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The characterization of the physicochemical properties of wheat flour and the rheological characteristics of dough is necessary to predict processing behavior, functionality, and end-product development. Differential scanning calorimetry, pasting analysis, FTIR spectroscopy, X-ray diffraction study, and rheological measurements were used to analyze the wheat flour of different cultivars. The thermal and pasting parameters varied significantly (p ≤ 0.05) among the cultivars and showed a negative correlation with amylose content. The FTIR spectra of all wheat flour showed a weaker intensity of absorption peak at 1540 cm–1 and 1420 cm–1 associated with amide II and amide III bands. The relative crystallinity showed a significant positive correlation with HPV and CPV (hot and cold paste viscosities) and a negative correlation with amylose content. The rheological characteristics were analyzed by amplitude sweep (AS), frequency sweep (FS), and creep-recovery test of dough. The AS/FS results showed a weak gel-like structure reflecting a more elastic nature than viscous behavior. Gʹ and Gʹʹ positively correlated with pasting viscosities i.e., peak (PV), CPV, and breakdown viscosities. Viscoelastic compliance (J1) of recovery showed a significant negative correlation with textural parameters, i.e., chewiness and gumminess. Principal component analysis (PCA) reflected 71% of the cumulative variance and PC1 accounted for maximum variance (34%) with PV, HPV, CPV, Tp (peak temperature), 1047/1022 cm–1, crystallinity, and G' as the main factors. [ABSTRACT FROM AUTHOR]

The present study displays a comprehensive investigation into the micro- and macrostructures of gluten and its responses to temperature-induced changes, employing various analytical techniques. The integration of time domain-nuclear magnetic resonance (TD-NMR), differential scanning calorimetry (DSC), size-exclusion high-performance liquid chromatography (SE-HPLC), field emission scanning electron microscopy (FESEM), solid-state nuclear magnetic resonance (ssNMR), and multiphoton laser microscopy (MLM) measurements facilitates the multidimensional examination of gluten's phase distribution and structure across various scales. Notably, TD-NMR helps to refine prior T2 assignments for hydrated gluten through dynamic T2 measurements at sub-zero temperatures. The innovative application of TD-NMR uncovers insights into freezable water quantities and their changes under varying temperature conditions. Through real-time analyses utilizing not only TD-NMR but also MLM techniques, along with SE-HPLC measurements, the study highlights increased lacunarities in the gluten structure, particularly between 60 and 85 °C. These structural changes are attributed to heating effects that unfold and denature proteins and culminate in aggregation and crosslinking phenomena, leading to the release of water into macropores, hence changes in the water distribution in the gluten matrix. [ABSTRACT FROM AUTHOR]

Cranberry pomace considered as a by-product of fruit industry contains seeds which may be processed to highly nutritive oil. Conventional extraction methods may be, however, harmful to natural environment, thus alternative, ultrasound-assisted extraction method may be useful tool to reduce environmental impact. In the following study, sonication was applied to extract oil from cranberry seeds. The aim of the study was to determine the most efficient conditions of ultrasound-assisted extraction of oil and to investigate sonication influence on the properties of final product. Ultrasound amplitude and extraction time were independent variables; yield and maximum induction time of oils were responses. The most efficient conditions were amplitude of 95% and extraction time of 11.38 min. Model predicted extraction yield of 22.55 ± 0.36% (vs. actual 21.98 ± 0.08%) and induction time of 52.60 ± 0.95 min (vs. actual 61.95 ± 3.06 min). Detailed analyses of oil extracted in the most efficient conditions and the control sample were performed. Kinetic parameters of oil oxidation, fatty acid profile and distribution, melting characteristics studies were carried out. Sonication influenced activation energy of oxidation reaction, contribution of chosen fatty acids (oleic, α-linolenic and eicosenoic fatty acids) and distribution of oleic and α-linolenic fatty acids in sn-2 position of triacylglycerols. Slight changes in melting profile of oils were also recorded. Scanning electron microscopy of cranberry seeds revealed that ultrasound treatment resulted in pore enlargement and fat agglomeration damage. Additional studies of thermal properties of cranberry seeds: differential scanning calorimetry and modulated differential scanning calorimetry were performed, which confirmed that cranberry seeds may be a new source of oil with unique properties. [ABSTRACT FROM AUTHOR]

Present research focused on polymeric fractions of two wheat varieties' (DBW88 and HI1500) evaluation for molecular weight and HMW-GS composition using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), degree of crystallinity using X-ray diffraction, microstructural assessment through scanning electron microscopy (SEM), for thermal profiling using differential scanning calorimetry (DSC) and secondary structure analysis employing Fourier transform infrared (FTIR) spectroscopy technique. Glutenin fractions were identified into high molecular weight (HMW) glutenin fractions (140 kDa to 75 kDa) and low molecular weight (LMW) glutenin fractions (45 kDa to 30 kDa) as per SDS-PAGE for both varieties. XRD results displayed amorphous nature of all extracted polymeric protein fractions. SEM results revealed dense stranded structure in gluten matrix due to the addition of polymeric wheat protein and its further subfractions with subtle variation. Thermal stability of glutenins of both varieties DBW88 (161.95 °C with 808.48 J/g) and HI1500 (160.64 °C with 785.57 J/g) were observed to be highest due to highly ordered structure, followed by HMW glutenins, gluten and LMW glutenins in case of DBW88 while LMW glutenins, gluten and HMW glutenins in case of HI1500. Highest proportion of β-sheets and β-turns was observed in HMW glutenins of DBW88 and LMW glutenins of HI1500. [ABSTRACT FROM AUTHOR]

This study investigated the influence of saponin glycyrrhizin on the formation and stability of solid lipid nanoparticles. The hypothesis was that glycyrrhizin facilitates the formation of stable crystalline lipid particles due to its molecular characteristics and slows down polymorphic transition. Tristearin solid lipid nanoparticles emulsified with glycyrrhizin at varying concentrations at pH 7 and 3 were generated by hot high-pressure homogenization. The influence of glycyrrhizin on the physical stability and crystallization behavior of solid lipid nanoparticles was evaluated by dynamic and static lights scattering, electrophoretic light scattering, optical microscopy, visual observations, and differential scanning calorimetry. The results showed that glycyrrhizin formed nanosized solid lipid nanoparticles at both pH 7 and 3. The glycyrrhizin concentration and the pH applied governed the crystallization behavior and the polymorphic stability as well as the physical appearance. Overall, glycyrrhizin showed remarkable ability to stabilize solid lipid nanoparticles against polymorphic transition over time. These results are relevant for food, pharmaceutical, and cosmetic industries to form stable carrier systems by using natural plant-based saponins as surfactants. [ABSTRACT FROM AUTHOR]

This paper discusses the signal quality of differential scanning calorimetry (DSC) measurements performed on high-protein materials, and takes grinded peanuts as an example. Four different samples were used, including three grades of roasted peanuts along with their raw counterpart. DSC signals with complex shapes were obtained, containing not only the contributions due to the denaturation of the arachin and non-arachin (conarachin) protein fractions, but also the endothermic responses for the fatty and/or starchy fractions. This study investigates how the recorded DSC signals are affected by selected experimental factors, such as the type of DSC pans used, the choice of the reference, and the sample preparation. The results show that high-volume stainless-steel (HVSS) pans should be preferred to standard aluminum pans, for they allow adding a large amount of water to the sample, which appears to improve the resolution of the measurements and makes it possible to measure the denaturation temperature (ϴd) of peanut proteins. The use of HVSS pans does not require to choose a specific reference. The measurements can be performed as soon as the water is added to the sample. Waiting for water homogenization has no influence on the quality of the DSC signals in the case of peanut samples. Finally, it may be interesting to add NaCl to the hydrated samples, for it increases the intensity of the enthalpy measurement for arachin's denaturation. With this set of parameters, DSC measurements can be successfully used to evaluate the integrity of peanut proteins before and after heat treatments, such as dry-roasting. [ABSTRACT FROM AUTHOR]

Consumers are increasingly interested in innovative products enriched with nutrients that counteract the development of civilisation-associated diseases. Thus, the development of new functional nutrient-enriched food products that meet consumer needs is therefore necessary. The aims of this study were to develop a novel shortbread cookie product by addition of red grape skin extract and oat β-glucan and to evaluate the influence of these modifications on physico‐chemical properties and consumer's acceptance. The red grape skin extract used in this product is a source of polyphenols which are beneficial for human health and extend product shelf life. β-glucan is a soluble fraction of dietary fibre that helps to lower reduce blood cholesterol and glycemic levels. The influence of grape skin extract, β-glucan and a combination of both on the β-glucan content, colour and texture parameters, thermal properties, total antioxidant activity, total phenolic content, volatile compounds profile and sensory properties of shortbread cookies was analysed. Product with modified formulations had higher total antioxidant activity, total phenolic content and were was more thermally stable than control samples. The obtained innovative functional products were characterized by an increased content of oat β-glucan, which is desirable from a nutritional point of view. The DSC measurements showed higher oxidative stability of cookies enriched with β-glucan and red grape skin extract. The additives caused significant changes in the colour and profile of volatile compounds of the finished final product but did not affect the sensory acceptance among consumers. The use of these additives represents a development in food technology that may be valuable in the food industry to increase the nutritional value and extend the shelf shelf-life of bakery products. [ABSTRACT FROM AUTHOR]

A novel insect oil (SRO) from Speciomerus ruficornis Germar larvae was obtained by artisanal non-solvent extraction and its physicochemical properties were investigated. The SRO presented low levels of acidity and peroxides, which is an indication of good quality and conservation standards. The composition of fatty acids showed major content of oleic (32.2%), lauric (21.3%), myristic (19.0%) and palmitic (17.6%) acids. The nutritional quality of its lipid fractions was evaluated through the atherogenicity (~ 3.1) and thrombogenicity (~ 2.2) indices, hypocholesterolemic/hypercholesterolemic (1.0) ratio, and calculated oxidability value (~ 0.82). SRO presented significant amounts of polyphenols, ~ 56 µg GAE mL−1 of oil, and a relevant antioxidant capacity, ~ 42 µg TE g−1 of oil, which could offer protection against oxidative agents. The FTIR spectra revealed high intensity bands ranging between 2924 and 2854 cm−1 and 1745 cm−1, related to the functional groups from long-branched fatty acids and triglycerides. The SRO presented great thermal behavior determined through thermogravimetric and differential scanning calorimetry analysis, which displayed peak temperature at ~ 388 °C and an endothermic peak around 10 °C related to crystallization of SFAs, respectively. The results of this study shows that SRO is an interesting solvent-free source of fatty acids with significant antioxidant capacity and good thermal behavior. Furthermore, different technologies to obtain SRO can be thought to increase its valuable application as a butter-like product in the food. [ABSTRACT FROM AUTHOR]

Chickpea (Cicer arietinum L.) is a legume of Fabaceae family whose grains are rich in proteins, total dietary fiber, unsaturated lipids, minerals and bioactive compounds with antioxidant activity. Therefore, chickpea flour can be an attractive high nutritional complement to wheat flour for the formulation of composite breads. In the present study, the thermal and rheological characteristics of the chickpea–wheat dough obtained by replacement of wheat flour with 100 and 200 g/Kg of chickpea flour were assessed by Differential Scanning Calorimetry (DSC), Rapid Visco Analysis (RVA), Dynamic Mechanical Thermal Analysis (DMA) and Texture Profile Analysis (TPA). Higher gelatinization temperatures in coincidence with higher pasting temperatures with lower breakdown and setback of the pastes were obtained for the chickpea–wheat mixtures. Furthermore, the viscoelasticity of the wheat dough changed with the presence of chickpea flour, leading to higher dynamic moduli (E', E") and lower values of tangent of the phase angle (tan δ = E"/E') suggesting the formation of a more elastic matrix. At higher deformations (TPA), higher values of hardness and elasticity were observed. These changes were associated with a marked disruption of the gluten network by the presence of certain chickpea components like proteins, assessed by different microscopic techniques. [ABSTRACT FROM AUTHOR]

Changes in the biophysical traits of the pectoral muscles of chickens with deep pectoral myopathy (DPM) were analysed with selected instrumental techniques. For comparative purposes, the research used both samples of pectoralis minor muscles of 39-42-day-old Cobb 500 broiler chickens and pectoralis major muscles with DPM symptoms, as well. Computer Image Analysis (CIA) revealed that the pectoral minor muscles with DPM were characterised by smaller area of muscle fibres' cross-sectional area (CSA) than normal muscles. A longitudinal section of DPM muscles also confirmed the presence of large spaces between the bundles of muscle fibres. The results of Differential Scanning Calorimetry (DSC) analysis showed that all the temperatures of transformations referring to minor muscles with myopathy symptoms were significantly lower than the temperatures noted in the muscles without DPM. The enthalpy values observed in both pectoral muscles with DPM were significantly lower than the values noted in healthy muscles. The water dynamics analysed by low-field NMR showed that the values of spin-lattice relaxation time T1 in p. major muscles without DPM were higher than the values in the muscles with the defect. On the other hand, an inverse dependence was observed in p. minor muscles samples. The value of the long relaxation time T22 was reduced in both muscles with pathological lesions. In conclusion, three advanced analytical tools used in this study (CIA, DSC, and LF NMR) provide new insight into the characterization of protein changes observed in the pectoral muscles of chicken broilers with DPM. [ABSTRACT FROM AUTHOR]

Black soldier fly (BSF, Hermetia illucens L.), an insect with high protein, has been proposed as a sustainable protein resource alternative for both food and feed for their nutritional composition and ease of rearing. The amino acid composition, nutritional value, in vitro digestibility, morphologies, and thermal properties of the BSF larvae proteins (BSFLP) based on two drying methods were investigated. Experimental results showed that their amino acid score could reach the requirement of FAO/WHO (dietary protein quality evaluation in human nutrition. Report of an FAO expert consultation. Food and nutrition paper no. 92. Food and Agriculture Organization and the World Health Organization, Rome, 2013) for indispensable amino acids for older children, adolescents, and adults. The proportion of essential amino acids to total amino acids (E/T) of both conventional dried BSFLP (CD-BSFLP) and microwave dried BSFLP (MD-BSFLP) was more than 40%. Lysine and valine were found to be the first limiting amino acid for CD-BSFLP and MD-BSFLP, respectively. Both of the in vitro digestible indispensable amino acid score (DIAAS) values of the BSFLP were more than 75%. The results of scanning electron microscopy, thermo-gravimetric analysis, and differential scanning calorimetry of the samples showed that microwave drying polymerized the protein particles and made them harder to digest. In conclusion, the BSFLP prepared by conventional drying (60 °C) had higher DIAAS and better digestibility. Moreover, the amino acid composition and high DIAAS (> 75%) indicated that the BSFLP could be utilized as a good source of animal protein for human nutrition. [ABSTRACT FROM AUTHOR]

The effect of sowing time of three facultative wheat varieties (late autumn or spring) on the content and properties of arabinoxylans (AX) adsorbed on the surface of starch granules in the process of washing out from flour, and the impact of AX on physicochemical properties of starch and filtration performance of enzymatic starch hydrolysates were determined in this study. The differential scanning calorimetry (DSC) was used to assess the susceptibility of native starches and starches deprived of AX to gelatinization and hydrolysis by α-amylase (under conditions used in industry). Processes of amylose-lipid complexes (AML) dissociation and re-association were monitored to determine values of transition enthalpy (Δ H), temperatures of the onset ( T ), peak ( T ) and completion ( T ) of the transition as well as to calculate Δ T ( T − T ). The time of wheat sowing affected properties of AX associated with starch granules that in turn influenced the characteristics of starch and its enzymatic hydrolysates. The presence of AX in starch granules negatively affected filtration of glucose syrups obtained under the same conditions as in industry. [ABSTRACT FROM AUTHOR]

The gelatinization of starch is crucial for the production of bakery products. Therefore, the examination of the characteristics and the extent of this process are of fundamental importance for research and product development. Typical analysis methods for studying structural starch changes during heating are performed in excess of water. Considering that wheat dough is a complex system with reduced water content, an option to analyze starch gelatinization under actual product conditions is missing. Therefore, an in situ method in a confocal laser scanning microscope (CLSM) equipped with a heating system was developed to monitor the starch gelatinization in samples with different flour to water ratios [(m:v) 1:0.39, 0.49, 0.51, 0.53, 0.55, 0.57, 0.59, 0.98, 4.91, 5.63 and 7.14]. The new method was used to investigate the start of starch gelatinization temperature ( T) by using thresholds based on first derivatives with highest correlation between T of CLSM and the onset temperature ( T) of differential scanning calorimetry. A highly significant linear correlation between T of A-type granules and T was observed ( R = 0.903). The size and shape of granules with a ratio of 1:0.98 show a clear impairment against samples with higher water content. The newly modified in situ method enables the measurement of starch gelatinization in different flour to water ratios independent of secondary factors. Consequently, it can be used for complex starch-based systems with reduced water content to investigate the actual starch granule structure disintegration. [ABSTRACT FROM AUTHOR]

The influences of various factors on the formation of 2,3-dihydro-3,5-dihydroxy-6-methyl-4( H)-pyran-4-one (DDMP) were investigated in a solid-state Maillard reaction system. Thermogravimetric analysis (TG) and differential scanning calorimetry analysis (DSC) showed that the solid-state Maillard reaction mainly occurred at around 150 °C. The DDMP formation from reducing sugars (glucose or fructose) and several selected amino acids ( l-proline, l-alanine, l-asparagine, l-threonine, l-tyrosine and l-lysine) was compared. Proline was found to have special activity in DDMP formation when reacted with glucose because of its special catalytic action. The influences of reactant ratios, oxygen, reaction temperature and reaction time on DDMP formation from the reaction of proline with glucose were studied. Reactant molar ratios of glucose to proline played important impact on DDMP formation, and the formation of DDMP was improved when the ratio was higher than 1:1 and achieved the highest level at 2:1. Oxygen had no obvious effects on DDMP formation. The effects of reaction time and temperature were investigated together and revealed the information on the highest yield and minimum temperature for DDMP formation. Furthermore, the kinetics of DDMP formation was studied, and DDMP formation in the initial stage was shown to follow an apparent first-order reaction with an activation energy of 68.8 kJ/mol. [ABSTRACT FROM AUTHOR]

Silver carp ( Hypophthalmichthys molitrix) is one of the major species of freshwater fish in China. Modification of myofibrillar proteins induced by high pressure processing (HPP) has been investigated at pressures ranging from 200 to 500 MPa for 10 min at 20 °C. Influence of high pressure on conformational changes of myofibrils was studied by means of differential scanning calorimetry (DSC), surface hydrophobicity measurement, ultraviolet absorption spectra and second-derivative spectroscopy, intrinsic spectrofluorimetry, Raman spectroscopic analysis and circular dichroism (CD). DSC analyses revealed that the conformational stability of myofibrils is reduced to different extents when they are exposed to a pressure over 200 MPa. More sulfydryl groups as well as hydrophobic regions and amino acid residues which had ultraviolet absorbance had been found significantly after HPP (≥300 MPa). Changes in the Raman spectra were interpreted as the occurrence of secondary structural changes in pressure-induced myofibrillar proteins. CD analysis results demonstrated that α-helix was destroyed after processed at 400 MPa for 10 min. The results implicated that HPP can be used as a possible means of improving the functional properties for growing demand for healthier fish products. [ABSTRACT FROM AUTHOR]

The solubility of carbon dioxide (CO) in a seafood model product with various amounts of salmon oil was investigated. Differential scanning calorimetry analysis of the salmon oil gave an onset temperature for crystallization at −14.75 ± 0.74 °C, showing that the oil was in liquid state in the temperature range used in this experiment (1-8 °C). Solubility of CO in salmon oil in liquid state was similar to water, with the same temperature dependency as water. Increased storage temperature decreased the amount of dissolved CO and increased the headspace CO and headspace gas volume. Headspace gas composition at equilibrium was linearly ( R = 0.979) related to the composition of the packaging gas, while increasing CO in the packaging gas increased the headspace gas volume and the amount of dissolved CO in the product. When designing modified gas-packaging regimes for products with marine fat, sum of fat and water can be used to estimate the amount of dissolved CO in the product. [ABSTRACT FROM AUTHOR]

Thermal denaturation of recombinant human lysozyme from rice has been studied by differential scanning calorimetry at acidic (4.2), neutral (7.2) and basic (9.2) pH levels at various heating rates, and it has been compared with thermal denaturation of human lysozyme isolated from milk at the same pH levels at a heating rate of 10 °C/min. Data obtained from heat-induced unfolding and subsequent refolding after heating indicate that thermal denaturation of both lysozymes undergoes a two-state process. The maximum temperature of the endothermic peaks and the enthalpy change of denaturation indicate that recombinant and milk lysozymes possess similar thermostability, which is higher at acidic than at neutral pH. On the other hand, both proteins are more thermolabile at basic pH. Lysozyme from human milk shows a higher tendency to aggregate than recombinant human lysozyme from rice during the thermal denaturation process. [ABSTRACT FROM AUTHOR]

Application of differential scanning calorimetry (DSC) to discriminate among extra virgin olive oils on the basis of cultivar–environment interaction was preliminary evaluated on Tunisian samples from two varieties (Chetoui and Chemlali) and different geographical origin relating thermal properties obtained by cooling and heating thermograms to chemical composition. Higher content of triunsaturated triacylglycerols and oleic acid and lower amount of palmitic acid were detected in Chetoui samples in comparison with Chemlali oils. Cooling thermograms exhibited two well distinguishable exothermic peaks in all samples; the major event at lowest temperature was taller and sharper in Chetoui samples whereas the other peaking at highest temperature was more evident for Chemlali oils. Crystallization enthalpy did not account for the differences observed in chemical composition between the two cultivars. On the contrary, Ton and Toff of crystallization were found to significantly differ according to the compositional differences due to cultivars and geographical provenience interaction. Heating profiles exhibited a minor exothermic peak followed by multiple endothermic events and appeared also distinctive of oil samples from two cultivars. All thermal properties obtained by the analysis of heating thermograms significantly differed among oil samples from different geographical provenience. The application of DSC appeared useful to differentiate samples of different cultivars and/or geographical proveniences. [ABSTRACT FROM AUTHOR]

α-Amylases, usually added to bread recipes as anti-firming agents, are known to produce low molecular weight dextrins by starch hydrolysis. The influence of these compounds on the gelatinization and retrogradation of starch was studied by differential scanning calorimetry. Adding oligosaccharides to starch caused a delay in gelatinization, although its extent was not quantified. However, oligosaccharides of degrees of polymerization (DP) 3–5 reduced the enthalpy of the retrogradation endotherm, shown as the staling endotherm. The addition of gluten to starch and starch/oligosaccharide mixtures had no effect on the gelatinization and retrogradation of starch. The retrogradation of starch in dough samples was also analysed, after 'baking' in the calorimeter, to obtain additional information about starch retrogradation during storage. Oligosaccharides of DP 3–5 also reduced the enthalpy of the retrogradation endotherm. This work provides evidence that oligosaccharides influence starch changes during the baking and storage of bread. These effects could be considered as the mechanism by which the bacterial α-amylase reduces starch retrogradation and acts as an anti-firming agent. [ABSTRACT FROM AUTHOR]

Differential scanning calorimetry (DSC) has been used to determine the oil content in dried olive pulp of Cassanese and Carolea tree cultivars and to follow their inoliation trends from September to January. DSC was performed by cooling samples of olive dried pulp from –10 to –60 °C at 1 °C/min and the amount of oil calculated from the peak area obtained. The enthalpy and temperature range of the crystallization peak for the pure oil were 61 J/g and –34 to –40 °C for the first cultivar and 54 J/g and –35 to –42 °C for the second one. The proposed DSC method is fast, specific, and reliable. It does not use solvents, requires smaller samples (<100 mg) than conventional solvent methods, and can detect real absence of water in the sample. [ABSTRACT FROM AUTHOR]

A freeze- and bake-stable glazing for pastry has been developed based on an optimization procedure in which starches and carrageenans as thickening agents were combined with sugar alcohols and sodium tripolyphosphate. Instrumental gloss measurement on test biscuits showed that glazing consisting of 3% ι-carrageenan and 15% sorbitol (w/w) had maximal gloss. This was confirmed on pastry products. In contrast to glazing based on mannitol, no crystallization problems were encountered for this glazing, for which differential scanning calorimetry showed that some water freezes at –3 °C followed by freezing of supercooled encapsulated water at –20 °C and by a glass transition at –61 °C. During normal frozen storage of preglazed, nonbaked pastry, the glazing is thus in a nonstable rubbery state with a limited resistance to water migration and ice crystal formation, which can be substantially improved by storage at temperatures below –61 °C. [ABSTRACT FROM AUTHOR]

Thermogravimetric analysis and differential scanning calorimetric measurements of 10 : 1 w/w starch/α-amino acid blends were carried out in air, and from room temperature to 450 °C. Admixtures of each of the 17 tested amino acids depressed the point of starch glassy transition and point of starch decomposition. Only decomposition products of proline reacted with starch in the blend of starch with proline. Other amino acids reacted prior to their decomposition. Among them alanine, isoleucine, and valine most readily reacted with starch. The reactions were assumed to be esterifications of amino acids by starch and/or the dextrins produced from starch. Arginine, histidine and lysine being basic amino acids reacted as bifunctional reagents with involvement of carboxylic and amino groups. [ABSTRACT FROM AUTHOR]

Understanding the interactions between sugar, starch, protein and water, which are the main components of a baked product, will advance the development of high quality, microwaveable products. This paper presents a mathematical model describing the quantitative relationships between water, sugar and protein on the gelatinization of wheat starch following 20 s of microwave heat as determined by differential scanning calorimetry. Addition of sugar decreased the degree of gelatinization of starch due to microwave heating significantly. Water and protein were not found to be as significant as sugar in delaying gelatinization. The effects of sugar and protein on the gelatinization of starch were pronounced in water-limited systems. The model could be used to describe systems containing 33–67% water, 0–33% sucrose and 0–5.8% protein, with a coefficient of determination of 0.91. [ABSTRACT FROM AUTHOR]