic groups. After thermal induction, UWPPI gel hardness increased and exhibited excellent water holding capacity. After the addition of EWP, rheological properties stabilized, and the hardness of UWPPI-EWP gels increased significantly, forming internally structured protein gels with a tightly ordered structure and increased brightness. Thus, HIU changed the structure and gelling properties of WPPI, and the addition of EWP further enhanced the performance of hybrid protein gels. PRACTICAL APPLICATION: High intensity ultrasonic changed the structure of water-soluble potato protein isolate (WPPI) and improved the properties of WPPI gels. The addition of egg white protein significantly improved the quality of mixed protein gels which showed great potential industrial value.

Low glycemic index (GI) food which is nutritious would be far more desirable for health. Oat bran and inulin have a wide range of food applications, as an additive to reduce the GI and increase dietary fiber content. This work aimed to formulate low GI and gluten-free biscuits by using potato flour, indica rice flour, oat bran, and inulin. Physical properties of biscuits such as in vitro digestibility, spread ratio, and sensory acceptance were determined. Extreme vertices design was applied to investigate the interactions among components. The presence of inulin decreased the water holding capacity (WHC) and pasting property of flour mixes, and increased the sensory acceptance and the darkness of biscuits. Oat bran increased WHC, pasting properties, spread ratio, and hardness compared to biscuit with potato flour and indica rice flour only. The incorporation of oat bran and inulin significantly ( p < 0.05) reduces the glycemic index of biscuits and enhances the taste, flavor, and overall acceptability. The incorporation of potato flour and oat bran ( p < 0.05) affected the L *, a *, b * and spread ratio significantly. When potato flour and indica rice flour at a ratio of 3:2 (PIRM):oat bran:inulin was 50%:28%:22%, the biscuit resulted in low GI value of 44.64. The incorporations of oat bran and inulin could represent a valuable strategy to enhance gluten-free bakery products’ physicochemical properties and sensory acceptability and reduce the in vitro glycemic response.

In this study, the addition of potato soluble dietary fiber (PSDF) in 0

The distribution of the flow field, the input energy of the twin-screw, and the dissipated energy on the fluid during the twin-screw extrusion process were calculated by the POLYFLOW software to establish the relationship between the rheological parameters of starch fluid and tensile properties of the final extrudate. The results demonstrated that the pressure difference, the input energy of the twin-screw, and the dissipated energy on the fluid were directly proportional to the zero-shear viscosity (eta(0)), reduced with the raise of the relaxation time constant (lambda) and raised with the raise of the power-law index (n). When the moisture content of starch fluid raised, the eta(0) value reduced, whereas the lambda value and n value increased. The pressure difference, the input energy of the twin-screw, and the dissipated energy on the fluid decreased, reducing the maximum tensile force of the final extrudate. Through numerical simulation and experimental verification, it was found that the changes of eta(0) value, lambda value, and n value restricted each other on the tensile properties of final extrudate. Based on the numerical simulation, the tensile properties of the final extrudate could be predicted through rheological parameters of starch fluid.

SummaryThe present study sought to investigate the rheological properties of wheat starch‐gluten (WS‐G) and potato starch‐gluten (PS‐G) model doughs with different gluten fractions to elucidate the effectiveness of using model dough to predict wheat dough properties. The highest linear viscoelastic region, frequency dependence, maximum creep compliance and the lowest viscoelastic modulus and zero shear viscosity were observed in the wheat dough, followed by WS‐G and PS‐G model doughs. PS exerted a more significant damage effect on the gluten network while WS shared a tight integration with gluten protein, forming a more stable dough structure. The viscoelasticity of the model doughs shared a close association with the wheat dough under increased gluten fraction, while the frequency dependence of the model doughs showed no trend towards wheat dough. Therefore, starch‐gluten model dough could not fully stimulate the functionality of wheat dough irrespective of its gluten fraction.

The denaturation and lower solubility of commercial potato proteins generally limited their industrial application. Effects of high-intensity ultrasound (HIU) (200, 400, and 600 W) and treatment time (10, 20, and 30 min) on the physicochemical and functional properties of insoluble potato protein isolates (ISPP) were investigated. The results revealed that HIU treatment induced the unfolding and breakdown of macmmolecular aggregates of ISPP, resulting in the exposure of hydrophobic and R-SH groups, and reduction of the particle size. These active groups contributed to the formation of a dense and uniform gel network of ISPP gel and insoluble potato proteins/egg white protein (ISPP/EWP) hybrid gel. Furthermore, the increase of solubility and surface hydrophobicity and the decrease of particle size improved the emulsifying property of ISPP. However, excessive HIU treatment reduced the emulsification and gelling properties of the ISPP. Meanwhile, HIU treatment changes the secondary structure of ISPP. It could be speculated that the formation of a stable secondary structure of ISPP initiated by cavitation and shearing effect might play a dominant role on gel strengthens and firmness. Meanwhile, the decrease in relative content of fl-turn had a positive effect on the formation of small particle to improve emulsifying property of ISPP.