Gelatinization Research Articles

Starch and Protein Characteristics of Chestnut Flours and Their Applications in Gluten-Free Products.

In the context of valorizing underutilized crops, this study investigated the starch and protein characteristics of chestnut varieties (Balestrera and Rossera) and their potential for use at 15% and 25% in reformulating gluten-free baked snacks and fresh pasta. Chestnut varieties differ in protein and starch content (Balestrera > Rossera), as well as in amylose, dietary fiber, and lipids (Balestrera < Rossera). Differences in starch and amylose content affected starch gelatinization (Balestrera < Rossera), pasting and retrogradation properties, and water absorption capacity at 90 °C (Balestrera > Rossera). No differences in water and oil absorption capacity and mixing properties were observed, neither in the protein profile nor in the nature of protein aggregates. Both varieties exhibited a good aptitude for producing gluten-free baked snacks and fresh pasta, even at enrichment levels of 25%. Overall, this study could provide valuable information for the development of gluten-free products using sustainable, underutilized crops.

Morphological, physicochemical, and pasting properties of pre-gelatinized starch prepared by high-pressure homogenizer: A comparative study on starches from different resources

Pre-gelatinized starch, a physically modified starch known for its ability to swell in cold water, has wide applications across various industries. This study assesses the feasibility of high-pressure homogenization (HPH) in producing pre-gelatinized starches and compares their morphological, physicochemical, and pasting properties from different sources. Starches from eleven sources, including mung bean, pea, wheat, sweet potato, cassava, corn, non-waxy rice, waxy rice, chickpea, lentil, and chestnut, were processed using HPH at 150 MPa for three cycles. The resulting pre-gelatinized starch granules exhibited disrupted surface structures, increased water absorption and solubility, decreased crystallinity, and altered gelatinization temperatures. Results showed that waxy rice pre-gelatinized starch had the highest degree of pre-gelatinization (90.27 %) and water absorption index (61.94 %), while chestnut pre-gelatinized starch had the highest water solubility index (21.58 %) and lentil pre-gelatinized starch demonstrated the highest gel strength (2178 g). X-ray diffraction analysis revealed a significant reduction in crystallinity, with values ranging from 13.96 % to 18.29 %. Additionally, the study observed variations in pasting properties, with cassava pre-gelatinized starch exhibiting the highest peak viscosity (5458 cP), trough viscosity (3864 cP), and final viscosity (6536 cP). These findings indicate that HPH is an effective method for producing pre-gelatinized starch with enhanced functional properties, enriching the scientific understanding of pre-gelatinized starches from different sources and promoting their application in the food industry and other sectors.

Rheology study of the starch gelatinization to understand the hematite depression process

Gelatinization of starch by NaOH is an essential stage for this depressant preparation to enhance its water solubility through the reverse cationic flotation. No investigation has explored the rheology of the starch gelatinization to demonstrate the hematite depression completeness. To fill the gap, this study examined the influence of a wide range of SNMRs (3:1, 5:1, 7:1, 9:1) to explore the efficiency of the gelatinization process. The main aim was to highlight how starch gel preparation can influence hematite depression in cationic reverse flotation. The steady and dynamic shear rheological measurements plus optical micrographs were assessed for the starch gel gelatinization process for different SNMR conditions. Various experiment outcomes indicated that through the starch gelatinization by SNMR>6:1, the solubilization did not occur completely (due to the presence of some pristine granules) and the gels exhibited solid-like behavior, as evidenced by < 1, 94.3s, and 32.0 Pa.s. The incomplete release of AP macromolecules into the solution was the cause of the poor hematite depression efficiency. Pretreating starch by SNMR ≤ 5:1 indicated a full release of both AM and AP species to the solution since the gels showed fluid-like behavior with >1, 0.7s, and 2.4 Pa.s. However, the excessive alkalinity promoted a reduction in the hydrodynamic size of macromolecules. These findings explain the better efficiency of SNMR=5:1 to depress hematite compared to SNMR=3:1. In general, starch preparation with SNMR=6:1 marked the onset of the sol-gel transition, and the gels exhibited a balance between fluid-like behavior and solid-like behavior.

How to cook pasta? Physicists view on suggestions for energy saving methods

Physics Nobel laureate Giorgio Parisi recently proposed a novel approach to cooking pasta that is more energy-efficient: Bring the water to a boil, add the pasta, cover the pot with a lid, and turn off the heat source. This heat-off-lid-on (hofflon) method saves energy. Other suggestions recommend soaking dried pasta in cold water to shorten the cooking process. However, there is a paucity of research examining the impact of different cooking methods on pasta texture and quality. In order to gain a deeper understanding of the effects of different cooking methods on the texture and strength of the pasta, a series of experiments were conducted. The experiments demonstrated significant variations in mechanical properties, adhesiveness, and cohesion. The hofflon method requires a longer cooking time due to the gradual decline in temperature. The process of soaking increases the water content of the pasta prior to cooking, which subsequently affects the behavior of proteins and starch when heated. These effects influence the manner in which proteins undergo alteration, the formation of cross-links, and the gelatinization of starch. Pasta prepared using the hofflon method exhibits reduced cohesion and softness, resulting in a texture that is softer and more mushy than that of al dente pasta. Presoaked samples display increased stickiness and a mushy texture when compared to pasta prepared using the classic method and hofflon pasta. The results of this study indicate the promise of developing straightforward models to illuminate the unique roles of proteins and starch during the structural transformation.

The effects of D-allulose on the gelatinization and gelling properties of wheat starch

D-Allulose, with its low calorie content and sweetness comparable to sucrose, has gained significant attention from researchers as an ideal substitute for sucrose. Here, we investigated the effects of D-allulose on the physicochemical properties and texture of wheat starch. The gelatinization results showed that D-allulose (D-allulose: wheat starch = 1:1 w/w) increased the pasting temperature (56.4 to 65.2 °C) and transition enthalpy (7.9 to 9.0 J/g) of wheat starch systems, and the impact was significantly lower than that of other commonly used small-molecule sugars (sucrose, fructose, glucose). In addition, rheological, texture, and X-ray diffraction analyses confirmed that the addition of D-allulose improved the hardness, gumminess, and recrystallization of retrograded wheat starch gels. Microstructure analysis indicated that the addition of D-allulose enhanced the structural density of wheat starch system, thereby significantly slowing down the retrogradation of wheat starch. D-allulose exhibited unique properties, promoting the gelatinization of wheat starch and delaying its retrogradation. These results will help to promote the wide application of D-allulose in starchy foods with special physiological functions.

Expanding the application of germinated wheat by examining the impact of varying alpha-amylase levels from grain to bread

Controlled germination is recognized for its potential to enhance both the nutritional profile and functional properties of grains, but there is limited information about the level of wheat germination that promotes functional changes without losing breadmaking potential. This research aims to analyze the physicochemical changes in wheat during germination for 36 hours, focusing on evaluating kernel changes, the flour breadmaking functionality, and bread characteristics. Pasting properties progressively decreased as the germination progressed, and apparent viscosity was barely detected after 36 hours germination. Initial decline in gluten index was observed at 24 and 36 hours germination, but gluten kept its aggregation capabilities. Optimal germination periods of 6 to 18 hours significantly improved flour functionality, evidenced by increased Gluten Performance Index, gluten index, and enhanced dough mixing properties. Further, mini-breads, developed after optimizing breadmaking conditions, displayed increased 2D areas in 24 and 36 hours and lower crumb hardness in 24 and 36 hours of germinated bread compared to those obtained with sound wheat flour. Significant correlations were found among alpha-amylase activity, Falling number, total and damaged starch content, RVA parameters, gelatinization enthalpy, and breadcrumb texture parameters. Developing mini bread using different levels of germinated flour demonstrates its viability for breadmaking offering a promising innovation within the whole-grain food industry.

Formaldehyde and propionic acid do not reduce starch gelatinization within a laboratory setting and may not contribute to reduced pellet quality

Formaldehyde and propionic acid do not reduce starch gelatinization within a laboratory setting and may not contribute to reduced pellet quality

Rheological, Thermal and Physicochemical Properties of Bioprocessed Flour From Cowpea, Sorghum and Orange Fleshed Sweet Potato

ABSTRACTThis study investigated the rheological, physicochemical, and thermal properties of fermented and germinated whole reddish‐brown cowpea, white sorghum and orange‐fleshed sweet potato. Germination substantially reduced the pasting and rheological attributes of flour suspensions compared to the fermentation process. This study observed notable increases in the hot paste, setback, and final viscosities after the fermentation of cowpea and sorghum, indicating an improvement in the ease of cooking and greater retrogradation tendency of starch molecules. Among the fermented flours, sorghum had the highest hot paste viscosity (848 mPa s) and final viscosity (1451 mPa s). The mechanical fingerprint revealed a viscoelastic solid character, with G′ &gt; G″ over the frequency range of 0–10 rad/s for all samples. Temperature sweep data showed a sharp increase in G′ at about 80°C, corresponding to the onset of starch gelatinization. Shear‐thinning behavior was observed, except in germinated and raw sorghum flours, where molecular rearrangement resulted in an initial viscosity rise at a low share rate (&lt; 20 s−1). Differential scanning calorimetric analysis revealed a marginal variation in the peak transition temperature of gelatinization (98°C–104°C for all flours except raw sorghum flour, 83.87°C). The fermented sweet potato flour indicated good flour particle flowability expressed as Carr's compressibility index (30.99) and the Hausner ratio (1.45); however, the available reducing sugars could have influenced its high percentage solubility (49.83%), thus impacting low pasting viscosities. The contrasting technological features suggest an avenue to intensify efforts in exploring composite bioprocessed flours for applications in novel foods.

Effects of microwave vacuum drying on drying characteristics, quality attributes and starch structure of germinated brown rice

Germinated brown rice (GBR) has high nutritional and health-promoting value, but the influence mechanism of microwave vacuum drying (MVD) on the quality properties of GBR is still unclear. This study investigated the effects of MVD parameters including microwave intensities (9, 12, and 15 W/g), drying temperatures (50, 60, and 70 °C), and vacuum pressures (0.03, 0.05, and 0.07 MPa) on the drying characteristics, quality attributes and starch structure of GBR. A falling-rate phase dominated the MVD process of GBR and temperature-controlled MVD significantly preserved the GABA content in GBR. MVD caused microstructural changes with rearrangement and gelatinization of starch granules in GBR. For the GBR under MVD, increasing the drying temperature resulted in a significant decrease in enthalpy (ΔH) and an increase in the degree of starch gelatinization (DSG) (P < 0.05), however, no significant effect of microwave intensity and vacuum pressure on ΔH and DSG (P > 0.05) was found. MVD reduced the relative crystallinity but hardly changed the crystal type or formed functional groups of starch molecules in GBR. Overall, temperature-controlled MVD conduced to the final quality of GBR. This study may provide a potential method to improve the quality attributes of GBR in product development applications.

Understanding Starch Gelatinization, Thermodynamic Properties, and Rheology Modeling of Tapioca Starch–Polyol Blends Under Pre- and Post-ultrasonication

Understanding Starch Gelatinization, Thermodynamic Properties, and Rheology Modeling of Tapioca Starch–Polyol Blends Under Pre- and Post-ultrasonication

Effect of glyceryl monopalmitate on the gelatinization, rheological and retrogradation properties of Japonica rice starch.

Starch-based food is easy to retrograde during cold storage after gelatinization, which leads to quality fission and a relatively short shelf life. Some lipids can effectively enhance the storage stability of starch gels by the formation of starch-lipid complexes. The present study aimed to investigate the effects of glyceryl monopalmitate (GMP) on gelatinization, rheological and retrogradation properties of Japonica rice starch (JS) at different conditions and to analyze the correlation between the physical-chemical properties and structural characteristics of the JS-GMP complex. The addition of GMP to JS could retard the process of starch gelatinization through forming JS-GMP complexes. The resulting JS-GMP pastes were typical pseudoplastic fluids with shear thinning, and their solid-like properties were prominent (tan δ < 1). In addition, the retrogradation of JS-GMP complex was more inhibited during storage at -18 than at 4 °C. The added amount of GMP was negatively and highly associated with the minimum viscosity, consistency coefficient, hardness and elasticity, whereas it was positively and highly correlated with the breakdown value, fluid characteristic index and relative crystallinity. The relative crystallinity of JS was affected by GMP in an approximate dose-dependent manner. The addition of GMP can influence the gelatinization properties, rheological properties and retrogradation characteristics of JS, and the formation of JS-GMP complex could improve the quality and storage stability of starch gel, which provides ideas for the quality control of starch-based food. © 2024 Society of Chemical Industry.

Optimization of Steaming Conditions for Bellflower Root (Platycodon grandiflorus) Using K-Means Clustering-Based Morphological Grading System

Bellflower roots were categorized into three clusters (class 0, class 1, and class 2) using K-means clustering based on their morphological factors: length (282.8 ± 29.53, 138.75 ± 26.8, and 209.89 ± 20.49 mm), thickness (16.25 ± 2.82, 16.77 ± 3.35, and 16.52 ± 3.05 mm), and body shape coefficient (5.80 ± 1.15, 12.73 ± 4.82, and 7.95 ± 1.71). Internal void formation, a key quality factor for bellflower root, was analyzed under pre-steaming conditions, identifying temperatures between 20 and 25 °C as optimal for storage. Within the clustered class, steaming for a prolonged duration increased the formation of internal voids and caused a decrease in normal stress values, total dissolved solids (TDS), and pectin content. Class 0, with larger and thicker roots, exhibited higher internal voids (57% void rate) due to uneven heat distribution and incomplete starch gelatinization. Class 2 roots demonstrated better structural integrity, with a void rate of 26% and a stress value of 48 kN/m2. These findings highlight the importance of morphological classification and optimal storage temperatures to improve the quality of steamed bellflower roots.

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

Potato starch (PS) is widely used in food, but its application is limited because of its poor heat resistance and easy aging. Therefore, it is necessary to adopt some modification methods to improve its performance and expand its application range. To improve these shortcomings of PS, the effect of yeast β-glucan (YG) at different concentrations (0%, 1%, 2% and 3%, w/v) on the gelatinization, structure and in vitro digestive properties of PS were investigated. The interaction of YG with PS was different because of different molecular weights. The addition of YG reduced the peak viscosity and increased the final viscosity of PS. YG made the texture of PS gel softer, and the effect of low molecular weight YG was more obvious. YG enhanced the thermal stability of PS. Fourier transform infrared spectroscopy showed that YG and PS interacted through hydrogen bonds. In addition, YG reduced the digestibility of PS in vitro. Collectively, the addition of β-glucan to PS can serve as a new approach to enhance the technological properties of PS in food applications. These results will provide theoretical basis for PS to develop into functional food. © 2024 Society of Chemical Industry.

Effects of galactomannans of varied structural features on the functional characteristics and in vitro digestibility of wheat starch

This study explores the effects of four natural galactomannans (GMs) with varying degrees of branching (fenugreek gum, guar gum, tara gum and locust bean gum) on the functional properties and in vitro digestibility of wheat starch (WS). Results from rapid viscosity analysis (RVA) and low-field nuclear magnetic resonance (LF-NMR) analysis revealed that GMs with lower branching degrees were correlated with higher paste viscosity, peak viscosity, and greater water-holding capacity in the WS-GM mixtures. Additionally, these lower branching GMs more effectively inhibited amylose leaching during starch gelatinization, leading to a softer gel texture and increased transparency of the mixtures. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis demonstrated that starch mixtures containing lower branching GMs exhibited reduced relative crystallinity and enthalpy values during aging. Furthermore, the incorporation of lower branching GMs resulted in decreased starch digestibility in vitro, thereby enhanced resistant starch content. These findings highlight the potential of selectively branched GMs to modulate the functional properties and nutritional profile of WS, providing a promising approach for the development of starch-based products with improved health benefits.

Dog Breed and Starch Gelatinisation Correlation in Food Digestibility and Faecal Traits.

Large dog breeds commonly produce unformed faeces. The present study hypothesised that foods for large dog breeds require higher starch gelatinisation (SG) to reduce organic matter flow to colon. Fifteen Rottweilers (Ro; 49.4 ± 6.12 kg), 18 Beagles (Be; 12.13 ± 1.75 kg) and 20 Shih-Tzus (ST; 4.62 ± 1.15 kg) were fed one of three diets, all based on the same sorghum formulation, processed to obtain three levels of SG: SG90 (91.8% SG), SG50 (50.7% SG) and SG30 (27.4% SG). Foods were provided for 23 days, and the coefficient of total tract apparent digestibility (CTTAD) of nutrients, faecal production and fermentation products, Na, K and Cl apparent absorption and gastrointestinal transit time (GTT) were evaluated. Results were submitted to analysis of variance considering SG, breed and their interactions, and means compared by the Tukey test (p < 0.05). All dogs promptly ate the foods. Faeces scores were lower for Ro than for Be and ST, and lower for SG30 than SG90 (p < 0.05). Faeces pH was higher, and total short-chain fatty acids were lower for SG90 than for SG50 and SG30 (p < 0.01), regardless of breed. No diet effect was observed for GTT (p > 0.05), but it was lower for Ro (41.7 ± 6.2 h) than for ST (48.7 ± 8.6 h). The CTTAD of nutrients was lower for SG30, intermediary for SG50 and higher for SG90 (p < 0.05), and among breeds CTTAD was higher for Be than ST and Ro (p < 0.05), which did not differ from each other, except for crude protein CTTAD which was lower for Ro (p < 0.05). The apparent absorption of Na and K was higher for the SG90 treatment, and for Be in comparison with Ro and ST (p < 0.05). Food SG had a remarkable influence on Ro faeces formation and on the CTTAD in all breeds. Greater fermentation in the colon and lower protein CTTAD may be involved in Ro unformed faeces formation.

Regulating effect of glycated rice bran protein aggregates and resultant emulsions on the gelatinization and retrogradation properties of rice starch

The effects of the rice bran protein aggregates (RBPAs), glycated rice bran protein aggregates (gRBPAs) and resultant emulsions on the gelatinization and retrogradation characteristics of rice starch (RS) were investigated. The gelatinization and retrogradation properties of RS were determined by rapid viscosity analyzer (RVA), differential scanning calorimetry (DSC), dynamic rheology, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The addition of the protein aggregates and the emulsions reduced the swelling of starch during the gelatinization process and the enthalpy change (ΔH) of RS. Meanwhile, during the long-term storage (4 °C for 21 d), the existence of the protein aggregates and the emulsions decreased the storage modulus (G′) and hardness of RS gel, thereby decelerating the retrogradation of RS. Besides, XRD analysis proved that when heated for 2 h, the relative crystallinity of the RS-gRBPAs mixture decreased by 6.08%, and the relative crystallinity of the corresponding RS-emulsions mixture reduced by 6.85%, which indicated the grafting of Dex could impede the retrogradation of RS. The inhibitory effect of adding the emulsions was more pronounced than that of adding corresponding protein aggregates. Furthermore, SEM analysis confirmed that the gel network structures of mixture were more uniform and compact compared with RS, which resulted from the protein aggregates and the emulsions inhibiting the internal combination through hydrogen bonds between starch molecules. Overall, these findings suggested that the protein aggregates and the emulsions prevented the retrogradation of RS, and could be potently used as a natural substitutes to enhance the quality and nutrition of starch-based foods.

Assessing the occurrence of barley starch annealing under heat, moisture and time conditions relevant for kilning: An experimental design approach

In this work, the possible occurrence of barley starch annealing under kilning conditions was investigated. Using an I-optimal response surface methodology, the impact of temperature (45–55 °C), moisture content (30–50%) and time (1–5h) on the gelatinisation behaviour of starch in green malt was studied. An increase in onset (0.5–4.3 °C) and peak temperature (0.5–2.7 °C) and a change in peak width (+0.5 to - 3.2 °C) of the starch gelatinisation endotherm showed the extent of annealing that occurred within an industrially relevant design space. Temperature was the main driver behind the observed changes, but also interaction effects between temperature, moisture content and time contributed. Combined with increasingly high starch gelatinisation temperatures in barley, the observed increases in peak gelatinisation temperature due to annealing could hamper fermentable sugar production during brewing.

Editing of the soluble starch synthase gene MeSSIII-1 enhanced the amylose and resistant starch contents in cassava

Foods with high amylose and resistant starch (RS) contents have great potential to enhance human health. In this study, cassava soluble starch synthase MeSSIII-1 gene mutants were generated using CRISPR/Cas9 system. The results showed that the storage roots of messiii-1 mutants had higher contents of amylose, RS, and total starch than those in CK. The rates of small and large-sized starch granules were increased. Additionally, amylopectin starch in messiii-1 mutants had a higher proportion of medium- and long- chains, and a lower proportion of short-chains than those in CK. The onset, peak, and conclusion temperatures of starch gelatinization in messiii-1 mutants were significantly lower than those in CK, and the peak viscosity, trough viscosity and final viscosity all increased. MeSSIII-1 mutation could increase the contents of sucrose, glucose, and fructose in cassava storage roots. We hypothesize that these soluble sugars serve a dual role: they provide the necessary carbon source for starch synthesis and act as sugar signals to trigger the transcriptional reprogramming of genes involved in starch biosynthesis. This process results in a collective enhancement of amylose, RS, and total starch contents, accompanied by changes in starch granule morphology, fine structure, and physicochemical properties.

The role of starch digestion in the brewing of gluten-free beers

Celiac disease affects an estimated 1% of the global population, and symptoms are triggered by the consumption of gluten in sensitized individuals. Other gluten sensitivities exist but are poorly characterized or often under-diagnosed, leading a number of people to pursue a gluten-free or gluten-reduced diet even in the absence of a diagnosis. Gluten is a complex suite of proteins from the prolamin fraction of storage proteins in barley, wheat, and rye, meaning that foods or beverages that are produced from these cereals will also contain gluten. Beer is one such beverage that is traditionally produced from malted barley and is thus incompatible with a gluten-free lifestyle. The simplest option to produce a gluten-free beer would seem to be to use alternative, gluten-free, grains such as millet, sorghum, teff, rice, corn or other starchy materials. However, barley has thousands of years of development as a brewing agent behind it and these alternative ingredients cannot be incorporated into the brewing process without substantial alterations. Particularly, these ingredients generally have much lower endogenous starch degrading activity and much higher starch gelatinization temperatures as compared to barley which makes generating sufficient fermentable sugars for yeast fermentation a challenge. In this review we will further elucidate these challenges as well as the solutions that are being developed to bring beer to the gluten-free masses.

The high molecular weight and large particle size and high crystallinity of starch increase gelatinization temperature and retrogradation in glutinous rice

The gelatinization and retrogradation properties of glutinous rice starch are important factors that affect its quality. In this study, the thermal properties, viscosity properties and retrogradation of starch from 152 natural glutinous varieties were investigated, and further explored the effects of starch structure on gelatinization temperature (GT) and retrogradation. The results demonstrated a strong positive linear correlation between thermal properties and retrogradation of glutinous rice. The high molecular weight, high crystallinity and large particle size of starch have significant positive effects on the thermal properties and retrogradation of amylopectin. Varieties of glutinous rice with high molecular weight starch, large starch particle sizes, and high crystallinity exhibited high GT and retrogradation rates (R%). Additionally, there was a significantly negative correlation between the range of gelatinization temperature and gelatinization enthalpy in raw starch, while a larger temperature range in retrograded starch corresponded to greater gelatinization enthalpy. The recrystallization of retrograded starch exhibited higher crystal heterogeneity and a broader range of melting points compared to raw glutinous starch. These findings provide valuable insights for breeding glutinous rice varieties with desirable retrogradation traits, particularly those with low R%.