Effect of Cross-Linking on Functional Properties of Legume Starches

Physicochemical, thermal, pasting, morphological, functional and bioactive binding characteristics of starches of different oat varieties of North-Western Himalayas

Starches were isolated from five oat varieties (SFO-1, SFO-3, Sabzar, SKO-20 and SKO-96) grown in North-Western Himalayas of India. Moisture content of the varieties ranged from 9.25 ± 0.09 to 13.21 ± 0.11 %, indicating their shelf-stability. Results suggested >90 % purity of starches as was evident from values of ash, proteins, and lipids. Amylose content results showed that all starches fall within category of intermediate-amylose starches. Lambdamax, blue value and OD620/550 were found significantly (p ≤ 0.05) higher in SKO-20. Sabzar exhibited higher starch hydrolysis percentage of 85.16 % whereas, lowest was observed in SKO-20 (78.12 %). Degree of syneresis was higher in SKO-20 however, its freeze-thaw stability was lesser. Wide peak in FTIR spectra at 3320 cm-1 confirms nature of starches. SKO-20 exhibited significantly higher onset gelatinization temperature (65.19 ± 1.06 °C) and enthalpy (15.78 ± 0.15 J/g) whereas, Sabzar exhibited lowest enthalpy. Pasting characteristics indicated lowest and highest final viscosity in SKO-20 (341.30 ± 2.11 mPas) and SKO-96 (1470 ± 4.56 mPas), respectively. SEM results indicated irregular and polygonal shape of starches with size <10 μm. SKO-20 exhibited lowest disintegration time of 2.08 ± 0.01 min and Sabzar showed highest (3.31 ± 0.07 min). SKO-20 released more curcumin (71.28 %) whereas, Sabzar released less. This suggests that SKO-20 could be used as better excipient for delivery of curcumin at target site.

Cross-linked modifications of starches from colored highland barley and their characterizations, digestibility, and lipolysis inhibitory abilities in vitro

To promote the stability and functionality of native starch from colored highland barley (CHBS), the cross-linked modifications with sodium trimetaphosphate (STMP)/sodium tripolyphosphate (STPP) and citric acid were conducted to prepare CHB resistant starches (CHRSs), whose physicochemical characteristics, digestibility, and lipolysis inhibitory potential were also assessed. Results showed that the resistant starch amounts in CHBS were significantly increased after cross-linking and differed slightly among CHRSs. Citric acid modification of CHBS resulted in significantly higher amylose amounts, solubilities, swelling powers, and water-binding capacities than those under STMP/STPP modification within the cultivars (p < 0.05), with their crystalline patterns of A-type (white and blue) and CB-type (black). STMP/STPP modified CHBS exhibited higher degrees of crystalline regions with B-type crystalline patterns. Due to the differences in structural properties and structure-based morphology, STMP/STPP cross-linked CHBS showed lower digestibility and citric acid cross-linked CHBS exhibited higher lipolysis inhibitory activities. Besides, the cross-linked modifications demonstrated more enhancements in functionalities of starches from white and blue cultivars than black cultivar.

Investigation on Nutritional, Phytochemical, and Antioxidant Abilities of Various Traditional Rice Varieties

Rice (Oryza sativa L.) is a popular grain that is consumed by almost half of the world's population. Rice has several distinct breeds classified as traditional and ancient grains. The consumption of rice by 60% of the world's population is a staple food. Entire grain rice, often known as brown rice, is the unpolished counterpart of white rice, containing bran, germ, and endosperm. Eating whole-grain rice is linked to many health benefits; thus, scientists have focused on identifying and quantifying bioactive chemicals in this meal. The present study assessed the physio-chemical, cooking attributes, mineral contents, phytochemicals, and free radical scavenging capabilities of conventional rice cultivars using known approaches according to particle size analysis. Rice grain lengths varied between 4.10 ± 16 and 6.20 ± 007. The length and thickness ratios of rice were not substantially different (p > 0.05). Kattuyanam has the maximum protein content (9.99 ± 06%) of all the rice varieties that were physio-chemical investigated. It also has highest phenolic content and antioxidant properties compared to gallic acid equivalent (334.900 ± 61 g) (GAE)/100 g, followed by anthocyanins and flavonoids. Total phenolic content and phenolic fractions of the HPLC profile in tested landraces indicate the presence of bioactive substances derived from traditional rice cultivars and a range of phytonutrients, including phenol, revealing their healthy potentials in the present study.

Effects of Cross-Linking on Physicochemical and Film Properties of Lotus (Nelumbo nucifera G.) Seed Starch

Lotus seed starch was cross-linked using sodium trimetaphosphate (STMP) in varying amounts (1, 3, and 5%), and its rheological, pasting, thermal, and physicochemical properties were investigated. These cross-linked lotus seed starches (CL-LS-1, CL-LS-3, CL-LS-5) were also used to produce films (CL-LSFs), which were then examined for their mechanical characteristics, water vapor permeability, moisture content, opacity, thickness, and water solubility. After cross-linking, the solubility, amylose content, and swelling power of all the starch samples decreased. Cross-linking resulted in an increased pasting temperature, while peak viscosity (PV) decreased, with CL-LS-5 exhibiting the lowest peak viscosity (1640.22 MPa·s). In comparison to native starch, the thermal characteristics of CL-LS demonstrated greater gelatinization temperatures (T_o, T_p, T_c) and gelatinization enthalpy (ΔH_gel). The gelatinization enthalpy of CL-LS varied between 152.70 and 214.16 J/g, while for native LS the value was 177.91 J/g. Lower moisture content, water solubility, and water vapor permeability were observed in the CL-LSFs. However, the cross-linking modification did not produce much effect on the film thickness. The highest tensile strength (12.52 MPa) and lowest elongation at break (26.11%) were found in CL-LSF-5. Thus, the starch films’ barrier and mechanical qualities were enhanced by cross-linking.

Impact of Heating Temperature on the Crystallization, Structural, Pasting, and Hydration Properties of Pre-Gelatinized Adlay Flour and Its Implementation in Instant Porridge Product

Pre-gelatinization by using an autoclave is the simplest lab-scale method for preparing instant flour from adlay. The effect of heating temperatures (60 °C, 80 °C, and 100 °C) on the structural and pasting properties of pre-gelatinized adlay flour was studied. Moreover, the sensory acceptability of instant porridge prepared from this flour was investigated. Results showed that the shapes of starch granules of pre-gelatinized adlay flour started to disappear at a temperature of 80 °C. However, the crystallinity of the flour gelatinized at 60 °C was higher than that of flours gelatinized at other temperatures. The treatment increased water absorption, water solubility, and swelling power of pre-gelatinized adlay flour. It changed the pasting properties of pre-gelatinized adlay flour and decreased the lightness of pre-gelatinized adlay flour. Overall, the panelists preferred the instant porridge made from pre-gelatinized adlay flour prepared from 100 °C

Physicochemical, Structural, Thermal and Rheological Properties of Flour and Starch Isolated from Avocado Seeds of Landrace and Hass Cultivars

The objective of this study was to obtain and characterize flours and starches from the avocado seeds of Hass and landrace cultivars. The morphological, physical-chemical, structural, thermal and rheological characteristics were evaluated. The flour yield of the Hass and landrace cultivars was 41.56 to 46.86% (w/w), while for starch, it was 35.47 to 39.57% (w/w) (cv. Hass and landrace, respectively). Scanning electron microscopy (SEM) revealed the presence of oval starch granules and other particles in flour, in contrast to flours, starches showed lower ash, proteins and lipids content. However, the amylose content was higher in starches (42.25–48.2%). Flours showed a higher gelatinization temperature (T_p = 73.17–73.62 °C), and their starches presented greater gelatinization enthalpy (∆H_gel = 11.82–13.43 J/g). All samples showed a B-type diffraction pattern, and the crystallinity was higher in the flours. The rheological analysis (flow curves and viscoelastic tests) evidenced a pseudoplastic (n = 0.28–0.36) behavior in all samples analyzed, but the consistency index (k) was higher in starches. In general, the flours and starches from avocado seeds presented interesting proximal, thermal and functional properties for possible application in food systems, and these findings could contribute to the revaluation of this by-product.

Hindgut fermentation of starch is greater for pulse grains than cereal grains in growing pigs

The nutritive value of starch, the major source of dietary energy in pigs, varies depending on its susceptibility for digestion. The botanical origin of starch determines starch structure, and therefore, digestibility. To compare digestibility of starch, fiber, gross energy (GE), crude protein, and amino acid (AA), and to characterize undigested starch of grains in growing pigs, seven ileal-cannulated barrows (initial body weight, 30 kg) were fed six diets containing 96% of one of six test ingredients (three pulse grains: zero-tannin faba bean, green field pea, or mixed-cultivar chickpea; three cereal grains: hulled barley, hard red spring wheat, or hybrid yellow, dent corn), or a N-free diet in a 7 × 7 Latin square at 2.8 × maintenance digestible energy. Grain samples were ground with a hammer mill through a 2.78-mm screen. Amylose content ranged from 29% to 34% for pulse grains and from 22% to 25% for cereal grains. The apparent ileal digestibility (AID) of starch was greater (P < 0.05) in cereal (94% to 97%) than pulse grains (85% to 90%) and was lowest (P < 0.05) in faba bean (85.3%) followed by field pea (87.2%) and chickpea (90.1%). However, apparent total tract digestibility (ATTD) of starch of all tested grains was close to 100%. Apparent hindgut fermentability (AHF, as ATTD - AID) of starch was greater (P < 0.05) in pulse grains (9.9% to 15%) than cereal grains (3.3% to 4.8%). The AHF of total dietary fiber tended to be the greatest (P < 0.10) for corn (43.5%) and lowest for wheat (25.3%). The AHF of GE was greater (P < 0.05) in pulse grains (17% to 20%) than in cereal grains (9% to 11%) and resulted in greater (P < 0.05) digestible energy (DE) contribution from hindgut fermentation for pulse grains than cereal grains (0.9 vs. 0.5 Mcal/kg). Wheat had the greatest standardized ileal digestibility of total AA (90.2%; P < 0.05). Confocal laser scanning microscopy images revealed that 20% to 30% of starch granules of pulse grains were entrapped in protein matrixes. In scanning electron microscopy images, starch granules were larger in faba bean and field pea than cereal grains. Digesta samples revealed pin holes and surface cracks in starch granules of corn and wheat, respectively. In conclusion, hindgut fermentation of starch and fiber was greater in pulse grains than cereal grains resulting in a greater DE value despite lower ileal DE for pulse grain than cereal grains. Defining the digestible and fermentable fractions of starch may enhance the accuracy of equations to predict the net energy value of these feedstuffs.

Understanding the multi-scale structure, physicochemical properties and in vitro digestibility of citrate naked barley starch induced by non-thermal plasma

Non-thermal plasma treatment is an emerging and effective starch modification technique. In this paper, plasma pretreatment was used to modify citrate naked barley starch for enhancing the ability of citric acid to access the starch structure. Plasma treatment did not alter the granule morphology and crystalline type of starch, but degraded the starch molecules and caused more short chains. Plasma pretreatment could etch the starch surface and depolymerize the starch molecules, which increased the accessibility of citric acid for uniform hydrolysis in the subsequent esterification reaction. Therefore, plasma pretreatment significantly promoted the structural and physicochemical modification of the citrate starch, including the enhancement of the degree of substitution, the short-range ordered degree and gelatinization temperatures, and the decreases in the molecular weight, long chains of amylopectin and pasting viscosities. Meanwhile, plasma pretreatment improved the efficiency of acid hydrolysis and decreased the enzymatic digestibility, so that it showed a higher resistant starch content in comparison with its corresponding citrate starch. This paper could provide a new insight into the lower digestion rate and improved functional properties of citrate starch.

Physicochemical and Structural Characterization of Potato Starch with Different Degrees of Gelatinization

Starch gelatinization has been widely studied previously, but there is still a lack of systematical research on the relationship between the degree of starch gelatinization (DSG) and its physicochemical and structural properties. In this study, potato starch samples with DSG ranging from 39.41% to 90.56% were obtained by hydrothermal treatment. The thermal, rheological, and structural properties, as well as the water-binding capacity of samples were investigated. A starch solution with a DSG of 39.41% was partially sedimented at room temperature, while starch with a DSG of 56.11% can form a stable paste with a fine shear-thinning property, as well as samples with a DSG larger than 56.11%. The endothermic enthalpy, gelatinization range, and short-range ordered structure of starch were negatively correlated with DSG, whereas onset gelatinization temperature, apparent viscosity, and water-binding capacity were positively correlated. The viscoelasticity of starch gels was negatively correlated with the DSG after full gelatinization (DSG > 39.41%). Starch granules gradually lose their typical shape and less birefringence can be observed with increasing DSG. Hydrothermal treatment has a more significant effect on the amount of exposed hydroxyl groups than the ordered and amorphous structures of partially gelatinized starch. This study built linear correlations between starch physicochemical properties and the DSG and provided comprehensive insight into the characteristics of partially gelatinized potato starch.

A current review of structure, functional properties, and industrial applications of pulse starches for value-added utilization

Pulse crops have received growing attention from the agri-food sector because they can provide advantageous health benefits and offer a promising source of starch and protein. Pea, lentil, and faba bean are the three leading pulse crops utilized for extracting protein concentrate/isolate in food industry, which simultaneously generates a rising volume of pulse starch as a co-product. Pulse starch can be fractionated from seeds using dry and wet methods. Compared with most commercial starches, pea, lentil, and faba bean starches have relatively high amylose contents, longer amylopectin branch chains, and characteristic C-type polymorphic arrangement in the granules. The described molecular and granular structures of the pulse starches impart unique functional attributes, including high final viscosity during pasting, strong gelling property, and relatively low digestibility in a granular form. Starch isolated from wrinkled pea-a high-amylose mutant of this pulse crop-possesses an even higher amylose content and longer branch chains of amylopectin than smooth pea, lentil, and faba bean starches, which make the physicochemical properties and digestibility of the former distinctively different from those of common pulse starches. The special functional properties of pulse starches promote their applications in food, feed, bioplastic and other industrial products, which can be further expanded by modifying them through chemical, physical and/or enzymatic approaches. Future research directions to increase the fractionation efficiency, improve the physicochemical properties, and enhance the industrial utilization of pulse starches have also been proposed. The comprehensive information covered in this review will be beneficial for the pulse industry to develop effective strategies to generate value from pulse starch.

Physicochemical and morphological properties of resistant starch type 4 prepared under ultrasound and conventional conditions and their in-vitro and in-vivo digestibilities

In the present work, cross-linked resistant starch (RS4) was prepared under sonication and conventional conditions at various levels of pH (9-12) and cross-linker concentration (sodium trimetaphosphate/sodium tripolyphosphate 99:1, 5-15%). It was found that phosphorous and resistant starch content was generally increased by increasing the cross-linker concentration, pH and application of sonication. The damage to the surface of sonicated granules was revealed by scanning electron micrographs. The presence of cross-linked phosphorous groups was demonstrated by FT-IR results through the appearance of a new peak at wave numbers of 1248-1252 cm^-1 that was more conspicuous in sonicated cross-linked samples. Sonicated cross-linked starches showed higher gelatinization temperatures and lower degrees of crystallinity, while no changes was detected in terms of A-type crystalline pattern. The development of viscosity was diminished prominently by the extreme cross-linking reactions in both sonicated and conventional cross-linked starches. The least glycemic index value was obtained for sonicated cross-linked starches which was negatively correlated to their higher RS content measured in-vitro. These results provide novel information on the preparation of cross-linked resistant starch under sonication conditions.

Reaction pattern differences impact physical properties of starches derivatized to the same extent in a model cross-linking system

This study investigated the physical properties of maize (MS) and wheat (WS) starches derivatized with 5-(4,6-dichlorotriazinyl)aminofluorescein (model cross-linking system) to have the same overall fluorescence intensity on starch molecules, but reacted either more uniformly throughout granules (UD) or more at granule surfaces (SD). Both MS and WS derivatives had lower swelling powers (SP) at 90°C than their respective native starches. The UD derivatives had lower SP (90°C) and greater retrogradation enthalpies than did SD derivatives, consistent with their lower peak and higher setback pasting viscosities. Also, SD starches were less soluble and retained a greater degree of granular integrity than UD starches in time-lapse, hot-stage light microscopy studies (50-95°C), likely due to a greater concentration of cross-links at the granule surface. The results confirm that derivatization patterns impact the physical properties of modified starches. Thus, varying derivatization patterns can be a strategy to tailor modified starch properties.

Physiochemical Properties of Cocoyam Starch Extracted in Two Media

Starch was extracted (isolated) from cocoyam with the aid of water solution of oxalic acid and ammonium oxalate in 8 samples of ratios, 1:3, 1:1, 3:1, 2:3, 2:1, 1:2 and 0:0 respectively. The physiochemical properties were investigated in order to unveil its characteristics and unravel the potentials for industrial applications of the cocoyam starch. The physiochemical properties investigated includes; Amylose and Amylopectin contents, water binding capacity, particle size distribution, swelling power and solubility. The results obtained showed that swelling power and solubility of the starch were temperature dependent. The solubility was found to increase with temperature increase as the cocoyam starch showed highest solubility within the 70-90°C temperature range. The swelling power was found fluctuating between the temperatures of 25-90°C. The swelling power starch sample isolated with blending ratios of 2:1 and 1:2 were temperature dependent. The Amylose content ranges from 3.06 to 31.21%.

Physiochemical Properties of Cocoyam Starch Extracted in Two Media

Starch was extracted (isolated) from cocoyam with the aid of water solution of oxalic acid and ammonium oxalate in 8 samples of ratios, 1:3, 1:1, 3:1, 2:3, 2:1, 1:2 and 0:0 respectively. The physiochemical properties were investigated in order to unveil its characteristics and unravel the potentials for industrial applications of the cocoyam starch. The physiochemical properties investigated includes; Amylose and Amylopectin contents, water binding capacity, particle size distribution, swelling power and solubility. The results obtained showed that swelling power and solubility of the starch were temperature dependent. The solubility was found to increase with temperature increase as the cocoyam starch showed highest solubility within the 70-90°C temperature range. The swelling power was found fluctuating between the temperatures of 25-90°C. The swelling power starch sample isolated with blending ratios of 2:1 and 1:2 were temperature dependent. The Amylose content ranges from 3.06 to 31.21%.

Theoretical Insights into Three Types of Oxidized Starch-Based Adhesives: Chemical Stability, Water Resistance, and Shearing Viscosity from a Molecular Viewpoint

To better understand the origin and difference associated with chemical stability, water resistance, and shearing viscosity of three types of different oxidized modified starch-based adhesives, a detailed theoretical investigation from a molecular viewpoint has been performed using the AM1 semiempirical level and the DFT-B3LYP level, respectively. As a result, our findings suggest that, by Mulliken population analysis (MPA), frontier orbital analysis, and electrostatic potential (EP) analysis based on B3LYP/6-31G calculations, the chemical stability, water resistance, and shearing viscosity of the oxidized modified starch-based adhesives are uniformly improved and corresponding difference for each property presents an identical order: the oxidized grafted cross-linked starch-based adhesive > the oxidized grafted starch-based adhesive > the oxidized starch-based adhesive, which is well consistent with experimental results.

Potato starch oxidation induced by sodium hypochlorite and its effect on functional properties and digestibility

The effects of different concentrations of sodium hypochlorite (active chlorine content at 0.1, 0.2, 1.0, 2.0, 3.0, and 4.0 g/100 g) on the properties of potato starch (PS) were investigated by determining the morphological, physicochemical, crystallinity, pasting, gel texture and digestive properties. The starch granules of PS oxidized with high oxidant concentrations caused cracks and pores, and oxidation mainly acts on the amorphous regions of the starch granules. As the sodium hypochlorite concentration increases, the carbonyl content, carboxyl content, solubility, and pasting temperature of PS increased, as measured using a Rapid Visco Analyser (RVA). The swelling power, breakdown, setback, and peak and final viscosities decreased according to the RVA (P<0.05). The gel strength increased under low-intensity oxidative treatments and decreased under high-intensity oxidative treatments. Oxidative treatment decreased the digestibility of gelatinized potato starch. The slowly digestible starch and resistant starch contents increased significantly, while the rapidly digestible starch content decreased after the oxidation modification (P<0.05). Overall, PS oxidation with sodium hypochlorite improved the functional characteristics of starch and decreased starch digestibility.

Effect of acetyl esterification on physicochemical properties of chick pea (Cicer arietinum L.) starch

Acetyl esterification of isolated Bengal gram starch was carried out using acetic anhydride as reactant. Modification of native starch at variant concentrations of acetic anhydride (6, 8 and 10 %, w/w) resulted in modified starch with 2.14, 3.35, 4.47% acetyl content and 0.082, 0.130 and 0.176° of substitution (DS) respectively. The acetyl esterification of native starch brought significant changes in physicochemical properties with respect to pasting behavior, granule morphology, thermal properties and retrogradation profile. Acetyl modifications of native starch increased swelling capacity, water absorption power and oil absorption capability by 17, 13 and 20 % respectively. Acetylation has decreased pasting temperature, pasting time, final viscosity and set back viscosity due to increase in amylsoe content, hydrogen bonding and porosity of starch granule. The acetyl modification was confirmed by IR spectra with the presence of an ester carbonyl group (C = O) at 1720.3 cm(-1) and absorption band at 174.8 cm(-1). In DSC evaluation there was decrease in To, Tp, Tc and ΔH of acetylated starch than native starch which resulted in reduced retrogradation by 56 %.