Sugar and polyol solutions as effective solvent for biopolymers

Decoupling texture from nutritional composition in sugar and fat reduced pound cake: A physico-chemical approach to bakery formulations

Reducing sugars and fats in cakes often compromises sensory properties, limiting consumer acceptance. This study proposes that the textural changes from 30% fat replacement (using dietary fibres) can be balanced by adjusting the water-sugar mixture properties through a concurrent 30% sugar replacement. Specifically, key physico-chemical parameters were investigated to design cake reformulation: (i) the volumetric density of hydrogen bonds, Φw,eff, affecting protein denaturation and starch gelatinization; (ii) the molar volume density of effective hydroxyl groups in the sugar molecules, NOH,s/vs, influencing starch pasting properties; (iii) the Flory-Huggins water interaction parameter, χeff, describing the hygroscopic properties of sugar mixtures; and (iv) the volume fraction of flour, Φflour. These parameters were independently varied and tested against phase transitions, dough rheology (temperature sweeps) and cake properties. Results indicated that all physico-chemical parameters (Φw,eff, NOH,s/vs, χeff, and Φflour) effectively described key physical properties associated with phase transitions and batter rheology during heating, as well as final cake properties. Biopolymer phase transitions and the viscoelastic behavior of batters were primarily governed by Φw,eff, while cake properties depended on all physico-chemical parameters combined. Sensory tests with naïve consumers confirmed that properly modulating these parameters yielded cakes with sensory attributes comparable to the reference. Notably, cakes with enhanced sweetness, softness, and moistness were achieved despite the 30% sugar and fat reduction, positively influencing liking. Overall, this study highlights a formulation strategy that decouples texture from nutritional composition, enabling improved sensory properties while lowering calorie density.

Soluble fibres modulate dough rheology and gluten structure via hydrogen bond density and Flory-Huggins water interaction parameter

Soluble fibres are gaining increasing interest for functional food applications like bread, but their interaction with gluten and effects on dough rheology are not fully elucidated. This study hypothesized that soluble fibres influence gluten structure and dough rheology by acting as plasticizers and humectants. Plasticizing properties depend on the effective number of hydrogen bonding sites available in the fibre molecule (N OH,s ). Humectant properties are related to the water interaction parameter derived from analysis of the sorption behaviour. Oligo-fructoses, inulins, polydextrose and a glucose syrup were added individually and in mixtures to wheat dough to test the hypothesis. PCA and multi-linear regressions showed that the G' from temperature sweeps increased with an increase in the effective volume fraction of hydrogen bonding sites (Φ w , e f f ) in the solvent and in the water interaction parameter (χ eff ). The enhanced G' corresponded to a reduction in tan(δ), indicating an increased elastic behaviour. The parametersΦ w , e f f and χ eff also explained the changes in phase transitions during heating, i.e. Tonset and Tpeak of starch gelatinization (R2 > 0.9). Image analysis of the gluten network revealed that fibre structure and physico-chemical properties influenced the gluten network by altering branching rate, lacunarity, and protein strand width. Comparing inulins and polydextrose of similar molecular weights (Mw) indicated that interactions with gluten were influenced more by N OH,s than Mw. High Mw inulins, with a linear structure, promoted junctions in the gluten network through hydrogen bonds, and possibly phase separation in gluten-rich and inulin-rich phases. In contrast, the more hydrophilic, branched polydextrose reduced junction formation in the gluten network due to fewer N OH,s . This study provides new insights into the physico-chemical properties of soluble fibres and their role in wheat dough functionality.

Hypotheses concerning structuring of extruded meat analogs

In this paper, we review the physicochemical phenomena occurring during the structuring processes in the manufacturing of plant-based meat analogs via high-moisture-extrusion (HME). After the initial discussion on the input materials, we discuss the hypotheses behind the physics of the functional tasks that can be defined for HME. For these hypotheses, we have taken a broader view than only the scientific literature on plant-based meat analogs but incorporated also literature from soft matter physics and patent literature. Many of these hypotheses remain to be proven. Hence, we hope that this overview will inspire researchers to fill the still-open knowledge gaps concerning the multiscale structure of meat analogs.

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.

Recent advance in technological innovations of sugar-reduced products

Sugar is crucial as an essential nutrient for humans as well as for providing texture, sweetness and so on to food. But with the rise in people's pursuit of health, it is becoming increasingly clear that excessive consumption of sugar can locate a load on the body. It has been that excessive sugar is associated with many diseases, such as dental caries, obesity, diabetes, and coronary heart disease. Therefore, researchers and industries are trying to reduce or substitute sugar in food without affecting the sensory evaluation. Substituting sugar with sweeteners is alternatively becoming the most traditional way to minimize its use. So far, the sweeteners such as stevia and xylitol have been are commercially applied. Several studies have shown that technological innovation can partially compensate for the loss in sweetness as a result of sugar reduction, such as cross-modal interactions that stimulate sweetness with aroma, nanofiltration that filters disaccharides and above, enzyme-catalyzed sugar hydrolysis, and microbial fermentation that turns sugar into sugar alcohol. This review summarizes these studies to enhance the safety and quality of sugar-reduced products, and will provide some theoretical frameworks for the food industry to reduce sugar in foods, meet consumers' needs, and promote human health.

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.

Environmentally Safe Photodynamic Control of Aedes aegypti Using Sunlight-Activated Synthetic Curcumin: Photodegradation, Aquatic Ecotoxicity, and Field Trial

This study reports curcumin as an efficient photolarvicide against Aedes aegypti larvae under natural light illumination. Larval mortality and pupal formation were monitored daily for 21 days under simulated field conditions. In a sucrose-containing formulation, a lethal time 50 (LT50) of 3 days was found using curcumin at 4.6 mg L-1. This formulation promoted no larval toxicity in the absence of illumination, and sucrose alone did not induce larval phototoxicity. The photodegradation byproducts (intermediates) of curcumin were determined and the photodegradation mechanisms proposed. Intermediates with m/z 194, 278, and 370 were found and characterized using LC-MS. The ecotoxicity of the byproducts on non-target organisms (Daphnia, fish, and green algae) indicates that the intermediates do not exhibit any destructive potential for aquatic organisms. The results of photodegradation and ecotoxicity suggest that curcumin is environmentally safe for non-target organisms and, therefore, can be considered for population control of Ae. aegypti.

Dry Heating of Cowpea Flour below Biopolymer Melting Temperatures Improves the Physical Properties of Bread Made from Climate-Resilient Crops

Improving the technological functionality of climate-resilient crops (CRCs) to promote their use in staple foods, such as bread, is relevant to addressing food and nutrition security in Africa. Dry heating of cowpea flour (CPF) was studied as a simple technology to modulate CPF physicochemical properties in relation to bread applications. For this purpose, the melting behavior of cowpea starch and proteins in CPF was first studied and modeled using Flory–Huggins theory for polymer melting. Next, dry-heating conditions were investigated based on the predicted biopolymer melting transitions in CPF to be well below starch and protein melting. The pasting properties (i.e., peak viscosity, final viscosity, breakdown and setback) of CPF could be selectively modulated depending on temperature-time combinations without altering the thermal behavior (i.e., melting enthalpies) of CPF. Water-binding capacity and soluble solids decreased with the increased severity of the temperature-time combinations. Dry-heated CPF added to CRC-based bread significantly improved crumb texture. In particular, dry heating at 100 °C for 2 h provided bread with the highest crumb softness, cohesiveness and resilience. The positive effects on the crumb texture could be largely related to enhanced starch integrity, as indicated by a reduction in breakdown viscosity after treatment. Overall, dry heating of CPF under defined conditions is a promising technology for promoting the use of CPF as a techno-functional and protein-rich ingredient in bread-type products.

Xylitol and Maltitol Improve the Rheological Property of Kappa-Carrageenan

To further extend the use of κ-carrageenan (κ-C) in real food systems (such as beverages), the understanding of gelation properties of κ-C with the presence of food ingredients is critical. The effects of xylitol and maltitol (up to 30 wt %) on the rheological and structural properties of κ-C were inspected by means of rheometer and Fourier transform infrared (FTIR). With the addition of xylitol, the gelation temperature increased from 44.1 to 57.3 °C, while the gelation temperature increased from 44.1 to 61.4 °C in maltitol systems. With the increasing concentration of both xylitol and maltitol, the values of fractal dimension d_f and complex modulus G* of κ-C increased, while the relaxation exponent n decreased from 0.87 to 0.39 of xylitol and 0.87 to 0.78 of maltitol, respectively. These indicated that the gel networks of aqueous κ-C were improved by the addition of xylitol and maltitol. The FTIR results showed that the interaction between κ-C and these polyols contributed to the increase of hydrogen bonds. The effects of maltitol on κ-C were stronger than those of xylitol because of more equatorial-OH bonds in maltitol. These findings contribute to a better understanding of the gelation processes of κ-C/polyols systems.

Thermodynamic description of the chemical leavening in biscuits

In this paper we describe the chemical reactions of leavening agents in baking biscuits on a sound thermodynamic basis. The model is part in a sequel targetted at physical understanding of biscuit baking with the purpose of reformulation of biscuits with respect to sucrose and sodium levels. The chemical leavening gases, CO2 and NH3, originate from the dissociation of sodium and ammonium bicarbonate. Next to water vapour, these produced gases create gas bubbles in the biscuit dough. The concentrations of the leavening agents and added salt lead to high ionic strength. Consequently, the activities of ions participating in the leavening reaction deviate strongly from ideality. The non-idealities are described using the Pitzer equations. The values of many parameters of the Pitzer model and equilibrium constants are obtained from the strong developed field of CO2 sequestering in ammonia solutions. The model describing the chemical reactions is coupled to a cell model describing the expansion of gas bubbles. Model simulations show that most of the produced gas originates from the bicarbonate, and the ammonium contributes significantly less. The functionality of ammonium as leavening agent is not quite clear, but it may help in reducing sodium levels.

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.

Curcumin in formulations against Aedes aegypti: Mode of action, photolarvicidal and ovicidal activity

Combating the Aedes aegypti vector is still the key to control the transmission of many arboviruses, such as Dengue, Zika, and Chikungunya. As few products are efficient for Aedes aegypti control, the search for new strategies have become pivotal., t Substances with photodynamic activity, such as curcumin and their formulations, are strongly encouraged, due to their multi-target mechanism of action. In this study, we evaluated the photolarvicidal and ovicidal activity of curcumin in the presence of sucrose (named SC) and d-mannitol (named DMC). To support the understanding of the larvicidal action of these formulations, Raman micro-spectroscopy was employed. We also studied the morphological changes in Danio rerio (Zebrafish) gills, a non-target organism, and demonstrate that this is an environmentally friendly approach. Both SC and DMC presented a high photo-larvicidal potential. DMC showed the highest larval mortality, with LC_50-24h values between 0.01 and 0.02 mg.L^-1. DMC also significantly decreased egg hatchability, reaching a hatching rate of 10 % at 100 mg.L^-1. The analysis of molecular mechanisms via Raman micro-spectroscopy showed that DMC is highly permeable to the peritrophic membrane of the larva, causing irreversible damage to the simple columnar epithelium of the digestive tube. Histological changes found in the D. rerio gills were of minimal or moderate pathological importance, indicating an adaptive trait rather than detrimental characteristics. These findings indicate that curcumin in sugar formulations is highly efficient, especially DMC, proving it to be a promising and safe alternative to control Aedes mosquitoes. Moreover, Raman micro-spectroscopy demonstrated high potential as an analytical technique to understand the mechanism of action of larvicides.

Theoretical investigation of the swelling of polysaccharide microgels in sugar solutions

In this paper, we explain the increased swelling of crosslinked polysaccharide microgels by the increase of sugar concentration using a modified Flory-Rehner theory. This theory is validated via the investigation of the swelling of dextran microgels in sugar solutions, which can be viewed as a model system for crosslinked starch in sugar solution and custard. An essential part of our modified theory is that starch perceives the sugar solution as an effective solvent rendering a certain hydrogen bond density. Our simulations show that the often experimentally observed maximum in swelling of starch at 20% sugar concentration is probably due to the fact that equilibrium is not reached within practical time scales. Also, we discuss the use of our theory as a tool in sugar reformulation issues of custard. From simulation results one can produce a state diagram showing which formulations render a creamy, space-filling network.

Predicting the solubility of mixtures of sugars and their replacers using the Flory-Huggins theory

In this paper we investigate whether the Flory-Huggins theory can describe the thermodynamics of solutions of simple carbohydrates, like sugars and polyols. In particular, we focus on the description of the solubility of the carbohydrates in water. This is investigated for both binary and ternary mixtures, having two types of these carbohydrates. This research question arises especially in the case of bakery products, where one seeks to replace sucrose with other simple carbohydrates - which are often polyols. Based on the model parameters obtained from fitting the theory to the experimental data of binary solutions, we show that the theory can predict (a) solubility data for ternary mixtures, over a broad range of concentrations and temperatures, and (b) the deliquescence point of binary mixtures of carbohydrate crystals as a function of temperature. The theory can even be applied to carbohydrates, which form hydrate crystals. Together with our earlier theories on the thermodynamics of complex food mixtures, we have now a complete thermodynamic framework to describe the phase and state transitions of food materials as confectionery and bakery products, where the question of sucrose replacement is urgent.

Understanding functionality of sucrose in biscuits for reformulation purposes

We review the functionality of sucrose during the manufacture of biscuits from the perspective of sugar replacement. Besides to providing sweetness, sucrose has important functionalities concerning structure and texture formation. These functionalities also need to be mimicked in reformulated biscuits. First, we review the hypotheses concerning the development of structure and texture of biscuits 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 biscuit during manufacturing in the supplemented state diagram, which indicates the important phase transitions occurring during mixing and baking. We propose that when reformulated biscuits follow similar paths in the state diagram, similar structures and textures can be obtained. Physical theories exist for predicting these phase transitions for existing sucrose-rich biscuits and also reformulated biscuits containing extensive sweeteners as sugar replacers. More accurate predictions of structure and texture can be eventually obtained if they are combined with computational models, including heat and moisture transfer.