New insights into how starch structure synergistically affects the starch digestibility, texture, and flavor quality of rice noodles

Effects of psyllium polysaccharide with different molecular weights on the digestibility, physicochemical properties of rice starch, and interaction forces between them

The effects of psyllium polysaccharides (PP) with different molecular weights (Mw) on the physicochemical characteristics, interaction forces, and digestibility of rice starch (RS) are methodically examined in this work. High-Mw PP (H-PP) (3.83 × 106 Da), medium-Mw PP (M-PP) (8.39 × 104 Da), and low-Mw PP (L-PP) (9.28 × 103 Da) were fractionated, characterized, and added to RS to clarify their effect on starch digestion. The results indicate that H-PP exhibited the most pronounced inhibitory effect on enzymatic hydrolysis, leading to a significant reduction in the estimated glycemic index (eGI) by enhancing the crystalline structure and short-range molecular order of RS. Mechanistic investigation revealed that PP molecules interact with RS through hydrogen bonding and electrostatic interactions, forming a structural barrier that impedes enzymatic accessibility. The intensity of these interactions was greatest in RS-H-PP and gradually decreased in RS-M-PP and RS-L-PP, corresponding with an increase in starch digestibility. These findings provide mechanistic insights into the molecular interactions regulating polysaccharide-starch systems and establish a theoretical basis for the development of functional starch-based foods with controlled glycemic responses.

Molecular mechanism underlying the modulation of typical properties of starch by Quillaja saponins: Multi-experimental evidence and two-stage MD simulation

Quillaja saponins (QS), a natural amphiphilic food additive, have significant potential in modulating the properties of starchy products. However, a systematic understanding of this phenomenon and the underlying molecular mechanisms remains lacking. In this study, two-stage molecular dynamics (MD) simulations combined with multiple experimental approaches were employed to investigate the modulation of starch properties by QS through six chain dynamic behaviors. The results revealed that the Bola-type structure of QS, characterized by its hydrophobic segment and hydrophilic ends, provides steric hindrance and additional hydrogen bonding sites, which disrupt the formation of interchain hydrogen bonds in starch. This interaction mode facilitated gelatinization (i.e., chain unwinding, pasting temperature: ↓4.1 °C), reduced paste viscosity (i.e., chain movement, ↓60.77 Pa.s), and retarded gelation (i.e., chain rearrangement and short-term reassociation, hardness: ↓5.50 gf) and retrogradation (i.e., long-term chain reassociation, hardening rate: ↓2.23 gf/d). Additionally, QS had minimal effects on starch digestibility (chain depolymerization). This study offers a novel strategy and theoretical basis for the property modulation of starch products.

Experimental characterization and dual-temperature molecular dynamics simulation on the intervention of tea saponin in starch chain dynamic behavior

In this work, the typical properties of starchy products were innovatively described as six types of chain dynamic behaviors. Dual-temperature molecular dynamic simulations, alongside multi-experimental methods, were employed to tandemly explore the intervention effect and mechanism of tea saponin (TS, 0 %-40 % w/w) on these behaviors. The findings reveal that the hydrophilic and hydrophobic ends of TS provide numerous sites for hydrogen bonding and steric hindrance, respectively, which hinder the formation of hydrogen bonds between starch chains. This interaction mode facilitated the chain unwinding (pasting temperature: 79.8 → 76.4 °C) and movement (viscosity: 267.67 → 38.92 Pa.s), and also retarded chain short/long-term reassociation (elastic modulus: 0.41 → 0.14 Pa/min; hardening rate: 2.72 → 0.07 gf/d) and rearrangement (hardness: 15.50 → 10.00 gf). Notably, a critical TS content was observed between 10 % and 20 % w/w, beyond which textural collapse (hardness: 15.50 → 10.00 gf) occurred. This research offers a new strategy and relevant theoretical backing for the property regulation of starch products.

Understanding the dual impact of oat protein on the structure and digestion of oat starch at pre- and post-retrogradation stages

Although extensive research has been conducted on the effects of protein-starch interaction on the gelatinization and microstructure of starch gels, the starch retrogradation process and protein component has been overlooked. Moreover, the dual regulatory effects of oat protein on starch gel microstructure and starch digestibility pre-and post-retrogradation still remains largely unexplored. In this study, the gelation behaviors, structure, and digestibility of oat protein-oat starch mixtures pre- and post-retrogradation were determined. The oat protein-starch samples exhibited lower setback values (314 cP) and higher relaxation peak time T23 (363.62 ms) compared to the oat starch samples (1994 cP and 160.51 ms), indicating that oat protein effectively delayed the short-term retrogradation and weakened the water-binding capacity of starch gel. Morphological and rheological analyses revealed that prior to retrogradation, oat protein promoted the formation of a looser network structure with weak shear resistance and consistency, while, after 7 d of retrogradation, an appropriate protein content (<30 %) facilitated the formation of an orderly and uniform honeycomb porous gel structure. Furthermore, oat protein increased the resistant starch content (RS) from 18.16 % to 32.66 % before retrogradation. After retrogradation, oat protein slowed down the increase in RS content by inhibiting the formation of starch crystal structure. Noteworthy, different oat protein components play various roles in starch gelatinization and retrogradation process.

Intervention mechanism of amphiphilic natural sweeteners on starch chain dynamic behavior: Computational and experimental insights

Amphiphilic natural sweeteners (i.e. steviol glycosides (STE) and glycyrrhizic acid (GA)) have been adopted to improve the quality of various starchy products, which can fundamentally be characterized as the intervention of the former in the chain dynamic behavior of the latter. However, these phenomena and related mechanisms still lack systematic insights. Herein, dual-temperature molecular dynamic simulations combined with experimental analysis were used to tandemly investigate the intervention of sweeteners in six types of chain dynamic behaviors that are strongly correlated with starch properties, including unwinding, movement, long/short-term reassociation, rearrangement, and depolymerization. The results show that STE and GA both promoted the chain unwinding and movement, and also retarded the chain short/long-term reassociation and rearrangement. Besides, GA exhibited a greater role than STE in facilitating chain unwinding and movement. Peculiarly, GA (0 %-40 % w/w) collaborated with starch to form a new microstructure, especially at high content (≥ 20 % w/w), which endowed starch with exceptionally high hardness (15.50 gf→189.36 gf) and hardening rate (2.72 gf/d→17.76 gf/d), and also placed a physical barrier to retard starch depolymerization (slowly digestible starch: 11.26 %→20.62 %). This work contributes data and theoretical support for the development of starch/amphiphilic natural sweetener composite matrices.

Effects of Substituting Wheat with Waxy Barley Bran Flour on Physical Properties, Health Functionality, and Sensory Characteristics of Noodles

When waxy barley (WB) is milled, 40% of the weight is typically discarded as bran. To utilize WB bran resources and improve health functionality, flours prepared from inner bran (IB) and outer bran (OB) layers were used to substitute partially wheat all-purpose flour (APF) for noodle preparation. The dough and noodle qualities were investigated based on analytical tests and sensory evaluations. Both methods revealed considerable darkening of the doughs and noodles upon OB substitution. Boiled noodles with 30% and 50% IB substitution had considerably lower total energy and breaking stress, whereas those with OB substitution had higher breaking stress at all substitution rates. Texture differences between sample groups were observed using analytical tests, but not via sensory evaluation. In addition, the boiled noodles with 50% OB demonstrated considerably lower taste preference in the sensory evaluation than the APF noodles. The comprehensive evaluation score was considerably lower for the boiled noodles with 30% or 50% OB than that of the APF noodles. The β-glucan and antioxidant contents increased with the IB or OB substitution rates. These findings show that APF can be substituted with IB at a substitution rate of 50%, while the substitution of OBF is limited to ≤10%.

Action of microbial transglutaminase (MTGase) on the processing properties of glutinous rice flour and the quality attributes of sweet dumplings and in vitro digestion

The development and manufacture of high-quality starch are a new research focus in food science. Here, transglutaminase was used in the wet processing of glutinous rice flour to prepare customized sweet dumplings. Transglutaminase (0.2 %) lowered protein loss in wet processing and reduced the crystallinity and viscosity of glutinous rice flour. Moreover, it lowered the cracking and cooking loss of sweet dumplings after freeze-thaw cycles, and produced sweet dumplings with reduced hardness and viscosity, making them more suitable for people with swallowing difficulties. Additionally, in sweet dumplings with 0.2 % transglutaminase, the encapsulation of starch granules by the protein slowed down the digestion and reduced the final hydrolysis rate, which are beneficial for people with weight and glycemic control issues. In conclusion, this study contributes to the production of tasty, customized sweet dumplings.

Suitability of early indica rice for the preparation of rice noodles by its starch properties analysis

The research was conducted to explore the affiliation between the physicochemical properties of rice noodles and rice starch of early indica rice samples of varying amylose content. 3 various types of rice samples were analyzed to uncover how amylose content influences rice noodles' quality. Findings revealed that primarily sensory scores differ in palatability, while textural disparity lies in hardness and chewiness. The higher hardness and chewiness values were correlated with higher sensory scores. Rice with lower amylose content demonstrates elevated solubility, swelling power, and crystallinity along with poor retrogradation resulting in inferior-quality noodles. Sensory scores and textural properties were proved to be associated with the distribution of branched starch molecule chain lengths. Noodles of higher sensory scores had more stable gel structure and improved elasticity. These findings underscore the critical role of amylose content and starch molecular structure in determining the suitability of early indica rice for noodle preparation.

Recent advances in germinated cereal and pseudo-cereal starch: Properties and challenges in its modulation on quality of starchy foods

Germination is an environmentally friendly process with no use of additives, during which only water spraying is done to activate endogenous enzymes for modification. Furthermore, it could induce bioactive phenolics accumulation. Controlling endogenous enzymes' activity is essential to alleviate granular disruption, crystallinity loss, double helices' dissociation, and molecular degradation of cereal and pseudo-cereal starch. Post-treatments (e.g. thermal and high-pressure technology) make it possible for damaged starch to reassemble towards well-packed structure. These contribute to alleviated loss of solubility and pasting viscosity, improved swelling power, or enhanced resistant starch formation. Cereal or pseudo-cereal flour (except that with robust structure) modified by early germination is more applicable to produce products with desirable texture and taste. Besides shortening duration, germination under abiotic stress is promising to mitigate starch damage for better utilization in staple foods.

Lycium barbarum pulp addition improves the dough properties and gluten protein structure

This study investigated the effects of Lycium barbarum pulp (LBP) on the properties of mixed dough and gluten protein. The results showed that appropriate addition of LBP (5 %) significantly improved the performance of the dough, promoted the aggregation of gluten protein, enhanced the water binding ability, and delayed the gelatinization of starch during cooking. Compared with the control group, the peak temperature (Tp) of the LBP sample gradually increased from 63.23 °C to 65.56 °C, the expansion force reduced by about 21.56 %, the absolute Zeta potential lowered by about 18.4 %, and the α -helix content and β -folding increased by 32.36 % and 10.23 %, respectively, indicating the more orderly and stable overall structure. However, LBP did not change the crystal configuration of starch and still showed typical type A line diffraction. Moreover, the addition of LBP increased the polyphenol content, which further improved the antioxidant properties and provided the possibility to improve the health potential of the flour.

Effects of debranched starch on physicochemical properties and in vitro digestibility of flat rice noodles

Aiming to develop flat rice noodles with both desirable textural quality and lower starch digestibility, we investigated the effect of adding indica rice debranched starch (RDBS) on the quality of flat rice noodles. In this study, adding RDBS to flat rice noodles enhanced their mechanical properties. Cooking characteristic analysis showed that incorporating RDBS into dried flat rice noodles increased the rehydration ratio by 16.1 % and reduced rehydration time by 26.5 %. Scanning electron microscopy (SEM) revealed the presence of microparticles formed through the self-assembly of RDBS within the network of flat rice noodles. X-ray diffraction (XRD) analysis demonstrated that the addition of RDBS elevated the crystallinity of the flat rice noodles, rising from 9.59 % to 22.57 %. In addition, the in vitro simulated digestion test suggested the addition of RDBS led to a threefold increase in the content of slowly digestible starch (SDS) and a ninefold increase in resistant starch (RS) content in flat rice noodles. This study found that adding RDBS into flat rice noodles can effectively reduce their digestion rate and improve their eating quality. It could be a promising approach for creating functional rice noodles aimed at alleviating public health concerns such as diabetes and obesity.

Influences of Weizmannia coagulans PR06 Fermentation on Texture, Cooking Quality and Starch Digestibility of Oolong Tea-Fortified Rice Noodles

Weizmannia coagulans is increasingly employed in food processing owing to its health benefits. Our previous research developed Oolong tea-fortified rice noodles with unique flavor and potent antioxidant activity; however, their texture still requires improvement. In this study, Oolong tea-fortified rice noodles were fermented using W. coagulans PR06 at inoculation amounts of 1%, 3%, and 5% (v/v), and assessed for cooking quality, texture, and starch digestibility. The results indicated that fermentation with 3% and 5% W. coagulans PR06 altered the amylopectin length distribution in the rice noodles and increased the degree of starch short-range order. Furthermore, the fermentation process increased the storage modulus (G') and loss modulus (G″) values, decreased the tan δ value, and strengthened the interactions among tea polyphenols, proteins, and starch in the rice flour gel. Consequently, this process increased the hardness and chewiness of the rice noodles, decreased their broken strip rate and cooking loss, and significantly reduced their in vitro starch digestibility. Overall, fermentation with W. coagulans PR06 markedly improved the texture and cooking quality of Oolong tea-fortified rice noodles while effectively delaying starch digestion. This study highlights the potential application of W. coagulans PR06 in developing diverse and functional rice noodle products.

Impacts of transglutaminase on the processing and digestion characteristics of glutinous rice flour: Insight of the interactions between enzymic crossing-linked protein and starch

Glutinous rice is extensively consumed due to its nutritious content and wonderful flavor. However, glutinous rice flour has a high glycemic index, and the storage deterioration of sweet dumplingsissevere. Transglutaminase (TG) was used to cross-link glutinous rice protein and improve the characteristics of glutinous rice products. The findings demonstrated that TG significantly catalysed protein cross-linking to form a dense protein network, reduced the viscosity of glutinous rice paste and improved the thermal stability. The protein network may physically block the access of starch granules to digestive enzymes to lower the digestion rate of starch, and attenuate the damage of ice crystal molecules to the starch structure to improve the freezing stability of starch gels. The cracking rate and water loss of sweet dumplings prepared using glutinous rice flour with TG treated for 60 min reduced significantly. In conclusion, this study broadened the application of TG in starch products.

Macromolecular, thermal, and nonthermal technologies for reduction of glycemic index in food-A review

Consumers rely on product labels to make healthy choices, especially with regard to the glycemic index (GI) and glycemic load (GL), which identify foods that stabilize blood sugar. Employing both thermal and nonthermal processing techniques can potentially reduce the GI, contributing to improved blood sugar regulation and overall metabolic health. This study concentrates on the most current advances in GI-reduction food processing technologies. Food structure combines fiber, healthy fats, and proteins to slow digestion, reducing GI. The influence of thermal approaches on the physical and chemical modification of starch led to decreased GI. The duration of heating and the availability of moisture also determine the degree of hydrolysis of starch and the glycemic effects on food. At a lower temperature, the parboiling revealed less gelatinization and increased moisture. The internal temperature of the product is raised during thermal and nonthermal treatment, speeds up retrogradation, and reduces the rate of starch breakdown.

Review of formation mechanisms and quality regulation of chewiness in staple foods: Rice, noodles, potatoes and bread

Staple foods serve as vital nutrient sources for the human body, and chewiness is an essential aspect of food texture. Age, specific preferences, and diminished eating functions have broadened the chewiness requirements for staple foods. Therefore, comprehending the formation mechanism of chewiness in staple foods and exploring approaches to modulate it becomes imperative. This article reviewed the formation mechanisms and quality control methods for chewiness in several of the most common staple foods (rice, noodles, potatoes and bread). It initially summarized the chewiness formation mechanisms under three distinct thermal processing methods: water medium, oil medium, and air medium processing. Subsequently, proposed some effective approaches for regulating chewiness based on mechanistic changes. Optimizing raw material composition, controlling processing conditions, and adopting innovative processing techniques can be utilized. Nonetheless, the precise adjustment of staple foods' chewiness remains a challenge due to their diversity and technical study limitations. Hence, further in-depth exploration of chewiness across different staple foods is warranted.

Developing high resistant starch content rice noodles with superior quality: A method using modified rice flour and psyllium fiber

The effects of high-resistant starch (RS) content rice flour, psyllium husk powder (PHP), and psyllium powder (PP) on the edible quality and starch digestibility of rice noodles were investigated in this study. High-RS rice noodles showed lower digestibility but poor edible quality. With the addition of PHP and PP, high-RS rice noodles' cooking and texture quality were improved significantly, especially the breakage rates, cooking losses, and chewiness (P < 0.05). Compared to traditional white rice noodle's estimated glycemic index (eGI) of 86.69, the eGI values for 5PHP-RN and 5PHP-2PP-RN were significantly decreased to 66.74 and 65.77, achieving a medium GI status (P < 0.05). This resulted from the high amylose and lipid content in the modified rice flour and psyllium, leading to increase of starch crystallinity. Besides, based on the analysis of Pearson's correlation, it can be found that PHP rich in insoluble dietary fiber (IDF) could improve high-RS noodle cooking and texture quality better, while PP rich in soluble dietary fiber (SDF) can further reduce the RDS content and its starch digestibility. Therefore, utilizing modified rice flour with an appropriate addition of PHP and PP can be considered an effective strategy for producing superior-quality lower glycemic index rice noodles.

Evaluating How Different Drying Techniques Change the Structure and Physicochemical and Flavor Properties of Gastrodia elata

We evaluated the drying characteristics and structure, as well as the physicochemical and flavor properties, of G. elata treated by hot-air drying (HAD), vacuum drying (VD), freeze drying (FD), microwave drying (MD), and microwave vacuum drying (MVD). We found that MD and MVD showed the shortest drying times, while FD and MVD were able to better retain the active ingredients and color of the samples. However, the different drying methods did not change the internal structure of G. elata, and its main components did not fundamentally change. In addition, E-nose and HS-SPME-GC-MS effectively differentiated the volatile components, and 36 compounds were detected by HS-SPME-GC-MS. Of these samples, alcohols and aldehydes were the main substances identified. In particular, MVD samples possessed the most species of organic volatiles, but the FD method effectively eliminated pungent odors from the G. elata. Overall, MVD shows the most obvious advantages, improving drying rate while maintaining the original shape, color, and active components in G. elata. Ultimately, MVD is the preferred method to obtain high-quality dried G. elata, and our drying-method characterizations can be used to investigate similar structural and chemical changes to similar herbs in the future.

Structure, properties, and resistant starch content of modified rice flour prepared using dual hydrothermal treatment

In this study, modified rice flour with high resistant starch (RS) content was prepared by dual hydrothermal treatment, which combined the heat-moisture treatment with the pressure-heat treatment method. The effects of dual hydrothermal treatment on the structure and properties of modified rice flour and their relationship with RS content were further discussed. The results showed that the RS content of modified rice flour was higher than that of rice flour (RF), and dual hydrothermal treatment was more effective than single hydrothermal treatment. Adhesion and aggregation occurred between the particles of modified rice flour. Both crystallinity and short-range ordering were increased in modified rice flour compared to RF. Moreover, the modified rice flour of dual hydrothermal treatment had higher crystallinity and a more ordered short-range structure of starch, which improved RS content to a certain extent. Compared to single hydrothermal treatment, the modified rice flour of dual hydrothermal treatment had a lower viscoelasticity and a better thermal stability. Both RF and modified rice flour gels were composed mainly of free water, with minimal amounts of bound and immobile water. The study may provide a reference for the production and application of modified rice flour.

Utilization of heat-induced curdlan gel to improve the cooking qualities of thermally sterilized fresh rice noodles

Thermal sterilization is the most economical and efficient method to guarantee the shelf life of extruded fresh rice noodles, but it often leads to a high cooking breakage rate and poor elongation at break of the noodles. The aim of this study was to improve the edible quality of sterilized fresh rice noodles through the addition of low concentrations of curdlan (0.38 %-1.13 %), which can form a thermal-irreversible gel to resist high-temperature sterilization. Compared with the control group without curdlan, the cooking breakage rate of sterilized fresh rice noodles with 1.13 % curdlan decreased from 16.85 % to 5.22 %, the tensile strain increased from 91.15 % to 147.05 %, and the microstructure was more dense and uniform. The results showed that adding the proper amount of curdlan is an effective strategy to improve the quality of sterilized fresh rice noodles.

Acceleration mechanism of the rehydration process of dried rice noodles by the porous structure

Rehydration of dried rice noodles (DRNs) is a time-consuming process, which is dominated by the compactness of noodle structure. Therefore, DRNs with differentiated porous structures were prepared, and their effect on the rehydration process was investigated. Porous structure can shorten rehydration time by reducing the time needed for water to migrate into the noodle core, or the water amount required for rehydration. Magnetic resonance imaging showed that although larger pores facilitate absorbing more water, the time for water to migrate into the noodle center is longer than that of medium size pores, as water needs to fill the periphery large hole before inward migration. SAXS analysis demonstrated that the presence of flexible starch molecular chains reduce the water required to achieve the maximum tensile strain of samples, thus shortening the rehydration time. Understanding the acceleration mechanism of porous structure on rehydration contributes to designing improved process of instant noodle products.

Interaction between long noncoding RNA (lnc663) and microRNA (miR1128) regulates PDAT-like gene activity in bread wheat (Triticum aestivum L.)

Amylose, a starch subcomponent, can bind lipids within its helical groove and form an amylose-lipid complex, known as resistant starch type 5 (RS-5). RS contributes to lower glycaemic index of grain with health benefits. Unfortunately, genes involved in lipid biosynthesis in wheat grain remain elusive. Our study aims to characterize the lipid biosynthesis gene and its post-transcriptional regulation using the parent bread wheat variety 'C 306' and its EMS-induced mutant line 'TAC 75' varying in amylose content. Quantitative analyses of starch-bound lipids showed that 'TAC 75' has significantly higher lipid content in grains than 'C 306' variety. Furthermore, expression analyses revealed the higher expression of wheat phospholipid: diacylglycerol acyltransferase-like (PDAT-like) in the 'TAC 75' compared to the 'C 306'. Overexpression and ectopic expression of TaPDAT in yeast and tobacco leaf confirmed its ability to accumulate lipids in vivo. Enzyme activity assay showed that TaPDAT catalyzes the triacylglycerol synthesis by acylating 1,2-diacylglycerol. Interestingly, the long non-coding RNA, lnc663, was upregulated with the TaPDAT gene, while the miRNA, miR1128, downregulated in the 'TAC 75', indicating a regulatory relationship. The GFP reporter assay confirmed that the lnc663 acts as a positive regulator, and the miR1128 as a negative regulator of the TaPDAT gene, which controls lipid accumulation in wheat grain. Our findings outline TaPDAT-mediated biosynthesis of lipid accumulation and reveal the molecular mechanism of the lnc663 and miR1128 mediated regulation of the TaPDAT gene in wheat grain.

Effects of Incorporated Emulsifiers Into Noodles on V-amylose Formation, Digestibility, and Structural Characteristics

There is growing interest in developing low glycemic alternatives to starchy foods. In this study, two emulsifiers, namely sodium stearoyl lactylate and egg yolk, were incorporated into the formulation of noodles (EYN and SSLN), and their effects on V-amylose formation, digestibility and structural characteristics of the noodles were investigated. The emulsifiers facilitated V-amylose formation in the noodles, indicated by the complexing indices. The EYN and SSLN exhibited markedly high resistant starch contents compared to the control noodle. The logarithm of slope plot analysis showed that the EYN and SSLN had low first-phase rate constants compared to the control noodles, suggesting a barrier effect to digestive enzymes exerted by V-amylose. The SSLN and EYN displayed a mixture of B- and V-type patterns with higher crystallinities and two distinct spectral features of the bands at 2854 cm- 1 and 1746 cm- 1 compared to the control noodles. Polarized light micrographs of the SSLN and EYN exhibited vague contours of numerous irregularly shaped starch fragments with strong birefringence. These results suggest that forming V-amylose crystals in the SSLN and EYN was responsible for their increased resistance to digestion through reformulating emulsifiers in modifying their nutritional functionalities.

Changes Induced by Heat Moisture Treatment in Wheat Flour and Pasta Rheological, Physical and Starch Digestibility Properties

Wheat is one of the main crops that is cultivated and consumed in the world. Since durum wheat is less abundant and more expensive than other types, pasta producers can use common wheat by applying various techniques to achieve the desired quality. A heat moisture treatment was applied to common wheat flour, and the effects on dough rheology and texture, and pasta cooking quality, color, texture, and resistant starch content were evaluated. The results revealed that heat moisture treatment temperature and moisture content induced a proportional increase in visco-elastic moduli, dough firmness, pasta cooking solids loss, and luminosity, as they were higher compared to the control. The breaking force of uncooked pasta decreased when the flour moisture content increased, while the opposite trend was observed for resistant starch content. The highest resistant starch values were obtained for the samples treated at the lowest temperature (60 °C). Significant correlations (p < 0.05) were obtained between some of the textural and physical characteristics analyzed. The studied samples can be grouped in three clusters characterized by different properties. Heat moisture treatment is a convenient physical modification of starch and flours that can be employed in the pasta industry. These results underline the opportunity to enhance common pasta processing and final product functionality by using a green and non-toxic technique to develop new functional products.

Factors influencing the starch digestibility of starchy foods: A review

Starchy foods are a major energy source of the human diet, their digestion is closely related to human health. Most foods require lots of processing before eating, therefore, many factors can influence starch digestibility. The factors that affect the digestibility of starches have been widely discussed previously, but the extracted starches in those studies were different from those present within the actual food matrix. This review summarizes the factors influencing the starch digestibility in starchy foods. Endogenous non-starch components hinder the starch digestive process. Food ingredients and additives decrease starch digestibility by inhibiting the activity of digestive enzymes or hindering the contact between starch and enzymes. Storage induce the retrogradation of starch, decreasing the digestibility of foods. Therefore, preparing starchy foods with whole grains, processing them as little as possible, using food additives reasonably, and storage conditions may all be beneficial measures for the production of low GI foods.

Potentially Health-Promoting Spaghetti-Type Pastas Based on Doubly Modified Corn Starch: Starch Oxidation via Wet Chemistry Followed by Organocatalytic Butyrylation Using Reactive Extrusion

Extruded spaghetti-type pasta systems were obtained separately either from native or oxidized starch prepared via wet chemistry with the aim of evaluating the effect of oxidation modification of starch. In addition to this, the butyrylation reaction (butyrate (Bu) esterification-short-chain fatty acid) using native or oxidized starch was analyzed under reactive extrusion (REx) conditions with and without the addition of a green food-grade organocatalyst (l(+)-tartaric acid) with the purpose of developing potentially health-promoting spaghetti-type pasta systems in terms of increasing its resistant starch (RS) values. These would be due to obtaining organocatalytic butyrylated starch or not, or the manufacture of a doubly modified starch (oxidized-butyrylated-starch oxidation followed by organocatalytic butyrylation) or not. To this end, six pasta systems were developed and characterized by solid-state ¹³C cross-polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR) spectroscopy, degree of substitution (DS), attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), pancreatic digestion, free Bu content analysis and in vitro starch digestibility. The results obtained here suggest that starch oxidation hydrolytically degrades starch chains, making them more susceptible to enzymatic degradation by α-amylase. However, the oxidized starch-based pasta systems, once esterified by Bu mainly on the amylose molecules (doubly modified pasta systems) increased their RS values, and this was more pronounced with the addition of the organocatalyst (maximum RS value = ~8%). Interestingly, despite the checked chemical changes that took place on the molecular structure of starch upon butyrylation or oxidation reactions in corn starch-based spaghetti-type pasta systems, and their incidence on starch digestibility, the orthorhombic crystalline structure (A-type starch) of starch remained unchanged.

Effects of HMW-GSs at Glu-B1 locus on starch-protein interaction and starch digestibility during thermomechanical processing of wheat dough

BACKGROUND

The composition of glutenin protein significantly affects protein-starch interactions and starch digestion characteristics in wheat dough matrices. To elucidate the effects of high molecular weight glutenin subunits at the Glu-B1 locus on dough processing quality, the detailed structural changes of protein, starch, and their complexes were compared in Mixolab dough samples of two near isogenic lines 7 + 8 and 7 + 9.

RESULTS

The results showed that the degree of protein aggregation increased continuously during dough processing, as did the destruction and rearrangement of the gluten network. Compared to 7 + 8, the stronger and more stable protein network formed in 7 + 9 dough induced intensive interactions between protein and starch, primarily through hydrogen bonds and isomeric glycosidic bonds. In 7 + 9 dough, the more compact and extensive protein-starch network significantly inhibited starch gelatinization during dough pasting, while during the dough cooling stage [from C4 (82.8 °C) to C5 (52.8 °C)], more protein-starch complexes composed of monomeric proteins and short-chain starch were generated, which remarkably inhibited starch retrogradation. All protein-starch interactions in the 7 + 9 dough improved the starch digestion resistance, as reflected by the high content of resistant starch.

CONCLUSION

The more extensive and intensive protein-starch interactions in the 7 + 9 dough inhibited the gelatinization and enzymatic hydrolysis of starch, thereby producing more slowly digestible starch and resistant starch. These findings demonstrate the feasibility of optimizing the texture and digestibility of wheat-based food products by regulating the behavior and interactions of proteins and starch during dough processing. © 2022 Society of Chemical Industry.

Starch-based noodles: Current technologies, properties, and challenges

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.

Flavor properties of Chinese noodles processed by dielectric drying

Volatile organic compounds (VOCs) significantly impact food flavor. In this work, Electron nose (E-nose), head space solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and head space-gas chromatography-ion mobility spectrometry (HS-GC-IMS) techniques were applied to analyze different drying effects: microwave, hot air, and radio frequency on the aroma of Chinese noodles. E-nose analysis suggests that aromatic differences are mainly from broad range-methane. HS-SPME-GC-MS and HS-GC-IMS identified 47 and 26 VOCs in the fresh and dried noodles, respectively. The VOCs in the dried noodles were mainly aldehydes, alcohols, and esters. Drying significantly reduced the types of VOCs in Chinese dried noodles. Microwave dried noodles exhibited the strongest aroma after the shortest time of treatment, suggesting microwave drying may be the best drying method for noodles. Using aromatic analysis, this paper provides useful information for understanding the flavor of flour products and offers new ideas for drying noodles.

Understanding the texture and digestibility attributes of rice noodles supplemented with common vetch starch

The effects of common vetch starch (CVS) substitution on rice noodle quality were investigated, aiming to improve their texture and reduce starch digestibility. The CVS had larger granule sizes, higher amylose content and more long branch chains compared with rice starch (RS). When the CVS substitution level was 20 %, the rice noodles had the best texture quality, as the mixtures with more total starch and amylose could form denser gel structures. Moreover, the starch chains were easier to rearrange to form double helix ordered structures, resulting in a slower digestion rate. With the further increase of CVS, the noodle structure weakened and the starch digestion rate increased. This was due to the formation of looser gel structures and less ordered structures as RS granules could be easily separated into different parts by large amount of CVS with larger granule sizes, and RS with more short chains tended to be cross-linked with RS during retrogradation. With increasing CVS substitution level, the estimated glycemic index (eGI) of rice noodles decreased and then tended to be stable. Therefore, appropriate CVS substitution could improve the texture quality of rice noodles and reduce the eGI value, and the best substitution level was 20 %.

Effect of static magnetic field treatment on the germination of brown rice: Changes in α-amylase activity and structural and functional properties in starch

The study aimed to explore the stimulating effect of static magnetic field (SMF) treatment on germinated brown rice (GBR) by monitoring changes in α-amylase activity and structural and functional properties of starch. Brown rice was exposed to SMF (10 mT, 60 min, 25 °C) and then germinated for 0 h -72 h at 30 °C. Compared with the control, SMF treatment improved α-amylase activity (15.2%), leading to the hydrolysis of starch into reducing sugar (8.2%) and increasing the germination rate (9.7% -158.8%), shoot length (9.1% -87.3%), root length (19.2% -110.0%), and fresh weight (0.9% -16.5%). In view of the properties of starch, SMF treatment also altered the surface microstructure, induced partial losses of birefringence, exerted no significant effect on the crystalline type, slightly increased the gelatinization temperatures, and significantly decreased the peak viscosity. This study suggested that SMF could serve as a prospective technique for GBR products processing.

Effects of water and gelatinized starch on the viscoelasticity of pizza dough and the texture of pizza crust

The soft texture of the pizza crust rim is generated by baking at a high temperature for a short period in a stone oven. In the case of baking in an electric oven, the pizza dough is baked at a much lower temperature and for a longer period, resulting in a harder texture. To improve the texture of electric oven-baked pizza crust, the effects of water and gelatinized starch on the viscoelasticity of pizza dough and the texture of pizza crust were investigated. Rheological properties (storage modulus, loss modulus, and yield stress) of pizza dough decreased with an increase in water content. When wheat flour in the dough was partially replaced with pre-gelatinized wheat starch, the rheological properties of the dough were maintained even at a high-water content. These results indicate that water-enriched dough can be prepared with gelatinized starch and baked using an electric oven. There was no significant difference in apparent density between the conventional and modified pizza crusts. Water content of the crumb part of the modified crust was significantly higher than that of the conventional crust. Texture analysis revealed that the modified pizza crust showed significantly lower stress at high strain than the conventional crust. In addition, sensory evaluation showed that the modified pizza crust exhibited greater firmness and stickiness than the conventional crust, which was attributed to the increased water content with gelatinized starch of the dough.