Starch gelatinization temperature in sugar and polyol solutions explained by hydrogen bond density

Exploring urea as a prospective auxiliary for starch functionalization: A concise review on modified starch properties and the sustainable packaging films

Urea is also known as carbamide, an inexpensive and eco-friendly additive for starch functionalization. This article reviews the potential role of urea in starch modification, with the prominence of the mechanism of urea action, alterations in the starch structure and functional properties. In addition, current literature conveys the prospective effect of urea in fabricating starch films for food packaging, and the relevant areas that need to be covered in the forthcoming research are specified at the end of the article section. Urea can modify the diverse physico-chemical and functional properties of starch. Starch-based films exhibit pronounced effects on their mechanical and barrier properties upon the incorporation of urea, although this effect strongly depends on the urea content and degree of substitution (DS). Overall, urea holds great potential for use in the starch and bioplastic film industries, as it produces biocompatible derivatives with desirable performance.

Purple rice starch in wheat: Effect on retrogradation dependent on addition amount

While individual starch types may not possess the ideal gelatinization and retrogradation properties for specific applications, the amalgamation of multiple starch varieties might bestow desirable physicochemical properties upon resulting starch-based products. This study explored the impact of incorporating purple rice starch (PRS), as a novel starch variant (up to 15 % PRS), on the gelatinization and retrogradation (within 14 days) of regular wheat starch (WS). Rheological and texture assessments demonstrated that the introduction of PRS diminished the viscoelasticity and hardness of fresh WS paste. Additionally, in the case of retrograded WS pastes stored at 4 °C for 1-14 days, the incorporation of 10 % or 15 % PRS effectively retarded the reduction in transparency and significantly reduced hardness, retrogradation degree, the ratio of absorbance at 1047/1017 cm-1, and relative crystallinity. Notably, 10 % PRS results in a more pronounced effect. Conversely, 5 % PRS induced an opposing impact on retrograded WS post-storage. Moreover, scanning electron microscopy revealed that as the proportion of PRS increased, the microstructure of gelatinized WS-PRS closely resembled that of pure PRS. In conclusion, the diverse effects of varying PRS proportions on WS alter the texture and characteristics of starch-based foods, underscoring the potential of starch blending for improved applications.

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.

Effect of different sweeteners on the thermal, rheological, and water mobility properties of soft wheat flour and their application to cookies as an alternative to sugar

The effects of different sweeteners on the physicochemical properties of soft wheat flour were investigated mainly in terms of thermal, rheological, and water mobility features, and their feasibilities as an alternative to sugar were evaluated in the cookie system. Kestose significantly reduced the solvent retention capacity of wheat flour, followed by sucrose, fructose, and allulose. Thermal analysis showed that the sucrose and kestose distinctly led to an increase in the gelatinization temperature of wheat flour, which was explained by lower T2 relaxation times. In addition, the pasting viscosities and thermo-mechanical properties of wheat flour containing kestose became lower compared to allulose, and these differences were morphologically confirmed by the real-time microscopic measurements during heating. Furthermore, when the sweeteners were incorporated into the cookie formulations, kestose played a positive role as a sugar replacer in the cookie system by presenting a comparable spread factor, texture, and color to cookies with sucrose.

Low-sugar egg-based dessert (sweet egg yolk drops): Characterization, consumer acceptance and driver of liking

The addition of sweeteners and fructooligosaccharides (FOS) to partially reduced-sugar syrup allows for the development of high-sugar egg-based desserts, which are a healthier alternative with good consumer acceptance. This study aimed to analyze the effects of different sweeteners and sugar reductions on physicochemical properties, consumer liking, and emotional responses of sweet egg yolk drops. Five experimental desserts were prepared: four with 25 % low-calorie sweeteners (erythritol, mannitol, sorbitol, and tagatose) combined with 25 % FOS in reduced-sugar syrup (50 %), and one as a control (full-sugar formulation). Substitution of erythritol (E50), mannitol (M50), and tagatose (T50) in the syrup significantly decreased the quality of the desserts. This implies a decrease in the sensory properties, leading to negative emotional responses among consumers. However, the application of external preference mapping (EPM) and hierarchical cluster analysis (HCA) revealed that two of the four commercial desserts and one control sample (F100) included sorbitol desserts (S50). Desserts in this group that are related to specific attributes as drivers of liking, such as appearance, yellowness, sweetness, cohesiveness, and juiciness evoke positive emotional responses in consumers ('Auspicious', 'Glad', 'Attractive', 'Secure', 'Loving', 'Natural'). Therefore, sorbitol and FOS are suitable sweeteners in reduced-sugar syrups for producing egg-based desserts with reduced calories and improved consumer acceptance. This study thus paves the way for the development of healthy dessert products.

Sucrose substitution in cake systems is not a piece of cake

Successful sucrose replacement in cake systems requires thorough understanding of its functionality. Time-domain 1H NMR showed that water in the viscous aqueous phase isolated from cake batter by ultracentrifugation [i.e. the batter liquor (BL)] exhibits low mobility by its low T2 relaxation time (T2,D RT). This is due to its interactions with sucrose or sucrose replacers. The T2,D RT itself is positively related with the effective volumetric hydrogen bond density of sucrose or sucrose replacers. Sucrose additionally co-determines the quantity and viscosity of cake BL and thereby how much air the batter contains at the end of mixing. Like sucrose, maltitol and oligofructose provide adequate volumes of BL with low water mobility and thus sufficient air in the batter, while the rather insoluble mannitol and inulin do not. Differential scanning calorimetry and rapid viscosity analysis revealed, however, that, in contrast to sucrose and maltitol, oligofructose fails to provide appropriate timings of starch gelatinisation and protein denaturation, resulting in poor cake texture. The shortcomings of mannitol and oligofructose in terms of respectively ensuring appropriate gas content in batter and biopolymer transitions during baking can be overcome by using mixtures thereof. This work shows that successful sucrose substitutes or substitute mixtures must provide sufficient BL with low water mobility and ensure appropriate timings of starch and protein biopolymer transitions during baking.

Oligosaccharide, sucrose, and allulose effects on the pasting and retrogradation behaviors of wheat starch

The pasting and retrogradation behaviors of starch are altered by the presence of sugars and are important in dictating the storage stability and texture of starch-containing foods. The use of oligosaccharides (OS) and allulose in reduced-sugar formulations is being explored. The objectives of this study were to determine the impacts of different types and concentrations (0% to 60% w/w) of OS (fructo-OS, gluco-OS, isomalto-OS, gluco-dextrin, and xylo-OS) and allulose on the pasting and retrogradation attributes of wheat starch compared to starch in water (control) or sucrose solutions using DSC and rheometry. Physicochemical properties of the additives and their effects on amylose leaching were also considered. Significant differences in starch pasting, retrogradation, and amylose leaching were found between the control and additive solutions, influenced by additive type and concentration. Allulose increased starch paste viscosity and promoted retrogradation over time (60% conc. PV = 7628 cP; ΔHret, 14 = 3.18 J/g) compared to the control (PV = 1473 cP; ΔHret, 14 = 2.66 J/g) and all OS (PV = 14 to 1834 cP; ΔHret,14 = 0.34 to 3.08 J/g). In the allulose, sucrose, and xylo-OS solutions, compared to the other OS types, the gelatinization and pasting temperatures of starch were lower, more amylose leaching occurred, and pasting viscosities were higher. Increasing OS concentrations elevated gelatinization and pasting temperatures. In most 60% OS solutions these temperatures exceeded 95 °C thereby preventing starch gelatinization and pasting in the rheological analysis, and in conditions relevant for inhibiting starch gelatinization in low moisture-sweetened products. Fructose-analog additives (allulose and fructo-OS) promoted starch retrogradation more than the other additives, while xylo-OS was the only additive that limited retrogradation across all OS concentrations. The correlations and quantitative findings from this study will assist product developers in selecting health-promoting sugar replacer ingredients that impart desirable texture and shelf-life properties in starch-containing foods.

Effects of Sucrose Replacement by Polyols on the Dough-Biscuit Transition: Understanding by Model Systems

This study investigated the impacts of the complete substitution of sucrose by maltitol and/or sorbitol on the dough-crumb transition in biscuits. To this end, the phenomena of starch gelatinization/melting were studied at different moisture contents, both in the biscuit dough and model systems, by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and by environmental scanning electron microscopy (ESEM). Observation of doughs in ESEM revealed sorbitol had a structure very different from sucrose and maltitol crystals. After forming the dough pieces, it could be seen that at least some sugar and maltitol crystals were still present while sorbitol flakes were solubilized. At a limiting real water content (~20% dry basis), adding sweeteners to the mixture increased the gelatinization temperature, more markedly for sucrose and maltitol, as well as increasing the enthalpy. These results were confirmed by the model systems analyses. The calorimetric study with mixing batch cells revealed that sorbitol dissolved completely while maltitol and sucrose competed with the flour constituents to capture water. The proportion of water available for the sorption of the starch grain and its gelatinization was therefore different according to the affinity of the sweetener for water, and might influence the degree and temperature of starch gelatinization/melting.

Curcumin-infused xerogel-based nutraceutical development and its 4D shape-shifting behavior

Cereal-based functional foods with shape-changing (four-dimensional [4D]) properties is a novel approach in the current scenario. The main objective of the research is to develop a bioactive compound incorporated in flat two-dimensional xerogel and its hydromorphic three-dimensional shape transformation. The spray-dried curcumin at three different concentrations was incorporated with hydrogel (wheat-barley flour 8%), and flat xerogel was formed by sessile drop drying at 30°C and 78% relative humidity. The top smooth and rough bottom surface of xerogel provided anisotropic swelling properties during the shape transformation. The antimicrobial and antioxidant properties of xerogel were examined, and the retention of curcumin during the shape transformation was also examined during the research. The porous structure of barley-wheat xerogel has enhanced the incorporation of water-insoluble bioactive components like curcumin. The diffusion properties of curcumin xerogel provided an antimicrobial effect against gram-negative pathogenic bacteria. The optimum temperature (70°C) during the shape-shifting provides the retention of bioavailability and functional properties of curcumin. The work describes the opportunities for developing xerogel incorporated with more bioactive and functional components and study its stability and hydromorphic 4D shape-changing behavior. PRACTICAL APPLICATION: Xerogel is a good carrier for different bioactive components. The development of curcumin-infused biodegrade, non-toxic, and cereal-based xerogel provide an excellent opportunity for the delivery of curcumin in a cost-effective way. The shape-changing easily consumable forms of xerogel will attract more consumers, and it retains the bioavailability of infused compounds during processing.

Mechanisms of the different effects of sucrose, glucose, fructose, and a glucose-fructose mixture on wheat starch gelatinization, pasting, and retrogradation

The gelatinization, pasting, and retrogradation of starch influence texture, quality, and shelf-life attributes of many foods. The purpose of this work was to document the effects of a 50:50 glucose:fructose (glc:fru) mixture and sucrose solutions on these starch traits to provide a fundamental basis to explain the different texture and shelf-life attributes of baked goods formulated with these sugars. Differential scanning calorimetry, rapid visco analyzer, and oscillatory rheometry were used to quantify the effects of glucose, fructose, glc:fru mixture, and sucrose at different concentrations (0% to 60% w/w), on the gelatinization temperature, pasting, and retrogradation properties of wheat starch. Distinct differences were found between the effects of sucrose and those of the monosaccharides including the glc:fru mixture. Sucrose elevated T_gel and pasting temperature most and decreased other RVA parameters compared to the monosaccharides as concentration increased. Fructose and the glc:fru mixture promoted amylopectin retrogradation, while retrogradation was inhibited in sucrose and glucose solutions. The glc:fru mixture had similar effects on starch properties compared to fructose under static measurement conditions (DSC), and the effects were in between those of glucose and fructose under dynamic conditions when shear was applied (RVA and rheology). These effects are explained by the phase separation and/or solute partitioning of the monosaccharide constituents of the glc:fru mixture. Sugar solution physicochemical properties correlated strongly with starch gelatinization and retrogradation. The results substantiate the important relationship between sugar physicochemical properties and solution dynamics with starch thermal properties, which in turn affect the texture and structure of starch-containing food products. PRACTICAL APPLICATION: The quality attributes of starch-containing baked goods are influenced by how different amounts and types of sugars affect starch cooking properties. The underlying mechanisms of the different sugar effects involve solution viscosity, intermolecular hydrogen bonding, and phase separation. Substituting one sugar for another has less effect on these starch properties in products with lower sugar concentrations than in products with more sugar. Mixtures of sugars behave differently than single sugars in different conditions due to phase separation. Baked goods made with glucose:fructose mixtures in place of sucrose likely have higher amounts of gelatinized starch and increased firmness (i.e., staling or retrogradation) over time.

Interactions in plasticizer mixtures used for sugar replacement

In our quest for novel ingredients to be used in sugar replacement strategies, we have investigated the thermodynamics of polycarboxylic acids, such as citric acid. We have demonstrated the applicability of the Flory-Huggins (FH) theory to describe the thermodynamics of polycarboxylic acids solutions. Moreover, for citric acid we can describe the complete phase diagram with the theory. It shows that polycarboxylic acids have similar plasticizing and hygroscopic properties as sugars and polyols. Regarding mixtures of polycarboxylic acids and carbohydrates, the FH theory is able to describe a) the water activity of the mixtures, b) the solubility of ternary mixtures of acids and sugars, c) the lowering of the deliquescence point for binary mixtures of crystals, and d) the melting point depression in eutectic mixtures. Unexpectingly, our investigations show there is a strong non-zero FH interaction parameter between carboxylic acids and carbohydrates. In our prior sugar replacement strategy we have assumed zero interactions between plasticizers. Here, we will readdress this assumption. Carefull investigations of solid-liquid equilibrium of eutectic mixtures involving polycarboxylic acids and/or carbohydrates, shows nearly zero interaction in eutectic mixtures consisting only of two carbohydrates or two polycarboxylic acids. We now hold the hypothesis that there is strong non-zero interaction if the mixture contains plasticizers strongly differing in the amount of hydrogen bonding groups. This strong interaction explains why these mixtures, like polycarboxylic acids and carbohydrates, are excellent candidates as deep eutectic solvents. Furthermore, we conclude that polycarboxylic acids are useful additions to the toolbox of sugar replacers, albeit that there are some limitations to their amounts used.

Redispersion of dried plant nanocellulose: A review

Nanocellulose has undergone substantial development as a high value-added cellulose product with broad applications. Dried products are advantageous to decrease transportation costs. However, dried nanocellulose has redispersion challenges when rewetting. In this work, drying techniques, factors affecting redispersibility, and strategies improving the nanocellulose redispersibility are comprehensively reviewed. Hydrogen bonds of nanocellulose are unavoidably developed during drying, leading to inferior redispersibility of dried nanocellulose, even hornification. Drying processes of nanocellulose are discussed first. Then, factors affecting redispersibility are discussed. Following that, strategies improving the nanocellulose redispersibility are analyzed and their advantages and disadvantages are highlighted. Surface charge modification and steric hindrance concept are two main pathways to overcome the redispersion challenge, which are mainly carried out by chemical modification, additive incorporation and non-cellulosic component preservation. Despite several advancements having been achieved, new approaches for enhancing the nanocellulose redispersibility are still required to promote the industrial-scale applications of nanocellulose in various domains.

Variable Effects of Twenty Sugars and Sugar Alcohols on the Retrogradation of Wheat Starch Gels

Starch retrogradation is desirable for some food textures and nutritional traits but detrimental to sensory and storage qualities of other foods. The objective of this study was to determine the impact of sweetener structure and concentration on the retrogradation of wheat starch gels. The effects of 20 sweeteners selected based on common food usage and stereochemical structures of interest, and ranging in concentration from 10 to 50%w/w, on the retrogradation of wheat starch gels were monitored spectrophotometrically over time. The sweeteners were sucrose, xylose, ribose, glucose, galactose, fructose, mannose, mannitol, L-sorbose, xylitol, tagatose, allulose, maltose, lactose, isomaltulose, isomalt, sorbitol, maltitol, and raffinose. Retrogradation rates and amounts were compared by Avrami equation rate constants (k = 0.1–0.7) and absorbance values measured on day 28 (Abs = 0.1–1.0), respectively. Both sweetener concentration and type significantly affected retrogradation. Gels made with sugar alcohols and high sweetener concentrations (≈≥40%) tended to retrograde more and faster, whereas gels made with sugars and low sweetener concentrations tended to have lower retrogradation rates and amounts. Sweeteners with more equatorial and exocyclic hydroxyl groups (e.g., glucose and maltitol) and those with larger molar volumes (e.g., isomaltulose and raffinose) tended to increase the rate and amount of retrogradation, particularly at higher concentrations. The impact of sweeteners on retrogradation was a balance of factors that promoted retrogradation (intermolecular interactions and residual short-range molecular order) and inhibiting behaviors (interference at crystallization sites), which are influenced by sweetener concentration and structure. Understanding which sweeteners at which concentrations can be used to promote or inhibit retrogradation is useful for product formulation strategies.

Oligosaccharides elevate the gelatinization temperature of wheat starch more than sucrose, paving the way for their use in reduced sugar starch-based formulations

The gelatinization of wheat starch influences the final structure and texture of baked goods. Sucrose effectively elevates the gelatinization temperature (T_gel) of starch more than many sweeteners, and maintaining a higher T_gel has been a challenge while reducing the amount of sucrose in baked goods. The objective of this study was to quantify the effects of 14 different oligosaccharides (OS: maltose, isomaltulose, kestose, maltotriose, melezitose, raffinose, stachyose, a fructo-OS, a galacto-OS, an isomalto-OS, lactosucrose, a xylo-OS, and two glucose-based dextrins), allulose, and sucrose at different concentrations (0 to 60% w/w) on the T_gel of wheat starch using DSC, and to determine which OS physicochemical properties best explained the T_gel results. OS type and concentration significantly altered T_gel. Many OS elevated the T_gel as much as or more than sucrose at the same solution concentrations, while allulose did not. The onset T_gel in water was 60 °C, in 60% sucrose was 96 °C, in 60% allulose was 80 °C, and T_gel increased up to 107-108 °C in 60% fructo-OS and Nutriose® solutions. The effects of OS on T_gel correlated most strongly (r > 0.95) with two OS solution parameters: the solvent effective volume fraction (ϕ_w,eff, related to solute intermolecular hydrogen bond density) and solution viscosity, to a lesser extent with solution water activity, and not to the glass transition temperature of the OS. Based on T_gel elevation, many of the OS are promising sucrose replacements in baked goods, which could facilitate their use in desirable higher fiber, reduced sugar starch-based baked product formulations.

Making Polyol Gummies by 3D Printing: Effect of Polyols on 3D Printing Characteristics

With growth of confectionery industry, there is a great demand for candy shape, and 3D printing technology is way to achieve it. The printing properties of gummy, which is formed of gelatin and low acyl gellan as gel, maltol, erythritol, sorbitol, and xylitol as sweeteners, were tested in this study. Gummies’ rheological properties, 3D printing properties, and textural qualities were measured using a rheometer, FTIR, and SEM in this study. The strength of the hydrogen bonds will be affected by the addition of polyol, after which the excluded volume effect of polyol and viscosity will become the most important aspect. Polyols increased the gelation temperature (Tgelation), improved the gel network, and improved hydrogen bonding in the gel, according to the findings. Yield stress, shear recovery performance, and gel strength were initially increased, then decreased, when polyol concentration was increased. It had a 40.59 °C gelation temperature, an 82.99% recovery rate, noticeable shear thinning features, high self-supporting performance, and textural qualities when ink with 35 g maltitol and 30 g erythritol gave the best printing performance. This research serves as a foundation for the development of individualized, bespoke 3D printed gummies in the future.

A Systematic Comparison of the Intrinsic Properties of Wheat and Oat Bran Fractions and Their Effects on Dough and Bread Properties: Elucidation of Chemical Mechanisms, Water Binding, and Steric Hindrance

This study aimed at elucidating the contribution of chemical interactions, water binding, and steric hindrance on the effect of wheat and oat brans and of their fractions, i.e., soluble and insoluble, on dough and bread properties. For such purpose, an inert filler, i.e., glass beads of comparable particle size and with no water binding capacity and moisture sorption properties, was also studied. The glass beads provided breads most similar to the control, indicating the limited role of steric hindrance. Brans and bran fractions showed distinct compositional and physical properties. The soluble fraction from oat bran, rich in β-glucan, was less hygroscopic than the wheat counterpart and could bind more water, resulting in larger detrimental effects on bread quality. The β-glucan content showed a prevalent role in affecting gluten development, the thermo-setting behaviour of the dough, and crumb texture, i.e., cohesiveness and resilience. Overall, the comparison between the two brans and their fractions indicated that the interplay between water binding, mainly provided by the insoluble fraction, and the plasticizing properties of the soluble bran fraction controlled the effects on bread volume and texture. From a compositional standpoint, β-glucan content was a determining factor that discriminated the effects of wheat and oat brans.

The effects of commercially available sweeteners (sucrose and sucrose replacers) on wheat starch gelatinization and pasting, and cookie baking

A variety of sucrose replacers (SRs) are increasing in popularity for reducing sucrose usage in low moisture baked goods (cookies, biscuits, etc.). The goal of this study was to link SR physicochemical properties to their observed effects on starch thermal properties, including results from differential scanning calorimetry, rapid viscoanalysis, particle size analysis, and model wire-cut cookie baking performance. The 12 SRs examined in this study were: Truvia, Splenda, Swerve, coconut palm sugar, Monk Fruit, erythritol, Benefiber, Miralax, blue agave syrup, yacon syrup, Sukrín Fiber Gold Syrup, and date syrup. The onset gelatinization temperature (T_gel ) of wheat starch increased significantly (P < 0.05) as sucrose and SR concentration increased (0 to 60% w/w), with significant variations in T_gel found between different sweetener types at the same concentration. Generally, as solution concentration increased, the larger SRs (degree of polymerization [DP]> 10) decreased paste viscosity (peak and final), decreased granule swelling, and increased T_gel compared to the control (water). The smaller SRs (DP < 10) increased both paste viscosity (peak and final) and granule swelling, unlike the larger SRs, and did not increase T_gel as much as larger SRs. The SRs which performed similar to sucrose in model cookie baking (fracturability, spread, color, etc.) and effects on starch properties (T_gel , paste viscosity, and granule swelling) were yacon, Sukrín, date syrups, and coconut palm sugar. The results linking sweetener physicochemical properties to their effects on starch gelatinization, pasting, and swelling can be used to guide reformulation strategies for potentially reducing sugar and/or increasing fiber content in foods. PRACTICAL APPLICATION: Several commercially available natural sweeteners and polymers (coconut palm sugar, date syrup, yacon syrup, Sukrín Fiber Gold syrup, and Benefiber) show promise for reducing or replacing sucrose in cookies, and other low-moisture baked goods, based on their similar effects on wheat starch gelatinization, pasting, and swelling, as well as performance in cookie baking trials. Compared to sucrose, some of these ingredients have a lower glycemic response and higher dietary fiber content, and act as prebiotics, thereby providing potential health benefit.

Impact of exogenous α-amylases on sugar formation in straight dough wheat bread

The use of bacterial or fungal α-amylases is common in wheat bread production to improve several quality-related parameters such as loaf volume, crust color or staling behavior. To study the impact of exogenous α-amylases on straight dough wheat bread, we quantitated mono-, di- and oligosaccharides and residual α-amylase activity in bread crumb during storage for up to 96 h. Discovery-driven proteomics of the five α-amylase preparations studied showed that only a few different amylases per preparation were responsible for the hydrolytic effect. Compared to the control, the supplementation with α-amylase from Bacillus amyloliquefaciens in wheat dough preparation led to major changes in the sugar composition of bread crumb during storage with the formation of oligosaccharides like maltopentaose, maltohexaose, maltoheptaose, and maltooctaose. A residual activity corresponding to 4.0% of the applied activity was determined in the breads prepared with α-amylase from B. amyloliquefaciens, but no residual activity was detected for any of the other fungal or bacterial α-amylases from Aspergillus oryzae or Thermoactinomyces vulgaris. Whether the detected residual activity is related to the characteristics of bread staling or bread crumb properties must be clarified in further studies.

Understanding functionality of sucrose in cake for reformulation purposes

We review the functionality of sucrose during the manufacture of cakes from the perspective of sugar replacement. Besides providing sweetness, sucrose has important functionalities concerning structure formation. These functionalities also need to be mimicked in reformulated cakes. First, we review the hypotheses, concerning the development of structure and texture of cakes during manufacturing, which are conveniently summarized in a qualitative way using the Complex Dispersed Systems methodology. Subsequently, we represent the changes of the state of the cake during manufacturing in a supplemented state diagram, which indicates the important phase transitions occurring during baking. From the analysis, we have learned that sucrose act both as a plasticizer and as a humectant, modifying the phase transitions of biopolymers, dough viscosity, and water activity. If sugar replacers exactly mimick this behavior of sucrose, similar textures in reformulated cakes can be obtained. Physical theories exist for characterizing the plasticizing and hygroscopic behavior of sugars and their replacers. We have shown that the starch gelatinization and egg white denaturation can be predicted by the volumetric density of hydrogen bonds present in the solvent, consisting of water, sugar or its replacers, such as polyols or amino-acids.

Effects of Sugars and Sugar Alcohols on the Gelatinization Temperatures of Wheat, Potato, and Corn Starches

The gelatinization temperature (T_gel) of starch increases in the presence of sweeteners due to sweetener-starch intermolecular interactions in the amorphous regions of starch. Different starch botanical sources contain different starch architectures, which may alter sweetener-starch interactions and the effects of sweeteners on T_gels. To document these effects, the T_gels of wheat, potato, waxy corn, dent corn, and 50% and 70% high amylose corn starches were determined in the presence of eleven different sweeteners and varying sweetener concentrations. T_gels of 2:1 sweetener solution:starch slurries were measured using differential scanning calorimetry. The extent of T_gel elevation was affected by both starch and sweetener type. T_gels of wheat and dent corn starches increased the most, while T_gels of high amylose corn starches were the least affected. Fructose increased T_gels the least, and isomalt and isomaltulose increased T_gels the most. Overall, starch T_gels increased more with increasing sweetener concentration, molar volume, molecular weight, and number of equatorial and exocyclic hydroxyl groups. Starches containing more short amylopectin chains, fewer amylopectin chains that span through multiple clusters, higher number of building blocks per cluster, and shorter inter-block chain lengths exhibited the largest T_gel increases in sweetener solutions, attributed to less stable crystalline regions.