Gelatinization Enthalpy Research Articles

A comprehensive analysis of edible and processing quality changes in three whole grain flours induced by dielectric barrier discharge atmospheric cold plasma treatment

SummaryDielectric barrier discharge atmospheric cold plasma (DBD‐ACP) treatment has been used to reduce microbial contamination on the surface of grains, contributing to improved food safety, however, its effect on the edible and processing of whole grain flours is not totally clear. In this study, the effect of DBD‐ACP (5 W, 0–20 min) on the nutritional, physicochemical and structural properties of whole quinoa (WQ), whole highland barley (WHB) and whole triticale (WT) were evaluated. Results showed that the effect of DBD‐ACP treatment on the nutrient composition of different flours differed between grain types. The total polyphenol content of WQ exhibited the most significant changes after 20 min of treatment, decreasing by 62.98%. In addition, DBD‐ACP treatment increased Thr, Phe and Tyr content and accelerated fat oxidation. The results of in vitro simulated digestion experiments indicated that DBD‐ACP treatment significantly reduced (P < 0.05) the final digestibility of three types of whole grain flours. Besides, 20 min of DBD‐ACP treatment significantly changed the physicochemical properties of samples, evidenced by improved hydration and pasting characteristics, increased water absorption index (WAI) and swelling power (SP) and reduced peak temperature (Tp) and gelatinisation enthalpy (∆Hg), especially in WQ20. Further structural analysis showed that DBD‐ACP treatment caused granule cross‐linking and reduced crystallinity of flours. In conclusion, this experiment provided a theoretical basis for the application of DBD‐ACP in grain processing.

Rheological properties, multiscale structure, and in vitro digestibility of a maize starch–konjac glucomannan–bamboo leaf flavonoid complex modified by dynamic high-pressure microfluidization

The effects of dynamic high-pressure microfluidization (DHPM) treatment on the rheological properties, multiscale structure and in vitro digestibility of complex of maize starch (MS), konjac glucomannan (KGM), and bamboo leaf flavonoids (BLFs) were investigated. Compared with MS, the MS–KGM–BLF complex exhibited reduced viscosity and crystallinity, along with increased lamellar thickness to 10.26 nm. MS–KGM–BLF complex had lower viscosity after DHPM treatment. The highest ordered structure and crystallinity were observed at 50 MPa, with the α value increasing from 3.40 to 3.59 and the d value decreasing from 10.26 to 9.81 nm. However, higher DHPM pressures resulted in a decrease in the α value and an increase in the d value. The highest gelatinization enthalpy and resistant starch content were achieved at 100 MPa DHPM, while the fractal structure shifted from surface fractal to mass fractal at 150 MPa. This study presents an innovative method for enhancing the properties of MS.

Dynamic development of changes in multi-scale structure during grain filling affect gelatinization properties of rice starch

Rice was collected over the entire grain filling period (about 40 days) to explore the multi-structure evolution and gelatinization behavior changes of starch. During the early stage (DAA 6–14), the significant reduction in lamellar repeat distance (10.04 to 9.68 nm) and relative crystallinity (26.6 % to 22.7 %) was due to initial rapid accumulation of amylose (from 9.38 % to 14.05 %) and short amylopectin chains. Meanwhile, the decreased proportion of aggregation structure resulted in a decrease in the gelatinization temperature and a narrowed range of gelatinization temperature also indicated an increase in homogeneity as starch matured. Gelatinization enthalpy was mainly controlled by aggregation structure, which was negatively and positively related to the amylose content and the degree of order respectively. Peak viscosity of starch pasting increased and reached a maximum (924 cP) at DAA-21 due to larger granule size. Amylose and short amylopectin chains with degree of polymerization 6–12 showed positive and negative correlation with short-term retrogradation ability (setback value) respectively. The dynamics of different scale structure during grain filling had varying degrees of impact on gelatinization properties.

Relations Between Amylose Content and Physicochemical Properties of Starches from White and Red Sorghum Varieties

AbstractThis research aims to determine the relationship between amylose content and physicochemical properties in white and red sorghum starches. Five varieties of red sorghum and four varieties of white sorghum were evaluated. The chemical properties, the amylose content, the resistant starch content, scanning electron microscopy, the absorption and solubility index in water, the viscosity profile, the thermal properties, and the correlation between the amylose content were determined. Sorghum starches had an amylose content between 24.51% and 34.34%, but did not show any relationship with color. Regarding the microstructure, the starches that appear larger granules (20–30 µm) have lower amylose content. Sorghum red varieties shown higher values in gelatinization enthalpy, pasting temperature and water absortion index, this effect was attributed to the formation of complexes with phenolic compounds. Starches with a higher proportion of amylose shown lower viscosity profiles and a high thermal stability. Correlation matrix analysis reveals that amylose content had a negative correlation with water absorption index, water solubility index, maximum viscosity, minimum viscosity, and positive correlation with the resistant starch content. The amylose content can define the potential application of the sorghum starches.

Interactions between corn starch and lingonberry polyphenols and their effects on starch digestion and glucose transport

This study investigated the interaction mechanism between corn starch (CS) and lingonberry polyphenols (LBP) during starch gelatinization, focusing on their effects on starch structure and physicochemical properties. Moreover, it explored the effect of this interaction on starch digestion and glucose transport. The results indicated that LBP interacted non-covalently with CS during starch gelatinization, disrupted the short-range ordered structure of starch, decreased gelatinization enthalpy of starch, and formed a dense network structure. Furthermore, the incorporation of LBP remarkably reduced the digestibility of CS. In particular, the addition of 10 % LBP decreased the terminal digestibility (C∞) from 77.87 % to 60.43 % and increased the amount of resistant starch (RS) by 21.63 %. LBP was found to inhibit α-amylase and α-glucosidase in a mixed manner. Additionally, LBP inhibited glucose transport in Caco-2 cells following starch digestion. When 10 % LBP was added, there was a 34.17 % decrease in glucose transport compared with starch digestion without LBP. This study helps establish the foundation for the development of LBP-containing starch or starch-based healthy foods and provides new insights into the mechanism by which LBP lowers blood glucose.

Experimental Warming Increased Cooked Rice Stickiness and Rice Thermal Stability in Three Major Chinese Rice Cropping Systems.

Climate warming is a critical environmental issue affecting rice production. However, its effects on cooked rice texture and rice thermal properties remain unstudied in China. To address this gap, we conducted a two-year multi-site field warming experiment using free-air temperature increase facilities across three major Chinese rice cropping systems. Interestingly, warming had a minimal impact on the hardness of cooked rice, while it significantly increased stickiness by an average of 16.3% under warming conditions. Moreover, compared to control treatments, rice flour exhibited a significant increase in gelatinization enthalpy, onset, peak, and conclusion temperatures under warming conditions, with average increments of 8.7%, 1.00 °C, 1.05 °C, and 1.17 °C, respectively. In addition, warming significantly declined the amylose content, remarkedly elevated the protein content and relative crystallinity, and altered the weight distribution of the debranched starch. Correlation analysis revealed significant relationships between cooked rice stickiness, rice flour thermal properties, amylose content, protein content, and partial starch structures. Therefore, warming-induced alterations in rice composition and starch structure collectively enhanced cooked rice stickiness and rice thermal stability.

Potential of polyphenols from Ligustrum robustum (Rxob.) Blume on enhancing the quality of starchy food during frying.

The increasing concerns about health have led to a growing demand for high-quality fried foods. The potential uses of Ligustrum robustum (Rxob.) Blume, a traditional tea in China, as natural additives to enhance the quality of starchy food during frying was studied. Results indicated that L. robustum polyphenols extract (LREs) could improve the quality of fried starchy food, according to the tests of color, moisture content, oil content, texture property, and volatile flavor. The in vitro digestion results demonstrated that LRE reduced the final glucose content from 11.35±0.17 to 10.80±0.70mmol/L and increased the phenolic content of fried starch foods from 1.23±0.04 to 3.76±0.14mg/g. The appearance and polarizing microscopy results showed that LRE promoted large starch bulges on the surface of fried starchy foods. Meanwhile, X-ray diffraction results showed that LRE increased the intensity of characteristic diffraction peak of fried starch with a range of 21.8%-28%, and Fourier transform infrared results showed that LRE reduced the damage to short-range order structure of starch caused by the frying process. In addition, LRE increased the aggregation of starch granules according to the SEM observation and decreased the enthalpy of starch gelatinization based on the differential scanning calorimetry results. The present results suggest that LREs have the potential to be utilized as a natural additive for regulating the quality of fried starchy food in food industries. PRACTICAL APPLICATION: The enhancement of L. robustum polyphenols on the quality of starchy food during frying was found, and its mechanisms were also explored. This work indicated that L. robustum might be used as a novel economic natural additive for producing high-quality fried foods.

Effect of freezing rates on α-amylase enzymatic susceptibility, in vitro digestibility, and technological properties of starch microparticles

The aim of this study was to evaluate the effect of freezing rates using direct (LF: Liquid nitrogen) and indirect (RF: Cryogenic refrigerator and UF: ultra-freezer) methods at temperatures of (−20, −80, and − 196 °C) on the enzymatic susceptibility with α-amylase for microparticles. In vitro digestibility parameters and technological properties were also analyzed. Lower rates resulted in larger ice crystals, damaging the starch structure. Hydrolysis was more pronounced at slower rates RF: 0.07 °C/min and UF: 0.14 °C/min, yielding maximum values of RDS: 37.63% and SDS: 59.32% for RF. Type A crystallinity remained unchanged, with only a noted increase in crystallinity of up to 6.50% for FR. Starch pastes were classified as pseudoplastic, with RF exhibiting superior textural parameters and apparent viscosity. (RF: 7.18 J g−1 and UF: 7.34 J g−1) also showed lower values of gelatinization enthalpy. Freezing techniques were viable in facilitating the diffusion of α-amylase and reducing RS by up to 81%.

Effect of osmotic pressure and simultaneous heat-moisture phosphorylation treatments on the physicochemical properties of mung bean, water caltrop, and corn starches

This study aimed to investigate the physicochemical properties of modified starch prepared through the simultaneous heat-moisture and phosphorylation treatment (HMPT) and osmotic pressure treatment (OPT) for water caltrop starch (WCS), mung bean starch (MBS), and amylose-rich corn starch (CS) for different time periods. Furthermore, variations in starch content [amylose and resistant starch (RS)], swelling powder (SP), water solubility index (WSI), crystallinity, thermal properties, gelatinization enthalpy (ΔH), and glycemic index (GI) were examined. This study demonstrates that neither HMPT nor OPT resulted in a significant increase in the resistant starch (RS) content, whereas all samples succeeded in heat-treating at 105 °C for another 10 min exhibited a significant increase in RS content compared to their native counterparts. Moreover, the gelatinization temperatures of the three starches increased (To, Tp, and Tc), whereas their gelatinization enthalpy (ΔH) and pasting viscosity decreased. In particular, the GI of all three modified starches subjected to HMPT or OPT showed a decreasing trend with modification time, with OPT exhibiting the best effect. Therefore, appropriate modification through HMPT or OPT is a viable approach to develop MBS, WCS, and CS as processed foods with low GI requirements, which exceptionally may be suitable for canned foods, noodles, and bakery products.

Relationship between Chalkiness and the Structural and Physicochemical Properties of Rice Starch at Different Nighttime Temperatures during the Early Grain-Filling Stage.

The chalkiness, starch fine structure, and physiochemical properties of rice starch were analyzed and their correlations were investigated under different nighttime temperatures during the early grain-filling stage. Compared to MT, medium temperature (MT) and low (LNT) and high (HNT) nighttime temperatures resulted in an increased chalky grain rate (CGR) and chalkiness degree (CD). LNT mainly affected the chalkiness by increasing peak1 (short branch chains of amylopectin), the branching degree, and the proportion of small starch granules but decreasing peak2 (long branch chains of amylopectin) and peak3 (amylose branches). This altered the pasting properties, such as by increasing the peak viscosity and final viscosity. However, HNT mainly affected the chalkiness by increasing peak2 and the crystallinity degree but decreasing peak1 and peak3. Regarding the thermal properties, HNT also elevated peak and conclusion temperatures. The CGR and CD were significantly and positively correlated with the proportions of small and medium starch granules, peak1, branching degree, gelatinization enthalpy, setback viscosity, and pasting time but markedly and negatively correlated with the proportion of large starch granules, amylose content, peak3, peak viscosity, and breakdown viscosity. These findings suggest that LNT and HNT disrupted the starch structure, resulting in increased chalkiness. However, their mechanisms of action differ.

Dielectric barrier discharge plasma pre-treatment to facilitate the acetylation process of corn starch under heating/cooling cycles

The objective of the current work was to evaluate the impacts of dielectric barrier discharge plasma and repeated dry-heat treatments on the acetylation process of corn starch. The combined modification resulted in a higher substitution degree of acetate groups on starch chains compared to the acetylation treatment alone. This outcome was linked to the increase in surface area and structural organization level of granules achieved through the application of plasma and heating/cooling cycles, respectively. The successful esterification of starch structure was verified through FTIR (1710 cm−1) and 1H NMR (2 ppm). With the increase in plasma treatment duration up to 20 min, gelatinization enthalpy increased (10.81 J/g) due to the cross-linking reaction. Starch acetate produced through the combined treatment could find the application in the development of low-calorie food formulations due to its high resistant starch (70.5 g/100 g) and low viscosity (43 mPa s).

Effect of amylose partial extraction on citrate esterification of potato starch and its role in structure and physicochemical modification

This study examines the impact and influence of amylose on the starch esterification reaction through partial extraction of amylose. Citric acid was added for the esterification reaction, and then the esterified starches' multiscale structure, physicochemical, and functional properties were evaluated. As the extraction time of amylose increased, the amylose content in the starch decreased. Higher concentrations of citric acid will lead to samples with a higher degree of substitution, with DS rising from 0.203 % (0 h) to 0.231 % (3.5 h) at CA3 treatment. While removing amylose had minimal effects on the crystal structure of starch granules, it did decrease the ratio of A and B1 chains and the molecular weight of amylose. Acid hydrolysis exacerbated these changes upon the addition of citric acid. Furthermore, removing amylose followed by citrate esterification resulted in lower pasting viscosity, enthalpy of gelatinization (from 13.37 J to 2.83 J), and degree of short-range ordering. Also, digestion shows a decrease caused by the increasing content of slow-digesting starch. The presence of amylose in starch granules does affect the formation of starch esters, and removing it before esterification modification may improve production efficiency and reduce costs to some extent.

Sub-high amylose maize starch: an ideal substrate to generate starch with lower digestibility by fermentation of Qu.

The fermentation of Qu (FQ) is a novel method to modify the properties of starch to expand its application and especially to increase the resistant starch (RS) content. Using waxy maize starch (WMS) as a fermentation substrate can increase the RS content significantly but it may be time consuming and not cost effective due to the almost negligible RS content of WMS. To solve this problem, we hypothesized that sub-high amylose starch (s-HAMS), with an amylose content close to 50% could be an ideal substrate for FQ. The results showed that FQ did not change the shape and the particle size of starch granules, the gelatinization peak (Tp), or the conclusion temperature (Tc), but the slowly digested starch content declined. Rapidly digested starch content fluctuated during FQ and the amylose content decreased within 36 h and then increased. Within 24h, FQ significanlty increased these values: the RS content, relative crystallinity (RC), the ratio of FTIR absorbances at 1047/1022cm-1, the diffraction peak at 19.8° in X-ray diffraction (XRD), and the gelatinization onset temperature (To) increased significantly, within 24 h of FQ. However, after 24 h of fermentation, the RS content, RC, the ratio of FTIR absorbances at 1047/1022 cm-1, and gelatinization enthalpy (ΔH) decreased significantly. Sub-high amylose starch is more suitable for FQ to produce low digestibility starch, and the increase in RS may be due to the formation of 'amylose-lipid' complexes (RS5). © 2024 Society of Chemical Industry.

Pasting, thermal and structural changes of part‐baked bread prepared under freezing conditions

SummaryIn frozen part‐baked bread technology, starch is influenced by various processing factors. This study aimed to investigate the effect of part‐baking time, freezing rate and frozen storage time on pasting, thermal and structural properties of part‐baked bread. Wheat dough was part‐baked for 0, 3 or 6 min and frozen at −20 °C using two freezing rates: slow (0.15 °C min−1) or fast (1.45 °C min−1). Next, samples were stored in frozen conditions for 56 days and analysed every 14 days for starch damage, pasting properties, thermal and X‐ray analysis. The level of damaged starch increased with 3 min (69.3%), and 6 min (88.8%) of part‐baking time for both freezing rates compared to no part‐baked. In pasting analyses, peak viscosity decreased 27.3% and 38.4% for 3 and 6 min of part‐baking time, respectively, at 0 days of frozen storage; however, this tendency was observed for all frozen storage time. The gelatinisation enthalpy (ΔHg) decreased as part‐baking time increased, showing the maximum reduction at 6 min of part‐baked (94.9%). In X‐ray diffraction analyses at 3 and 6 min of part‐baking, the intensity of the signal increased 4.4% and 10.9%, respectively, probably due to the starch gelatinisation. These results can serve as a valuable guide for developing strategies to enhance the quality of part‐baked bread and improve production performance.

Characterization of flours from some underutilized carbohydrate sources of Thailand for potential food applications

Northern Thailand's underutilized crop flours were examined for morphology, chemical composition, thermal, and techno-functional properties to broaden carbohydrate sources and assess their potential as plant-based food analogs and other food ingredients. Samples were as follows: Elephant foot yam (A), and Purple yam or Greater yam (DA-P), Water yam (DA-W), Five-leaf yam (DP), D. daunaea Prain & Burkill (DD), and Lesser yam (DE). Scanning electron micrographs revealed varied starch granule shapes and size ranging from 9 to 31 mm. XRD showed A-type crystallinity for sample A, B-type for DA-P, DA-W, DP, and DE, and C-type for DD. DP flour has the highest protein and starch content. DD and DE flours had the highest fat and fiber content with the least amylose content. DP, DA-P, and A flours displayed excellent thickening capacity, whereas DD and DE flours exhibited low viscosity and resistance to disintegration induced by heat and shear. DA-W flour exhibits moderate physicochemical properties, rendering it versatile for a multitude of applications. Gelatinization enthalpy (ΔH) ranged from 3.46 J/g to 8.14 J/g, indicating DA-P granular structure had more crystallites while A flour had lower thermostability. All flours exhibited unique characteristics, offering diverse options as texturizing agents for food analog formulation.

Starch from Unripe Apples (Malus domestica Borkh) as an Alternative for Application in the Food Industry.

This study investigated the properties of starch isolated from the unripe fruit of two apple cultivars (Malus domestica Borkh) grown in southern Poland (Central Europe). The chemical composition of both starches, molecular mass, their granulation, thermal characteristics, swelling characteristics, and rheological characteristics were studied. The starches differed significantly in ash, phosphorus, and protein content. The water-binding capacity at temperatures of 25-65 °C was similar, while differences of 20% appeared at higher temperatures. In contrast, a significant difference was found in the solubility of the two starches in the temperature range of 25-75 °C. The study showed that apple starches have a relatively low tendency to retrograde, with the enthalpy of gelatinization for starch from the Oliwka variety being 40% higher than that from the Pyros variety. However, the starches differed in the hardness of the gels formed, i.e., one variety formed soft gels with an internal structure resistant to external forces, while the other formed hard gels.

Effects of stir-frying on the processing characteristics and in vitro digestion of oat flour during storage

This study focused on stir-frying, a traditional Chinese method for treating oats before milling. The effects of stir-frying on the processing properties and in vitro digestion of oat flour during storage have not been explored. The results revealed that stir-frying treatment caused a greater amylopectin content of the oat flour, which made the oat flour easier to improve water absorption and expansion ability. The WAI of stir-fried oat flour was notably greater than that of raw oat flour, while the results of WSI were opposite. The enthalpy of gelatinization of the two oat flours increased significantly (p < 0.05) during storage, and the gelatinization characteristics changed significantly after 9 months of storage. SEM and CLSM studies showed that the dough made from stir-fried oat flour exhibited a well-formed gel network structure, better clumping performance and fat stability during storage. Compared with raw oat flour, stir-fried oat flour had a faster starch hydrolysis rate, a greater rapidly digestible starch (RDS) content, and a lower resistant starch (RS) content. The effect of storage time on the digestibility of stir-fried oat flour was less compared with raw oat flour. Overall, stir-frying improved the processing adaptability, digestibility, and stability of oat flour during storage.

Preparation and physicochemical properties: a new extruded rice using cassava starch and broken rice flour

With the increasing demand for nutrition and health, many researchers are trying to develop a rice product with lower aging rate and convenient nutrient fortification. Being composed of high amylopectin content, cassava starch (CS) shows a lower retrogradation tendency compared to rice starch. So, it has a broad application prospect to partially replace rice starch with CS in rice by extrusion technology. In this study, a new extruded rice (ER) was prepared by broken rice flour and CS using single-screw extruder through “improved extrusion cooking technology,” and the maximum addition level of CS in ER was 30%. Color parameters and texture profile analysis showed that ER was a little darker in appearance with lower hardness, adhesiveness and chewiness. Rapid visco analysis demonstrated that the viscosity of ER paste appeared earlier during the initial heating phase and displayed a lower retrogradation trend than normal rice in the cooling process. The gelatinization temperature and gelatinization enthalpy decreased with the increasing CS in ER, while the degree of gelatinization increased to 76.36% when the content of CS was 30% after extrusion. The X-ray diffraction patterns of control was typical A-type structure, while ER changed to V-type structure with a lower degree of crystallinity. The microstructure observation showed that ER exhibited a looser and more porous structure with increasing the content of CS, which facilitated easier cooking and nutritional enhancement.

Rice starch modification by thermal treatments with avocado oil: Autoclave versus microwave methods

This study aimed to evaluate the physical and chemical alterations in rice starch modified by heat-moisture treatment (HMT) using an autoclave and a microwave, in association with avocado oil (AO), and evaluate the effects on thermal and structural properties, in vitro digestibility, and estimated glycemic index (eGI). Samples were adjusted to 30 % (w/w) moisture and 2, 4 and 8 % AO. HMT was conducted at 110 °C for 1 h in the autoclave (A0%, A2%, A4%, and A8%) and at 50 °C for 3 min in the microwave (M0%, M2%, M4%, and M8%). Both procedures did not alter the starch crystallinity pattern (type-A). Pasting viscosity, setback, relative crystallinity, and gelatinisation enthalpy decreased as the AO content increased in both HMT processes. The M8% showed reduced digestibility, decreased eGI (72.99, p < 0.05), and lower starch hydrolysis concentration (62.75 %, p < 0.05). The application of HMT with the addition of AO may be an interesting process for obtaining resistant starch since its content increased after both treatments (A8%, M4%, and M8%). The microwave process proved efficient, making it possible to use a lower temperature, less time, and less energy for modification and obtain starches with improved characteristics.

Ultrasound-assisted annealing treatment to improve physicochemical and digestive properties of banana flour.

Banana flour can provide a solution to people with gluten intolerance, as it is gluten-free. Native banana flour may have limited functionality in certain applications. In this study, banana flour was modified by ultrasonic (US) and annealing (ANN) treatments at four incubation time spans, namely 12, 24, 36 and 72 h, separately or combined sequentially (US-ANN) to enhance the physicochemical and digestive properties. US led to exposed granular surfaces and damaged non-starch components. Both treatments, at extended incubation time, increased crystallinity, resulting in a narrower starch gelatinization temperature range. The swelling power was significantly lower for ANN and US-ANN compared to US alone, providing a delay of gelatinization temperature. However, none of the treatments affected the gelatinization enthalpy. Furthermore, US increased peak viscosity, breakdown, final viscosity and setback whereas the opposite results were obtained for ANN and US-ANN. Additionally, US prior to ANN significantly increased the resistant starch (RS) content for annealing times over 24 h, especially for the US-ANN treatment for 72 h, which provided the highest RS content (49.3%) compared to ANN treatment for 72 h (44.0%) and native flour (36.3%). US prior to ANN treatment offers an alternative method to improve the functional and digestive properties of banana flour, extending the range of applications. © 2024 Society of Chemical Industry.