Gelatinization Research Articles

Effects of microwave power and hot air temperature on the physicochemical properties of dried ginger (Zingiber officinale) using microwave hot-air rolling drying

In this study, the effects of microwave power and hot air temperature on various physicochemical properties of ginger dried by the microwave hot-air rolling drying (MHARD). The result showed that the increase of both two conditions significantly accelerated the drying. The increased microwave power from 0.6 to 0.9 W/g caused more damaged microstructure, facilitated the released starches, and improved the released bioactive compounds, leading an increased antioxidant activity. However, these compounds were degraded once it further increased to 1.2 W/g. The increased hot air temperature from 60 to 70 °C contributed to the retention of compounds while its further increase to 80 °C caused those degradations. Meanwhile, increased hot air temperature led to decreased relative crystallinity by promoting starch gelatinization. The aromatic profile could be tailored by altering microwave power and hot air temperature. This work aims to provide insights to future researchers on the development ginger products using the MHARD technique.

Impact of mashing protocol on the formation of fermentable sugars from millet in gluten-free brewing

The production of fermentable sugars (FS) in gluten-free (GF) brewing is hindered by the high starch gelatinization temperatures of GF malts and lower diastatic power compared to barley malt. Our previous work has demonstrated that starch gelatinization was the primary hurdle, and when decoupled from a single mash phase, high concentrations of FS could be produced. However, more research was required to improve the applicability of GF brewing. In this study, millet was used as a model GF malt demonstrating that despite the low α-amylase and β-amylase activities compared to barley malt ∼ 90 % of the FS (∼110 g/L) could be produced within 40 min. Limitations to enzyme extraction and separation due to coarse milling and lautering initially limited FS by ∼ 30 g/L, requiring additional processing or exogenous enzyme supplements that improved fermentable sugar generation by ∼ 20 g/L. Overall, millet is a promising brewing ingredient, provided appropriate mashing procedures are implemented.

Revealing color change and drying mechanisms of pulsed vacuum steamed Cistanche deserticola through bioactive components, microstructural and starch gelatinization properties

Cistanche deserticola is a famous herbal medicine and has been used worldwide for its kidney-tonifying and anti-aging values. This study investigated the effects of pulsed vacuum steaming (PVS) on bioactive phenylethanoid glycosides (PhGs), total soluble sugars, polysaccharides, color, drying characteristics, microstructure, and starch gelatinization properties of Cistanche deserticola. PVS pretreatment significantly increased PhGs and soluble sugar content while reduced the polysaccharides content. And increasing the material core temperature to 75 °C at the largest diameter was proposed as the optimal steaming condition and the PhGs content was increased by 1.11 times compared with that by atmospheric steaming. The color of steamed samples changed to oily black due to Maillard reaction. PhGs content was significantly (P < 0.05) positively correlated with total color difference (ΔE). Steaming until the ΔE value of 15.95 could achieve the maximum accumulation of PhGs, corresponding to the highest increasing ratio of echinacoside and acteoside. Starch was completely gelatinized and formed a barrier layer adhering to the cell surface when the material core temperature reached 75 °C at the largest diameter, explaining why after steaming the Cistanche deserticola drying time was prolonged by 85.71 %. The study can provide an innovative steaming technology and optimal process parameters for obtaining high-quality Cistanche deserticola decoction pieces, as well as propose a non-destructive testing method to quickly predict PhGs content based on color parameters during the steaming process.

Thermostability and catalytic ability enhancements of 1,4-α-glucan branching enzyme by introducing salt bridges at flexible amino acid sites

The 1,4-α-glucan branching enzymes (GBEs, EC 2.4.1.18), is reported to catalyze the formation of α-1,6 branching points in carbohydrates, which has ability of changing the structure of starch by adjusting the points and frequency of branch points in starch. In practical uses, GBEs are expected to be used at relatively high temperature because of high temperature requirement of starch gelatinization process. However, the present GBE does not meet the requirements, which limits the application of GBEs in starch modification industry. In order to enhance the thermostability of GBE, we combined the values of B-factor and accessible surface area, as well as the opportunity of building potential salt bridges in this enzyme. As a result, amino acid sites 73 and 137 in GBE from Geobacillus thermoglucosidans STB02 were selected in our research. The results show that substitution of Lys with Glu at amino acid 137 site resulted in an approximately 36.6 % enhancement in half-time; replacement of Gln with Asp at this site resulted in a 26 % improvement in thermostability. In addition to thermostability, catalytic ability is another factor to be concerned in our study. We constructed combined mutants with high catalytic efficiency and high thermostability. Compared with wild type, the resulting mutants have advantages in maltodextrin modification, of which product exhibited stronger stability than unmodified maltodextrin. Our study provides a new approach to increase thermostability of present GBE and create mutants with high thermostability and catalytic ability.

Effects of Reheating Methods on Rheological and Textural Characteristics of Rice Starch with Different Gelatinization Degrees.

Pregelatinized starch (PGS) is often used to improve the processing quality of foodstuffs, but little attention has been paid to the effects of different reheating methods and degree of starch gelatinization (DSG) on their rheological and textural properties. In this study, pregelatinized rice starches (RS) with gelatinization degrees ranging from 58% to 100% were prepared via different Rapid Visco Analyser (RVA) heating procedures and reheated in various methods, including high-power microwave (HM), low-power microwave (LM), and water bath. The rheological behavior and textural properties were explored, and the results demonstrated that the consistency, gel strength, hardness, and springiness of PGS in all tested samples decreased significantly after reheating. The storage modulus (G') of PGS increased dramatically while the thermal stability decreased. Interestingly, the reheating methods possessed various effects on the starch of different DSG.

Effects of Plasma Treatment on Chemical and Physical Properties of Pigmented Rice Flour

Abstract The objective of this research was to study the effects of plasma treatment at different power levels (100, 120, and 140 W) and exposure times (5, 10, and 15 min) on the physical and chemical properties of pigmented rice flours from Kum Doi Saket cultivar. An increase in plasma power and exposure time resulted in decreases of moisture contents, solubility, and swelling power of the rice flour, while the resistant starch content was increased. The amylose content tended to decrease when plasma power and exposure time was increased. In this study, plasma treatment at 140 W for 10 min maintained the highest anthocyanin content in Kum Doi Saket rice flour (68.35 – 98.63 mg/100 g). Pasting property analysis by RVA revealed decreases in peak viscosity, breakdown and setback viscosities. The pasting temperature of Kum Doi Saket rice flour was significantly decreased (P ≤0.05) after plasma treatment. Plasma treatment did not affect the onset temperature (To) and ΔH of starch gelatinization as analyzed by a DSC, while peak temperature (Tp) and end set temperature (Te) of flour sample were increased (P ≤0.05). Plasma effects on size, shape and surface roughness of flours were observed by SEM. Higher plasma power and treatment time caused more micro-pores on the surface of flour particles, especially after being treated at 140 W for 15 min. Keywords: Pigmented rice flour, Cold plasma technology, Flour properties, Cross-linking

Development of a biomaterial based on chayotextle starch (Sechium Edule)-gelatin blend. Molecular, mechanical, physical, barrier and structural properties

Films made from a mixture of Chayotextle starch-Gelatin (SG) were prepared in concentrations of SG13, SG22 and SG31 respectively. Two controls were considered; gelatin (G) and starch films (S). Glycerol was added as a plasticizer to all treatments at 2%. G treatment presented higher elasticity, permeability and solubility in comparison to those treatments using starch. FT-IR showed that both ingredients gelatin and starch respected their molecular spaces. However, their contribution was relevant for the formation of the matrix of films. The lowest percentage of crystallinity appeared in S films with 30.8%. This value increased up to 48.5 % in the G treatment. The variation of ratios in the mixture gelatin-starch resulted in different degrees of structural composition and these changes could be configured, adapted and applied to the requirements of the food engineering, pharmaceutical, and biomedical industry.

Effects of hawthorn addition on the physicochemical properties and hydrolysis of corn starch.

Hawthorn powder were mixed with corn starch and heated in water to make corn starch-hawthorn mixtures (CS-Haw) and then the physicochemical properties and hydrolysis characteristics of the mixtures were measured. Results showed that the addition of hawthorn powder decreased the viscosity of corn starch, and prolonged the pasting temperature, while the microstructure analysis indicated that hawthorn particles aggregated on the surfaces of starch granules, reducing the chance of starch contacting with water, then delayed the starch gelatinization. The presence of hawthorn powder also reduced the G' value to varying degrees and the loss tangent of CS-Haw was significantly higher than that of corn starch. The addition of hawthorn powder in large amounts also increased the rapidly digestible starch, while decrease the slowly digestible starch and resistant starch. The present research will provide basic theoretical support for the application of hawthorn in healthy starch food processing.

Mater-Bi/Brewers' Spent Grain Biocomposites-Novel Approach to Plant-Based Waste Filler Treatment by Highly Efficient Thermomechanical and Chemical Methods.

Thermoplastic starch (TPS) is a homogenous material prepared from native starch and water or other plasticizers subjected to mixing at a temperature exceeding starch gelatinization temperature. It shows major drawbacks like high moisture sensitivity, poor mechanical properties, and thermal stability. To overcome these drawbacks without significant cost increase, TPS could be blended with bio-based or biodegradable polymers and filled with plant-based fillers, beneficially waste-based, like brewers’ spent grain (BSG), the main brewing by-product. Filler modifications are often required to enhance the compatibility of such composites. Herein, we investigated the impact of BSG thermomechanical and chemical treatments on the structure, physical, thermal, and rheological performance of Mater-Bi-based composites. Thermomechanical modifications enhanced matrix thermal stability under oxidative conditions delaying degradation onset by 33 °C. Moreover, BSG enhanced the crystallization of the polybutylene adipate terephthalate (PBAT) fraction of Mater-Bi, potentially improving mechanical properties and shortening processing time. BSG chemical treatment with isophorone diisocyanate improved the processing properties of the composites, expressed by a 33% rise in melt flow index. Depending on the waste filler’s selected treatment, processing, and rheological performance, thermal stability or interfacial adhesion of composites could be enhanced. Moreover, the appearance of the final materials could be adjusted by filler selection.

Effects of the addition of high‐temperature water on the bubble structure, rheological properties, and sensory characteristics of gluten‐free rice flour bread

AbstractThis study investigated the effect of hot water on the rheological properties of the batter, bubble structure, and sensory properties of the bread. We focused on the thickening effect of starch gelatinization and developed a method to produce gluten‐free rice flour bread without additives by increasing the temperature of the water used in the production of gluten‐free rice flour bread. Hot water at 50–80°C was more effective than 5°C in improving bubble number and bubble size. In batters prepared using water at 68 and 70°C, which had excellent bubble structure, the frequency‐dependent fluctuations of the storage and loss moduli were smaller, while the loss coefficient values were larger. The batters showed more favorable sensory qualities at higher temperatures than the cold‐water batters. Appropriate temperature control of the water added during batter preparation can enable easier and cost‐effective preparation of high‐quality gluten‐free rice flour bread.Novelty impact statement Appropriate temperature control of the water added during batter preparation improved the quality of gluten‐free rice flour bread. Batter prepared with water at 68 and 70°C improved rheological properties, bubble structure, and sensory properties significantly.

Comprehensive study on gluten composition and baking quality of winter wheat

AbstractBackground and ObjectivesProtein and gluten content and composition are important for the baking quality of wheat flours. Our aim was to provide a comprehensive characterization of 82 wheat flours to analyze the influence of protein composition on rheological and baking quality parameters.FindingsProtein composition, starch gelatinization behavior, as well as rheological (microfarinograph, gluten aggregation, extensibility), and baking parameters were determined. The correlation matrix showed no significant correlations between gluten composition and loaf volume. Parameters of the gluten aggregation test allowed a prediction of gluten, gliadin, and glutenin content with an absolute root mean square error of cross validation of 7.5, 6.0, and 3.2 mg/g, respectively, using partial least squares regression. Starch gelatinization temperature had an effect on gluten aggregation.ConclusionsThe gluten aggregation test was suitable to predict gluten, gliadin, and glutenin content. The lack of correlations between protein composition and loaf volume indicates that baking quality is the result of a complex combination of different parameters.Significance and NoveltyOur study is the first to comprehensively analyze 82 wheat flours, especially in terms of gluten composition. We show that flour blends can reach excellent baking quality even if quality indicators like crude protein or extensibility are comparatively low.

An adaptive grain-bulk aeration system for squat silos in winter: Effects on intergranular air properties and grain quality

Grain can be stored for long periods under suitable storage conditions. The present study investigated the effects of cooling aeration on the intergranular air properties and grain quality of wheat stored in two squat silos during winter. In the first silo, 4759 tonnes of bulk wheat were downward-aerated in a suction-type way by four 11 kW centrifugal ventilation fans at an airflow rate of 10.1 m3/(h·t). The fans were firstly controlled by software based on a smart de-moisturization aeration model, and the grain bulk lost 0.8% moisture content (MC) and its average temperature was decreased by 5.8 °C. When the fans were then controlled using smart cooldown aeration model, the average bulk temperature decreased from 17.0 to 5.2 °C, and the average bulk MC was reduced by 0.6%. The cooling fronts moved predictably through the bulk layers during cooldown aeration, which consumed energy at a rate of 0.067 . In a second silo, 4,675 tonnes of wheat were also downward-aerated at 9.8 m3/(h·t) using smart cooldown aeration model and four 5.5 kW mixed-flow fans. There was a 0.7% MC loss and the average bulk temperature decreased by 6.7 °C. Except for the middle part (fourth and seventh) bulk layers, the other bulk layers in this silo had cooling fronts that moved at similar speeds. The energy consumed by cooldown aeration was 0.040kWh(t·∘C)−1 and 58% unit energy consumption was lowered when compared to a local grain squat silo with geosynclinal ventilation ducts under artificially controlled cooling-ventilation operations. The running conditions for the ventilation fans during cooldown aeration in the squat silos were verified. (i) The temperature difference between the grain bulk and ambient air was ≥ 4 °C. (ii) The humidity ratio of the grain bulk was higher than that of the ambient air. The equilibrium relative humidity of the intergranular air tended to decrease in both silos. After cooldown aeration, the wheat kernels had a higher water absorption rate and fatty acid value, retentive peak temperature of gelatinization, and a higher dough development time, protein network strength, and starch gelatinization rate. The proposed aeration control system has good application potential in squat silos used for grain storage.

Effects of Different Extraction Methods on the Gelatinization and Retrogradation Properties of Highland Barley Starch.

The purpose of this study was to compare the gelatinization and retrogradation properties of highland barley starch (HBS) using different extraction methods. We obtained HBS by three methods, including alkali extraction (A-HBS), ultrasound extraction (U-HBS) and enzyme extraction (E-HBS). An investigation was carried out using a rapid viscosity analyzer (RVA), texture profile analysis (TPA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectrometry (FTIR). It is shown that the different extraction methods did not change the crystalline type of HBS. E-HBS had the lowest damaged starch content and highest relative crystallinity value (p < 0.05). Meanwhile, A-HBS had the highest peak viscosity, indicating the best water absorption (p < 0.05). Moreover, E-HBS had not only higher G′ and G″ values, but also the highest gel hardness value, reflecting its strong gel structure (p < 0.05). These results confirmed that E-HBS provided better pasting stability and rheological properties, while U-HBS provides benefits of reducing starch retrogradation.

High mashing thickness negatively influences gelatinisation of small and large starch granules and starch conversion efficiency during barley malt brewing

The breakdown of starch into fermentable sugars is essential for several industrial processes, including beer production. Nowadays, high ratios of barley malt to water are used to improve brewhouse efficiency. Recent findings, however, indicate that small starch granules in barley malt could reduce starch conversion efficiency. In this study, the gelatinisation behaviour of small and large starch granules in function of mashing thickness was assessed. A mashing process was performed with malt to water ratios ranging from 1:6 to 1:2.5 (high gravity), leading to wort with 12 and 25 g of extractable components per 100 g wort, respectively. The sugar yield in wort decreased from 79% to 66% with increasing malt to water ratios due to reduced maltose production. It was hypothesised that sugars and other components in the mash increased the starch gelatinisation temperature. Therefore, small and large starch granules were isolated from barley malt, and the impact of wort and individual wort component on the gelatinisation temperature of these granules was assessed. An increase in the amount of extracted components with 2.5 g per 100 g wort during mashing resulted in a 1 °C increase in starch gelatinisation temperature for both types of granules. For high gravity brewing, this proved problematic. Gelatinisation was delayed to such an extent that β-amylase was not able to produce the maximal amount of fermentable sugars from primarily the small starch granules anymore, explaining the reduced sugar yield. • Mashing yield and sugar yield decrease with increasing mashing thickness. • The loss in sugar yield is due to less efficient maltose production. • Starch losses during mashing can be mainly attributed to small starch granules. • The impact of wort on starch gelatinisation is similar for large and small granules. • Extract content of wort is strongly correlated with starch gelatinisation temperature.

Food texture design in sugar reduced cakes: Predicting batters rheology and physical properties of cakes from physicochemical principles

Sugar reduction in bakery products such as pound cake is a challenging task due to the multiple functionalities of sugars. Sucrose affects flour pasting behaviour, starch gelatinization and protein denaturation temperatures and batter rheology. Hence, sugar replacement can substantially alter the structure and texture of the baked product. In this study, batter rheology, phase transitions during baking and the physical properties of the baked cakes were studied as affected by 50% sugar replacement. The novelty of the study lies on relating the physical properties of batter and cakes to three physicochemical parameters computed from the cake formulations: i) the volumetric density of effective H-bonding sites available in the sugar-water phase Φ w , e f f ; ii) the number of H-bonding sites effectively available for intermolecular interactions within the molar volume of a sugar N OH,s /v s and iii) the volume averaged interaction parameter of the sugars with water χ eff . Batter rheology and phase transitions during baking showed to be a linear function of Φ w , e f f . Cake volume and crumb hardness were also controlled by Φ w , e f f . Crumb cohesiveness was a non-linear function of N OH,s /v s . The water activity of cake batters and cake crumbs were a linear function of χ eff . This relations were valid with mixtures of four different types of compounds: sucrose, xylitol, an oligofructose and l -proline. In conclusion, sugar replacement in cake can be optimized by matching the physicochemical parameters Φ w , e f f , N OH,s /v s and χ eff of the sucrose reference. Since different mixture of ingredients can be used to obtain similar physicochemical parameters, the study suggests the possibility to uncouple the physical properties of cakes from nutritional composition with regards to added sugars. Hence, the approach provides opportunities to substantially increase the amounts of health promoting ingredients such as dietary fibres in sweet bakery products. • Physicochemical parameters (i.e. Φ w , e f f , N OH,s /v s and χ eff ) were studied to design sugar reduced cakes. • Cake batter rheology and phase transition were controlled by Φ w , e f f • Flour pasting viscosity was controlled by N OH,s /v s . • Water activity of cake batter and crumb was controlled by χ eff . • The physical properties of cakes can be designed using Φ w , e f f and N OH,s /v s .

Pasting and gelation behaviors and in vitro digestibility of high-amylose maize starch blended with wheat or potato starch evaluated at different heating temperatures

Different approaches have been adopted to overcome the inherent shortcomings of native starches, and blending of different native starches has attracted much attention due to the “clean-label” feature and the low processing effort and cost. In the current study, we blended high-amylose maize starch (HA7) with wheat (WHE) or potato (POT) starch at 1:1 ratio (dry weight basis; dwb) and then comprehensively examined their thermal properties, pasting and gelling behaviors over the heating temperature range of 95–140 °C, and in vitro digestibility in comparison with three individual starches. With an excess amount of water (starch:water = 1:3), gelatinization of individual starches generally appeared to be independent in the two starch blends. An exceptionally low percentage of retrogradation was observed for gelatinized HA7-WHE blend during cold storage, which could be partially ascribed to the formation of a large amount of amylose-lipid complexes (ALC). Greater resistance to thermal degradation and thixotropic breakdown during pasting at 120 °C was found with HA7-WHE blend when compared with HA7-POT blend. Both starch blends could form gels with moderate strength (74.3–109.4 g) after cooking at 120 and 140 °C. The determined resistant starch (RS) and slowly digestible starch (SDS) contents of water-boiled HA7-WHE blend were higher than the calculated values when assuming simple additivity of the two starches. The interactions at both granular and molecular levels and the presence of ALC were responsible for the reported unique techno-functional attributes of HA7-WHE blend, which rendered it suitable for diverse food and industrial applications. • More amylose-lipid complex in high-amylose (HA7)-wheat (WHE) starch blend (1:1 dwb). • Gelatinized HA7-WHE blend had the least %retrogradation (9.2%) of all the starches. • HA7-WHE blend showed strong resistance against high-temperature cooking at 120 °C. • Starch blends had moderate gel strength (74.3–109.4 g) after 120 and 140 °C cooking. • Water-boiled HA7-WHE blend showed enhanced in vitro enzymatic resistance.

Determination of Rheological Properties of Alternative Flour Substituted Doughs

All over the world, healthy foods, functional foods, diet foods and many similar terms are on the agenda. Consumers are offered different types of foods for a healthy diet. To this end, studies to improve the functional properties of bread have gained momentum. One of the ways to improve the functional properties of bread is to use flours with more functional properties than wheat flour. However, the effects of the added flours on the rheology of the dough are also different. The aim of this study is to determine the effects of flours (buckwheat (10-30%), carob (3, 6, 9, and 12), chickpea (10-50%), oat (10-50%), and barley (10-50%)) in different proportions added to bread flour on the rheological properties of the dough. The Mixolab® (Chopin) instrument was used to determine the rheological properties. A standard protocol for flour analysis was used for the analysis of bread flour and other flour mixtures. Various rheological and other dough properties were determined, such as water holding capacity, development time, stability, amylase activity, and degree of flour retrogradation. Using the obtained Mixolab® curve, C1 values for water retention and stability, C2 values for protein quality, C3 values for starch gelatinization, C4 values for amylase activity, and C5 values for degree of starch degradation were measured. C1 changed between 1.05 and 1.16 Nm, C2 between 0.33 and 0.58 Nm, C3 between 1.22 and 2.13 Nm, C4 between 0.96 and 1.98 Nm, and C5 between 0.95 and 2.81 Nm depending on the flour ratio and type used. As a result of the tests, it was determined that the most suitable flour for bread flour profile is 30% barley flour, 20% oat flour, 9% carob flour and 20% buckwheat flour, separately for each added flour.

Post-extrusion physical properties, techno-functionality and microbiota-modulating potential of hempseed (Cannabis sativa L.) hull fiber

One-third of hempseed is composed of fiber, yet this major nutrient is far understudied than the seed's oil, protein, polyphenol or cannabinoid fractions. Here we provided a comprehensive and novel study covering the monosaccharide-linkage composition, physical, functional and microbiota-shifting properties of the fiber-rich (>77%) hempseed hull, which is a major industrial processing by-product. Xylose and cellulose-derived 4-linked glucopyranosyl linkage residue dominated the monosaccharide profile and 1D/2D NMR molecular assignments of hempseed hull. Processing with extrusion technology altered the particle size distribution, FTIR structural characteristics, X-ray diffraction crystallinity and thermal stability of hempseed fiber. Extruded hempseed fiber showed significantly greater soluble fiber content, water and oil binding capacity, dynamic modulus and flow viscosity values in oil and oil-water dispersions, delayed starch gelatinization and inhibited its retrogradation. Integration of 16S rRNA gene sequencing and the rapidly emerging metaproteomics revealed a higher population of Megasphaera elsdenii and Lactobacillus spp., along with their expressed ferredoxin and enolases respectively, in porcine faecal samples after fermentation with hempseed hull fiber. Higher production of propionic, butyric and valeric acid from the microbiota was further observed in fiber-treated faecal inoculum. Finally, the possible microbiota modulating-effect of fiber-bounded unique phenylpropionamides ( N - trans -caffeoyltyramine and lignanamides) from hempseed hull was assessed for the first time. • The effects of extrusion on the fiber profile of hempseed hull were investigated. • Linkage and NMR analysis revealed the molecular composition of hempseed fiber. • Functionality of hempseed fiber was tested in oil, water and starch matrices. • Hempseed fiber may alter gut microbial populations and their expressed proteins. • Microbiota and phenolic amides interaction were explored.

The Changes in Starch Gelatinization Behavior under the Influence of Acetic Acid in Vegetable Sponge Cake Batter in Order to Obtain New Snacks.

(1) Background: Adding white vinegar to the batter of a sponge cake without biological fermentation requires the effects of acidification on the batter to be checked, in particular concerning batter-to-crumb transition. (2) Methods: µDSC analyses were carried out on three batters formulated from flour, colza oil, salt, carrot, and water with or without the addition of white vinegar. (3) Results: Wheat, chickpea, and quinoa starches had gelatinization temperatures (TGe) of 60.1, 72.4, and 70.5 °C at batter humidity and gelatinization enthalpies (ΔHGe) of 9.2, 15, and 9.1 J/gdry starch. Due to the effect of the salt and carrot, the corresponding wholemeal batter had TGe of 64.2, 74.1, and 72.4 °C and ΔHGe of 10.5, 15.3, and 10.9 J/gdry starch. Acidified batters at pH 4 saw their TGe decrease, and their enthalpies increase compared to the controls. The calorimetric study of model mixtures revealed three different evolutions of ΔHGe as a function of pH, explained by the isoelectric behavior of flours and/or the attack of starch by acetic acid. (4) Conclusions: These results could be useful for adapting the cooking step of the acid batter in order to produce alternative snacks.

Influence of starch with different degrees and order of gelatinization on the microstructural and mechanical properties of pectin cryogels: A potential pore morphology regulator

The applications of cryogels are defined by their porous morphology as well as mechanical properties. To achieve efficient regulation of porous properties for pectin cryogels, we selected starch as a potential polysaccharide regulator. Pectin/starch composite cryogels with different degrees of gelatinization were formulated, and two ways of starch gelatinization were considered: starch gelatinization occurred before or after pectin crosslinking during forming the hydrogel network. The results showed that high gelatinized starch (73.8 %–100.0 %) rendered pectin cryogels with denser pore morphology and higher mechanical strength. The pore diameter transferred from 160–200 μm to 40–60 μm with the degree of gelatinization, while the total porosity decreased by about 15 % and the specific surface area increased by about 100 m2/g. When starch gelatinization occurred before pectin crosslinking, the hydrogen bond interactions between gelatinized starch and pectin were formed to accelerate the gelation rate of the pectin Ca2+-dependent network. When gelatinization occurred after pectin crosslinking, the pre-formed pectin network delayed the breakdown of the starch crystalline structure during gelatinization. The qualitative regulation of the pore morphology in pectin cryogels by incorporating starches with varying degrees of gelatinization was confirmed.