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Rice starch has been used in various agri-food products due to its hypoallergenic properties. However, rice starch has poor solubility, lower resistant starch content with reduced retrogradation and poor functional properties. Hence, its industrial applications are rather limited. The lack of comprehensive information and a holistic understanding of the interaction between rice starch and endo/exogenous constituents to improve physico-chemical properties is a prerequisite in designing industrial products with enhanced functional attributes. In this comprehensive review, we highlight the potentials of physically mixing of biopolymers in upgrading the functional characteristics of rice starch as a raw material for industrial applications. Specifically, this review tackles rice starch modifications by adding natural/synthetic polymers and plasticizers, leading to functional blends or composites in developing sustainable packaging materials, pharma- and nutraceutical products. Moreover, a brief discussion on rice starch chemical and genetic modifications to alter starch quality for the deployment of rice starch industrial application is also highlighted.

In this study, the starches were isolated from three botanical sources (i.e., rice, sweet potato, and lotus seed). The size distributions of starch granules and molecules were determined by asymmetrical flow-field flow fractionation (AF4), and compared with those measured from optical microscopy (OM) and dynamic light scattering (DLS). Furthermore, the starches were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). AF4 coupled online with UV–visible, multiangle light scattering (MALS), and differential refractive index (dRI) detectors (AF4-UV-MALS-dRI) was employed for the investigation of the digestion and retrogradation properties of starches. Meanwhile, the relationships between the size of starch at nano- to microscale and its functional properties (i.e., digestibility, retrogradation, and thermal properties) were studied by Pearson correlation analysis. AF4-UV-MALS-dRI was proved to be a rapid and gentle method for the separation and size characterization of starches at both micro- and nano-molecule levels. Moreover, it was demonstrated that AF4-UV-MALS-dRI is a useful tool for the monitoring of the digestion and retrogradation properties of starches. The results suggested that the sizes of starch granules and molecules were to some extent correlated with their thermal properties and digestibility, but not with retrogradation property.

The objective of this study was to investigate morphology, molecular crystalline structure, and digestibility of debranched mung bean starches with or without microwave treatment and retrogradation at different temperature. The mung bean starch was firstly debranched with pullulanase, and then the debranched starch containing 20% moisture content was treated by microwave irradiation for 3 min with or without further retrograded at +25, +4, or −18 °C for 24 h. All treated starches exhibited the B + V-type crystalline polymorph as determined by the XRD and the 13CNMR. The FT-IR results showed that the debranched starches had lower degree of order but higher degree of double helix than those of the native starch. The microwave treatment or further recrystallization of the debranched starch for more 24 h significantly improved crystalline structure of starch granules with higher degree of relative crystallinity, degree of order, and degree of double helices. The resistant starch content of the treated starch was in a range of 39.7–52.8%, significantly higher than that of the native starch (15.6%). As a result, the microwave-assisted debranched starch with further crystallization for 24 h was found to have highly ordered structure of granules, which highly resisted to the enzyme digestion.

Low temperature (LT) at late growth stages is an important abiotic stress that affects the grain end–use quality of summer maize. In the present work, two experiments were conducted to study the effects of LT on the structural and functional properties of starches using two waxy maize hybrids (‘Suyunuo5’ and ‘Yunuo7’). In field trial, the plants were sown on July 1 (normal sowing date) and August 1 (late sowing date). In pot trial, the plants were sown on July 1, grown at natural environment till silking, and suffered two post–silking temperatures (normal temperature and LT were set as 28/20 and 23/15 °C, respectively). The result showed that the starch was composed of more small granules with oval polytope when sown late (August 1) or subjected to LT post–silking. The LT–stressed starch presented high proportion of short amylopectin chains and low relative crystallinity (RC). LT reduced the pasting viscosity, gelatinization enthalpy, and gelatinization temperatures but increased the retrogradation tendency. In conclusion, the low pasting viscosity and high retrogradation tendency under LT condition were caused by the decreased granule size, amylopectin chain length, and RC.

The objective of this study was to reveal the process of starch retrogradation and quality changes of Nianzhuan stored at 4, −18 °C, and freeze-thaw cycles treatment for different lengths of time. XRD revealed that Nianzhuan starch displayed an increasing trend of crystallinity with prolonged storage time and numbers of freezing-thawing cycles, which was likely due to a more orderly crystalline matrix in starch. The Raman full width at half-maximum (FWHM) of the bands at 2913 cm−1 of the three storage methods all decreased. According to DSC analysis, an increase in ∆H was detected, and a significant (P T o and T p were found at −18 °C, and freeze-thaw treated samples, indicating more thermal energy were needed to disrupt re-crystallization. Good correlations between crystallinity, FWHM, ∆H, and hardness, springiness, chewiness were tested. The results of this study would provide useful information for the process of starch-based product Nianzhuan.

The effects of repeated retrogradation (RR, range from 1 to 3 times) at different temperatures (4 °C; 4/25 °C, with a 24 h interval; 25 °C) on the in vitro digestibility and structures of Tartary buckwheat starch (TS) were investigated in this study. Results demonstrated that TS treated by RR for 1 time under 4/25 °C contained the maximum content of slowly digestible starch (SDS, 35.25%); TS treated by RR for 3 times under 25 °C contained the maximum content of resistant starch (RS, 54.92%). As the increase of RR cycle times, the value of relative crystallinity, the ratios of 1047/1022 cm−1 and 995/1022 cm−1 increased, the starch pore wall thickened, and more smooth fragments appeared (observed by scanning electron microscope), while the value of melting temperature range trended to decrease. The crystallization type of TS changed from type “A” to a mixture of “B + V” after retrogradation treatment. Pearson correlation analysis revealed that the content of rapidly digestible starch (RDS) was negatively correlated with the ratio of 995/1022 cm−1, transition temperatures, and enthalpy (P

Traditional methods for the determination of starch aging indicators often have a series of shortcomings such as time‐consuming, high cost, large human error, damage to samples, environmental pollution, and high requirements for inspectors. Therefore, it is meaningful to find or establish a dynamic fingerprint identification pattern that can detect the aging degree of starch during the process of processing or storage quickly and accurately. It not only provides guidance for starch food processing but also saves a lot of human, material resources, and time. Terahertz technology is an emerging molecular spectroscopy technology in the 21st century. It is with low energy and basically harmless to the human body. It can also realize nondestructive testing of samples. In the experiment, the samples were prepared by the tableting method and the samples containing 20% of 50 mg samples were prepared with polyethylene as the diluent. The thickness of the samples was 1 mm and the diameter was 13 mm. The terahertz time‐domain spectrometer was used to obtain the spectral information of aging starch at different aging times. After the pretreatment of the spectrum by vector normalization, first derivative, and multiple scattering correction, the prediction models of aging days, crystallinity, and resilience of aging starch were established, respectively. The determination coefficient (R 2) of the established models is all greater than 95%, indicating that the established models are highly reliable and can be used to predict the aging days, crystallinity, and retrogradation degree of starch. And the R 2 of the prediction model based on the refractive index spectrum is greater than that of the absorption coefficient spectrum. The experimental method obtains the dynamic fingerprint identification map of starch in the aging process, realizes the real‐time monitoring and detection of the starch aging process, and provides an effective means for the production and processing of starch‐related industries., The determination coefficients (R 2) of the established models were all greater than 95%, indicating that the established models had high reliability and could be used to predict the days, crystallinity, and degree of regression of starch aging. This paper provides a solid foundation for real‐time monitoring and determination of aged starch.

Adding hydrocolloids into native starch is a secure and effective method of physical modification. In this study, the effect of sodium alginate (AG) on the gelatinization, rheological, and retrogradation properties of rice starch (RS) was investigated by measuring the pasting parameters, melting enthalpy (ΔH), rheological characteristic parameters, intensity ratio of 1047 cm−1 to 1022 cm−1 (R1047/1022), and relative crystallinity (RC) of RS–AG blends. Rapid visco analysis shows that AG could significantly change the gelatinization parameters of RS. Differential scanning calorimetry results show that the ΔH values of RS initially decreased in the low AG concentration range (0.10%–0.30%), but increased in the high AG concentration range (0.30%–0.50%). Dynamic rheological analysis reveals that the modulus (G′, G′′) and the loss tangent (tan δ) increased with the rise of the AG concentration from 0.10% to 0.50%. Fourier transform infrared spectroscopy and X-ray diffraction patterns collectively prove that the crystallinity of RS decreased with the addition of AG during the retrogradation periods. The interactions between AG and starch molecules in RS–AG blends were hypothesized to correlate with the aforementioned results.

The present study evaluated Amaranthus caudatus (AC) and A. hypochondriacus (AH) starches obtained as coproduct during protein extraction for composition, granule size, amylopectin fine structure, thermal, retrogradation, pasting and dynamic rheological-properties to elucidate structure-function relationships. The starches exhibited unimodal particle size distribution with mean granule size of 1.26–3.12 μm. AC starch with larger granules (mean granule size 3.12 μm) than AH starches (1.26–1.59 μm) gelatinized at lower temperatures (lower DSC transition and pasting temperatures), showed higher paste viscosities and produced more elastic gels (lower tan δ and higher Gʹ). Starch granule size related positively with the proportion of amylopectin chains with DP 12. Starches with greater proportion of amylopectin chains with DP > 12 showed higher gelatinization temperatures, while shorter chains (DP

BACKGROUND Starch retrogradation and moisture migration of boiled wheat noodles (BWNs) result in quality deterioration and short shelf life. The objective of this research was to investigate whether konjac glucomannan (KGM) could improve the quality of BWNs and further establish the shelf-life prediction model. RESULTS The moisture distribution, recrystallization, and thermal properties of BWNs during refrigerated or ambient temperature storage were determined. Low-field nuclear magnetic resonance data showed that KGM addition induced left-shifts of T21 and T22 values, indicating that KGM limited the mobility of bound and immobile water among noodle matrices. X-ray diffraction spectra revealed that KGM did not change the crystal patterns of BWNs but could inhibit the starch recrystallization after refrigerated storage. The Tp and ΔH values of retrograded samples notably (P

Three different storage temperatures including room temperature (RT), 4 °C and −20 °C were investigated in this study, with respects to their effects on the retrogradation property and in vitro digestibility of gelatinized sago starch. Storage at −20 °C resulted in the highest amount of both intra- and intermolecular double helices and a fracture-like structure under scanning electron microscopy (SEM). These crystallites were more homogenous while less thermally stable than that from RT and 4 °C storage conditions. Storage at RT significantly increased the stability and heterogeneity of the formed crystallites, resulting in a sponge-like structure under SEM. Causally, the digestion rate of retrograded sago starch by α-amylase was significantly lowered after storage at −20 °C compared to that at RT and 4 °C. The crystallite heterogeneity, thermal stability, and ratio of inter- to intramolecular double helices were possibly the main driven factors for the observed digestion rates instead of the amount and micro-morphology of the crystallites. These results supply potential tools for the manufacture of food products with slower starch digestibility.

The influences of soy protein isolate hydrolysate (SPIH) obtained during different pressure treatments for 4 h on pasting and short-term retrogradation behaviors of maize starch (MS) were investigated. The results showed solubility of MS markedly increased, whereas swelling power decreased with increased SPIH concentration and pressure. Compared with native MS, the addition of SPIH led to decrease of peak viscosity, final viscosity, setback, and breakdown, whereas pasting temperature was increased. Meanwhile, differential scanning calorimetry (DSC) analysis also showed an increase in gelatinization temperature. In addition, low-field nuclear magnetic resonance (LF-NMR) analysis indicated that the tight association of water and starch molecules was observed with increasing pressures and additions of SPIH. Confocal laser scanning microscopy (CLSM) and atomic force microscope (AFM) images indicated that SPIH obtained at 200 MPa dispersed in the MS gel system to block the formation of hydrogen bonds and inhibit the recrystallization of MS. Fourier transform infrared (FTIR) spectroscopy analysis demonstrated that the addition of SPIH resulted in a decrease in hydrogen bonds within the starch molecules and the result supported above CLSM and AFM measurement results. The results proved that the addition of SPIH could effectively influence pasting characteristics and inhibit the short-term retrogradation of MS, which can be helpful to the application of SPIH in starch-based functional foods.

Sweet potato has great potency to be developed as an alternative carbohydrate source in the form of modified sweet potato flour. Autoclaving retrogradation is a physical modification method to improve the physicochemical characteristics of flour. The purpose of this study was to determine the effect of the autoclaving retrogradation method on the characteristics of various sweet potato flour: dietary fiber, resistant starch, starch digestibility, nutritional content, and antioxidant , and to determine the best modified sweet potato flour. The experimental design used a non-factorial completely randomized block design with four replications. The treatment consisted of 6 types of sweet potato, namely control (purple sweet potato without treatment), orange sweet potato, purple sweet potato, honey-sweet potato, red sweet potato, and purple white sweet potato ). The results showed that there were significant differences in dietary fiber, levels of resistant starch, digestibility of starch, nutritional content, and antioxidant activity amongst various types of modified sweet potato flour. The best modified sweet potato flour was found in modified red sweet potato flour which contain ed 44.64% dietary fiber, 19.75% resistant starch, 13.50% starch digestibility, 66.32% antioxidant activity , with comparable nutritional content .

The complex and unique structure of starches is associated to the conditions existing during processing and storage and contribute to specific interactions with water. These interactions can lead to starch transitions such as gelatinization and retrogradation, which have key importance in food and non-food applications. Water content plays a critical role in the structure-function capacity of starches, which depend on starch granules capacity to adsorb water and disperse in aqueous media. The presence of salt, sugars, non-starch polysaccharides, proteins, and lipids influences starch behavior in aqueous media, affected by competitive interactions of starch with these constituents. Gelatinization and retrogradation are associated to the interaction of starches with water. The first phenomenon describes water absorption by the starch molecules in the presence of shear and temperature and under excess of water whereas the second phenomenon describes the interaction of starch molecules under limited water availability.

Purpose: To investigate the effects of dry heat, microwave and ultrasonic treatments on the physicochemical properties of potato starch alone or blended with pectin. Methods: The physicochemical properties of potato starch gels prepared using microwave, ultrasonic and dry heat treatments were assessed. Pasting properties, gel strength, thermal properties and crystal texture of the potato starch were determined using Rapid Visco analyzer, texture profile analyzer, differential scanning calorimeter and x-ray diffractometer. Results: Dry heat and ultrasonic treatments significantly increased the peak viscosity of the potato starch, and significantly decreased its setback and pasting temperatures (p < 0.05). Dry heat treatment significantly increased the hardness, while dry heat and ultrasonic treatments significantly improved retrogradation of the potato starch (p < 0.05). Transparency of potato starch paste was significantly increased by the different treatments, except microwave treatment (p < 0.05). Potato starch gels blended with pectin and subjected to any of the treatments exhibited significantly increased hardness, when compared with raw potato starch (p < 0.05). The retrogradation of the potato starch was significantly improved by the different treatments. Dry heat and ultrasonic treatments significantly decreased the syneresis of potato starch with or without pectin (p < 0.05). The three treatments also significantly affected the gelatinization enthalpy of the potato starch with or without pectin, and exerted some effects on the crystallinity of the gels. Conclusion: The results obtained in this study suggest that differences in physicochemical properties of potato starch gels are due mainly to the degree of damage to starch granules caused by different treatments. The addition of pectin to potato starch gel greatly improves its hardness and retrogradation.

Background Consumers are increasingly concerned with high sugar and aging quality in bread. The use of sugar alcohols as sugar replacers in bakery products is a common practice, due mainly to their modulating process properties, improving quality and health benefits. They are not only sweeteners with reduced-calorie, commonly used in combination with other sweeteners to achieve desirable taste and sweetness level, but also improvers for bread and other cereal foods to obtain a stable and strong network, retard staling, good taste and longer shelf-life. Scope and approach The review summarized the effects of sugar alcohols on dough rheological properties, elucidated the rate of fermentation and specific volume, illustrated moisture distribution and migration, analyzed the retrogradation in sugar alcohol-bread, and further provide insights in utilization of sugar alcohols in bakery industry. Key findings and conclusions Molecule structure, size and level of sugar alcohols in bread could affect dough rheological characterization, starch pasting, gelatinization, and retrogradation, and further have an effect on bread quality. Such effects might be contributed to hydrogen bonds formed between hydroxyl groups in sugar alcohols and starch chains. Starch retrogradation and water migration are two main factors played key role in influencing bread staling. Sugar alcohols are highly associated with moisture migration and redistribution further to affect bread aging and quality. However, information in the above area is limited. The mechanism of action in antistaling and/or starch recrystallization in bread influenced by sugar alcohols will be explored in this review.

At present, the yield of common buckwheat, which is mainly grown in northern Shaanxi of China, is low and the grain quality is poor. Nitrogen is an important nutrient for the growth of common buckwheat, and appropriate nitrogen application can improve the grain quality. Nitrogen fertilizer could alter the starch granule morphology shapes and the granule size distribution. With increasing nitrogen levels, branch number, flower clusters number, grain number per plant, contents of protein and fat, size distribution of “C” granules, and percentages of light transmittance significantly increased, whereas amylose content and retrogradation decreased. All the samples displayed typical A-type X-ray diffraction patterns. Starch showed higher pasting temperature and gelatinization enthalpy but lower trough and final viscosities under high nitrogen levels. These results suggested N2 treatment was more suitable for common buckwheat growth, principal components and correlation analysis revealed that nitrogen fertilizer significantly affected the physicochemical properties of common buckwheat starches.

Background The starchy crops which normally form the staple diet of people are rich in carbohydrates. People leading a sedentary lifestyle and consuming high amounts of carbohydrate-rich food normally invite obesity and type-II diabetes. Upon digestion of starchy food, postprandial blood glucose level rises rapidly and sharply, which reflects a high glycemic index (GI) value. Scope and approach Various factors affect starch digestibility and the GI of a food or its products. The internal factors such as amylose, lipid, protein, phytic acid, dietary fibre and resistant starch (RS) have been correlated with lower GI value. The external factors which affect GI and starch digestibility include cooking, processing, retrogradation, soaking and germination. Various food matrices are also responsible for alteration in the GI value. Moreover, changes in the environmental conditions including abiotic and biotic stresses are also responsible for the change in starch structure and composition which ultimately affects GI of starchy crops. Key findings and conclusions The GI and starch digestibility of foods are affected by intrinsic and extrinsic factors which affect strategies for management of sugar level to ensure better human health. High amylose, RS, lipid and protein in the food were found to reduce starch hydrolysis. Further, retrogradation, various cooking methods and modification of starch by physical and chemical means resulted in lower GI and increased RS considerably. Analysis and management of postprandial blood glucose level while eating starchy crops would help to understand the risk of diabetes and other lifestyle-related diseases.

We prepared a high-molecular-weight modified dextrin (MWS-1000) from a partial hydrolysate of waxy corn starch with a weight average molecular weight of 1 × 106 (WS-1000) using Paenibacillus alginolyticus PP710 α-glucosyltransferase. The gel permeation chromatography showed that the weight average molecular weight of MWS-1000 was almost the same as that of WS-1000. The side chain lengths of WS-1000 and MWS-1000 after isomaltodextranase digestion were also shown to be similar to each other by high-performance anion exchange chromatography with pulsed amperometric detection. Since MWS-1000 confirmed the presence of α-1,6 bonds by enzyme digestibility, methylation, and 1H-NMR analyses, it was presumed that the structure of MWS-1000 was based on the introduction of α-1,6 glucosyl residues at the nonreducing ends of the partial hydrolysate of waxy corn starch. Furthermore, the MWS-1000 solution was not retrograded even during refrigerated storage or after repeated freeze–thaw cycles.

Physical homogenization was applied to the production of a starch-lipid complex formed through a hydrophobic interaction between amylose and fatty acid molecules. In addition, vegetable oils as a source of fatty acids and wheat starch as a source of amylose molecules were used to produce the starch-lipid complex. The complex index was significantly (p

Different treatments of autoclaving, pullulanase debranching and/or ultrasound were applied to prepare debranched lentil starch (DBLS). Their fine structures can affect the retrogradation patterns of DBLSs, which consequently could affect their potential use as delivery carrier of sensitive bioactive compounds. An attempt was made to use these DBLSs as wall materials to encapsulate rutin, aiming to improve the bioaccessibility, meanwhile to enhance the aqueous solubility and stability of rutin molecules. Their encapsulation efficiency, structural characteristics, thermal stability, morphological features, antioxidant activity and in vitro release behavior under simulated upper gastrointestinal tract environment were evaluated. The results suggested that rutin was dispersed in the DBLS polymer matrix, showing the amorphous nature that further authenticates the encapsulation and entrapment of rutin. The structural analyses of microparticles revealed that rutin could interacted with DBLS biopolymer chains by hydrogen bonds, making the starch molecular chains less susceptible to interact with themselves for reordering. The encapsulation efficiency was found to be in an opposite trend with those values obtained for relative crystallinity, melting enthalpy, degree of order/double helices of DBLS wall materials before encapsulation. The release rate results indicated that DBLS carrier with lower Mw, DPn and higher molecular order was beneficial for the slower release of rutin encapsulated in the microparticles.

Rice starch isolated (NS), was subjected to chemical and thermomechanical modification with previous hydrolysis (MHS) and without previous hydrolysis (MS) to be evaluated on main starch properties as degree of substitution (DS), color, water absorption and solubility index (WAI, WSI), viscosity, texture, thermal properties (differential scanning calorimetry DSC) and structural properties (infrared-IR, Xray-Rx analysis, and relative crystallinity index-ICR). The modified starches were compared to native starch (NS). The DS obtained in both starches was within the range allowed by the FDA for its safety use as food ingredient (0.01-0.2). The modification showed an increase in WAI and WSI values, being WAI value higher in MS (4.80) and WSI value higher in MHS (32.06). The viscosity of retrogradation showed a significant decrease (P

Starch was extracted from the rice bean which is largely underutilized and modified by physical (i.e. heat moisture treatment and retrogradation) and chemical (i.e. esterification and acid alcohol modification) methods. Both, physical and chemical modifications significantly (p heat moisture treated (434.3 nm) > retrograded (355.4 nm) > esterified (218 nm) > acid alcohol treated starch (234.5 nm). The study revealed that the particle size of rice bean starch was reduced by both physical and chemical modifications. FE-Scanning electron microscopy was used to study the morphological characteristics of starches and it was observed that retrogradation had a pronounced effect on the starch granules morphology.

Background Fruit mousses are products with a relatively low amount of dietary fiber in a single portion, but with additional portions of soluble fiber they may be good alternative to fiber-rich snacks as take-away food. In the present study, the properties of new soluble dextrin fiber (SDexF) from potato starch were assessed to establish whether it could be used to enrich fruit mousses. The properties of SDexF that can affect processing and storage stability of enriched mousses were studied and compared with those of native potato starch and semiproducts (resulting from various drying temperatures). The effect of the addition of SDexF on the pasting properties of mousse was also analyzed. Results The application of food-grade hydrochloric and citric acids as catalysts in the dextrinization of food-grade potato starch allowed to SDexF to be obtained. Despite the differences in characteristics of the semiproducts, the final SDexF preparations were very similar in the meaning of solubility, dextrose equivalent (DE), retrogradation, and pasting properties. SDexF preparations were characterized by a significantly lower retrogradation tendency, peak viscosity, final viscosity, and gelatinization enthalpy in comparison with both native starch and semiproducts. Soluble dextrin fiber was successfully added to banana-apple mousse. The addition of SDexF to mousse did not cause any undesirable changes to the viscosity of the product, and surprisingly even resulted in mousse with lower viscosity. Turbidity and RVA studies revealed that SDexF was stable and retrogradation processes can be negligible during storage. Conclusion The SDexF obtained from potato starch can be a novel functional substance to increase the dietary fiber content of fruit or fruit and vegetable mousses. © 2020 Society of Chemical Industry.

The use of hydrocolloids to modify the properties of native starches has been on the rise in the recent times due to the market demand for natural, safe and economical food ingredients. The objective of this study was to investigate the effect of gum Arabic from Acacia senegal var. kerensis to modify pasting and textural properties of corn and cassava starches, as an alternative to chemical and enzymatic modification. Blends were prepared by substituting the starches with gum at different levels (0%, 0.5%, 2.0%, 4.0%, 6.0% and 8.0%), whereas native corn and cassava starches were used as control. The pasting properties of the starch-gum mixed systems were determined using the Brabender viscograph while the textural properties (firmness, consistency, cohesiveness and work of cohesion) were determined using Texture Analyzer. Results showed that the gum Arabic significantly decreased all the viscosity parameters (peak viscosity, final viscosity, break down and setback values) of both starches at all levels of substitution. However, there was no significant effect of gum Arabic on the pasting temperature (72.05°C - 71.85°C) for corn starch and (68.90°C - 68.65°C) for cassava starch. The degree of gel firmness and consistency was higher in corn starch than in cassava starch and the effect of gum addition differed with each starch. The findings from this study indicate that gum Arabic significantly modified the pasting and textural properties of corn and cassava starches due to strong interaction between the gum and the starches. Hence, this property of gum Arabic could be useful in controlling starch retrogradation and determining starch end use functionality.

Herein, the formation of starch-lipid complexes in steamed bread (SBr) free from and supplemented with fatty acids of varying chain lengths, including lauric acid (LA), glycerol monolaurate (GML), stearic acid (SA), and glycerol monostearate (GMS) and their effects on in vitro enzymatic digestibility were investigated. The enthalpy value of SBr samples (1.86-3.46 J/g) was significantly decreased (P 0.05) compared to wheat starch samples (5.64-7.17 J/g) fortified with fatty acids. The relative crystallinity (16.5%-32.8%) of SBr corresponds to the content of starch-lipid complexes. SBr supplemented with fatty acids exhibited softer texture than lipid-free SBr stored at 4 °C for 0, 1, 4, and 7 days. Higher enzyme resistance was observed in SBr samples supplemented with fatty acids and the content of resistant starch (RS) was increased from 7.54% to 23.13% in SBr supplemented with LA. As demonstrated by microscopic computed tomography (mCT), the crystalline structure of SBr samples supplemented with LA and GML have a higher density than SBr fortified with SA and GMS; the findings which are in line with thermal properties and X-ray diffraction analysis. In sum, the formation of starch-lipid complexes could be considered as a new way to improve the SBr textural features during storage.

The physicochemical properties of jackfruit seed starch (JSS) were investigated and compared with rice (RS) and potato (PS) starch. The amylose content of JSS (25%) was similar to PS (27%) but higher than RS (17%). The small granules of JSS (7.9 μm) was comparable to RS (9.7 μm), and both starches had A-type crystallinity. In contrast, PS had larger granules (43.4 μm) and displayed B-type crystallinity. The DSC results showed that peak gelatinization temperature of JSS (85.0°C) was significantly higher than RS (66.9°C) and PS (63.7°C), corresponding to higher pasting temperatures and lower swelling power at lower temperatures. There was no significant difference in stability between the starch gels after four freeze-thaw cycles. Formation of JSS gels with significantly higher hardness, chewiness and elastic modulus (G′), but lower fracturability demonstrated JSS ability to form strong gels. This would be beneficial for food applications requiring gelation with firm and elastic textural attributes.

In this work, the physicochemical properties of native waxy rice starch (WRS) and alcohol-alkali-treated waxy rice starch (AAT-WRS) were studied in the presence of sucrose. The results indicated that the addition of sucrose improved the transparency and freeze-thaw stability of WRS pastes and AAT-WRS pastes. Differential scanning calorimetry showed that the gelatinization temperatures of WRS increased with increased sucrose concentration, but the gelatinization enthalpy increased at low concentration of sucrose and decreased at high concentration. Rheological measurements indicated that sucrose addition had no significant effect on the pseudoplastic shear-thinning behaviors of WRS pastes and AAT-WRS pastes, but changed the apparent viscosity. Dynamic moduli (G′ and G″) values of WRS pastes and AAT-WRS pastes with or without sucrose showed frequency dependency and sucrose addition dependency. The elastic behavior was dominant over viscous in the WRS-sucrose mixed pastes, while the AAT-WRS-sucrose mixed pastes was the opposite. The textural paraments of WRS and AAT-WRS before or after retrogradation increased with the increasing concentration of sucrose. These results suggested that sucrose potentially changed the physicochemical properties of WRS and AAT-WRS.

The impact of the internal part of aewx amylopectin on the gel network and digestibility during retrogradation was investigated using wx amylopectin as a reference. After β-amylolysis for 60 min (aewx-60), greater shifts in both λmax value and absorbance of iodine binding profiles were observed, accompanied by an increment of short chains (DP 3–5) with reducing the external long chains (DP 17.2). For the amylopectin gels aged 7 days at 4 °C, aewx had greater intermolecular aggregation of double helices to form junction zones, resulting in remarkably higher G′, which was significantly greater than that of wx amylopectin or aewx-60. Moreover, aewx amylopectin had a greater RS accompanied by a reduction in RDS after retrogradation. The gel network models of retrograded amylopectins were built to interpret more molecular interactions for aewx than those of wx. The results revealed that aewx amylopectin with a higher proportion of longer external chains prompted the flexibility to align and interact for the formation of double helices and enzyme-resistant structures.

Aims: This research is aimed at developing a method of processing to increase the quantity of resistant starch in garri and reduce its glycemic index using pullulanase-producing Bacillus subtilis organism. Place and Duration of Study: Department of applied microbiology and brewing, Nnnamdi Azikiwe University, Awka between January, 2018 and February, 2019. Methodology: The organism was isolated from different cassava processing sites in Anambra metropolis, Nigeria. It was then identified based on phenotypic, biochemical and molecular characteristics After which the pullulanase assay, the fermentation studies, resistant starch analysis and glycemic index was analysed. Results: Pullulanase assay result showed Bacillus subtilis as a very good pullulanase producing organism with a pullulanase quantity of. The resistant starch content was found to be higher for the samples fermented with the choice organism and retrograded at 10oC at 14.29%, than the control garri sample fermented without any organism and not retrograded at 4.73%. The glycemic index was relatively high in all the garri samples, however, the lowest glycemic index, 62% was observed in the garri sample produced with the choice organism. Conclusion: This research has been able to show that pullulanase enzyme from Bacillus subtilis is a very useful industrial raw material in production of functional foods with low glycemic index.

Canistel seeds are part of the residues of Canistel fruit which can be used as functional foods, such as flour to be processed into various foods. This research was aimed at determining the physicochemical properties of canistel seed flour. Canistel seed was made into flour with two treatments; they were Blanched Canistel Seed Flour (BCSF) (at 80oC for 10 minutes)and Unblanched Canistel Seed Flour (UCSF). The flour process involves sorting, washing, treatment, stripping the shell and epidermis, washing again, drying, flaking and sieving.Physical analysis carried out included yield (by difference method), white degree of spectrophotometric reflectance method (Chromatometer), starch gelatinization profile using Rapid Visco Analyzer (RVA), the morphology of starch granules using polarization microscopy and Scanning Electron Microscope (SEM). Chemical analysis conducted on the BCSF and UCSF samples included proximate,amylose, amylopectin and starch content. Blanching at 80°C for 10 minutes had a significant effect on the physical properties of Canistel seed flour;yields were higher (41.6%) and chromatometric (colour) levels were lower (80.61). Pasting properties profile showed that UCSF had higher peak viscosity, breakdown viscosity but lower setback viscosity compared with the BCSF.Scanning Electron Microscope (SEM)and polarized light microscope showed starch granule structure changed due to the blanching. The appearance of starch granules on UCSF shows a tight starch granule. The appearance of starch granules on BCSF shows blanching treatment has changed the shape of the starch granules to be broken or damaged. The unblanched canistel seed flour (UCSF)showed that the starch granule still had birefringence appearance. This shows that the granule structures of the UCSF remained undamaged. Observation of the morphology of starch granules using polarization microscopy on BCSFshowed the starch granule was not visible and there was no appearance of birefringence. The loss of birefringence indicates that the starch granules had been damaged due to heating or hydrolysis. Chemical analyses on the samples showed significantly higher amylose content (24.79) but lower amylopectin content (31.39) in BCSF than UCSF.Starch, fat and carbohydrates contents were not significantly different (p>0.05) between BCSF and UCSF.Ash and protein content were significantly higher (p>0.05) in UCSF compared to the BCSF. Blanching of canistel seed flour reduces the swelling power of starch granules, increases retrogradation, accelerates thickening, decreases nutrition content, and changes microstructure of Canistel seed flour

The aim of the study was to compare the properties of resistant starch (RS3) formed during extrusion of corn and sorghum starches. The extrudates were stored for 7 and 14 days at 4 °C to allow for molecular rearrangement i.e. retrogradation. The extruded starches were analyzed for enzymatic digestibility, long range (X-ray diffraction, XRD) and short range (FTIR) molecular order, thermal characteristics (DSC) and rheological properties as affected by temperature. The highest RS (70.64%) was obtained for sorghum extrudate (ES14) as compared to corn extrudate (EC14) (64.90%), on 14th day of storage. The increase in RS correlates with the increase in percent crystallinity (%Xc), too. The (ES14) reported the highest %Xc among all extrudates i.e.37.83. The XRD results showed an additional peak at 13° and 20°, reflecting the formation of V-type pattern in all samples. The FTIR spectroscopy also exhibited increase in the ratio of 1047 cm−1/1151 cm−1 and 1047 cm−1/1022 cm−1. The extruded starch showed significantly higher thermal stability and lower cold paste viscosity. The significant (p ≤ 0.05) decrease in the glycemic index was obtained as the storage time increased. The (ES14) exhibited glycemic index equal to (EC14) i.e.55.53 and 52.53, respectively; thereby making it a suitable substitute of corn starch.

BACKGROUND Rice is one of the most commonly consumed cereal grains and is part of staple diets in the majority of the world. However, it is regarded as an incomplete protein, with lysine being a limiting amino acid. OBJECTIVES Our objectives were to determine the bioavailability of lysine in school-age children consuming cooked white rice and to assess the effect of rice starch retrogradation. METHODS Bioavailability or metabolic availability (MA) of lysine was determined using the indicator amino acid oxidation (IAAO) method in a repeated-measures design. Six healthy school-age children (3 boys, 3 girls) with a mean ± SD age of 6.8 ± 0.98 y randomly received 4 crystalline l-lysine intakes (2, 6, 10, 14 mg · kg-1 · d-1), and 5 rice intakes to provide lysine at 8, 11, or 14 mg · kg-1 · d-1. The 14 mg · kg-1 · d-1 intakes were measured twice as warm rice and once as cold rice (to assess the impact of starch retrogradation on MA). Diets provided protein at 1.5 g · kg-1 · d-1 and calories at 1.7 times the participant's measured resting energy requirement, and were isonitrogenous. Breath samples were collected at baseline and during an isotopic steady state for 13C enrichment measurement. The MA of lysine from rice was determined by comparing the IAAO response of rice with l-lysine using the slope-ratio and single intake methods. Starch retrogradation was characterized using differential scanning calorimetry. RESULTS MA of lysine in warm rice measured in school-age children was 97.5% and was similar to a repeated rice study (97.1%) within the same study population. MA of lysine was reduced significantly (P

Rice (Oryza sativa L.) quality depends mainly on the characteristics of starch stored in kernels. Understanding the changes in starch characteristics in kernels during variety improvement would have great significance to improve rice quality. This study was designed to investigate the starch characteristics in the kernels and associated physiological traits of indica rice varieties in the lower reaches of the Yangtze River in China in last 80 years. Eight representative mid-season indica rice varieties were grown in the field. The results showed that the grain yield was significantly increased with the improvement of varieties and such an increase was mainly attributed to the increase in total number of spikelets. The tall varieties applied in the 1940s–1950s had higher protein content, relative crystallinity and infrared (IR) ratio of 1 045/1 022 cm−1. The semi-dwarf varieties applied in the 1980s–1990s had higher gel consistency, amylopectin content, IR ratio of 1 022/995 cm−1, and breakdown value. With the improvement of varieties, the amylose content, large-sized starch granule number and volume distribution, onset and peak of gelatinization temperature, gelatinization and retrogradation enthalpy, setback value, pasting temperature, viscosity of peak, hot and final, and 1-aminocycopropane-1-carboxylic acid (ACC) concentrations in panicles and root bleeding were gradually decreased, whereas the medium-sized starch granule number and volume distribution, activities of key enzymes in grains, and zeatin (Z)+zeatin riboside (ZR) contents in panicles and root bleeding at grain filling stage were gradually increased. Correlation analysis showed that starch thermodynamic characteristics were closely related to starch structure and components, key enzymes and hormones. The results suggest that starch quality was enhanced through the optimization of starch components, structure, thermodynamics, and the regulation of key enzymes in grains and hormones in panicles and root bleedings at grain filling stage during the improvement of mid-season indica rice.

High temperature (HT) during grain filling is one of the most important environmental factors limiting maize yield and grain quality. Nitrogen (N) fertilizer is essential for maintaining normal plant growth and defense against environmental stresses. The effects of three N rates and two temperature regimes on the grain yield and quality of fresh waxy maize were studied using the hybrids Suyunuo 5 (SYN5) and Yunuo 7 (YN7) as materials. N application rates were 1.5, 4.5, and 7.5 g plant−1, representing low, moderate, and high N levels (LN, MN, and HN, respectively). Mean day/night temperatures during the grain filling of spring- and summer-sown plants were 27.6/21.0 °C and 28.6/20.0 °C for ambient temperature (AT) and 35/21.0 °C and 35/20.0 °C for HT, respectively. On average, HT reduced kernel number, weight, yield, and moisture content by 29.8%, 17.9%, 38.7%, and 3.3%, respectively. Kernel number, weight, yield, moisture, and starch contents were highest under MN among the three N rates under both temperature regimes. HT reduced grain starch content at all N levels. HT increased grain protein content, which gradually increased with N rate. Mean starch granule size under MN was larger (10.9 μm) than that under LN and HN (both 10.4 μm) at AT. However, the mean size of starch granules was higher under LN (11.7 μm) and lower under MN (11.2 μm) at HT. Iodine binding capacity (IBC) was lowest under MN and highest under HN among the three N levels under both temperature regimes. In general, IBC at all N rates was increased by HT. Peak viscosity (PV) was gradually reduced with increasing N rate at AT. In comparison with LN, PV was increased by MN and decreased by HN at HT. Retrogradation percentage gradually increased with N rate at AT, but was lowest under MN among the three N rates at HT. LN + AT and MN + HT produced grain with high pasting viscosity and low retrogradation tendency. MN application could alleviate the negative effects of HT on the grain yield and quality of fresh waxy maize.

Starch fine molecular structures are of essentially important in determining its pasting and retrogradation properties. In this study, 10 different starches from various botanical sources were selected to investigate the combined action of amylose and amylopectin molecules in determining the starch physicochemical properties. Correlation between starch structural parameters with the pasting and retrogradation properties showed that amylose and amylopectin CLDs do not affect these properties in isolation. Such as, the amount of amylose long chains and amylopectin short chains are both positively correlated with the melting temperatures and enthalpy of retrograded starches. Furthermore, relatively longer amylose short to medium chains can result in higher trough and breakdown viscosity, while higher amount of amylopectin medium to long chains result in higher peak viscosity. The results help a better understanding of the importance of amylose and amylopectin fine molecular structures in determining starch functional properties.

Red glutinous rice is native from Pacitan and is still limited to local region consumption. The color of the rice flour showed that it has bioactive content, which is the potential to wider the use. The effect of pregelatinization using heat and moisture treatment by boiling on physicochemical (starch, amylose, anthocyanin, gel consistency, Lab color, SEM figure) and pasting properties of red glutinous rice flour was determined. The time and temperature of pregelatinization were 5, 10, and 15 minutes and 50°C, 60°C, and 60°C. The experiment was done with a completely randomized design with three replications. Starch content range to 62-77%, amylose content 3.29-5.75%, anthocyanin 2.64-6.71 mg/100g, Moisture 6.16-7.45, L 72.5-73.95, redness 5.11-6.00, yellowness 8.87-9.62, and gel consistency 9.7-12 cm. the increase of time and temperature of pregelatinization lead to decrease of amylose, starch, and anthocyanin content, and viscosity. After pregelatinization, the setback viscosity was lower it means that the rate of retrogradation is lower than native starch. SEM figure also showed that pregelatinization using heat and moisture treatment did not destroy the starch granules.

Green biocomposites based on corn starch plasticized with isosorbide and glycerol and filled with microcrystalline cellulose (MCC) were processed. The structural interactions, dynamomechanical properties, water absorption, and soil biodegradability were investigated by different techniques considering the effect of the type and amount of plasticizer and the MCC addition. The changes along the time of the structural interactions and the dynamomechanical properties of these materials and the influence of the retrogradation phenomenon were also studied. The use of isosorbide as plasticizer instead of glycerol improved the stiffness, the water absorption and the biodegradation rate of thermoplastic starch (TPS). Moreover, no evidence of retrogradation for isosorbide was observed. An isosorbide content of 35% and the addition of MCC filler enhanced in a greater extent these properties with a complete biodegradability in 7 month. These green biocomposites can be an alternative for food packaging applications.

Grain quality parameters of winter common wheat under the influence of ha/Ha (hard vs. Soft) genes, determining grain hardness vs. grain softness, as well as genotypes for the Wx-A1, Wx-B1, and Wx-D1 genes, responsible for either amylose or amylopectin type of endosperm starch, were examined. The influence of environmental conditions on the formation of these parameters in different wheat genotypes during grain ripening was demonstrated. It was demonstrated that the grain softness in comparison with the grain hardness and amylopectin form led to a considerable decrease in water absorption capacity (Absorption) of the grain. The environment affects variation of this trait in amylose genotypes, but does not affect absorption in amylopectin forms. Differences in grain hardness affected the gluten parameter, but showed no response to the environmental influence. Genotypes differing in Wx genes had no hereditary effect on this parameter. The influence of environment factors on the formation of this parameter was revealed. In the years favorable for the wheat grain ripening, the values of viscosity and retrogradation indices were considerably lower in amylopectin forms compared to amylose ones. In the conditions of increased humidity during this period, the differences between these groups of genotypes are smoothed out, and very low viscosity and retrogradation index values are observed. Unlike environmental factors, the differences in grain hardness had no effect on these grain quality parameters. The amylase index in amylopectin forms was stable over the years and did not vary in this group of genotypes and also did not differ from that in amylose genotypes. The response of this index to environmental conditions in the groups of amylose-type cultivars was observed. In the years with the weather conditions favorable for wheat ripening, the viscosity index can be used for identification of amylopectin genotypes.

Pea flour was extruded at 50, 70, and 90 °C. The in vitro digestibility and characteristics of native and extruded pea flour were investigated. The in vitro starch digestibility (IVSD) and in vitro protein digestibility (IVPD) of the extruded pea flour were higher than those of the native pea flour and increased with increasing extrusion temperature from 50 to 90 °C. The rapidly digestible starch increased to 28.34% at 90 °C, the highest slowly digestible starch (SDS) content was 22.70% at 50 °C, and resistant starch content decreased to 4.71% at 90 °C. The IVPD increased from 80.94% relative to the native pea flour to 90.21% at 90 °C. Improved swelling power enabled the extruded pea flour to exhibit better performance and higher breakdown viscosity and lower setback viscosity than the native pea flour demonstrated that extrusion reduced the thermal stability and retrogradation tendency. Increasing extrusion temperatures greatly reduced the relative crystallinity (based on X-ray diffraction analysis) from 32.69% relative to the native pea flour to 9.76% at 90 °C. Extrusion treatment also reduced β-sheet content (based on Fourier transform infrared spectroscopy analysis) from 36.40% relative to the native pea flour to 31.79% at 90 °C. IVPD and IVSD improved, and the SDS content increased at 50 °C and 70 °C, thereby indicating that extruded pea flour can be applied to healthy food products.

A comparative study of the moisture content, mobility of water protons and retrogradation process in muffin samples with the addition of extruded (ME) flour (10%) during storage (14 days) was carried out and compared to control samples without the addition (MO). A significant increase in water content during swelling of the extruded flour was found. The proton magnetic relaxation signal for both ME and MO showed a two-component character for the fast-decay region (free induction decay, FID experiment) and a three-component character for the slow-decay (CPMG experiment) one. The relaxation times T(2) characterizing the protons of both water and non-aqueous fraction decreased during the experiment except for the protons of the fat fraction. The values of relaxation times T(2) for ME exceeded the values for MO, which reflects the increased water content in ME. The amplitude of the signal of water protons (two components of CPMG) decreased for ME more slowly (by about 3–5 days), which can serve as a characterization the shelf life of the muffins. Estimation of the retrogradation rate according to the Avrami model showed a lower value of the rate for ME compared to MO, which may reflect the increased moisture content in ME.

The rapid fabrication of starch gels with excellent mechanical properties still presents a challenge. This study aimed to develop a simple alcohol soaking method to fabricate strong starch gels in a short time. The mechanical properties, crystallization behaviors, and structural characteristics of starch gels were investigated by rheological testing, texture profile analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and low-field nuclear magnetic resonance (LF-NMR). The mechanical strength of the starch gel increased from 170.21 g to 666.16 g. The gelation time of starch gel decreased from 12 h (traditional retrogradation) to 2 h. DSC indicated that the enthalpy of starch gel increased from 0.88 J/g to 2.90 J/g. XRD analysis showed that the crystallinity of starch gel increased from 3.8% to 8.9% after alcohol soaking. Alcohol dehydrated the starch gels system, so that amylopectins were arranged to form more crystals. This new simple approach, alcohol soaking to form strong starch gels, can expand the applications of starch in food, agriculture, and textiles.

The use of carboxymethyl cellulose (CMC) in oil and gas well drilling operations has improved the filtration loss and mud cake properties of drilling muds. The introduction of starch has also reduced, for example, the viscosity, fluid loss, and mud cake properties of the drilling fluids. However, normal starch has some drawbacks such as low shear stress resistance, thermal decomposition, high retrogradation, and syneresis. Hence, starch modification, achieved through acetylation and carboxymethylation, has been introduced to overcome these limitations. In this study, modified starches, from cassava and maize, were used to enhance the properties of water-based muds under high-pressure high temperature (HPHT) conditions, and their performances were compared with that of the CMC. The mud samples added with acetylated cassava or maize starch exhibited the smallest filtrate volumes and filtrate losses within the American Petroleum Institute specification. Therefore, these modified starch-added muds could replace CMC as fluid loss agents since, unlike it, they can withstand HPHT conditions.