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Two levels of chemically modified starches (starch citrates and lactates) prepared at 20% and 40% w/v concentration was subjected to extrusion to produce pregelatinized starches (PG). Starch citrates and lactates modified at 20% and 40% level were referred as (SC20 and SC40) and (SL20 and SL40), respectively. These PG starches underwent significant structural changes during extrusion as depicted by scanning electron micrographs. Native starches showed lower swelling power and water binding capacity but formed harder gels compared to chemically modified pregels. The dynamic rheology of these polymers (extruded modified starches) suggested visco-elastic property i.e. (G' > G''). Citrates demonstrated higher G' than lactates in both frequency and temperature sweep tests. Stability of storage moduli over entire temperature range confirmed that addition of citrates and lactates led to strengthening of gel structure through cross linking and esterification. Non-newtonian behavior was shown by all samples as determined through steady shear flow test with flow behavior index <1. Starch citrate (SC20-PG) demonstrated higher shear stress values. While, SC40-PG depicted anti-thixotropic behavior as measured through in-shear structural recovery measurements. On the basis of results obtained, the dual modification (chemical followed by extrusion) may impart fruitful applications in various food products., Competing Interests: Declaration of competing interest There is no conflict of interest between the authors., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This study describes the effects of hydroxypropylation (HP) on sorghum and corn cold water soluble (CWS) starches prepared via alcoholic alkaline treatment (AAT). Propylene oxide (5% and 12% on starch weight basis) was used to modify both sorghum and corn starches. SEM analysis revealed that HP modification prior to AAT altered the granular morphology of native CWS starches. The characteristic peaks at 2980.28 cm -1 and 2979.87 cm -1 indicated the presence of hydroxypropyl groups and the complete loss of the granular order for HS12-CWS (hydroxypropylated sorghum CWS starch treated with 12% propylene oxide based on dry starch weight) and HC12-CWS (hydroxypropylated corn CWS starch treated with 12% propylene oxide based on dry starch weight) starches. Increase in swelling power and water binding capacity of HP modified CWS starches was observed. However, Percent transmittance was significantly reduced due to fragmented water-soluble granules. HP-modified CWS starch gels exhibited a more rigid gel network. Broader linear viscoelastic range suggesting greater stability and well dispersed behavior of HP-CWS starches. High G' values of HP-CWS starches were due to the ordered and elastic gel network that resisted deformation. Furthermore, all HP-CWS starches exhibited higher shear and thermal resistance compared to unmodified CWS starches., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The aim of the study was to compare the properties of resistant starch (RS 3 ) 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 (ES 14 ) as compared to corn extrudate (EC 14 ) (64.90%), on 14th day of storage. The increase in RS correlates with the increase in percent crystallinity (%Xc), too. The (ES 14 ) 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 (ES 14 ) exhibited glycemic index equal to (EC 14 ) i.e.55.53 and 52.53, respectively; thereby making it a suitable substitute of corn starch., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In the present study, starch was modified by a) cross-linking through addition of 3% mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) based on starch weight b) acetylation through addition of 2%, 4% and 6% acetic anhydride based on starch weight c) dual modification i.e. cross-linking using 3% mixture of STMP and STPP followed by acetylation at 2%, 4% and 6% levels based on starch weight. These starches were then used to develop edible films followed by their characterization. Experimental results revealed that films with increased thickness were obtained from acetylated and cross linked starches whereas, dual modified starch films had reduced thickness compared to native starch film. Films from acetylated and dual modified starches retained more moisture compared to native and cross linked starch films while dual modified starches were more water soluble than acetylated and native starch films. All modified starch films were more clear and transparent compared to native starch films. Films from acetylated starches depicted lower tensile strength but they were more elastic and flexible than native and cross linked starch films. In contrast, dual modified starch films showed excellent mechanical properties and lower water permeability compared to native starch film., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This study investigated the impact of citric acid modification combined with alcoholic-alkaline treatment on physicochemical, textural and rheological properties of sorghum and corn starches. Both starches were modified with citric acid (CA) using concentrations (20 and 40%) w/w and were named as SCA and CCA, respectively. SEM analysis revealed that CA modified CWS (cold water-soluble) starches had cracks and more sharp edges as compared to their native counterparts. In FTIR spectra a new peak at 1730.50 cm -1 and 1733.12 cm -1 confirmed formation of distarch esters for SCA40 and CCA40. Increase in swelling power of CWS starches was observed after citric acid modification. Textural analysis showed that SCA20 and SCA40 formed smooth and soft gels suggesting reduced retrogradation tendency of these starches. The broader linear viscoelastic region of CCA40 and SCA40 indicated high shear resistance and well dispersed behavior of CWS citrates. Moreover, it was observed that all CWS starches showed increase in storage modulus (G') and loss modulus (G″) values at higher frequencies indicating elastic behavior. CA modification conferred heat and shear stability to starches. This study provides the basic knowledge for the application of CA modified CWS starches in many instant, refrigerated and frozen food products., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Barley starch was dual modified by hydroxypropylation using 8% and 12% propylene oxide, separately, based on starch weight (dry basis) followed by cross-linking through addition of 1% mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) to form 8HPCL and 12HPCL E1442 (hydroxypropylated-distarch phosphate) barley starches, respectively. These modified starches were incorporated at 5% and 8% levels in soups. Functional characteristics of starches like swelling power, solubility and water retention capacity greatly improved after dual modifications. Paste clarity increased fivefold in case of 12HPCL (starch prepared using 12% propylene oxide and 1% mixture of STMP and STPP) modified barley starch. Higher level of hydroxypropylation also declined the retrogradation process in starches. All soups demonstrated thixotropic behaviour with flow behaviour indices less than one. Soup [S-(8HPCL) 8 ] made with addition of 8% (8HPCL) barley starch demonstrated highest linear viscoelastic region (LVR), yield stress (τ y ) and complex viscosity (Ƞ ⁎ ). Lowest value of tan δ (0.09) was also observed for S-(8HPCL) 8 soup, suggesting its higher consistency. Native barley starch when added to soup at a level of 5% was the least acceptable in terms of sensory characteristics., (Copyright © 2018. Published by Elsevier B.V.)

The present study isolated starch from corn and sorghum grains through wet milling procedure. Sorghum starch is considered an alternative to corn starch in future, due to similar functional properties. However, agronomically sorghum is a cheap input cost crop compared to sorghum and can grow in drought hit areas. Lactic acid and citric acid modifications along with heat-moisture treatments were performed on both sorghum and corn grains followed by their comparison in terms of functional, textural, thermal, pasting and digestibility characteristics. For both corn and sorghum starches, the resistant starch increased after chemical modifications. The RS content of acid and acid-heat moisture treated starches were in the range of 77.9-90%, significantly higher than those of native starches (64.6-68.8%). The modifications increased the gelatinization temperature, decreased the peak and cold paste viscosity of starches. Chewiness significantly reduced after lactic and citric acid treatment along with heat-moisture treatments. The crystallinity to amorphous ratio measured through Fourier Transform infrared reduced after all chemical treatments. Percent light transmittance was further reduced after heat-moisture treatments, however the effect on corn starch was more pronounced i.e. it declined from 16.5 to 5.2%. The acid-heat moisture treatments had considerably lowered the glycemic index of starch. The GI reduced from 74 to 49.7 and 60 to 48.5 when treated with acid in the presence of heat and moisture. Thus, these starches could be used in production of low-calorie foods., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Pasting and functional properties of water chestnut starch (WCS) alone and mixture of WCS and xanthan gum (XG) were determined by addition of NaCl (0.5, 1, and 2%) at fixed water chestnut starch (5%) and xanthan gum (0.3%) concentration. Results indicated that presence of NaCl had a significant impact on functional and pasting properties of both WCS alone and WCS - XG mixture. Pasting temperature of WCS and WCS - XG mixture increased linearly with increasing salt content, whereas a reverse trend was observed in peak viscosity and sets back in case of WCS alone. It was found that addition of NaCl decreased the swelling power of WCS alone, while it increased in case of WCS - XG mixture. The water absorption of WCS - XG improved drastically by the addition of NaCl while a rapid decline in syneresis was observed with WCS - XG mixture. The transparency of both WCS and WCS - XG mixture were found to be increased after the addition of NaCl., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In the present study, modifications were done by varying concentration of citric and lactic acid (20 g and 40 g) to produce starch citrates (SC 20 , SC 40 ) and lactates (LA 20 , LA 40 ), followed by alcoholic alkaline treatment to produce cold water swelling modified starches (CWS). These modified starches were then compared to their native hot water swelling (HWS) counterparts in terms of functional properties. The CWS starches demonstrated instant viscosity even at room temperature and thus eliminate the need of heating assembly. The CWS (SC 40 ) showed the highest swelling power and water binding capacity among all samples. Morphological characteristics revealed enlargement and roughening of granules after alcoholic alkaline treatment. Absence of 1047 cm -1 peak in FTIR spectra of CWS samples verified the loss of crystalline structure. The least percent retrogradation of 31.33% was exhibited by HWS SC 40 . Percent increase in hardness of gels after 7 days' storage showed remarkable decline in retrogradation tendency of CWS samples. Absence of gelatinization peak and high initial viscosity of CWS samples confirmed gelatinization due to alcoholic alkaline treatment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Starch-based films possess potential application in food packaging, due to their biodegradability, lower cost, stretchability and clarity. The aim of this work was to develop novel edible films from native, acetylated and hydroxypropylated pearl millet starches with improved flexibility, transparency and water barrier properties. Each film contained a fixed concentration of starch (3 g/100 g) and glycerol (30%, w/w based on starch weight). The effect of levels of acetylation (4% and 8%, w/w) and hydroxypropylation (10% and 30%, w/v) on the rheological, physical, thermal, mechanical and barrier properties of films was investigated. SEM results showed that modified starch films possessed smoother surface in comparison to native starch film (NF). Rheological evaluation depicted that filmogenic solution of 30% hydroxypropylated starch was more viscous than other solutions. Films containing 4% and 8% acetylated starches showed excellent moisture barrier property as depicted by their low water vapor permeability (WVP) and water solubility (WS). The extent of these improvements depended on the levels of acetylation. Elongation at break (%EAB) and transparency (%T) of 10% and 30% hydroxypropylated starch films were higher than NF and increased with increasing amount of propylene oxide. Glass transition temperature (T g ) was lowered by addition of modified starches in film formulation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The present study prepared citrates and lactates from rice starch which were then given alcoholic-alkaline treatment to produce cold water soluble (CWS) starches. These chemically modified starches were then compared in terms of rheological parameters to their hot water soluble starches (without alcoholic-alkaline treatment). FTIR spectra showed characteristic peak between 1710-1727 cm -1 which confirmed esterification of starch via citrate and lactate groups. All samples demonstrated viscoelastic character i.e. storage moduli (G') exceeded loss moduli (G″). Both CWS and HWS starch citrates prepared by addition of 40 g citric acid to 100 g of starch exhibited highest G' and G″ suggesting highly structured and strong gels. Dynamic frequency and temperature sweep clearly showed that alcoholic alkaline treatment disrupted the granular conformity due to gelatinization of starch and as a result CWS starches were more susceptible to break down. Steady shear flow test confirmed that all samples were non-Newtonian while results of In-shear structural recovery measurements indicated anti-thixotropic behavior of CWS starch lactates., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this study mango kernel starch (MKS) based heat sealable pouches were developed for packing of red chili powder. The films were prepared by casting technique using glycerol, sorbitol and 1:1 mixture of glycerol and sorbitol and were sealed. All films showed better heat sealing capacity but glycerol films plasticized exhibited higher seal strength than their counterparts. The red chili powder was packed in the MKS film pouches while commercially available polyethylene (PE) film was used as control. The pungency and color of red chili powder was monitored during six months storage at 40°C. The capsaicinoid content was extracted from the red chili with acetonitrile and evaluated quantitatively using spectrophotometric method. The extractable color was measured by ASTA method using acetone. The results showed significant differences in color and pungency of chili packed in MKS and PE pouches. The highest reduction in capsaicinoid content (pungency) of chili powder was observed in PE pouch (25.9%) while lowest was observed in MKS pouch containing sorbitol (15.7%). Similarly color loss was also highest in chili packed in PE pouch while lowest in MKS-sorbitol pouch., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The effect of the partial or total substitution of gum arabic (GA) with native (NA), octenyl succinic anhydride (OSA) and succinylated (SUC) sorghum starches on microencapsulation of nutmeg oleoresin was studied using spray drying technique. The oleoresin with 10% load is emulsified by using three different combinations of GA along with native and modified sorghum starches. The proportion of GA and sorghum starch was fixed at 75:25, 50:50, and 25:75. Most of the feed emulsions were having good emulsion stability and lower emulsion viscosity. The highest oil retention of 95% with 84.07% encapsulation efficiency was achieved when GA: NA starch was used in the fraction of 25:75. The highest encapsulation efficiency of 95.38% was obtained by GA: OSA in a ratio of 75:25. Results obtained suggested that both NA and OSA starches could be considered as a good alternative to gum arabic for microencapsulation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study investigated the effect of treatment of guar gum coating coupled with essential oils. Harvested unripe green mangoes (UGM) were preserved using edible coatings containing essential oils of Nigella sativa, Coriandrum sativum, Foeniculum vulgare and Laurus nobilis derived using two different solvents (methanol and ethanol) and stored at refrigeration temperature (10°C, 80-85% relative humidity). Physiological and biochemical parameters that assess the quality of fruits were determined. Microbiological analysis was also performed at the start and end of shelf life. Generally, it was observed that ethanolic essential oils supplemented coatings conferred a greater retention of fruit quality as compared to both controls. Bacterial counts were significantly reduced in fruits that were coated with ethanolic essential oil edible coatings. Secondly, the coatings supplemented with ethanolic and methanolic essential oils extended shelf life up to 24days whereas treated and untreated control decayed after 10 and 6days respectively (P<0.05). These results suggested the application of these edible coatings for preservation of unripe green mangoes during cold storage., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This work investigated the effect of hydroxypropylation on the physicochemical characteristics of Basmati and Irri rice starches with milk and water. The effect of hydroxypropylated starches on the storage, texture stability and sensory characteristics of rice pudding was studied. Pudding was prepared by replacing 3%, 5% and 10% of Irri rice flour with native and hydroxypropylated starches isolated from two predominant rice varieties of Pakistan; Irri and Basmati. Syneresis was not observed in pudding made with hydroxypropylated starches and native basmati starch. On the contrary, pudding prepared with Irri rice flour and Irri starches showed poor keeping quality. Sensory analysis showed that modification of rice starches did not significantly alter the color, flavor, taste and overall acceptability of pudding. The results suggested that rice pudding, a very popular dessert of South Asia could be prepared with improved storage characteristics using hydroxypropylated starches without altering the taste and acceptability of the product., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Custards were prepared using five ingredients: milk powder, modified pearl millet starch, sugar, vanilla essence and water. The effect of adding hydroxypropylated starch (HPS), succinylated starch (SUS), oxidised starch (OXS) and acetylated starch (ACS) on cold storage stability, pasting, textural and sensory properties was studied and compared to custards containing native pearl millet starch (NS). Interestingly, all chemically modified starches reduced syneresis and no water weeping was observed in custard sample incorporating hydroxypropylated starch (HPC) even after 7days of cold storage. Viscoamylographic analysis revealed that custard containing succinylated starch (SUC) had the highest peak viscosity (108.8 BU), whereas HPC showed the least set back viscosity (19.0 BU). Sensory results suggested that assessors preferred HPC over other custards. Custards are preferred for their chewy semi-solid texture. Incorporation of hydroxypropylated starch (HPS) increased hardness, gumminess and chewiness which subsequently led to higher sensory scores during subjective analysis. Also, no retrogradation peak was observed for HPS and acetylated starch (ACS) when rescanned after 14 days. Thus, it could be concluded that HPS could be used in custards to confer low temperature stability by reducing syneresis., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study was performed to determine the effect of xanthan, guar, CMC and gum acacia on functional and pasting properties of starch isolated from water chestnut (Trapa bispinosa). Morphological properties of water chestnut starch with CMC were studied by scanning electron microscopy (SEM). The addition of hydrocolloids significantly enhanced the solubility of water chestnut starch (WCS) while reduced swelling power and freeze-thaw stability. The hydrophilic tendency of WCS was increased by xanthan gum; however, with addition of gum acacia it decreased significantly. Starch was modified with guar and gum acacia exhibited highest% syneresis. Guar gum was found to be effective in increasing the clarity of water chestnut starch paste. The addition of CMC significantly reduced the pasting temperature of WCS indicating ease of gelatinization. The setback was accelerated in the presence of xanthan gum but gum acacia delayed this effect during the cooling of the starch paste. Only xanthan gum was found to be effective in increasing breakdown showing good paste stability of WCS., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Mango kernel starch (MKS) coatings containing different plasticizers were used to extend the shelf life of tomato. The coating slurry was prepared by gelatinizing 4% mango kernel starch, plasticized with glycerol, sorbitol and their 1:1 mixture (50% of starch weight; db). The samples were kept at room temperature (20°C) and analyzed for shelf life. Significant difference in coated and control fruits were observed and all the coated fruits delayed ripening process that was characterized by reduction in weight loss and restricted changes in soluble solids concentration, titratable acidity, ascorbic acid content, firmness and decay percentage compared to uncoated sample. The formulations containing sorbitol were found to be the most effective followed by combined plasticizers (glycerol: sorbitol) and glycerol. Sensory evaluation conducted to monitor the change in color, texture and aroma also proved the efficacy of MKS coating containing sorbitol by retaining the overall postharvest quality of tomato during the storage period. The results showed that MKS could be a promising coating material for tomatoes that delayed the ripening process up to 20days during storage at 20°C with no adverse effect on postharvest quality., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Starches extracted from two dominant varieties of rice, Basmati and Irri were subjected to acid hydrolysis by preparing starch slurry of 35% (w/v) in HCl solutions of concentrations 0.1M, 0.3M and 0.8M. The scanning electron micrographs showed that granular morphology of starches significantly changed after acid hydrolysis. Acid thinning improved the solubility of starches whereas decline was observed in swelling power and water retention capacity. Paste clarity of both acid treated Basmati and Irri rice starches reduced gradually upon cold storage. Also reduction in values of pasting, peak viscosity, hot paste viscosity, cold paste viscosity and set back were observed in acid thinned Basmati and Irri rice starches. The DE values increased with the increase in HCl concentration for both Basmati and Irri starch. The hardness of 0.8M HCl treated Basmati starch gel was found significantly lower than all treated and untreated starches. The gelatinization enthalpy for Basmati starch significantly reduced after acid hydrolysis with 0.1M, 0.3M and 0.8M HCl solutions at p <0.05., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Composite films were developed by the casting method using mango kernel starch (MKS) and guar and xanthan gums. The concentration of both gums ranged from 0% to 30% (w/w of starch; db). Mechanical properties, oxygen permeability (OP), water vapor permeability (WVP), solubility in water and color parameters of composite films were evaluated. The crystallinity and homogeneity between the starch and gums were also evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The scanning electron micrographs showed homogeneous matrix, with no signs of phase separation between the components. XRD analysis demonstrated diminished crystalline peak. Regardless of gum type the tensile strength (TS) of composite films increased with increasing gum concentration while reverse trend was noted for elongation at break (EAB) which found to be decreased with increasing gum concentration. The addition of both guar and xanthan gums increased solubility and WVP of the composite films. However, the OP was found to be lower than that of the control with both gums. Furthermore, addition of both gums led to changes in transparency and opacity of MKS films. Films containing 10% (w/w) xanthan gum showed lower values for solubility, WVP and OP, while film containing 20% guar gum showed good mechanical properties., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The effects of different concentrations of guar and xanthan gums on functional properties of mango kernel starch (MKS) were studied. Both guar and xanthan gum enhanced the water absorption of MKS. The addition of xanthan gum appeared to reduce the SP (swelling power) and solubility at higher temperatures while guar gum significantly enhanced the SP as well as solubility of MKS. The addition of both gums produced a reinforcing effect on peak viscosity of MKS as compared to control. Pasting temperature of MKS was higher than that of starch modified by gums indicating ease of gelatinization. Guar gum played an accelerative effect on setback but xanthan gum delayed the setback phenomenon during the cooling of the starch paste. Both gums were found to be effective in reducing the syneresis while gel firmness was markedly improved., (Copyright © 2016 Elsevier B.V. All rights reserved.)