Retrogradation Of Rice Starch Research Articles

Influence of O/W emulsion on gelatinization and retrogradation properties of rice starch

An investigation was conducted into the effects of micro- and nano-emulsion on gelatinization and retrogradation of rice starch (RS). According to the results, the addition of emulsion contributed to the decline in the maximum viscosities, gelatinization enthalpy and a restriction on granular swelling during the gelatinization process of RS, and reduce the final gel strength of RS. During storage at 4 °C of the starch gel, the addition of emulsion was discovered to reduce the gel firmness and water mobility of RS gels during cold storage. The crystallinity of RS was found to be reduced from 11.59% to 6.81% after storage at 4 °C for 14 days. The microstructure of RS gel with emulsion was observed to be denser and more uniform compared with that of RS without emulsion after cold storage. As indicated by the result of starch retrogradation, emulsion was capable to prevent the interactions between starch molecules, retain the compact structure of starch gel, and decline the mobility of starch intra-granular water. These findings suggested that the addition of emulsion inhibited the short- and long-term retrogradation of RS, and promoted the application of emulsion in the starchy foods.

Synergistic effects of plant protein hydrolysates and xanthan gum on the short- and long-term retrogradation of rice starch

Controlling and delaying the retrogradation of gelatinized rice starch (GRS) can improve the quality of GRS-based foods during storage. Here, we evaluated the influence of corn protein hydrolysates (CPHs), rice protein hydrolysates (RPHs), wheat protein hydrolysates (WPHs), and soybean protein hydrolysates (SPHs) on inhibiting the short- and long- term retrogradation of RS-xanthan gum mixtures. Compared with WPHs, RPHs, CPHs, the SPHs cooperating with xanthan gum (SPHs-XT) showed the highest inhibitory effect. The increased loss tangent (tan δ) in the dynamic viscoelastic measurement suggested that SPHs-XT enhanced the liquid-like properties of GRS gel. The decreased storage modulus (G') and the reduced setback value indicated that the short-term retrogradation of GRS was restrained by SPHs-XT. Meanwhile, during a 14-day storage at 4 °C, the hardness of GRS gel was significantly decreased from 1382.5 g to 201.4 g after the addition of SPHs-XT before storage determined by using a texture profile analysis (TPA), and the relative crystallinity of the retrograded GRS was decreased from 18.18% to 8.15% determined by using a X-ray diffraction (XRD) with a corresponding decrease of the retrogradation enthalpy determined by using a differential scanning calorimetry (DSC). These results suggested that SPHs-XT could inhibit the the long-term retrogradation of GRS. Moreover, the water molecules were determined to be locked in GRS gel after the addition of SPHs-XT by using a low-field nuclear magnetic resonance (LF-NMR). In addition, thin membranes and filaments formed by the addition of SPHs-XT in GRS gel were observed by using a scanning electron microscopy (SEM), suggesting a decreased cross-linking of GRS molecules by the addition of SPHs-XT to form ordered structures. These results indicated that the addition of SPHs-XT is a potential to inhibit the short- and long-term retrogradation of GRS and further to improve the nutrition of the GRS based products.

Effects of limited moisture content and storing temperature on retrogradation of rice starch

The objective of this study is to investigate the effects of limited moisture content and storing temperature on the retrogradation of rice starch. Starch was gelatinized in various moisture contents (30–42%) and rice paste was stored at different temperatures (4 °C, 15 °C, 30 °C, −18/30 °C and 4/30 °C). X-ray diffraction (XRD) analysis revealed that after retrogradation, the crystalline type of rice starch changed from A-type to B + V type. The B-type crystallinity of retrograded rice starch under 30 °C was the highest among the five temperature conditions, and an increase in B-type crystallinity with increasing moisture content was observed. Differential scanning calorimetry (DSC) results revealed that rice starch retrogradation consists of recrystallization of amylopectin and amylose, and is mainly attributed to amylopectin. The higher moisture content was favorable for amylopectin recrystallization, whereas the moisture content had little effect on the amylose recrystallization. The optimal temperature for amylopectin and amylose recrystallization was 4 °C and 15 °C, respectively. The amylopectin recrystallization enthalpy of rice starch stored at 4/30 °C was mediated between 4 °C and 30 °C but always higher than that at −18/30 °C. On the whole, after being heated at 42% moisture content and stored at 4 °C, rice starch showed the maximum total retrogradation enthalpy (8.44 J/g).

Distribution of short to medium amylose chains are major controllers of in vitro digestion of retrograded rice starch

In many cultures, rice is let to cool for a while after cooking before being consumed, which results in some retrogradation of the starch. The in vitro digestibility of 16 cooked rice starches after extended cold (4 °C) storage, which leads to extensive retrogradation, was investigated from the perspective of their starch molecular fine structure. Size-exclusion chromatography (SEC) and fluorophore-assisted carbohydrate electrophoresis (FACE) were used to characterize the starch chain-length distributions (CLDs) and whole molecular size distributions. The retrograded starch gel network was studied by differential scanning calorimetry and scanning electron microscopy. Pearson correlation analysis with in vitro digestibility revealed that the starch digestion rate was positively correlated with cell size and cell wall thickness within the formed gel network, which was mainly derived from the interactions of amylose short-medium chains and not strongly related to amylopectin molecular structure. This suggests that rather than just altering amylose content, modification of amylose fine molecular structure (e.g. increasing the amount of short-medium amylose chains) can also slow rice starch digestibility.

Effect of rice protein on the water mobility, water migration and microstructure of rice starch during retrogradation

The effects of rice protein on the water mobility, water migration and microstructure of rice starch during retrogradation were investigated by low field-nuclear magnetic resonance (LF-NMR), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The addition of rice protein limited the migration of water in rice starch gels and delayed the decrease of the spin-spin relaxation time during storage. The nuclear magnetic imaging showed that the gel without rice protein shrank when it was stored for 7 days, while the gel with rice protein did not change significantly. The SEM indicated that the gel with rice protein had a tighter and more uniform structure than the gel without rice protein. Microstructure analysis proved that adding rice protein could inhibit starch recrystallization, and the inhibitory effect was dependent on the concentration of rice protein. The inhibitory effect of rice protein on the retrogradation of rice starch was hypothesized to be mainly due to the addition of rice protein imported the space restriction, which reduced the cross-linking of starch molecules to form an ordered structure, inhibited the moisture migration in the gel, and enhanced the water-holding capacity of starch gels.

Structure and Mechanical Properties of Retrograded Rice Starch and Cow Bone Powder Composite Sponge

To study the effect of addition purified cow bone (CB) powder (20, 30, 40 and 50 wt%) in slurry suspension of retrograded rice starch (RRS). The composite sponges were used as in bone repair. The RRS-CB composite sponges were prepared from the mixture of RRS, CB and additive into distill water. The prepared samples were characterized including SEM, XRD, physical and mechanical properties. The results of optimized condition have shown the samples of 40 wt% CB that had the swelling rate as 102± 0.01%, area of expansion was 20 ± 0.03 % for 72 hours and the compressive strength was 64.35±0.05KPa. In addition, it was found that this content resulted in sufficient soft porous material, foldable by hand and self recovered body.

EFFECT OF SUCROSE AND SODIUM POLYPHOSPHATE ON RETROGRADATION OF RICE STARCHES

Starch retrogradation is a process occurred in many food products made from starch-containing raw materials. It affects qualities of food during storage. In this research, the effects of sucrose and phosphate on rice starch retrogradation were studied. Experiments were conducted with sucrose content ranged from 1 – 5 % (w/w) and sodium polyphosphate – from 0.1 – 1 % (w/w). Results showed that sucrose and polyphosphate reduced the syneresis of starch gel 1.19 - 1.44 and 4.6 - 4.87 times respectively. Both substances reduced the hardness of starch gel, but sucrose reduced the stickiness while polyphosphate increased stickiness of rice starch gel.

Inhibition of gelatinized rice starch retrogradation by rice bran protein hydrolysates

The retrogradation of gelatinized rice starch (GRS) during the shelf life of a product is the biggest barrier related to starch-containing foods. The objective of this study was to produce rice bran protein hydrolysate (RBPH) using proteolytic enzymes (alcalase, flavourzyme, protamex, neutrase, bromelain, papain and trypsin) to suppress the retrogradation of GRS and understand the physical phenomena underlying the reduced retrogradation of GRS by RBPH during short- and long-term storage. Mixtures of GRS incorporated with Protamex-hydrolyzed rice bran protein at 1h (PRBPH-1) at a degree of hydrolysis of 15.1% were still fresh after storage at 4°C for 14 d. The dynamic time sweep results obtained at 4°C for 180min showed that PRBPH-1 reduced the storage modulus to a greater extent, indicating that PRBPH-1 suppressed the short-term retrogradation of GRS. Differential scanning calorimetry (DSC) clearly showed that PRBPH-1 significantly decreased the retrogradation enthalpy during the 28-d storage at 4°C, and the retrogradation kinetics were analyzed by the Avrami model. In addition, the recrystallization of GRS based on X-ray diffraction spectroscopy was reduced from 15.41% to 4.86% when the GRS: PRBPH-1mass ratio increased from 100:0 to 100:12. Confocal laser scanning microscopy, atomic force microscopy and scanning electron microscopy demonstrated that PRBPH-1 dispersed between GRS molecules to block the formation of hydrogen bonds to inhibit the recrystallization of GRS. These findings suggested that PRBPH-1 inhibited the short- and long-term retrogradation of GRS, and can be potently employed as a natural alternatives for improving the quality and nutrition of starch-containing foods.

Effect of curdlan and xanthan polysaccharides on the pasting, rheological and thermal properties of rice starch.

The effects of microbial polysaccharides xanthan and curdlan on the pasting, viscoelastic properties and retrogradation of rice starch were studied. The additions of xanthan and curdlan increased the peak viscosities and decreased the final viscosities. The breakdown viscosities were increased by the curdlan addition, but were decreased by the xanthan addition. The dynamic viscoelastic results showed that the addition of xanthan in rice starch significantly increased storage modulus and loss modulus. The rice starch gel with xanthan addition exhibited higher resistances to the stress and produced a stronger microstructure network. The creep recovery data were well fitted by a 4-element Burger's model. Differential scanning calorimetry showed that the addition of curdlan and xanthan decreased the melting enthalpy values and retarded the retrogradation of the rice starch gel during storage at 4°C for 12days. The pasting and thermal results demonstrated that the addition of xanthan could significantly inhibited the retrogradation of rice starch. It was concluded that the addition of curdlan and xanthan modified the rheology of rice starch gel in different ways and interacted under different models based on their molecular structures.

Effect of high-speed jet on flow behavior, retrogradation, and molecular weight of rice starch

Effects of high-speed jet (HSJ) treatment on flow behavior, retrogradation, and degradation of the molecular structure of indica rice starch were investigated. Decreasing with the number of HSJ treatment passes were the turbidity of pastes (degree of retrogradation), the enthalpy of melting of retrograded rice starch, weight-average molecular weights and weight-average root-mean square radii of gyration of the starch polysaccharides, and the amylopectin peak areas of SEC profiles. The areas of lower-molecular-weight polymers increased. The chain-length distribution was not significantly changed. Pastes of all starch samples exhibited pseudoplastic, shear-thinning behavior. HSJ treatment increased the flow behavior index and decreased the consistency coefficient and viscosity. The data suggested that degradation of amylopectin was mainly involved and that breakdown preferentially occurred in chains between clusters.

Effect of pullulan on the short-term and long-term retrogradation of rice starch

The effect of pullulan (PUL) on the retrogradation of rice starch (RS) was investigated by means of rapid visco-analyzer (RVA), rotational rheometer, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). RVA results showed that addition of pullulan significantly decreased the breakdown and setback values, which meant that the short-term retrogradation of RS was inhibited. The dynamic time sweep of samples also proved the retarding effect of pullulan on the retrogradation of RS. DSC curves showed clearly that pullulan significantly reduced the retrogradation enthalpy of amylopectin, and the kinetics of retrogradation was analyzed using the Avrami model. XRD results showed that recrystallinity of RS was reduced from 11.565% to 8.841% with the addition of pullulan and this was in line with the DSC results. It could be concluded that the addition of pullulan apparently influenced not only the short-term retrogradation of amylose, but also the long-term retrogradation of amylopectin.

Branched limit dextrin impact on wheat and waxy starch gels retrogradation

The effect of branched limited dextrin (BLD) on starch retrogradation was investigated to explain the anti-firming mechanism of α-amylase. The influence of BLD on the gelatinized wheat and waxy rice starch retrogradation was characterized by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WXRD). DSC and WXRD results showed that retrogradation of wheat and waxy rice starch gels were reduced with the addition of branched limit dextrins (F75 and F88). Avrami equation was used to analyze the enthalpies of retrograde wheat starch gels, and the value of k indicated that F75 and F88 reduced the kinetics of starch retrogradation. In addition, molecular dynamic (MD) simulation was adapted to predict the interaction of BLD and starch fraction, and the results showed that the BLD reduced starch retrogradation by the interplay between starch and BLD.

Effects of Cellulose, Lignin and Hemicellulose on the Retrogradation of Rice Starch

Effects of Cellulose, Lignin and Hemicellulose on the Retrogradation of Rice Starch

The effect of xanthan on short and long‐term retrogradation of rice starch

AbstractThe short‐term retrogradation of the rice starch (RS)/xanthan (Xan) mixtures was investigated by Brabender‐E viscograph and dynamic rheometer while the long‐term retrogradation was investigated by DSC and pulsed NMR (PNMR), respectively. RS and 0, 2.5, 5, and 10% Xan (based on RS weight) were prepared into RS/Xan mixtures at the ratios of 100:0, 40:1, 20:1, and 10:1 w/w, respectively. With increasing Xan concentration, the reduced setback (SB) value suggests the decrease of short‐term retrogradation. The gelation rate constant (k) of the mixtures increased during the storage at 4°C for 5 h due to phase separation. The endothermic enthalpy of the pastes of RS/Xan mixture after being stored at 4°C for 1, 3, 5, 7, 14, and 21 days were lower than the native starch stored for the same days. The spin–spin relaxation time (T2) indicating the water mobility of starch gels was detected. T2 decreased gradually with extending storage time, which may be attributed to the retrogradation of RS. T2 of the system with xanthan was apparently higher than that without. The overall results demonstrate the remarkable inhibitory effects of Xan on the retrogradation of RS.

EFFECTS OF LOW‐ AND ULTRALOW‐TEMPERATURE FREEZING ON RETROGRADATION AND TEXTURAL PROPERTIES OF RICE STARCH GEL DURING STORAGE

ABSTRACTIn the current research, rice starch gel was frozen by low temperature (−20, −30 and −60C) or ultralow temperature (−100C), and then stored at 4C for 21 days or −18C for up to 5 months to evaluate the retrogradation and textural properties. Retrogradation enthalpy (ΔHr) of rice starch was determined by a differential scanning calorimetry, and textural properties were determined by a texture analyzer. The results showed that low‐temperature and ultralow‐temperature freezing can effectively retard starch retrogradation during freezing process, while the freezing process has no significant influence on the thermal properties of rice amylose‐lipid complex during storage. On the other hand, retrogradation and textural properties of rice starch gel were related to amylose and amylopectin ratio when stored. Therefore, the amylose and amylopectin properties and freezing process have a synergistic effect on retrogradation and textural properties of rice starch gel during storage.PRACTICAL APPLICATIONSStarch retrogradation is an unavoidable phenomenon for the texture of many ready meals, which is a major problem for industry to produce high‐quality starch‐based ready‐to‐eat meals. The low‐ and ultralow‐temperature freezing combined with frozen storage can effectively retard rice starch retrogradation and maintain the textural properties of rice starch gel for at least 5 months, and this optimum method is very useful for food industry to produce high‐quality starchy foods.

Fractal analysis of the retrogradation of rice starch by digital image processing

The surface profiles of retrograded rice starch (RS) samples stored at different times were obtained by horizontal sectioning and scanning electron microscopy (SEM). SEM images showed that the surface topography of the retrograded RS samples possessed fractal characteristics, which was also proven by fractal analysis. The fractal features for analysis were extracted using a new image processing method. The average fractal dimensions of the retrograded RS samples stored for 1, 5, 10, and 15days were 1.6587, 1.7333, 1.7807, and 1.8340, respectively. The method indicated that the fractal dimension increased as the extent of retrogradation increased. The good correlation between fractal dimensions and the retrogradation enthalpies of the retrograded samples were established using a fitted binomial model (R2=0.9976). These results show that the fractal dimensions obtained using this new image processing method could effectively quantify the extent of retrogradation.

Effect of green tea polyphenols on the gelatinization and retrogradation of rice starches with different amylose contents

The effect of green tea polyphenols (GTP) on the property of rice starch was investigated. 0, 5, 10 and 15% of GTP (based on rice starch weight) was added to rice starches with high (HAC), intermediate (IAC) and low (LAC) amylose contents, respectively. The gelatinization and retrogradation properties of rice starches with different amylose content containing different levels of GTP were analyzed by differential scanning calorimetry (DSC). The results exhibited that GTP could retard retrogradation of the three rice starches, which was further proved by X-ray diffraction investigation. In the DSC analysis, the temperature and enthalpy of starches gelatinization decreased with the concentration of GTP increasing. After storage at 4°C for 20 days, retrogradation enthalpy (ΔHret) for all rice starches with different levels GTP began to appear, and the ΔHret and degree of retrogradation (DR%) of the three rice starches significantly decreased with the increased level of GTP. The X-ray diffractogram indicate that all the three gelatinized rice starch gels showed B-type X-ray diffraction patterns, and the B-type X-ray diffraction patterns gradually disappeared with the concentration of GTP increasing. Key words: Green tea polyphenols, rice starch, gelatinization, retrogradation, differential scanning calorimetry, X-ray diffraction.

Effects of Various Salts on the Reheating Behavior of Retrograded Rice Starch and Cooked Rice

The influence of sodium salts and chlorides at various concentrations (0.05, 0.10, 0.50, and 1.00%) on the reheating behavior of retrograded rice starch and cooked rice was investigated. The degree of gelatinization of the all retrograded rice starch gels and the cooked rice containing sodium salts and chlorides increased after reheating compared to the starches without salt. Gelatinization also showed an increasing trend as the concentration of sodium salts and chlorides increased. The increase of gelatinization after reheating the samples containing sodium salts and chlorides was greater than 38.0%. The reheated retrograded rice starch and cooked rice containing Na₃PO₄ showed the lowest set back value and retrogradation rate constant. Among all the samples, the cooked sample containing Na₃PO₄ showed the highest increment of gelatinization after reheating. Also, this same sample showed the lowest retrogradation degree.

Slowly digestible starch prepared from rice starches by temperature-cycled retrogradation

The temperature-cycled retrogradation of rice starch used to prepare slowly digestible starch was investigated in this study. Our results showed that a maximum slowly digestible starch content of 51.62% was obtained from waxy rice starch at the optimal tested conditions: temperature cycles of 4/25 °C, at intervals of 24 h, and 7 days of storage. The results also indicated that there was a higher onset temperature ( T o), a narrower melting temperature range ( T c − T o), and a higher ratio (1047 cm −1/1022 cm −1) of the slowly digestible starch products prepared under the temperature-cycled condition than that under the isothermal retrogradation. Furthermore, it was evident that the in vitro glycemic index of slowly digestible starch products with temperature-cycled retrogradation was reduced more than that with isothermal storage. These results suggest that the temperature-cycled retrogradation is applicable to prepare the high yield of slowly digestible starch from waxy rice starch.

효소저항성 쌀전분의 첨가가 마들렌의 품질 및 텍스처 특성에 미치는 영향

This study attempted to examine the application of retrograded starch (RS3) isolated from rice flour into Madeleine which is easy to make, supply enough energy and micro nutrients with adequate drinks, and prevent an adult disease. This could be a popular food to anyone regardless of age and gender who avoid rice and become high value-added, processed rice foods. For this, control Madeleine was made from wheat flour and an experimental one was made from 5 or 10% rice RS3 addition as well as wheat flour. Four different types of rice were produced from Premium Ho-Pyong Rice, that is, dry milled rice flour(RFD), soaked for 8 hours and milled, followed by air-dried rice flour(RFW), rice starch(RST), and retrograded rice starch or enzyme-resistant starch(RS3). The results found were as follows: Proximate compositions were decreased with soaking to make RFW, RST and RS3, compared to RFD. RS3 had the highest L, +a and with the lowest +b, changing it to a dark color, explaining the need for heat control during processing. At , the swelling power was shown in the order of RST>RFW>RFD>RS3 and the solubility of RS3 was the highest. There were significant differences in viscosities of peak, trough, cold, breakdown and total setback of all rice samples using RVA (p