Ice cream cone fortified with spent coffee ground: Chemical composition, quality and sensory characteristics, and in vitro starch digestibility

The objective of the study was to evaluate the effect of the incorporation of spent coffee grounds in ice cream cones on the quality, sensory characteristics, and in vitro starch digestibility. The incorporation of spent coffee grounds in ice cream cones increased the content of dietary fiber and phenolic compounds. However, the quality and texture characteristics decreased with the addition of spent coffee grounds. The in vitro starch digestibility decreased significantly, resulting in a significant increase in resistant starch content. Fitting starch digestibility using the LOS-plot model revealed the presence of two sequential first-order digestion rates. Sensory analysis revealed that the panelists well accepted ice cream cones fortified with spent coffee grounds. The results suggest that spent coffee grounds are a potential ingredient for the formulation of food matrices with reduced starch digestibility, which contributes to the prevention of chronic degenerative diseases such as type II diabetes.

Structures, gelatinization properties and enzyme hydrolyses of starches from transparent and floury grains of rices subjected to field natural extreme high temperature

Three rice varieties underwent the field natural extreme high temperature (EHT) with daily average temperature over 30 °C from 21 to 89 days after sowing, and had transparent, chalky and floury grains. The structures, gelatinization properties and enzyme hydrolyses of starches from transparent and floury grains were investigated. Compared with control transparent grains, floury grains subjected to EHT markedly decreased the contents of amylose molecules, amylopectin A chains and amylopectin B1 chains and increased the contents of amylopectin B2 and B3+ chains and the average branch-chain length of amylopectin. Both transparent and floury grains had A-type starches, but floury grain starches exhibited higher relative crystallinity, gelatinization temperature, retrogradation and pasting viscosities than transparent grain starches. Floury grain starches had lower hydrolysis rates than transparent grain starches. Native starches were more resistant to digestion but gelatinized and retrograded starches were more prone to digestion in floury grains than in transparent grains.

Cutting-edge progress in green technologies for resistant starch type 3 and type 5 preparation: An updated review

Resistant starch (RS) is a dietary fiber that resists starch hydrolysis in the small intestine, and is fermented in the colon by microorganisms. RS not only has a broad range of benefits in the food and non-food industries but also has a significance impact on health promotion and prevention of non-communicable diseases. RS types 3 and 5 have been the focus of research from an environment-friendly perspective. RS3 is normally formed by recrystallization after physical modification, whereas RS5 is obtained by the complexation of starch and fatty acids through the thermomechanical methods. This review provides updates and approaches to RS3 and RS5 preparations that promote RS content based on green technologies. This information will be useful for future research on RS development and for identifying preparation methods for functional food.

Recent advances in the impact of gelatinization degree on starch: Structure, properties and applications

During home cooking or industrial food processing operations, starch granules usually undergo a process known as gelatinization. The starch gelatinization degree (DG) influences the structural organization and properties of starch, which in turn alters the physicochemical, organoleptic, and gastrointestinal properties of starchy foods. This review summarizes methods for measuring DG, as well as the impact of DG on the starch structure, properties, and applications. Enzymatic digestion, iodine colorimetry, and differential scanning calorimetry are the most common methods for evaluating the DG. As the DG increases, the structural organization of the molecules within starch granules is progressively disrupted, the particle size of the granules is altered due to swelling and then disruption, the crystallinity is decreased, the molecular weight is reduced, and the starch-lipid complexes are formed. The impact of DG on the starch structure and properties depends on the processing method, operating conditions, and starch source. The starch DG affects the quality of many foods, including baked goods, fried foods, alcoholic beverages, emulsified foods, and edible inks. Thus, a better understanding of the changes in starch structure and function caused by gelatinization could facilitate the development of foods with novel or improved properties.

Investigation of the effect of ultrasonication on starch-fatty acid complexes and the stabilization mechanism

The complexation of physically modified starch with fatty acids is favorable for the production of resistant starch. However, there is a lack of information on the effect of ultrasonication (UC) on the structure and properties of starch complexes and the molecular mechanism of the stabilization. Here, the multi-scale structure and in vitro digestive properties of starch-fatty acid complexes before and after UC were investigated, and the stabilization mechanisms of starch and fatty acids were explored. The results showed that the physicochemical properties and multi-scale structure of the starch-fatty acid complexes significantly changed with the type of fatty acids. The solubility and swelling power of the starch-fatty acid complexes were significantly decreased after UC (P < 0.05), which facilitated the binding of starch with fatty acids. The XRD results revealed that after the addition of fatty acids, the starch-fatty acid complexes showed typical V-shaped complexes. In addition, the starch-fatty acid complexes showed a significant increase in complexing index, improved short-range ordering and enhanced thermal stability. However, the differences in the structure and properties of the fatty acids themselves resulted in no significant improvement in the multi-scale structure of maize starch-palmitic acid by UC. In terms of digestibility, especially the complexes after UC were more compact in structure, which increased the difficulty of enzymatic digestion and thus slowed down the digestion process. DFT calculations and combined with FT-IR analysis showed that non-covalent interactions such as hydrogen bonding and hydrophobic interactions were the main driving force for the formation of the complexes, with binding energies (lauric acid, myristic acid and palmitic acid) of -30.50, -22.14 and -14.10 kcal/mol, respectively. Molecular dynamics simulations further confirmed the molecular mechanism of inclusion complex formation and stabilization. This study is important for the regulation of starchy foods by controlling processing conditions, and provides important information on the role of fatty acids in the regulation of starch complexes and the binding mechanism.

A mechanistic study of chestnut starch retrogradation and its effects on in vitro starch digestion

Starch retrogradation is a mechanism that is associated with the quality of starch-based food products. A thorough understanding of chestnut starch retrogradation behavior plays an important role in maintaining the quality of chestnut foods during processing and storage. In this study, we investigated the effects of storage time on the structural properties and in vitro digestibility of gelatinized chestnut starch by using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and solid-state 13C nuclear magnetic resonance (NMR). The results showed that the long-range crystallinity and short-range molecular order of retrograded chestnut starch first rapidly increased from 3 h to 3 d and then decreased from 3 d to 7 d, followed by a slight increase from 7 d to 14 d with retrogradation. With the extension of storage time at 4 °C, there were generally obvious increases in single and double helical structures, which were stacked into long-term ordered structure, resulting in increased enthalpy changes as detected by differential scanning calorimetry spectroscopy (DSC) and reduction of the digestion rate of retrograded chestnut starch. Overall, this study may provide important implications for manipulating and improving the quality of chestnut foods.

Effects of fatty acids and glycerides on the structure, cooking quality, and in vitro starch digestibility of extruded buckwheat noodles

This study aimed to explore the effects of various lipids on the structure, cooking quality, and in vitro starch digestibility of extruded buckwheat noodles (EBNs) with and without 20% high-amylose corn starch (HACS). Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction revealed that lauric acid bound more strongly to starch than did stearic acid and oleic acid, and the binding capacity of fatty acids with starch was stronger than that of glycerides. The presence of HACS during extrusion facilitated increased formation of starch-lipid complexes. Evaluations of cooking quality and digestion characteristics showed that EBNs containing 20% HACS and 0.5% glycerol monooleate demonstrated the lowest cooking loss (7.28%), and that with 20% HACS and 0.5% oleic acid displayed the lowest predicted glycemic index (pGI) (63.54) and highest resistant starch (RS) content (51.64%). However, excessive starch-lipid complexes were detrimental to EBNs cooking quality and the resistance of starch to digestive enzymes because of the damage to the continuity of the starch gel network. This study establishes a fundamental basis for the development of EBNs with superior cooking quality and a relatively lower GI.

Composite hydrogels assembled from food-grade biopolymers: Fabrication, properties, and applications

Biopolymer hydrogels have a broad range of applications as soft materials in a variety of commercial products, including foods, cosmetics, agrochemicals, personal care products, pharmaceuticals, and biomedical products. They consist of a network of entangled or crosslinked biopolymer molecules that traps relatively large quantities of water and provides semi-solid properties, like viscoelasticity or plasticity. Composite biopolymer hydrogels contain inclusions (fillers) to enhance their functional properties, including solid particles, liquid droplets, gas bubbles, nanofibers, or biological cells. These fillers vary in their composition, size, shape, rheology, and surface properties, which influences their impact on the rheological properties of the biopolymer hydrogels. In this article, the various types of biopolymers used to fabricate composite hydrogels are reviewed, with an emphasis on edible proteins and polysaccharides from sustainable sources, such as plants, algae, or microbial fermentation. The different kinds of gelling mechanism exhibited by these biopolymers are then discussed, including heat-, cold-, ion-, pH-, enzyme-, and pressure-set mechanisms. The different ways that biopolymer molecules can organize themselves in single and mixed biopolymer hydrogels are then highlighted, including polymeric, particulate, interpenetrating, phase-separated, and co-gelling systems. The impacts of incorporating fillers on the rheological properties of composite biopolymer hydrogels are then discussed, including mathematical models that have been developed to describe these effects. Finally, potential applications of composite biopolymer hydrogels are presented, including as delivery systems, packaging materials, artificial tissues, wound healing materials, meat analogs, filters, and adsorbents. The information provided in this article is intended to stimulate further research into the development and application of composite biopolymer hydrogels.

Preparation and characterization of carboxymethylated Anemarrhena asphodeloides polysaccharide and its effect on the gelatinization of wheat starch

In this study, a carboxymethylated Anemarrhena asphodeloides polysaccharide (CM-AARP) with an molecular weight (Mw) of 7.8 × 104 Da was obtained. CM-AARP was composed of four monosaccharides including d-mannose, d-glucose, d-galactose, and l-arabinose. Nuclear magnetic resonance (NMR) spectra revealed that the skeleton of CM-AARP was identical to that of AARP. Compared with AARP, CM-AARP had a superior inhibition effect on the gelatinization of wheat starch (WS) under the same condition. The addition of CM-AARP and AARP at 12 % enhanced the gelatinization temperature (60.47 ± 1.30 °C) of WS to 73.88 ± 0.49 °C and 69.75 ± 0.52 °C, respectively. CM-AARP could maintain the crystal structure of WS during gelatinization, the relative crystallinity with the 12 % CM-AARP addition was determined as 29.18 % ± 1.49 %, exceeding that of pure WS at 21.96 % ± 0.66 %. Moreover, CM-AARP influenced the rheological behavior of the gelatinized WS by reducing the viscosity and improving the fluidity. The results suggested that CM-AARP played an essential role in starch gelatinization and was a potential stabilizer in the starch-based food industry.

The importance of starch chain-length distribution for in vitro digestion of ungelatinized and retrograded foxtail millet starch

The digestibility of ungelatinized, short-term retrograded and long-term retrograded starch from foxtail millet was investigated and correlated with starch chain length distributions (CLDs). Some variations in starch CLDs of different varieties were obtained. Huangjingu and Zhonggu 9 had higher average chain lengths of debranched starch and lower average chain length ratios of amylopectin and amylose than Dajinmiao and Jigu 168. Compared to ungelatinized starch, retrogradation significantly increased the estimated glycemic index (eGI), whereas significantly decreased the resistant starch (RS). In contrast, long-term retrograded starches have lower eGI (93.33-97.37) and higher RS (8.04-14.55%) than short-term retrograded starch. PCA and correlation analysis showed that amylopectin with higher amounts of long chains and longer long chains contributed to reduced digestibility in ungelatinized starch. Both amylose and amylopectin CLDs were important for the digestibility of retrograded starch. This study helps a better understanding of the interaction of starch CLDs and digestibility during retrogradation.

Strategic exploration of whole grain cereals in modulating the glycaemic response

In the current context, diabetes presents itself as a widespread and complex global health issue. This study explores the significant influence of food microstructure and food matrix components interaction (protein, lipid, polyphenols, etc.) on the starch digestibility and the glycaemic response of post-prandial glycemia, focusing on the potential effectiveness of incorporating bioactive components from whole grain cereals into dietary strategies for the management and potential prevention of diabetes. This study aims to integrate the regulation of postprandial glycaemic homeostasis, including the complexities of starch digestion, the significant potential of bioactive whole grain components and the impact of food processing, to develop a comprehensive framework that combines these elements into a strategic approach to diabetes nutrition. The convergence of these nutritional strategies is analyzed in the context of various prevalent dietary patterns, with the objective of creating an accessible approach to mitigate and prevent diabetes. The objective remains to coalesce these nutritional paradigms into a coherent strategy that not only addresses the current public health crisis but also threads a preventative approach to mitigate future prevalence and impact.

Insight to starch retrogradation through fine structure models: A review

The retrogradation of starch is crucial for the texture and nutritional value of starchy foods products. There is mounting evidence highlighting the significant impact of starch's fine structures on starch retrogradation. Because of the complexity of starch fine structure, it is a formidable challenge to study the structure-property relationship of starch retrogradation. Several models have been proposed over the years to facilitate understanding of starch structure. In this review, from the perspective of starch models, the intricate structure-property relationship is sorted into the correlation between different types of structural parameters and starch retrogradation performance. Amylopectin B chains with DP 24-36 and DP ≥36 exhibit a higher tendency to form ordered crystalline structures, which promotes starch retrogradation. The chains with DP 6-12 mainly inhibit starch retrogradation. Based on the building block backbone model, a longer inter-block chain length (IB-CL) enhances the realignment and reordering of starch. The mathematical parameterization model reveals a positive correlation between amylopectin medium chains, amylose short chains, and amylose long chains with starch retrogradation. The review is structured according to starch models; this contributes to a clear and comprehensive elucidation of the structure-property relationship, thereby providing valuable references for the selection and utilization of starch.

Effects of soluble dietary fiber from pomegranate peel on the physicochemical properties and in-vitro digestibility of sweet potato starch

The effects of soluble dietary fiber (SDF) from pomegranate peel obtained through enzyme (E-SDF) and alkali (A-SDF) extractions on the structural, physicochemical properties, and in vitro digestibility of sweet potato starch (SPS) were investigated. The expansion degree of SPS granules, pasting viscosity, gel strength and hardness were decreased after adding E-SDF. The setback was accelerated in the presence of A-SDF but E-SDF delayed this effect during the cooling of the starch paste. However, the addition of A-SDF significantly reduced the breakdown of SPS and improved the freeze-thaw stability of starch gels, even at low concentrations (0.1 %), while E-SDF showed the opposite result. The structural characterization of SDF-SPS mixtures showed that A-SDF can help SPS form an enhanced microstructure compared with E-SDF, while polar groups such as hydroxyl group in E-SDF may bind to leached amylose through hydrogen bonding, leading to a decrease in SPS viscoelasticity. In addition, the results of in vitro digestion analysis indicated that A-SDF and E-SDF could decreased the digestibility of SPS and increased the content of resistant starch, especially when 0.5 % E-SDF was added. This study provides a new perspective on the application of SDF from pomegranate peel in improving starch-based foods processing and nutritional characteristics.

Effect of water content on gelatinization functionality of flour from sprouted sorghum

Sorghum starch granules are encapsulated in a rigid protein matrix that prevents the granules from fully swelling and gelatinizing. Sprouting and subsequent drying treatment can affect the gelatinization properties of sorghum starch. This study aimed to evaluate the gelatinization properties of flours from unsprouted (US) and sprouted (S50, S40) sorghum dried at 50 °C (6h) and 40 °C (12h), respectively. Swelling power (Sp), thermal properties (DSC) and 1H molecular mobility and dynamics were evaluated at different water contents (38-91%). Sp increased with increasing water content, with S40 showing the lowest values, probably due to prolonged amylase activity and thus starch breakdown. Sprouting increased gelatinization temperatures; however, these differences disappeared for high water contents (82 and 91%). From a molecular point of view, sprouted samples showed a decrease in protons associated to the rigid protein matrix and starch structures. 1H CPMG results showed the presence of 4 populations at 38% water content. The evolution of the more mobile population with increasing water content supported the assignment of more mobile water fraction to this population. Sprouting decreased the mobility of populations in unheated samples, suggesting an increase in molecular bonds between flour biopolymers and water. After heating, however, increased molecular mobility in S40 indicated the formation of a weaker network between starch, protein, and water at the molecular level. These results suggest that post-sprouting drying treatment influences sorghum gelatinization, with potential modulation by water content. This study contributes to understanding the application of sprouted sorghum in foods with different moisture content.

Heat-moisture and acid treatments can increase levels of resistant starch in arrowroot starch without adversely affecting its prebiotic activity in human colon microbiota

Carbohydrates are an important macronutrient whose processing and digestive fate can have numerous beneficial or adverse effects on consumer health. This study investigated the impact of heat-moisture treatments (HMT) and citric acid treatments (CAT) on arrowroot starch (ARS) with a focus on its physicochemical properties, digestibility, and influence on gut microbiota. The results revealed that HMT and CAT did not alter the colloidal characteristics of ARS but significantly affected the balance between amorphous and crystalline regions. Changes in thermal properties, morphology, and particle size were also observed. These can influence ARS shelf life and functional properties in various food applications. Furthermore, certain treatments in both processing methods increased the resistant starch (RS) content of ARS, with HMT for 16 hours at 80 °C and CAT with 0.6 M citric acid, resulting in the most pronounced effects. These changes coincided with reductions in rapidly digestible starch (RDS) levels and improvements in the ratio of slowly digestible starch (SDS) to RDS, which could potentially improve glycemic control. This study also examined the impact of processed ARS on colonic microbiota composition. It found that ARS-derived RS formed under HMT and CAT did not negatively affect the prebiotic potential of the RS fraction. Both treatments were associated with lowering the Firmicutes to Bacteroidetes ratio (F/B), a marker of gut health, and decreasing the relative abundance of Proteobacteria, microbes associated with adverse health effects. Additionally, CAT-derived RS showed a significant increase in the relative abundance of Roseburia, a beneficial gut bacterium. In conclusion, processing ARS through HMT and CAT techniques has the potential for enhancing its RS content, improving its glycemic impact, and positively influencing the gut microbiota composition, potentially contributing to gut health and metabolic well-being.

Effect of dielectric barrier discharge (DBD) plasma treatment on physicochemical and 3D printing properties of wheat starch

In recent years, the focus has shifted towards carbohydrate-based hydrogels and their eco-friendly preparation methods. This study involved an investigation into the treatment of wheat starch using dielectric barrier discharge (DBD) plasma technology over varying time gradients (0, 2, 5, 10, 15, and 20 min). The objective was to systematically examine the impact of different treatment durations on the physicochemical properties of wheat starch and the suitability of its gels for 3D printing. Morphology of wheat starch remained intact after DBD treatment. However, it led to a reduction in the amylose content, molecular weight, and crystallinity. This subsequently resulted in a decrease in the pasting temperature and viscosity. Moreover, the gels of the DBD-treated starch exhibited superior 3D printing performance. After a 2-min DBD treatment, the 3D printed samples of the wheat starch gel showed no significant improvements, as broken bars were evident on the surface of the 3D printed graphic, whereas DBD-20 showed better printing accuracy and surface structure, compared to the original starch without slumping. These results suggested that DBD technology holds potential for developing new starch-based gels with impressive 3D printing properties.

Effects of food processing on in vitro glucose release of high methylester pectin-enriched doughs

The incidence of type 2 diabetes is linked to consuming processed, high-glycemic foods low in dietary fiber. Soluble dietary fibers are known to improve blood glucose tolerance. This study examined the impact of processing on the in vitro glucose release of fiber-rich, high-glycemic foods. The impact of composition and microstructure on in vitro glucose release and starch digestibility was evaluated in doughs - untreated, baked at 180 °C, and extruded at 150 °C and 180 °C - with partial enrichment of high-methylester pectin. Pectin enrichment decreased starch digestibility, altered the food matrix, and doubled in vitro chyme-viscosity resulting in reduced glucose release in baked (180 °C), and extruded (150 °C) products. Baking or extrusion cooking increased starch digestibility - converting slowly into rapidly available starch and free glucose. Additionally, resistant starch levels were enhanced by up to fivefold. The variations in glucose release originated from a complex interplay between starch digestibility, viscosity, and the food matrix.

Probing structural features in potato starch granules at moderate hydration through the modelling of 1H->13C polarization transfer kinetics

The structural arrangement of starch polymers in presence of water is known to impact the functional properties of starchy products. In this study, the hydration of potato starch granules was investigated at the molecular level through various 1H->13C polarization transfer solid-state Nuclear Magnetic Resonance (ss-NMR) experiments. The impact of increasing the water content from 12.3 % to 45.9 % was assessed using 13C Cross Polarization Magic Angle Spinning (CPMAS), Variable Contact Time (VCT-CPMAS), Variable Spin Lock (VSL-CPMAS), and T One Rho QUEnching (TORQUE) NMR sequences. Of these, VCT-CPMAS proved to be the most promising. When applied with an optimal number of contact times, it enabled the application of several mathematical models that provided detailed insights into the structuring of protons in the hydrated potato starch granules. At low hydration (12.3 %), the models enabled various structural domains to be distinguished, which we suggest are associated with helical and amorphous structures. At moderate hydration (45.9 %), we tested two fitting models. Two pools of protons were revealed, corresponding to loosely ordered structures on the scale of tens of nanometers. These findings suggest varying water distribution during starch hydration and are likely to indicate variable hydration levels in the multilamellar amorphous structures of starch granules.

Study on the gelatinization and digestive characteristics of wheat starch and potato starch under low moisture conditions

This study explored the gelatinization and digestive characteristics of wheat and potato starches under low moisture conditions using identical processing parameters. The results revealed that potato starch exhibited greater resistance to digestion than wheat starch, with an enzyme hydrolysis rate 18 % to 30 % lower than wheat starch under the same conditions. The analysis of particle size, swelling power, and low-field NMR demonstrated that potato starch required almost 40 % more moisture for full gelatinization than wheat starch, indicating that low-moisture conditions could not meet the significant water demand of potato starch. Additionally, the DSC analysis showed that potato starch had superior thermal stability, with To of 62.13 °C and ΔH of 16.30 (J/g). Subsequently, the microscopy results showed that the partially gelatinized wheat starch had a rough, porous surface, allowing enzymes for direct access to hydrolysis. In contrast, the potato starch had smoother and less damaged particles without visible pores, enzymes had to degrade it progressively, layer by layer. Furthermore, potato starch still exhibited a lower enzyme hydrolysis rate than wheat starch under the same gelatinization levels. Overall, potato starch is more resistant to hydrolysis and gelatinization in low-moisture environments, making potato starch suitable for low-digestibility products like potato biscuits or chips.

Influence of contrasting cultivation altitudes on the physicochemical, digestive, and functional properties of four Musa starches produced in Cameroon

BACKGROUND

Bananas and plantains are important food sources for many people in the world. Their high starch content places them among the highest energy providers. This study aimed to determine the effects of altitude on banana starch properties in Cameroon. A dessert banana, a cooking banana, a plantain cultivar, and a plantain-like hybrid were grown at low and high altitudes (respectively at 80 m and 1300 m above sea level).

RESULTS

Starch analyses showed an increase in moisture and pH values against a drop in total titratable acidity and dry matter content with respect to altitude. Amylose content, as well as water absorption capacity, oil absorption capacity and syneresis of high-altitude plantain and plantain-like hybrid, were significantly higher. Starch digestibility was low and ranged between 13.4% and 37.9% after 2 h of incubation. High-altitude plantain starches contained more amylose and were more resistant to enzymatic hydrolysis.

CONCLUSION

Starches from CARBAP K74 and Kelong mekintu, grown at high altitude, showed good water and oil absorption capacities, low digestibility, and high resistance. The adequate properties of these banana starches predispose them for use as thickeners and gelling agents as well as ingredients for the formulation of low-calorie foods. This study highlights the importance of altitude when discussing banana and plantain starch properties. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Delivery of encapsulated bioactive compounds within food matrices to the digestive tract: recent trends and future perspectives

Encapsulation technologies have achieved encouraging results improving the stability, bioaccessibility and absorption of bioactive compounds post-consumption. There is a bulk of published research on the gastrointestinal behavior of encapsulated bioactive food materials alone using in vitro and in vivo digestion models, but an aspect often overlooked is the impact of the food structure, which is much more complex to unravel and still not well understood. This review focuses on discussing the recent findings in the application of encapsulated bioactive components in fabricated food matrices. Studies have suggested that the integration of encapsulated bioactive compounds has been proven to have an impact on the physicochemical characteristics of the finished product in addition to the protective effect of encapsulation on the fortified bioactive compound. These products containing bioactive compounds undergo further structural reorganization during digestion, impacting the release and emptying rates of fortified bioactive compounds. Thus, by manipulation of various food structures and matrices, the release and delivery of these bioactive compounds can be altered. This knowledge provides new opportunities for designing specialized foods for specific populations.

A global set of barley varieties shows a high diversity in starch structural properties and related gelatinisation characteristics

The gelatinisation temperature and bimodal granule size distribution of barley starch are important characteristics regarding resource efficiency and product quality in the brewing industry. In this work, the diversity in starch amylose content and granule proportions in a set of modern barley varieties (N = 23) was investigated and correlated with their starch gelatinisation behaviour. Milled barley samples had peak starch gelatinisation temperatures ranging from 60.1 to 66.5 °C. Upon separating the barley starch from the non-starch compounds, sample-dependent decreases in starch gelatinisation temperatures were observed, indicating the importance of differences in barley composition. The peak gelatinisation temperatures of milled barley and isolated barley starches were strongly correlated (r = 0.96), indicating that the behaviour of the starch population is strongly reflected in the measurements performed on milled barley. Therefore, we investigated whether amylose content or starch granule size distribution could predict the gelatinisation behaviour of the starches. Broad ranges in the small starch granule volumes (13.9-32.0 v/v%) and amylose contents (18.2-30.7 w/w%) of the barley starches were observed. For the barley samples collected in the north of the USA (N = 8), the small starch granule volumes correlated positively with the peak gelatinisation temperatures of barley starches (r = 0.90, p < 0.01). The considerable variation in starch properties described in this work highlights that, besides starch content, starch gelatinisation temperature or granule size distribution might provide brewers with useful information to optimise resource efficiency.

Novel Type of Slowly Digested Starch Complex with Antioxidant Properties

With the increasing number of diabetic patients in the world, there is an urgent requirement to reduce the incidence of diabetes. It is considered that a viable prophylactic treatment for type 2 diabetes mellitus is to reduce starch digestibility and oxidative stress. In this study, a novel type of slowly digested starch [pea starch (PS)-gingerol complex] was fabricated to evaluate its in vitro enzymatic digestibility and antioxidant activities. Theoretical and experimental analyses showed that PS can encapsulate gingerols with long alkyl chains to form starch-gingerol complexes, which are further stacked into a mixture of V6- and V7-crystallites. These complexes, in particular the PS-10-gingerol complex, showed high resistance to amylolysis and good antioxidant activities. This study demonstrates that these novel starch-gingerol complexes have the potential to deliver antioxidants encapsulated in starch with slow-digesting properties and reduce oxidative stress. Moreover, this new type of slowly digested starch with antioxidant properties showed great potential in the prevention of type 2 diabetes.

Wheat-Based Glues in Conservation and Cultural Heritage: (Dis)solving the Proteome of Flour and Starch Pastes and Their Adhering Properties

Plant-based adhesives, such as those made from wheat, have been prominently used for books and paper-based objects and are also used as conservation adhesives. Starch paste originates from starch granules, whereas flour paste encompasses the entire wheat endosperm proteome, offering strong adhesive properties due to gluten proteins. From a conservation perspective, understanding the precise nature of the adhesive is vital as the longevity, resilience, and reaction to environmental changes can differ substantially between starch- and flour-based pastes. We devised a proteomics method to discern the protein content of these pastes. Protocols involved extracting soluble proteins using 0.5 M NaCl and 30 mM Tris-HCl solutions and then targeting insoluble proteins, such as gliadins and glutenins, with a buffer containing 7 M urea, 2 M thiourea, 4% CHAPS, 40 mM Tris, and 75 mM DTT. Flour paste's proteome is diverse (1942 proteins across 759 groups), contrasting with starch paste's predominant starch-associated protein makeup (218 proteins in 58 groups). Transformation into pastes reduces proteomes' complexity. Testing on historical bookbindings confirmed the use of flour-based glue, which is rich in gluten and serpins. High levels of deamidation were detected, particularly for glutamine residues, which can impact the solubility and stability of the glue over time. The mass spectrometry proteomics data have been deposited to the ProteomeXchange, Consortium (http://proteomecentral.proteomexchange.org) via the MassIVE partner repository with the data set identifier MSV000093372 (ftp://MSV000093372@massive.ucsd.edu).

Advancements in enhancing resistant starch type 3 (RS3) content in starchy food and its impact on gut microbiota: A review

Resistant starch type 3 (RS3), often found in cooked starchy food, has various health benefits due to its indigestible properties and physiological functions such as promoting the abundance of gut beneficial microbial flora and inhibiting the growth of intestinal pathogenic bacteria. However, it is challenging to develop starchy food with high RS3 content. This review aims to provide a detailed overview of current advancements to enhance RS3 content in starchy food and its effects of RS3 on gut microbiota. These approaches include breeding high-amylose cereals through gene editing techniques, processing, enzyme treatments, storage, formation of RS3 nanoparticles, and the incorporation of bioactive compounds. The mechanisms, specific conditions, advantages, and disadvantages associated with each approach and the potential effects of RS3 prepared by different methods on gut microbiota are summarized. In conclusion, this review contains important information that aims to provide guidelines for developing an efficient RS3 preparation process and promote the consumption of RS3-enriched starchy foods to improve overall health outcomes.

Improvement on wheat bread quality by in situ produced dextran-A comprehensive review from the viewpoint of starch and gluten

Deterioration of bread quality, characterized by the staling of bread crumb, the softening of bread crust and the loss of aroma, has caused a huge food waste and economic loss, which is a bottleneck restriction to the development of the breadmaking industry. Various bread improvers have been widely used to alleviate the issue. However, it is noteworthy that the sourdough technology has emerged as a pivotal factor in this regard. In sourdough, the metabolic breakdown of carbohydrates, proteins, and lipids leads to the production of exopolysaccharides, organic acids, aroma compounds, or prebiotics, which contributes to the preeminent ability of sourdough to enhance bread attributes. Moreover, sourdough exhibits a "green-label" feature, which satisfies the consumers' increasing demand for additive-free food products. In the past two decades, there has been a significant focus on sourdough with in situ produced dextran due to its exceptional performance. In this review, the behaviors of bread crucial compositions (i.e., starch and gluten) during dough mixing, proofing, baking and bread storing, as well as alterations induced by the acidic environment and the presence of dextran are systemically summarized. From the viewpoint of starch and gluten, results obtained confirm the synergistic amelioration on bread quality by the coadministration of acidity and dextran, and also highlight the central role of acidification. This review contributes to establishing a theoretical foundation for more effectively enhancing the quality of wheat breads through the application of in situ produced dextran.

Starch spectra of Ampelopteris prolifera (Retz.) Copel, a new addition to the existing lexicon and its comparison with a local potato cultivar (Solanum tuberosum L. cv. Kufri Jyoti)

Novel kinds of starch spectra were generated from a lesser-known plant, making this investigation unique. The recent trend of starch characterization shows the establishment of novel bioresources from nonconventional unexplored databases. The present endeavor was made to obtain the starch fingerprint of Ampelopteris prolifera (rhizome) belonging to seedless vascular plants. For comparison, a commercial local cultivar of potato (Kufri Jyoti) was taken. The starch particle of A. prolifera shows much uniqueness depicting its novelty viz., crystallinity index of 60.04 %, powder diffractogram at (2θ scale)17.57° to 39.78°; this diffractogram pattern is reported from this study as newer one i.e. R type(whereas potato starch is CB type); characteristic peak at 2θ = 20.07° suggests starch-lipid complex formation and V type crystallinity (i.e. RS 5 type); FTIR spectra showing the presence of more short chain branching; high gelatinization temperature(84.62 ± 0.10), particle size and zeta value of A. prolifera is 4.00 ± 0.81 μm and - 18.91 ± 3.58 mV respectively. Bragg's peak from the single crystal X-ray diffraction has been generated for the first time of A. prolifera. Extraction of the starch particle was performed in chilled water. Therefore, the present study suggests wide-spectrum commercial utility and cost-effective production.

The important role of starch fine molecular structures in starch gelatinization property with addition of sugars/sugar alcohols

The relationship between the fine structure of starch and its gelatinization properties is not well studied, particularly in relation to the influence of sugar or sugar alcohol. In this study, seven starches with distinct molecular structures were investigated to determine how different sugars and sugar alcohols affect their gelatinization properties. The inclusion of sugars and sugar alcohols resulted in a significant elevation of starch gelatinization temperatures (∼ 8 °C), especially with sucrose, isomaltose and isomalt. Nevertheless, the influence of these sugars/ sugar alcohols on the gelatinization temperature range and enthalpy change varied depending on the particular starch varieties. According to the correlation analysis, sugars and sugar alcohols mainly exert their impact on the starch gelatinization temperature range and enthalpy change by possibly interacting with amylose chains possessing a degree of polymerization ranging from 100 to 1000 (p < 0.05) and inhibiting the amylose leaching during gelatinization. These findings help a better understanding of the complex relationship between starch fine structure and gelatinization properties under the influence of sugars and sugar alcohols.

Potential relation between starch granule-associated proteins and retrogradation properties of buckwheat starch

To elucidate the effect of starch granule-associated proteins (SGAPs) on retrogradation properties of buckwheat starch, the retrogradation properties of Tartary buckwheat starch (TBS) and common buckwheat starch (CBS) before and after removal of SGAPs were systematically investigated, with wheat starch (WS) as reference. A significant decrease in gel strength of starches and density of starch aggregates were observed after removing SGAPs. The results were in line with the changes in retrogradation enthalpy of starches and short-range ordered structure of starch aggregates. After removing SGAPs, the retrogradation enthalpy of TBS decreased from 4.16 J/g to 3.74 J/g, CBS decreased from 4.05 J/g to 3.35 J/g and WS decreased from 3.27 J/g to 2.81 J/g, respectively. Taken together the results of LF-NMR, FTIR and rheological analysis, it can be concluded that SGAPs could promote the hydrogen bond interactions between starch molecules by competitively binding with water molecules, enhancing the rearrangement of starch molecules and forming a more ordered structure. Overall, the study suggested that the presence of SGAPs could enhanced the interaction between starch molecules chains, thus accelerated the retrogradation process. The research results provide more information about SGAPs in buckwheat starch and support further study for manipulation of starch properties.

Resistant starch and the gut microbiome: Exploring beneficial interactions and dietary impacts

The intricate relationship between resistant starch (RS) and the gut microbiome presents a dynamic frontier in nutrition science. This review synthesizes current understandings of how RS, an indigestible form of starch found naturally in certain foods and also enhanced through various modification methods, interacts with the gut microbiome. We particularly focus on how RS fermentation in the colon contributes to the production of beneficial volatile fatty acids (VFAs) such as butyrate, acetate, and propionate. These VFAs have been recognized for their vital roles in maintaining gut barrier integrity, modulating inflammation, and potentially influencing systemic health. Additionally, we discuss the dietary implications of consuming foods rich in RS, both in terms of gut health and broader metabolic outcomes. By consolidating these insights, we emphasize the significance of RS in the context of dietary strategies aimed at harnessing the gut microbiome's potential to impact human health.

The influence of short-range molecular order in gelatinized starch on the formation of starch-lauric acid complexes

A model system of gelatinized wheat starch (GWS) and lauric acid (LA) was used to examine the effect of residual short-range molecular order in GWS on the formation of starch-lipid complexes. The extent of residual short-range molecular order, as determined by Raman spectroscopy, decreased with increasing water content or heating duration of gelatinization. The enthalpy changes, crystallinity, short-range molecular order and the in vitro enzymic digestion of GWS-LA complexes increased initially to a maximum and then declined as the short-range molecular order in GWS decreased, showing that there was an optimal amount of residual short-range molecular order in GWS for maximizing GWS-LA complexes formation. Below this optimum amount, the limited disruption of short-range molecular order may constrain the mobility of amylose chains for complexation with LA, whereas with excessive disruption above this amount the amylose chains may be too disorganized or entangled to form complexes with LA. The susceptibility of GWS-LA complexes to enzymatic hydrolysis was influenced by both long- and short-range structural order, and to a lesser extent the amounts of complexes. This study showed clearly the role of short-range molecular order in gelatinized starch in influencing the formation of GWS-LA complexes.

A review of starch-based biocomposites reinforced with plant fibers

Renewable and biodegradable resources have gained increasing attention as promising alternatives to synthetic plastics. Among the diverse raw materials employed in bioplastics production, starch emerges as an attractive, low-cost, and largely available source. However, the inherent properties of starch-based materials often limit their utility across various applications, necessitating strategic modifications to enhance their performance. A common approach to boost these materials involves incorporating natural fillers into biopolymer matrices. Incorporating natural fibers within starch matrices enables the development of biocomposites with improved properties while retaining their renewable and biodegradable characteristics. This review briefly addresses fundamental aspects of starch structure, obtention, and processing, as well as the main pre-treatments of natural fibers and processing methods currently applied to produce starch-based composites. It also highlights the most recent advances in this field, elucidates the effect of the incorporation of fibers on the biocomposite properties, and discusses the critical parameters affecting the synergic combination between starch and fibers.

The European Polysaccharide Network of Excellence (EPNOE) research roadmap 2040: Advanced strategies for exploiting the vast potential of polysaccharides as renewable bioresources

Polysaccharides are among the most abundant bioresources on earth and consequently need to play a pivotal role when addressing existential scientific challenges like climate change and the shift from fossil-based to sustainable biobased materials. The Research Roadmap 2040 of the European Polysaccharide Network of Excellence (EPNOE) provides an expert's view on how future research and development strategies need to evolve to fully exploit the vast potential of polysaccharides as renewable bioresources. It is addressed to academic researchers, companies, as well as policymakers and covers five strategic areas that are of great importance in the context of polysaccharide related research: (I) Materials & Engineering, (II) Food & Nutrition, (III) Biomedical Applications, (IV) Chemistry, Biology & Physics, and (V) Skills & Education. Each section summarizes the state of research, identifies challenges that are currently faced, project achievements and developments that are expected in the upcoming 20 years, and finally provides outlines on how future research activities need to evolve.

The combined actions of the granule surface barrier and multiscale structural evolution of starch on in vitro digestion of oat flour

The digestive properties of oat-based food have garnered considerable interest. This study aimed to explore the internal and external factors contributing to different digestion properties of oat flour under actual processing conditions. Analysis of the ordered structure of oat starch revealed that an increase in gelatinization moisture to 60 % led to a decrease in crystallinity, R1047/1022 value, and helical structures content to 0, 0.48 %, and 1.45 %, respectively. Even when the crystal structure was completely destroyed, the short-range structure retained a certain degree of order. Surface structure observations of starch granules and penetration experiments with amylase-sized polysaccharide fluorescence probes indicated that non-starch components and small pores effectively hindered the diffusion of the probes but low-moisture (20 %) gelatinization substantially damaged this barrier. Furthermore, investigations into starch digestibility and starch molecular structure revealed that the ordered structure remaining inside the starch after high gelatinization delayed the digestion rate (0.028 min-1) and did not increase the content of resistant starch (7.10 %). It was concluded that the surface structure and non-starch components of starch granules limited the extent of starch digestion, whereas the spatial barrier of the residual ordered structure affected the starch digestion rate.

Effect of plasma-activated water on the formation of endogenous wheat starch-lipid complexes during extrusion

The aim of this study was to investigate the effect of plasma-activated water (PAW) during extrusion on the formation of endogenous starch complexes with wheat starch (WS) as a model material. Using PAW during the extrusion process resulted in an increase in amylose content from 27.87 % to 30.07 %. Results from Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry indicated that the PAW facilitated the formation of endogenous starch-lipid complexes during extrusion. PAW120 (distilled water treated by plasma for 120 s) showed a better promotion effect than PAW60 (distilled water treated by plasma for 60 s). EWS120 (WS extruded using PAW120) exhibited lower peak viscosity and swelling power, but higher solubility, particle size, and resistant starch content compared with EWS0 (WS extruded using distilled water) and EWS60 (WS extruded using PAW60). In a word, the acidic substances in PAW may lead to hydrolysis of starch and generate more amylose, thus improving the amount of endogenous starch-lipid complexes. The present study provides a novel extrusion method to obtain modified starch with higher RS content than common extrusion, which has potential application in the industrial production of functional foods with low glycemic index.

Impact of granule-associated lipid removal on the property changes of octenylsuccinylated small-granule starches

Starch granule associated lipids (GALs) are known to alter the properties and functions of small granule starches. To test the hypothesis that the removal GALs from small granule starches could increase the overall reactive surface and improve octenyl-succinylation (OSA) modification efficiency, four small granules starches from rice, oat, quinoa, amaranth and a waxy maize starch were subjected to defat, OSA esterification and combined defatted and OSA treatment. The combined treatment showed a significant improvement in the degree of substitution for all starches from both tritration and 1H NMR methodologies. Confocal microscopy revealed a more uniform distribution of OSA groups on the starch surface. After GALs removal, the bimodal granule size distribution was diminished but reappeared during OSA modification. Pasting viscosity increased for the OSA and GALs removed quinoa, waxy maize and amaranth starches, but it decreased on modified rice and oat starches. OSA treatment alone significantly altered the gelling and rheological properties towards a more soft and less stable starch structure. The combined treatment compensated these changes to some extent and filled the property gap between the native and OSA modified starches. This study demonstrated that removing GALs can achieve more profound OSA derivatization.

Savory Cracker Development for Blood Glucose Control and Management: Glycogen Storage Diseases

The blood glucose response of savory slow energy-release crackers (GLY-HYP) were evaluated in volunteers carrying glycogen storage diseases (GSDs), Types I (Ia) and IV. The crackers have been shown previously to provide a "flat" slow glucose response in healthy volunteers, for up to 4 h. On average for the mixed-sex volunteer group aged 53 to 70 for Type I, the blood glucose concentration increased from baseline to a maximum of 9.5 mmol/L at 60 min and remained above baseline for up to 210 min; overall, above 5 mmol/L for 4 h. In common with healthy individuals, a relatively flat blood glucose response was recorded. For Type IV, mixed-sex patients aged between 55 and 72, the blood glucose concentration reached maximum of 10.2 mmol/L at 45 min and then stayed above baseline for 150 min. Again, overall, above 5 mmol/L for 4 h. Altogether, these data indicate that these crackers would provide a valuable contribution to the nutritional needs of people of different age groups with GSDs (Clinical Registration Number: HRC10032021).

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

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

Interaction between potato starch and barley β-glucan and its influence on starch pasting and gelling properties

The interactions between potato starch (PtS) and barley β-glucan (BBG) were investigated by preparing PtS-BBG mixtures, and the pasting, rheological, gelling and structural properties were evaluated. Rapid viscosity analysis suggested that BBG reduced the peak and breakdown viscosity, while increasing the setback viscosity of PtS. PtS-12%BBG showed the lowest leached amylose content (12.02 ± 0.36 %). The particle size distribution pattern of PtS was not changed with the addition of BBG, and the median diameter of PtS-12%BBG (88.21 ± 0.41 μm) was smaller than that of PtS (108.10 ± 6.26 μm). Rheological results showed that PtS and PtS-BBG gels exhibited weak gel behaviors, and BBG could remarkably affect the elastic and viscous modulus of PtS gels. Textural analysis suggested that the strength and hardness of PtS gels were increased when few BBG (<6 %, w/w) was present in the system. BBG improved the freeze-thaw stability of PtS gels. Structural analysis indicated that hydrogen bonds were the main force in the PtS-BBG systems. These results indicated that BBG interacted with starch via hydrogen bonds, which delayed starch gelatinization and improved gelling properties of PtS gels. Overall, this study gained insights into starch-polysaccharide interactions and revealed the possible applications of BBG in food processing.

Three anthocyanin-rich berry extracts regulate the in vitro digestibility of corn starch: Physicochemical properties, structure and α-amylase

This study aimed to compare the regulatory effects of blue honeysuckle anthocyanins (BHA), blueberry anthocyanins (BBA), and blackcurrant anthocyanins (BCA) on the in vitro digestibility of corn starch in terms of starch physicochemical properties and structure, as well as α-amylase inhibition. The results revealed that adding all three anthocyanins lowered digestibility in the following order: BHA > BCA > BBA. The terminal digestibility (C∞) decreased from 73.84 % to 57.3 % with the addition of 10 % BHA, while the resistant starch (RS) content increased from 4.39 % to 48.82 %. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis indicated that anthocyanins and starch interacted through noncovalent bonds. Differential scanning calorimetry (DSC) analysis showed that the gelatinization enthalpy was dramatically lowered in all three anthocyanin groups, with 10 % BHA producing a 38.58 % drop. Rheological property analysis showed that anthocyanins increased the apparent viscosity and modulus with starch. The interaction between anthocyanin and α-amylase was mainly through the formation of hydrogen bonds and hydrophobic forces. This research provides theoretical guidance for developing low glycemic index (GI) anthocyanin starch-based foods.

Physicochemical, thermal, pasting, morphological, functional and bioactive binding characteristics of starches of different oat varieties of North-Western Himalayas

Starches were isolated from five oat varieties (SFO-1, SFO-3, Sabzar, SKO-20 and SKO-96) grown in North-Western Himalayas of India. Moisture content of the varieties ranged from 9.25 ± 0.09 to 13.21 ± 0.11 %, indicating their shelf-stability. Results suggested >90 % purity of starches as was evident from values of ash, proteins, and lipids. Amylose content results showed that all starches fall within category of intermediate-amylose starches. Lambdamax, blue value and OD620/550 were found significantly (p ≤ 0.05) higher in SKO-20. Sabzar exhibited higher starch hydrolysis percentage of 85.16 % whereas, lowest was observed in SKO-20 (78.12 %). Degree of syneresis was higher in SKO-20 however, its freeze-thaw stability was lesser. Wide peak in FTIR spectra at 3320 cm-1 confirms nature of starches. SKO-20 exhibited significantly higher onset gelatinization temperature (65.19 ± 1.06 °C) and enthalpy (15.78 ± 0.15 J/g) whereas, Sabzar exhibited lowest enthalpy. Pasting characteristics indicated lowest and highest final viscosity in SKO-20 (341.30 ± 2.11 mPas) and SKO-96 (1470 ± 4.56 mPas), respectively. SEM results indicated irregular and polygonal shape of starches with size <10 μm. SKO-20 exhibited lowest disintegration time of 2.08 ± 0.01 min and Sabzar showed highest (3.31 ± 0.07 min). SKO-20 released more curcumin (71.28 %) whereas, Sabzar released less. This suggests that SKO-20 could be used as better excipient for delivery of curcumin at target site.

Indigenous Australian grass seeds as grains: macrostructure, microstructure and histochemistry

Utilization of grains of local grasses by Australia's First Nations people for food and connection to Country has largely been lost due to colonization. Native Australian grain production has the potential to deliver environmental, economic, nutritional and cultural benefits to First Nations people and the wider community. Revitalization of the native grain food system can only be achieved if relevant properties of the grains are elucidated. This study aimed to characterize the grain structure and histochemistry of four Australian native grasses: Dactyloctenium radulans (Button Grass), Astrebla lappacea (Curly Mitchell Grass), Panicum decompositum (Native Millet) and Microlaena stipoides (Weeping Grass). For these species, as well as wheat and sorghum, whole-grain images were obtained via stereo microscopy, starch and the embryo were visualized, and sections of fixed grains were imaged via bright-field and fluorescence microscopy. The shape, size and colour of the whole native grains varied between the species. The aleurone layer was one-cell thick in the native species, as in the domesticated grains, except for Weeping Grass, which had a two-cell-thick aleurone. In the native grains, endosperm cell walls appeared thinner than in wheat and sorghum. Starch granules in Button Grass, Curly Mitchell Grass and Native Millet were found mainly in the central region of the starchy endosperm, with very few granules in the sub-aleurone layer, whereas Weeping Grass had abundant starch in the sub-aleurone. Protein appeared most abundant in the aleurone and sub-aleurone layers of the native grains, although in Button Grass, the starchy endosperm was observed to be rich in protein, as in wheat and sorghum. As a proportion of the whole grain, the embryo was larger in the native species than in wheat. The differences found in the grain properties among the four native Australian species have important implications for the agri-food industry in a changing climate.

Analysis of the action pattern of sequential α-amylases from B. stearothermophilus and B. amyloliquefaciens on highly concentrated soluble starch

Hydrolysis of highly concentrated soluble starch (60%, w/w) was performed using sequential α-amylases from Bacillus stearothermophilus (T, 0.2%, w/w) and Bacillus amyloliquefaciens (B, 0.1%, w/w) to identify their possible action patterns. We found that T reduced the average molecular weight (Mw) of soluble starch from 52,827 Da to 31,914 Da and significantly affected its branched chain length. Compared with soluble starch, the chains with DP 6-12 and DP ≥ 13 in the T samples were diminished by 46% and 96%, respectively. This resulted in an attenuation in the proportions of exterior and inner chains, as well as low iodine binding capacity of the hydrolysates. In contrast, a slower decrease in the average Mw of soluble starch occurred after TB incubation, and the level of DP 6-12 further lowered, causing a gradual decline in the iodine binding capacity of the hydrolysates. Gathered data revealed an unusual action pattern of sequential α-amylase treatment at high substrate concentrations. Bacillus stearothermophilus α-amylase exhibited more pronounced endo-hydrolysis of amylopectin, whereas the attack of Bacillus amyloliquefaciens α-amylase on the exterior chains was enhanced in amylopectin residues. These findings suggest that the synergy of various α-amylases is an effective strategy to promote the dextrinization of highly concentrated starch and finely modify the molecular structure of starch.

Drying and intermittence processes on the polished and brown rice physicochemical and morphological quality by near-infrared spectroscopy, X-ray diffraction, and scanning electron microscopy

In this study was correlate the effects of drying time and intermittence of paddy rice on the physical, physicochemical, and morphological quality of polished and brown rice using near-infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Rice grain batches from mechanized harvesting with moisture contents between 24 and 20% (w.b.) were immediately subjected to drying and intermittence (average temperature of the grain mass of 40 °C) for a time of 14 h (number of times that the product underwent the drying and intermittence processes). For each drying time, grain sampling was performed to evaluate the physical quality of paddy rice and the physicochemical and morphological quality of polished and brown rice. The accumulated drying time provided an increase in the temperature of the grain mass, altering the physicochemical and morphological quality of polished and brown rice. The intermittence process did not contribute for the quality of the polished rice.

Understanding the Relationship between the Molecular Structure and Physicochemical Properties of Soft Rice Starch

The relationship between the molecular structure and physicochemical properties of soft rice starch (SRS) has been investigated in this research. The amylose content of SRS ranged from 10.76% to 11.85%, classified as the very low amylose type. Compared to waxy and japonica rice starch, the largest amount of small starch granules and the highest viscosity were shown in the SRS. The results of X-ray diffraction and Fourier transform infrared proved that the SRS depicted a typical A-type pattern with a low short-range ordered structure. Additionally, SRS had a great deal of A and B1 chains. Molecular weights and density of starch from soft rice were lower than those from waxy rice but higher than those from japonica rice. Furthermore, SRS possessed a higher amount of resistant starch. Correlation analysis indicated that the amylose content and the chain-length distributions of amylopectin play a major role in influencing the molecular structure and physicochemical properties of rice starch. In conclusion, the low amylose content, highest viscosity, and other excellent properties of soft rice starch make it have bright application prospects in instant rice and rice cakes.

Effects of Siraitia grosvenorii seed flour on the properties and quality of steamed bread

Siraitia grosvenorii seeds are rich in abundant active compounds beneficial to human health. To clarify the digestion characteristics of Siraitia grosvenorii seed flour (SSF) and promote the use of SSF in the processing of functional staple foods, SSF was prepared, its composition and physicochemical properties were studied, and the processing characteristics of SSF-wheat flour were systematically investigated. The results showed that the torque curve and other parameters of the dough were significantly affected by the amount of SSF added. With the increase of SSF proportion, the water absorption showed an increasing trend, while the degree of protein weakening first weakened and then enhanced. At 20% SSF, the dough was more resistant to kneading. In response to an increase in SSF, the L* value decreased significantly, and the a* and b* values increased gradually, while the specific volume decreased gradually. Additionally, the hardness, adhesiveness, and chewiness of the bread enhanced gradually, while its elasticity, cohesiveness, and resilience decreased gradually. After the addition of 30% SSF, the inner tissue of steamed bread was more delicate. With an increase in SSF proportion, the predicted glycemic index (pGI) of steamed bread weakened markedly. Overall, these results showed that SSF, as a kind of food ingredient with hypoglycemic activity, can be used in the production of new functional steamed bread products. This study provides basic research data for the development of products containing S. grosvenorii seed.

The Effect of Different Milling Methods on the Physicochemical and In Vitro Digestibility of Rice Flour

Preparation methods have been found to affect the physical and chemical properties of rice. This study prepared Guichao rice flour with wet, dry, semi-dry, and jet milling techniques. Differences in the particle size distribution of rice flour were investigated in order to assess their impact on pasting, thermal, gel, starch digestibility, and crystalline structure using an X-ray diffractometer (XRD) and a Rapid Visco Analyzer (RVA) across in vitro digestibility experiments. The results showed that semi-dry-milled rice flour (SRF) and wet-milled rice flour (WRF) were similar in damaged starch content, crystalline structure, and gelatinization temperature. However, compared with dry-milled rice flour (DRF) and jet-milled rice flour (JRF), SRF had less damaged starch, a higher absorption enthalpy value, and a higher gelatinization temperature. For starch digestibility, the extended glycemic index (eGI) values of WRF (85.30) and SRF (89.97) were significantly lower than those of DRF (94.47) and JRF (99.27). In general, the physicochemical properties and starch digestibility of WRF and SRF were better than those of DRF and JRF. SRF retained the advantages of WRF while avoiding the high energy consumption, high water consumption, and microbial contamination disadvantages of WRF and was able to produce better rice flour-associated products.

Interactions between tea polyphenols and nutrients in food

Tea polyphenols (TPs) are important secondary metabolites in tea and are active in the food and drug industry because of their rich biological activities. In diet and food production, TPs are often in contact with other food nutrients, affecting their respective physicochemical properties and functional activity. Therefore, the interaction between TPs and food nutrients is a very important topic. In this review, we describe the interactions between TPs and food nutrients such as proteins, polysaccharides, and lipids, highlight the forms of their interactions, and discuss the changes in structure, function, and activity resulting from their interactions.

Microwave-Induced Behavior and Digestive Properties of the Lotus Seed Starch-Chlorogenic Acid Complex

The effect of chlorogenic acid (CA) on the dielectric response of lotus seed starch (LS) after microwave treatment, the behavior and digestive characteristics of the resulting starch/chlorogenic acid complex (LS-CA) at different degrees of gelatinization and the inhibition of α-amylase by chlorogenic acid were investigated. The variation in dielectric loss factor, ε″, and dielectric loss tangent, tanδε, of the microwave thermal conversion indicated that LS-CA had a more efficient microwave-energy-to-thermal-energy conversion efficiency than LS. This gelatinized LS-CA to a greater extent at any given temperature between 65 and 85 °C than LS, and it accelerated the degradation of the starch crystalline structure. The greater disruption of the crystal structure decreased the bound water content and increased the thermal stability of LS-CA compared to LS. The simulated in vitro digestion found that the presence of the LS-CA complex improved the slow-digestion property of lotus seed starch by increasing its content of resistant and slowly digested starch. In addition, the release of chlorogenic acid during α-amylase hydrolysis further slowed starch digestion by inhibiting α-amylase activity. These findings provide a foundation for understanding the correlation between the complex behavior and digestive properties of naturally polyphenol-rich, starch-based foods, such as LS, under microwave treatment, which will facilitate the development of starch-based foods with tailored digestion rates, lower final degrees of hydrolysis and glycemic indices.