Decrease In Gelatinization Enthalpy Research Articles

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.

Impact of lipids on the functional, rheological, pasting and thermal properties of ultrasound-processed canary seed flours

Canary seed, a gluten-free cereal, is renowned for its high content of fats, starch, and proteins. The extraction of oil is often necessary to extend flour shelf life or obtain purified starch and protein fractions. Similar to many gluten-free flours, it may require additional thermal treatments to enhance its suitability to formulate several food products. Thus, this study investigated the impact of ultrasound (US) treatment on the techno-functional and physicochemical properties of both whole (WCS) and defatted (DWCS) canary seed flours. The US treatment slightly increased water and oil absorption capacities in WCS. Lipids in the flour and treatment temperature affected the surfactant properties. Untreated and treated defatted DWCS flours exhibited higher emulsifying activity (up to +36%) and foaming capacity (up to +340%) than WCS. The presence of lipids and US treatment influenced protein extraction, with changes in albumins (WCS and DWCS), globulins (DWCS) and prolamins (WCS) recovery. US treatment altered pasting and rheological properties of all studied flours, impacting viscosity and starch-lipid complex formation. Rheological properties were lipid-dependent, and defatted samples formed stronger gels. US treatment decreased gelatinization enthalpy in WCS (up to −9.5%) and increased it in DWCS (up to +11.3%) flours. Moreover, lipids significantly influenced retrogradation, which was absent in untreated and treated WCS flours. US-treated flours displayed similar diffraction patterns to untreated samples, but with reduced intensities as temperature increased. The untreated defatted sample exhibited a 9% lower crystallinity. These findings highlight the benefits of US treatment and defatting for improving gluten-free food products formulated with canary seed flour.

Effect of Heat–Moisture Treatment on the Physicochemical Properties, Structure, Morphology, and Starch Digestibility of Highland Barley (Hordeum vulgare L. var. nudum Hook. f) Flour

This study modified native highland barley (HB) flour by heat-moisture treatment (HMT) at different temperatures (90, 110, and 130 °C) and moisture contents (15%, 25%, and 35%). The effects of the treatment on the pasting, thermal, rheological, structural, and morphological properties of the native and HMT HB flour were evaluated. The results showed that HMT at 90 °C and 25% moisture content induced the highest pasting viscosity (3626-5147 cPa) and final viscosity (3734-5384 cPa). In all conditions HMT increased gelatinization temperature (To, 55.77-73.72 °C; Tp, 60.47-80.69 °C; Tc, 66.16-91.71 °C) but decreased gelatinization enthalpy (6.41-0.43 J/g) in the HMT HB flour compared with that in the native HB flour. The HB flour treated at 15% moisture content had a higher storage modulus and loss modulus than native HB flour, indicating that HMT (moisture content, 15%, 25%, and 35%) favored the strengthening of the HB flour gels. X-ray diffraction and Fourier-transform infrared spectroscopy results showed that HMT HB flour retained the characteristics of an A-type crystal structure with an increased orderly structure of starch, while the relative crystallinity could be increased from 28.52% to 41.32%. The aggregation of starch granules and the denaturation of proteins were observed after HMT, with additional breakage of the starch granule surface as the moisture content increased. HMT could increase the resistant starch content from 24.77% to 33.40%, but it also led to an increase in the rapidly digestible starch content to 85.30% with the increase in moisture content and heating temperature. These results might promote the application of HMT technology in modifying HB flour.

Effect of Heat-Moisture Treatment on the Physicochemical Properties and Starch Digestibility of Mix Powder (Wheat Flour-Black Soybean Flour) and Corresponding Cookies.

In order to improve the nutritional value and reduce starch the digestibility of black soybean cookies, superfine black soybean flour was modified by heat-moisture treatment (HMT). The physicochemical properties, structure analysis of the flour samples and corresponding dough, and nutritional, physical, and textural properties of the cookies were investigated. After HMT, the water and lactic acid retention capacity and the oil binding capacity of mix powder dramatically increased, being almost twice the value of the untreated sample. HMT increased gelatinization temperature by about 10 °C but decreased gelatinization enthalpy. HMT had no apparent effect on the morphology and size of granules, but some cracks and pores appeared on the HMT-mix powder granules and corresponding dough. Fourier transform infrared spectroscopy analysis showed that the ordered structure of dough was unaffected during HMT. After HMT, the thickness, density, and baking loss of the cookies increased, and the spread ratio decreased. HMT dramatically increased the chemical score of cookies from 12.35% in mix powder cookies to 19.64% in HMT-mix powder cookies. HMT decreased the rapidly digestible starch content, while the slowly digestible starch increased from 45.97% in mix powder cookies to 49.31% in HMT-mix powder cookies, and RS increased from 21.64% to 26.87%. Overall, HMT did not have a negative effect on the processing properties and microstructure and secondary structure of the dough, or the physical properties and quality of the cookies, but significantly improved the nutritional properties and decreased the starch digestibility of the cookies.

Physicochemical Properties of Enzymatically Modified Starches

The physicochemical properties of native, annealed and enzyme-treated chickpea (CP), corn (CS), Turkish bean (TB) and sweet potato (SPS) were investigated. Germinated sorghum extract (GSET) was used as the source of enzymes. Starches were annealed in excess water by holding the slurry at 60 °C for 60 min with or without GSET. The flow curves/rheological data were fitted to the power law, Casson and Herschel–Bulkley models. Starches exhibited shear thinning behavior and a variation in the flow behavior index (n) (0.34–0.82) as a function of the starch type. The consistency index (k) of CP and CS decreased with annealing and GSET treatment but increased for TB and SPS. Annealed and GSET-treated SPS exhibited the highest yield stress compared to the other starches, except for CP. The temperature dependency of all starches was well described by the Arrhenius model (r2 = 0.88–0.99). The activation energy (Ea) values were in the range of 660–5359 (J/mol). The TB exhibited the most Ea and SPS the least. With the exception of SPS, annealing appeared to increase the Ea of all tested starches, but the range of Ea was broader for SPS and CS. Annealed and GSET starches exhibited an increase in the gelatinization temperatures (onset and peak) and a decrease in gelatinization enthalpy (ΔH). The syneresis and water holding capacity decreased after annealing or GSET treatment.

Effects of various roasting temperatures on the structural and functional properties of starches isolated from tigernut tuber

Roasting pretreatment enhances the commercial qualities of tigernut oil. Oil extraction leaves behind meal, which is a potential source of starch. For industry to use this starch, its physicochemical characteristics of starch in meals after oil extraction with different roasting temperatures must be known, but have not been reported. In this investigation, the physicochemical properties of starches extracted from tigernut tubers before and after roasting at four different temperatures were investigated. Roasting increased the number of double helices and the ratios of A chains while decreasing crystallinity. There were differences in starch structure among samples roasted at different temperatures, which induced functional differences. The increase in A chains led to a decrease of peak viscosity, and improvement in freeze-thaw stability; the destruction of molecular interactions caused a decrease in pasting temperature; damage to the crystalline structure caused the decrease in gelatinization enthalpy and transition temperatures. As for differences in rheological properties, the interference of non-starch components and molecular interactions appear to be major factors. This study provides scientific information for the complete utilization of tigernut tubers.

Comparative Study on the Effects of Citric Acid Modification and Hydroxypropylation on the Physiochemical and Digestibility Characteristics of Acid‐Hydrolyzed Corn and Sorghum Starches

AbstractSorghum (Sorghum bicolor L.) crop is of great importance as it can be grown in drought‐hit areas. The starch extracted from sorghum has properties similar to corn (Zea mays L.) starch and is therefore considered as a productive future alternative. Starch has many technological constraints and the modifications help in improving the properties. Corn and sorghum starches are acid‐thinned prior to citric acid modification and hydroxypropylation. The acid‐hydrolyzed citrate and hydroxypropylated starches are characterized for their functional and digestibility characteristics. The modifications help in maintaining the resistant starch fraction of acid‐thinned starches. The resistant starch fraction ranges between 59–64% and 53–68% for corn and sorghum starch, respectively. The Fourier Transform Infrared spectroscopy results show decrease in crystalline to amorphous ratio (R = 1047 cm−1/1022 cm−1) for sorghum starch citrates. The X‐ray diffraction pattern exhibits a decrease the proportion of crystallinity of acid‐hydrolyzed esterified starches. Differential scanning calorimetry curves exhibit decreased gelatinization enthalpy for both modifications. A significant decrease (p ≤ 0.05) in peak viscosity is also observed for hydroxypropylated starches. The modifications increase the slowly digestible fraction of corn and sorghum starches from 12.7% to 24.4% and from 16.7% to 28.9%, respectively.

Effect of microwave processing on physicothermal properties, antioxidant potential, in vitro protein digestibility and microstructure of durum wheat semolina

The effect of microwave treatment on the physicothermal properties, antioxidant activity, protein digestibility and structural features of durum wheat semolina was investigated by varying time periods (1, 1.5 and 2 min) in a microwave oven set at 900 W. Results suggested that microwave treatment on durum wheat semolina caused a significant improvement in functional properties like water holding capacity (1.91 ± 0.08 to 2.63 ± 0.04 g/g), oil holding capacity (2.25 ± 0.36 to 3.05 ± 0.09 g/g), swelling power (6.08 ± 0.06 to 9.23 ± 1.15 g/100 g) and solubility (0.11 ± 0.01 to 0.13 ± 0.15 g/100 g). Overall colour difference (∆E*) increase from 22.63 ± 0.36 (untreated) to 31.14 ± 0.27 (2 min), while significant decrease in gelatinization enthalpy (2.49 ± 0.08 to 1.53 ± 0.09 J/g) and peak viscosity (1501 ± 5.29 to 127 ± 3.60 cP) was seen after the treatment. Total phenolic content (free + bound) decreased from 2.61 ± 0.01 to 0.98 ± 0.03 mg GAE/g, while antioxidant activity expressed as inhibitory concentration (IC50) improved (1.60 ± 0.05 to 0.79 ± 0.01 mg/ml) as microwave heating progressed. In vitro protein digestibility decreased significantly (71.35 ± 0.05 to 53.64 ± 0.04%) as the duration of microwave heating increased. Microstructure examination revealed small defects and rupturing of starch granules, whereas FTIR spectra of durum wheat semolina did not change by microwave heating.

Influence of heat treatment on starch structure and physicochemical properties of oats

Heat treatment is used to physically modify starch to meet requirements for certain food products such as canned food, bread or noodles. In oats, the application of heat is used to inhibit activities of enzymes that cause undesirable effects on the end-product quality. However, it may also affect starch structure and functional properties of oats. This study examined the effects of heat treatment processing on starch molecular structure and physicochemical properties of oats using eight oat genotypes grown at four sites in Australia. Compared to non-heat-treated oats, heat treatment resulted in shorter amylopectin chains, higher amounts of long amylose chains and higher amylose content where amylose content and the relative amounts of long and short amylose chains are important determinants of functional properties of cereal-based food products. Heat treatment also increased gelatinization and pasting temperature but decreased gelatinization enthalpy, breakdown viscosity, final viscosity and setback viscosity. The peak viscosity remained unchanged. The results of this study show how heat-treated oats changes starch structure and properties, which could impact on processing for specific food products.

Effects of ultrasonic and enzymatic treatment on physical and chemical properties of brown rice

AbstractBrown rice (Oryza sativa Linn.) was subjected to ultrasonic treatment (UT) and enzymatic treatment (ET) with cellulase (CT), glucoamylase (GT), and α‐amylase (AT). UT showed no significant effect on thermal properties, crystalline pattern and, glycemic response of brown rice. AT decreased gelatinization enthalpy from 7.19 g/J (control) to 5.31 g/J and reduced degree of crystallinity from 23.06% (control) to 21.02%. These changes significantly increased glycemic index of AT brown rice. CT and GT had insignificant effect on crystallinity and thermal properties of rice. Both UT and ET decreased hardness of cooked rice from 206.05 to 189.63–148.87 N in which the AT cooked rice was the softest. Both AT and UT were potentially used as novel processes to develop the soften brown rice. However, UT brown rice had lower glycemic response, required shorter cooking time, and was more practically produced in industrial scale than ET brown rice.Practical applicationsSoaking is the hydration process, which is normally used for brown rice before cooking. However, it is inconvenient and time‐consuming. Results of this study revealed the effects of enzymatic and ultrasonic treatments (UTs) on modifying of the bran layer and changing of physiochemical properties of rice grains. These changes promoted water uptake, reduced hardness, and improved cooking properties of brown rice. In consideration of glycemic response, UT represents good practice in the production of soften brown rice without soaking before cooking.

Novel Oxidized and UV‐Irradiated Araucaria angustifolia Pine Seed Starch for Enhanced Functional Properties

Starch is an important raw material for industrial processes. Therefore, an investigation of new sources of starch and starch modification methods is necessary. The dual oxidation effect on the properties of the native pine seed starch is investigated. Native starch is extracted from pine seeds and its proximate composition determined. The starch is then subjected to a dual oxidation process in standard NaClO or H2O2 solutions (0.2; 0.5; 0.8 mol L−1) and simultaneous exposure to ultraviolet light irradiation (UVC λ = 254 nm). Thermogravimetric (TG‐DTA) curves reveal enhanced stability to thermal degradation of the dual NaClO/UV process modified starch up to 20%. Differential scanning calorimetry (DSC) shows a strong decrease in gelatinization enthalpy due to the action of the UV‐rays coupled with the sodium hypochlorite (NaClO) solution. The H2O2/UV modified starch has a high final viscosity while the NaClO/UV starch pastes have a low tendency to recrystallize. Furthermore, structural analysis using an X‐ray diffractometer and scanning electron microscopy (SEM) show crystallinity patterns of type A starch and that the shape of the starch granules are unaltered following the modification processes. Color parameters show a strong increase in the L* value (for whiteness) for the NaClO/UV treated samples. The modified starches demonstrate improved physicochemical properties which are suitable for several industrial applications including as stabilizers for frozen bakery products, whitening agents for paper products, and tableting agents for cosmetic and pharmaceuticals products.

High-Pressure Treatment of Non-Hydrated Flour Affects Structural Characteristics and Hydration.

In recent years, high-pressure treatment (HPT) has become an established process concerning the preservation of food. However, studies dealing with the structural, and consequently functional modification of non-hydrated starchy matrices (moisture content ≤ 15%) by HPT are missing. To close this knowledge gap, pressure (0–600 MPa, 10 min) and pressurization time depending (0–20 min, 450 MPa) alterations of wheat flour were investigated. Pressure rise from 0 to 600 MPa or pressurization time rise from 0 to 20 min resulted in a decline of amylopectin content from 68.3 ± 2.0% to 59.7 ± 1.5% (linearly, R2 = 0.83) and 59.6 ± 0.7% (sigmoidal), respectively. Thereby, detectable total amount of starch decreased from 77.7 ± 0.8% linearly to 67.6 ± 1.7%, and sigmoidal, to 69.4 ± 0.4%, respectively. Increase in pressure caused a linear decrease in gelatinization enthalpy of 33.2 ± 5.6%, and linear increase in hydration properties by 11.0 ± 0.6%. The study revealed structural and technological relevant alterations of starch-based food matrices with low moisture content by HPT, which must be taken into consideration during processing and preservation of food.

The Modifications in Physicochemical and Functional Properties of Proso Millet Starch after Ultra‐High Pressure (UHP) Process

Proso millet starch suspensions (30%, W/V) are subjected to UHP treatment at 150, 300, 450, and 600 MPa for 15 min in order to produce a modified starch for food applications. Besides, the UHP‐gelatinized starch gels are stored at room temperature for 192 h and the recrystallization characteristics are investigated during the storage time. The gelatinization extent of starch is increased with the increase in pressure level and the starch is fully gelatinized at 600 MPa. The XRD patterns show that the UHP at 600 MPa converted the A‐type crystals to the B‐type. The DSC data reveal an increase in gelatinization temperatures and a decrease in gelatinization enthalpy after treatment at 150–450 MPa. Pasting property analysis shows that trough and final viscosity, pasting temperature and peak time are increased; however, peak and breakdown viscosity are decreased with the increase in pressure level up to 600 MPa. UHP treatment resulted in a higher swelling capacity and solubility at a relatively low temperature. XRD and DSC are also used to monitor retrogradation through the growth of diffraction peaks of the recrystallized starch and the increase in the melting enthalpy. The extent of retrogradation is plotted as a function of the storage time.

Physico-functional and antioxidant properties of sand-roasted chickpea (Cicer arietinum)

The effect of roasting on the physical, color, thermal, functional and antioxidant properties of chickpea was investigated. Chickpea grains were roasted in sand at three temperatures (180, 200 and 220°C) for different times (5, 10 and 15min). Highest surface area and lowest bulk density were obtained for grains roasted at 220°C for 15min. The lightness ‘L’ of flour decreased from 88.48 (unroasted) to 78.73 (220°C, 15min) while significant increase in ‘a’ and ‘b’ color values was observed from −0.73 to 2.25 and 22.43 to 24.83, respectively on roasting. Significant decrease in enthalpy of gelatinization (−0.14 to −0.46J/g), enthalpy of amylase-lipid complex (4329–2293J/g), total flavonoid content (22.89–16.64mg quercetin equivalents/100g) and antioxidant activity (22.85–7.36%) was observed upon roasting. However, roasting led to an increase in water absorption capacity (0.89–3.64g/g), water absorption index (1.97–3.52) and oil absorption capacity (1.60–3.54g/g).

Effect of salt addition on gelatinization and rheological properties of sweet potato starch–xanthan gum mixture

The effect of NaCl at different concentrations (1.0–5.0%) on the gelatinization and rheological properties of sweet potato starch (SPS)–xanthan gum (XG) mixtures was examined. Steady shear rheological properties of SPS–XG–NaCl mixtures were determined from the rheological parameters for the power law and Casson flow models. The consistency index (K), apparent viscosity (ηa,100,), and Casson yield stress (σoc) values of SPS–XG–NaCl mixtures were much lower than those of the control (0% NaCl) and also decreased with an increase in the NaCl concentration. The storage modulus (G′) values of SPS–XG–NaCl mixtures were much higher than the loss modulus (G″), indicating that the addition of NaCl influences the synergistic effect in the elastic properties of XG in the SPS–XG–NaCl mixture systems. The addition of NaCl resulted in a significant increase in the peak, breakdown, final, and setback viscosities, and pasting temperature of SPS–XG mixture. In general, differential scanning calorimeter (DSC) studies conveyed that the presence of NaCl resulted in an increase in the gelatinization temperatures (To, Tp, and Tc) and a decrease in gelatinization enthalpy (ΔH). In general, these results suggest that the addition of the NaCl to SPS–XG mixtures modified the pasting, rheological, and thermal properties, depending on the NaCl concentration.

Effect of Sucrose Addition on Rheological and Thermal Properties of Rice Starch–Gum Mixtures

Abstract The effect of sucrose at different concentrations (0, 10, 20, and 30% w/w) on rheological and thermal properties of 5% (w/w) rice starch (RS) pastes mixed with guar gum (GG) and xanthan gum (XG) was examined. The flow behavior index (n) values of RS–gum mixtures in the presence of sucrose were higher than those of the control (0% sucrose), whereas their K and σ oc values were lower. The RS–XG–sucrose mixtures showed much higher dynamic moduli values than the control, while the RS–GG–sucrose mixtures, except for the 30% sucrose concentration, showed lower values, indicating that the viscoelastic properties of RS–XG mixtures were greatly affected by the addition of sucrose. In general, differential scanning calorimetry studies showed that the presence of sucrose resulted in an increase in the gelatinization temperatures and a decrease in gelatinization enthalpy. These results could facilitate the development of RS-based products with improved thermal and rheological properties.

Effects of Heat Stress at Different Grain‐Filling Phases on the Grain Yield and Quality of Waxy Maize

ABSTRACTEffects of heat stress (mean day/night temperatures of 35.2/16.1 and 27.4/15.6°C for heat stress and control, respectively) during different grain‐filling phases (1–10, 11–20, 21–30, 31–40, and 1–40 days after pollination [DAP]) on the grain yield and quality of waxy maize were investigated using two varieties. Heat stress decreased the number and weight of grains, thereby reducing grain yield. The effects of heat stress at an early grain development stage (before 20 DAP) were severe. Compared with the control, starch deposition was not affected by heat stress in Suyunuo5, and it was only decreased by heat stress at 1–10 DAP in Yunuo7. Protein content responses to heat stress were variety and stage dependent. Heat stress increased the iodine‐binding capacities of both varieties. Peak and breakdown viscosities were decreased by heat stress, and the effects gradually decreased with postponement of high temperature. Heat stress increased gelatinization temperature and retrogradation percentage for both varieties, and the response was stage dependent. Heat stress during the whole grain‐filling period increased the pasting and gelatinization temperatures but decreased gelatinization enthalpy. Changes in protein and starch contents as well as the proportion of long chains in amylopectin affected the pasting and thermal properties.

Effects of high temperature after pollination on physicochemical properties of waxy maize flour during grain development

Waxy maize is grown in South China, where high temperatures frequently prevail. The effect of high-temperature stress on grain development of waxy maize is not known. High temperature decreased the grain fresh weight and volume, and lowered the grain dry weight and water content after 22 days after pollination (DAP). Plants exposed to high temperature had low starch content, and high protein and soluble sugar contents at maturity. Starch iodine binding capacity and granule size were increased by heat stress at all grain-filling stages. The former parameter decreased, while the latter parameter increased gradually with grain development. High temperature increased the peak and breakdown viscosity before 30 DAP, but the value decreased at maturity. Pasting and gelatinization temperatures at different stages were increased by heat stress and gradually decreased with grain development under both high-temperature and control conditions. Gelatinization enthalpy increased initially but decreased after peaking at 22 DAP under both control and heat stress conditions. High temperature decreased gelatinization enthalpy after 10 DAP. Retrogradation percentage value increased with high temperature throughout grain development. High temperature after pollination changes the dynamics of grain filling of waxy maize, which may underlie the observed changes in its pasting and thermal properties.

The Effect of Tribomechanical Micronization and Activation on Rheological, Thermophysical, and Some Physical Properties of Tapioca Starch

The aim of this research was to investigate the effect of tribomechanical treatments on rheological, thermophysical, and some physical properties of tapioca starch. Samples of tapioca starch were treated using laboratory equipment for tribomechanical micronization and activation (TMA equipment). Before and after the TMA treatment, analysis of the particle size and particle size distribution was carried out, in addition to scanning electron micrography in tapioca starch. Scanning electron micrography showed that tribomechanical processing of tapioca starch resulted in breaking accumulations of starch granules in the form of granules. Pasting parameters have shown that maximal viscosities of model starch suspension have been decreasing after tribomechanical treatment. On the basis of gelatinization curves, it can be concluded that there are changes in the gelatinization point after treatment, and there is decrease in enthalpy of gelatinization for model suspension. After tribomechanical treatment, changes in physical properties of starch suspensions were determined, as well as specific swelling capacity, solubility index, and turbidity of tapioca starch suspensions.

Physical Properties of Resistant Mungbean Starch Prepared by Enzyme and Acid Treatment

The physical properties of enzyme and acid treated mungbean RS were studied. The crystal form was transformed into B type from C type with enzymatic and acid treatment.The solubility and transmittance decreased and mungbean RS content and the water-binding values increased with increase in enzyme and acid hydrolysis. The thermal properties observed by DSC showed a decrease in enthalpy of gelatinization (ΔH) and increases in onset (To), peak temperature (Tp) and conclusion temperature (Tc) upon enzyme and acid hydrolysis. The ratio of volume of resistant starch samples wasn’t much different. However, a significant reduction in starch pasting viscosity was observed with enzyme and acid treating