Paste Clarity Research Articles

Rapid preparation of anti-retrogradation starch by choline chloride based deep eutectic solvents: A comparative study

Legumes are a widespread and cheap source of starch. However, legume starches are prone to retrogradation in applications. Therefore, enhancing the resistance to retrogradation is important to ensure the quality of starch products. In this study, the effects of amines, alcohols, and carboxylic acids deep eutectic solvents (DESs) on the retrogradation properties of pea starch (PS) were investigated. The results showed that the starches treated with carboxylic acid DESs for only 30 min exhibited low paste viscosity, high paste clarity and anti-retrogradation. The carboxylic acid DESs treatment resulted in holes or cracks appearing on the starch surface, a decrease in molecular ordering, relative crystallinity, and amylose content. The thermal enthalpy of starch as well as the pasting viscosity were substantially reduced after the treatment. The paste clarity and the resistance to retrogradation were significantly improved. Conversely, the structure, pasting and retrogradation properties of starch treated with amine and alcohol DESs exhibited only slight differences compared to PS. The carboxylic acid DESs took a short time for the starch modification, and the modified starch paste with low viscosity, high clarity, and resistance to retrogradation. The study could provide an environmentally-friendly and cost-effective method for the preparation of starch with well anti-retrogradation properties.

Physiochemical, Pasting, and Morphological Properties of Native Oat Starch and Citrate‐Modified Oat Starch

AbstractStarch is widely utilized in the food industry, but its native form may have limitations in terms of functionality and nutrition. This study examines the characteristics of native oat starch and explores its potential for chemical modification by cross‐linking, with the aim of gaining a deeper understanding of its functionality. Citrate‐modified oat starch (COS) is generated by cross‐linking native oat starch (NOS) with citric acid. Chemical analysis reveals distinctions between NOS and COS, notably in terms of resistant starch content, which is elevated in COS. X‐ray diffraction (XRD) results reveal that NOS exhibits crystalline peaks characteristic of A‐type starch, distinguishing it from COS. In contrast, COS displays absent crystalline peaks, attributed to cross‐linking. Swelling factor, solubility, and paste clarity along with most of the pasting properties are found to be significantly lower for COS compared to NOS. The scanning electron microscopic images show how cross‐linking can alter the morphology of the NOS. The findings from this investigation highlight significant distinctions between NOS and COS. The cross‐linking process successfully enhances the resistant starch content and imparted distinctive properties absent in native oat starch. Consequently, there is potential for incorporating modified oat starch as a food ingredient.

Transformative effects of lactic acid fermentation on maize and quality protein maize: Phytochemical characterization, functional properties, and structural features

AbstractBackground and ObjectiveFermentation has a huge potential to improve the nutritional and functional properties by using the biological activity of the grain itself. The current study was performed to optimize the conditions for the fermentation of Quality Protein Maize (QPM) and maize further; the impact of fermentation treatment on the bio‐techno‐functional properties of QPM and maize flour was assessed.FindingsThe technological properties, including oil absorption capacity, water solubility index, emulsion activity and stability, foaming capacity and stability, protein solubility, gel consistency, and least gelation concentration, were found to be increased with the fermentation treatment, while water absorption capacity, paste clarity, and swelling power observed a decline. The findings suggested elevated levels of all the bioactive constituents with the fermentation process. The modulations at the molecular level were confirmed by the scanning electron micrographs of fermented flour. Further, changes in the peaks of Fourier transform infrared spectra and the emergence of new peaks were also reported.ConclusionsThe fermentation treatment altered the techno‐functional properties, bioactive constituents, macromolecular structure, and molecular interactions of QPM and maize flour.Significance and NoveltyLimited literature is available dedicated to the assessment of the nutritional, techno‐functional, and phytochemical components in QPM and maize as influenced by the fermentation process. Further, changes in the structural and molecular interactions in the flour components due to fermentation treatment have not been studied comprehensively.

Structural characterization and physicochemical properties of grain amaranth starch

With potato starch (PS) and corn starch (CS) as the controls, the structure and physicochemical properties of grain amaranth starch (GAS) and its binding with dihydromyricetin were investigated in this study. The results indicated that GAS granules were small in size (3.21 ± 0.13 μm) and had a low amylose content (11.57 ± 0.91%). GAS exhibited low paste clarity, solubility, and swelling power, but demonstrated good freeze-thaw stability and resistance to retrogradation. Although the pasting temperature of GAS was high (75.88 ± 0.03 °C), its peak viscosity, breakdown viscosity, and setback viscosity were significantly lower than those of PS and CS. GAS was classified as A-type starch, with a high molecular weight and broad distribution (Mw, 3.96 × 107 g/mol; PDI, 2.67). For its chain length distribution, chain B1 had the highest proportion (50.09%), while chain B3 had the lowest proportion (13.50%). The complexation of GAS with dihydromyricetin effectively enhanced its ABTS and DPPH free radical scavenging capacities.

Isolation and physiochemical characterization of Red kidney bean (Phaseolus vulgaris L.) starch

The current study focuses on the isolation and physiochemical characterisation of starch from Phaseolus vulgaris L. The yield of the starch was about 25.8 %. The size of the starch granules ranged between 10 and 25μm. The starch had a higher water binding capacity, swelling power and solubility but had low paste clarity. P. vulgaris starch exhibited high freeze thaw stability. The bulk, tapped and particle densities of the starch were 1.64 g/cm3, 2.06 g/cm3 and 0.66 g/cm3 respectively. The porosity of the starch was about 64.1%. The estimated Carr index and Hausner’s ratio indicated good flowability of the starch powder. X-ray diffraction analysis indicated that the starch was C-type starch. Fourier-transform infrared spectroscopy revealed the functional group corresponding to that of starch. Thermo gravimetric analysis indicated good thermostability.

Structural and functional properties of ozone-treated quinoa starch

Ozone is a very powerful oxidizing agent and can rapidly decompose without generating waste. Ozone was applied to oxidize quinoa starch suspensions (10 g/100 g) were subjected to oxidation by ozonization and the effect of ozone generation time (OGT: 10, 20 and 30 min) was investigated on their structural and functional properties. As OGT increased from 10 to 30 min, amylose content and relative crystallinity reduced. Gel-permeation chromatography analysis indicated amylose depolymerization and structural analysis by FTIR revealed that ozonized starches had a considerable reduction in the degree of crystallinity with increasing OGT. Carbonyl/carboxyl group contents, paste clarity (26 %), oil absorption capacity (23 %) and peak apparent viscosity, values increased significantly (p ≤ 0.05) for treated samples. Ozone increased the mean diameter (D [2,3]), the onset temperature (DSC), and pasting properties. Thus, ozonization is a powerful method to modify starch, as well as a safe and inexpensive oxidizing process.

Modified Arrowroot Starch: Impact of Multiple Acetylation on Physical, Chemical, and Physicochemical Characteristics

Abstract Modifying single-acetylated starch in arrowroot starch has improved starch quality, especially in paste clarity properties. It was conducted to determine the effect of the double acetylation modification method on the physical, chemical, and physicochemical characteristics of modified arrowroot starch. It used a completely randomized design with variations in the concentration of acid acetate and the immersion time of single acetylation modification. The best single Acetylated Starch is the treatment of variations in adding 2% acetic acid concentration for 60 minutes soaking time, which then proceeds with double acetylation modification. Double acetylation has a paste clarity level of 25.02%, moisture content of 13.33%, Amylose Content of 30.62%, Water Absorption of 3.77 g/g, Swelling power of 9.30 g/g, and Solubility of 5.19%. The pasting properties have a Peak Viscosity of 5716 cP, Through Viscosity of 2336 cP, Breakdown Viscosity of 3380 cP, Final Viscosity of 2750 cP, Setback Viscosity of 414 cP, Peak Time of 5 minutes, and Pasting Temperature 70.90°C. The dual acetylation improves the solubility and swelling power compared with single acetylation and unmodified starch.

Enhancing starch functionality through synergistic modification via sequential treatments with cold plasma and electron beam irradiation

The impact of dual sequential modifications using radio-frequency (RF) plasma and electron beam irradiation (EBI) on starch properties was investigated and compared with single treatments within an irradiation dose range of 5–20 kGy. Regardless of sequence, dual treatments synergistically affected starch properties, increasing acidity, solubility, and paste clarity, while decreasing rheological features with increasing irradiation dose. The molecular weight distribution was also synergistically influenced. Amylopectin distribution broadened particularly below 10 kGy. Amylose narrowed its distribution across all irradiation doses. This was due to dominating EBI-induced degradation and molecular rearrangements from RF plasma. With the highest average radiation-chemical yield (G) and degradation rate constant (k) of (2.12 ± 0.14) × 10−6 mol·J−1 and (3.43 ± 0.23) × 10−4 kGy−1, respectively, upon RF plasma pre-treatment, amylose underwent random chain scission. In comparison to single treatments, dual modification caused minor alterations in spectral characteristics and crystal short-range order structure, along with increased granule aggregation and surface irregularities. The synergistic effect was dose-dependent, significant up to 10 kGy, irrespective of treatment sequence. The highest synergistic ratio was observed when RF plasma preceded irradiation, demonstrating the superior efficiency of plasma pre-treatment in combination with EBI. This synergy has the potential to lower costs and extend starch's technological uses by enhancing radiation sensitivity and reducing the irradiation dose.

Rheological and gelling properties of atmospheric pressure cold plasma treated finger millet (Eleusine coracana) starch

Interest in exploring alternative starch sources like finger millet is rising due to wide starch applications. However, native starch often lacks desired qualities, including rheological properties. Modification is thus necessary for specific end uses. Plasma treatment as a greener and sustainable method for starch modification was therefore, studied for its ability to impact rheological properties of finger millet starch (FMS). Considerable changes in the rheological properties on FMS was noted, a significant decrease and increase (p < 0.05) in the peak viscosity (from 3.35 to 0.553 Pa.s) and paste clarity respectively was observed, indicating occurrence of depolymerization. However, intermediate plasma-treated samples (200 V) observed a decrease in paste clarity attributed to aggregate formation and cross-linking. Cross-linking was also confirmed by findings of frequency sweep where a continuous decrease in G’ values of plasma treated FMS gel was interrupted by sudden increase. Despite depolymerization causing alteration of rheological behaviour such as decrease in shear thinning properties, gel strength observed a contradictory increase. This was attributed to incorporation of functional group and absence of shear responsible for network formation giving higher gel strength to FMS gels. This is elaborated in detail in the study. The study thus concluded that cold plasma significantly impacted all the rheological properties of the FMS and hence can prove to be beneficial for modification of starch rheological parameters.

Physicochemical and functional properties of short-chain fatty acid starch modified with different acyl groups and levels of modification

Rice and quinoa starches are modified with short-chain fatty acids (SCFA) with different SCFA acyl chain lengths and levels of modification. This work is aimed to investigate the impact of modifying rice and quinoa starches with short-chain fatty acids (SCFAs) on various physicochemical properties, including particle size, protein and amylose content, thermal behavior, pasting characteristics, and in vitro digestibility. Both native and SCFA-starches showed comparable particle sizes, with rice starches ranging from 1.58 to 2.22 μm and quinoa starches from 5.18 to 5.72 μm. SCFA modification led to lower protein content in both rice (0.218–0.255 %) and quinoa starches (0.537–0.619 %) compared to their native counterparts. Esterification led to the reduction of gelatinization and pasting temperatures as well as the hardness of the paste of SCFA-starches were reduced while paste clarity increased. The highest level of modification in SCFA-starch was associated with the highest amount of resistant starch fraction. Principal component analysis revealed that modification levels exerted a greater influence on starch properties than the types of SCFA used (acetyl, propionyl, and butyryl). These findings is importance in considering the degree of substitution or level of modification when tailoring starch properties through SCFA modification, with implications for various applications in food applications.

Comparative Study on the Emulsification of Octenyl Succinic Anhydride Modified Sweet Potato Starch: As Macromolecular and Particulate Stabilizers

AbstractSweet potato is one of the essential starch materials for food and feed world widely. However, its application is limited by the low viscosity and poor stability of native starches. Herein, sweet potato starch is modified by octenyl succinic anhydride (OSA) in the aqueous system. The optimization for esterification is studied using response surface methodology. The characteristics of OSA‐modified sweet potato starch are investigated, and its emulsifying properties as macromolecular and particulate stabilizers in the oil‐in‐water systems are compared. The optimal process conditions for OSA modification are: reaction time 4.0 h, temperature 38.8 °C, pH of the reaction system 8.2, starch concentration 32.2%, OSA amount 3.0%. The degree of substitution is 0.0185, and reaction efficiency is 79.7% under the optimum conditions. The new peaks at 1725 and 1573 cm−1 are observed by Fourier transform infrared spectroscopy. Compared with native starch, OSA‐modified sweet potato starch exhibits higher viscosities, improved paste clarity, and decreased retrogradation. The confocal laser scanning microscope results show that the gelatinized starch macromolecule and ungelatinized starch particles can arrange at the water–oil interface. The OSA‐modified sweet potato starch is both an effective macromolecular emulsifier and a particulate stabilizer, effectively stabilizing oil‐in‐water emulsions.

Physicochemical, Rheological Properties, and In‐Vitro Starch Digestibility of Flours and Starches from Pigeon Pea, Cowpea, Pinto Bean, and Navy Bean

AbstractThe physicochemical, rheological properties, and digestibility of flours and starches from pigeon pea, cowpea, pinto bean, and navy bean are investigated. Pinto bean flour (PBF) and Pinto bean starch (PBS) show the highest water absorption capacity (WAC), while cowpea flour (CPF) and cowpea starch (CPS) show the highest oil absorption capacity (OAC)‐ than other pulse flour or starches. All pulse flours show higher solubility than all pulse starches. However, the swelling power (SP) of all flours is lower than starches and SP is comparatively different among starches. Paste clarity, and relative crystallinity (RC), are higher in all flours compared to starches. However, pasting properties and consistency index (K) are lower in flour compared to starches. All the flours and starches exhibit CA‐type crystallinity.The Scanning Electron Microscrographs reveals smooth granular surfaces of all starch and flour. Both flours and starches show flow behavior (n &lt; 1) and viscosity decreased with increasing shear rate indicating the non‐Newtonian fluid behavior. All starches show higher rapidly digestible starch (RDS) and resistant starch (RS) content but lower slowly digestible starch (SDS) content than all flours. These flours and starches can be used as valuable ingredients for formulating functional food, soup, and starch gel.

Optimization of Synthesis of Cassava Starch Phosphates by Response Surface Methodology and Characterization of the Modified Starches

AbstractCassava starch has not been widely exploited in modified starch sector, despite its beneficial and peculiar properties including bland taste and flavor, easy extractability, and good paste clarity. In this study, cassava starch is phosphorylated using sodium tripolyphosphate (STPP) and sodium trimetaphosphate (STMP) at different pH levels according to a central composite design and optimized reaction conditions for maximum phosphorus content. The granule morphology, crystalline pattern, pasting properties, physicochemical properties, and in vitro starch digestibility of the modified starches are determined. The reaction conditions have significant effects on the P content. The highest P content (0.160%) is obtained for the sample synthesized using 8% of STMP and 4% of STPP (based on starch dry weight) at a pH of 9.0. X‐ray diffraction analysis revealed no noticeable change in crystalline properties of the modified starches in comparison to native starch. Samples with lower %P have similar granule morphology as the native starch, whereas at higher levels of P, granule rupture and agglomeration are noticed. Wide differences in the pasting and swelling properties are observed among the modified starches. Crosslinked starches formed at higher levels of pH show highly reduced paste viscosity and restricted in vitro starch digestibility.

Structural, physicochemical and functional properties of high-pressure modified white finger millet starch

The effect of high-pressure processing (HPP) modification (200, 400, and 600 MPa for 10 min) on the physico-chemical, functional, structural, and rheological properties of white finger millet starch (WFMS) was studied. Measured amylose content, water, and oil absorption capacity, alkaline water retention, and pasting temperature increased significantly with the intensity of pressure. All color parameters (L, a, b values, and ΔC) were affected by HPP treatment, and paste clarity of modified starch decreased significantly with an increase in storage time. The samples' least gelation concentration (LGC) is in the range of 8–14 %. An increasing solubility and swelling power are noted, further intensifying at the elevated temperature (90 °C). The structural changes of WFMS were characterized by XRD, SEM, and FTIR spectroscopy. Starch modified at 600 MPa showed a similar pattern as ‘B’-type crystalline, and the surfaces of starch deformed because of the gelatinization. Applied pressure of 600 MPa affected the FTIR characteristic bands at 3330, 2358, and 997 cm−1, indicating a lower crystallinity of the HPP-600 modified sample. According to DSC analysis, even at 600 MPa, WFMS is only partially gelatinized. This work provides insights for producing modified WFM starches by a novel physical modification method.

Isolation and Characterization of Starch from Different Potato Cultivars Grown in Croatia

Starch is a polysaccharide that is widely used in food and other industries; therefore, due to its great potential, it is attempted to be maximally isolated from various foods rich in starch. Commonly, potatoes are used for starch production due to the relatively high starch content in tubers, and the process itself is complex and includes several steps. The aim of this study was to isolate and characterize starch from eight potato varieties. First, the basic chemical composition of the potato samples was determined, and then the isolation was carried out under laboratory conditions. The isolated starch was air dried, then ground and sieved through a 400 µm sieve. The basic chemical composition, amylose content, starch color, swelling capacity and solubility index, clarity of starch pastes, texture of starch gels and thermo-physical properties (gelatinization and retrogradation) were determined in the obtained starch samples. The results showed that the SL 13–25 potato variety had the lowest starch content, while the Stilleto variety had the highest starch content. The content of protein, fat, ash and crude fiber was relatively low in all of the isolated starches, indicating their high purity. Also, the difference in the color of the isolated starches was difficult to see. The highest amylose content had starch from Saprodi, while the lowest was observed in starch from SL 13–25. Starch from the cv. Dartiest had the highest, while starch from the cv. Sereno had the lowest gel strength. The starch of the cv. Dartiest also had the highest clarity value. The retrogradation transition temperatures and enthalpies were lower compared to the gelatinization temperatures and enthalpies. With the increasing temperature, both the swelling capacity and the solubility index of all the samples increased. According to the obtained differences, this study confirmed the significant influence and role of different cultivars on starch characteristics.

Effect of acetylation on the functional characteristics of lima bean (Phaseolus lunatus)

The limited functionality of native starches and powders in diverse applications necessitates their chemical modification for enhanced use. The effect of acetylation on the functional properties of lima bean (Phaseolus lunatus) powder is presented in this study, and its potential as a modified food ingredient was evaluated. Acetylation was performed at 2.11% (LAA), 2.48% (LAB), 3.40% (LAC), and 3.70% (LAD) levels of acetylation, with unmodified lima bean powder (LCC) serving as a control. The paste clarity, turbidity, sedimentation volume, pasting attributes, starch digestibility, bulk density, and water/oil absorption capacities were evaluated. Acetylation improved yield (64.50% to 72.10%) and pasting properties (1166.0 to 4147.0 RVU), pasting temperatures (84.0 to 88.18 °C), and pasting times (4.67 to 7.0 min). Notably, acetylation increased water absorption capacity while decreasing oil absorption capacity and turbidity, indicating a modified interaction with hydrophilic and hydrophobic components. Light transmittance ranged from 3.3% to 18.7%, demonstrating increased paste clarity in acetylated powders. Acetylation impacted starch digestibility and retrogradation tendencies, with acetylated powders showing a reduced inclination for retrogradation. The solubility and swelling power of the powder were temperature-dependent and increased with elevated temperatures. Therefore, acetylation significantly improves the functional profiles of lima bean powder, suggesting its potential for specialized food formulations, pharmaceuticals, and industrial uses. This study paves the way for the innovative use of modified lima bean powder in formulations where tailored functionality is essential, heralding a new era of application for legume-based powders in food technology.

Physical, chemical, and rheological properties of flour from accessions of Frafra potato (Solenostemon rotundifolius)

Frafra Potato (FP) is a climate-smart crop facing extinction in the tropical regions of Africa due to inadequate information about its properties. This study determined the physicochemical, functional, and rheological characteristics of flours from ten FP accessions to gauge their suitability for culinary purposes. The flour yield from FP tubers ranged from 59.3 % (E134) to 69.3 % (E111). While FP flours (FPF) exhibited consistent colour across accessions, variations in paste clarity were noted, ranging from 5.2 % (E145 and Maa-Lana) to 8.6 % (WAAPP). The least gelation concentration varied from 8 % (WAAPP) to 12 % (E 82, 111, 132, 134, 145). Released accessions showed higher protein and ash content than unreleased ones. Mineral composition differed significantly among accessions, including iron, calcium, zinc, and phosphorus, each with varying bioavailability percentages. Vitamin A content also varied across accessions. Proteins common in tuber crops, such as lipoxygenase, patatin, sporamin, tarin, and protease inhibitors (Bowman-Birk PIs), were identified in FPF. Amino acid analysis revealed nineteen amino acids, including seven essentials. FPF characteristics included a bulk density of 0.9 g/ml, oil and water binding capacities of 3 g/g and 1.3 g/g respectively, a pH of 6.4, and titratable acidity of 0.5. All FP flours displayed standard non-Newtonian behaviour, exhibiting pseudoplastic properties. They also showed a type II sigmoidal sorption curve, indicating increased equilibrium moisture content with higher water activity. Moisture sorption studies predicted a safe storage maximum allowable moisture content. These findings have practical implications for flour packaging and storage. The study underscores the culinary potential of Frafra potato and its role in addressing food and nutrition security in Ghana and Sub-Saharan Africa.

Selected Physicochemical, Thermal, and Rheological Properties of Barley Starch Depending on the Type of Soil and Fertilization with Ash from Biomass Combustion.

The following study analyzed the impact of fertilizing barley with fly ash from biomass combustion grown on two types of soil, Haplic Luvisol (HL) and Gleyic Chernozem (GC), on the properties of starch. The experiment was conducted in 2019 (A) and 2020 (B), and barley was fertilized with ash doses (D1-D6) differing in mineral content. In the tested barley starch samples, the amylose content, the clarity of the paste, and the content of selected minerals were determined. The thermodynamic characteristics of gelatinization and retrogradation were determined using the DSC method. Pasting characteristics, flow curves, and viscoelastic properties of starch pastes were performed. Starches differed in amylose content and paste clarity. The highest gelatinization and retrogradation enthalpy (ΔHG and ΔHR) values were recorded for samples GCD1A and HLD5B. None of the tested factors significantly affected the pasting temperature (PT), but they had a significant impact on the remaining parameters of the pasting characteristics. The average PT value of barley starches was 90.9 °C. However, GCD2A starch had the highest maximum viscosity and the highest rheological stability during heating. GCD2A paste was characterized by the highest apparent viscosity. It was shown that all pastes showed non-Newtonian flow and shear-thinning and had a predominance of elastic features over viscous ones. The resulting gels had the characteristics of weak gels. Ash from burning wood biomass is an innovative alternative to mineral fertilizers. It was shown that the use of such soil fertilization influenced the properties of barley starch.

Optimizing the making of modified plantain flour by the mixed-culture of lactic acid bacteria and yeast

Fermentation factors in the making of modified plantain flour must be optimized to obtain optimum conditions that produce the desired characteristics of flour/starch. In this research, we used mix-cultured lactic acid bacteria (LAB) and yeast for plantain fermentation. Response Surface Methodology (RSM) was used to explain the quantitative relationship between input and response variables. The design used is Combine D-optimal. The quantitative independent variables (X) selected were A = culture concentration (lower limit 2%; upper limit 6%) and B = fermentation time (lower limit 8 hours; upper limit 24 hours). Descriptive variables were C = type of plantain (C1 = “tanduk” plantain; C2 = “nangka” plantain) and D = type of culture (D1 = SC; D2 = LAB1 + LAB2; D3 = LAB1 + LAB3; D4 = LAB2 + LAB3; D5 = LAB1 + LAB1 + SC; D6 = LAB1 + LAB3 + SC; D7 = LAB2 + LAB3 + SC). Parameters of flour characteristic analyzed or response (Y) were carboxyl number (Y1), total acid (Y2), swelling number (Y3), pH (Y4), paste clarity (Y5), gelatinization properties: peak (Y6); trough 1 (Y7); breakdown (Y8); final viscosity (Y9); setback(Y10); peak time (Y11); pasting temperature (Y12), water content (Y13), color : *L (Y14); *a(Y15); *b (Y16) and c (Y17). The result showed that a combination of 6% culture concentration and 12.62 hours of fermentation time with a desirability value of 0.66 was the optimum condition with carboxyl value 0.15, total acid 0.47, swelling rate 13.49, peak time 5397.02, breakdown 2259.22, final viscosity 4125.22, setback 98.99, and dL 65.59.&#x0D; Keywords: modification flour, optimum condition, fermentation&#x0D;

Investigating the effect of natural fermentation in modifying the physico-functional, structural and thermal characteristics of pearl and finger millet starch.

In recent years, millets are often considered an emerging crop for sustainable agriculture. Therefore, millets can be exploited as an alternative source of starch which has many applications ranging from food, packaging, bioplastics, and others. However, starch is seldom used in its native form and is more often modified to enhance its functional properties. In literature, many traditional millet-based food recipes often incorporate a fermentation step before cooking. Therefore, using this traditional knowledge fermentation has been explored as a potential method for modifying millet starch. Pearl millet (PM) and finger millet (FM) flour were allowed to naturally ferment for 24 h followed by starch extraction. Compared to native (N) starch,water/oil holding capacity and least gelation concentration of fermented (F) starch decreased with no significant change in swelling power. The solubility, paste clarity and in vitro digestibility of starch were significantly affected by fermentation. X-ray diffraction (XRD) data indicates that after fermentation, crystallinity increased while the A-type crystalline structure remained intact. Fourier-transform infrared (FTIR) spectra showed no deletion or addition of any new functional groups. Thermal characterization by differential scanning calorimetry (DSC) showed that the enthalpy of gelatinization of PM starch decreased while that of FM starch increased after fermentation. The results indicate that 24 h natural fermentation had a significant impact on functional properties of starch without altering the structural architecture of starch granules. Therefore, fermentation can be further explored as a low-cost alternative for starch modification. © 2023 Society of Chemical Industry.