Optimisation of conditions of synthesis of oxidised starch from corn and amaranth for use in film-forming applications

Effect of gamma ray dose on granular and molecular structures of gamma ray-irradiated cassava starch and its application in bioplastics

In this study, the effect of gamma ray irradiation on the granular and molecular structures of cassava starch was examined. Cassava starch was irradiated with various gamma ray doses of 25, 50, 75, and 100 kGy. After irradiation, the starch turned yellow, but its granular morphological characteristics remained intact. However, the inner part and the 'Maltese cross' of the starch granules irradiated with 100 kGy were broken, and its crystallinity decreased considerably. The pH reduction (from 5.6 to 3.7) and carboxyl content increase (up to 0.38 %) confirmed the formation of carboxyl groups on the irradiated starch chains. Gamma ray irradiation caused glycosidic bond cleavages, resulting in shortened amylose chains and debranched amylopectin chains containing terminal carboxyl groups. The irradiated starches with different molecular weights have high potential for use in food and non-food applications, for example, in bioplastics. Thermoplastic-irradiated starch (TPIS) materials, and their blends with poly(lactic acid) (PLA) were prepared via extrusion. Both TPIS and PLA/TPIS blends exhibited considerably increased melt flow index values compared with those from the unirradiated starch at approximate increases of 420-2260% and 2-55%, respectively. The improved melt flow ability and reduced viscosity are advantages for some plastic conversion processes such as injection molding.

Natural fermentation of potato (Solanum tuberosum L.) starch: Effect of cultivar, amylose content, and drying method on expansion, chemical and morphological properties

Natural fermentation with sun-drying is a modification that promotes the expansion capacity of starch, and its effects on potato starch have not been reported so far. The aim of this study was to evaluate the effects of the amylose content of potato (Solanum tuberosum L.) starches and natural fermentation followed by oven or sun drying on its properties. Cassava starch was also used a control. Native and fermented starches were evaluated based on their chemical composition, amylose, carboxyl and carbonyl content as well as their thermal, pasty, and morphological properties. The fermentation water was evaluated by pH and titratable acidity to control the process. Puffed balls were prepared to evaluate expandability, mass loss, porosity and texture. The fermentation intensity was greater for potato and cassava starch with low-amylose content than for potato starch with higher amylose content. In addition, the acidity of the fermentation water increased faster with cassava starch than with potato starches. The fermented potato starches with the highest amylose content had low acidity and low expansion capacity compared to the fermented potato and cassava starches with low-amylose content. Fermentation and sun-drying of low-amylose potato and cassava starches increased the expansion and reduced the hardness of the puffed balls.

Benign electrolytic modifications of starch: effects on functional groups and physical properties

Herein, a low-cost electrolytic technology for starch modification has been developed using abundant chloride salt as a redox mediator. The effects of electrolysis conditions on the in situ starch modification are investigated in detail, including chloride concentrations, applied voltages, and electrolysis durations. The modification mechanisms are determined by the type of chlorine species (Cl2, HClO, ClO-, and HCl) generated during the process. Following electrolysis, carbonyl and carboxyl groups ranging from 0.056 to 1.3 g/100 g of starch and 0.006 to 0.5 g/100 g of starch, respectively, were observed. Starch granule median size can be reduced from 15.3 μm to 13.5 μm. In addition to the pronounced changes in granule size, shape, and functional groups, electrolysis leads to increased moisture resistance, higher crystallinity, and substantial alterations in the pasting properties.

Effect of chemical treatments on the functional, morphological and rheological properties of starch isolated from pigeon pea (Cajanus cajan)

Different chemical treatments (cross-linking, oxidation, and hydroxypropylation) were used to modify pigeon pea starch, and its effect on physiochemical, pasting and rheological properties were studied. Cross-linking and oxidation decreased while hydroxypropylation increased the swelling power of pigeon pea starch. All starch samples showed a decrease in their paste clarities. FTIR spectra of all starch samples displayed characteristic absorption bands of starch at wave numbers 1076, 1148, 1376, and 1632 cm-1. A significant reduction occurred in peak, cold paste, hot paste, and setback viscosity after chemical modification. Rheological determinations showed that starch pastes had viscoelastic behaviour. G' and G″ of all starch paste increased after chemical modification. Native and chemically treated starches revealed oval to elliptical-shaped granules and no change was observed after modification when examined in SEM. These results confirmed that the undesirable properties of native pigeon starch can be suitably altered via chemical treatments to make them suitable for several food applications.

Effects of Annealing on the Properties of Gamma-Irradiated Sago Starch

The increase in health and safety concerns regarding chemical modification in recent years has caused a growing research interest in the modification of starch by physical techniques. There has been a growing trend toward using a combination of treatments in starch modification in producing desirable functional properties to widen the application of a specific starch. In this study, a novel combination of gamma irradiation and annealing (ANN) was used to modify sago starch (Metroxylon sagu). The starch was subjected to gamma irradiation (5, 10, 25, 50 kGy) prior to ANN at 5 °C (To-5) and 10 °C (To-10) below the gelatinization temperature. Determination of amylose content, pH, carboxyl content, FTIR (Fourier Transform Infrared) intensity ratio (R1047/1022), swelling power and solubility, thermal behavior, pasting properties, and morphology were carried out. Annealing irradiated starch at To-5 promoted more crystalline perfection as compared to To-10, particularly when combined with 25 and 50 kGy, whereby a synergistic effect was observed. Dual-modified sago starch exhibited lower swelling power, improved gel firmness, and thermal stability with an intact granular structure. Results suggested the potential of gamma irradiation and annealing to induce some novel characteristics in sago starch for extended applications.

Impact of microwave irradiation on chemically modified talipot starches: A characterization study on heterogeneous dual modifications

In this study, the effect of chemical modifications such as oxidation, esterification and crosslinking was investigated alone and in combination with microwave irradiation on a non-conventional starch with 76% starch yield acquired from the trunk of matured talipot palm. The single- and dual-modifications imparted significant changes in the morphological, crystalline, pasting and rheological properties and digestibility of talipot starch. Characteristic peaks were observed in single- and dual-oxidized, esterified and crosslinked starches indicating their respective functional groups. All modifications significantly decreased (p ≤ 0.05) the relative crystallinity (RC) of talipot starches except for crosslinking, and the least RC (11.33%) was observed in microwave irradiated esterified starch. Microwave irradiation prior to chemical modifications showed a significant impact in the swelling and solubility of talipot starches. The decreased setback viscosity and increased light transmittance in single- and dual-microwave irradiated talipot starches showed their lowered retrogradation tendency, suitable for frozen foods. The resistant starch (RS) content was majorly improved in all heterogeneously dual modified talipot starches by incorporating more functional groups owed to structural and crystalline destruction in starch granules upon microwave irradiation. The highest RS content (45.02%) was observed in microwave irradiated esterified uncooked talipot starch.

Combination of Sorbitol and Glycerol, as Plasticizers, and Oxidized Starch Improves the Physicochemical Characteristics of Films for Food Preservation

The aim of this work was to use glycerol (Gly) and sorbitol (Sor) as plasticizers with oxidized starch potato (OS) to produce biodegradable and environmentally friendly films, and to demonstrate the resulting physicochemical and functional viability without subtracting the organoleptic characteristics of the food. Analyses by water vapor permeability (WVP), attenuated total reflection Fourier transform infrared spectra (ATR-FTIR), scanning electron microscopy (SEM), tensile strength (TS), and transparency (UV) showed that the best film result was with 1.5 g of Gly and 2.0 g of Sor, conferred shine, elasticity 19.42 ± 6.20%, and mechanical support. The starch oxidized to 2.5%, contributing a greater transparency of 0.33 ± 0.12 and solubility of 78.90 ± 0.94%, as well as less permeability to water vapor 6.22 ± 0.38 gmm^-2 d^-1 kPa^-1. The films obtained provide an alternative for use in food due to their organic compounds, excellent visual presentation, and barrier characteristics that maintain their integrity and, therefore, their functionality.

Iron Tetrasulfonatophthalocyanine-Catalyzed Starch Oxidation Using H2O2: Interplay between Catalyst Activity, Selectivity, and Stability

Oxidized starch can be efficiently prepared using H₂O₂ as an oxidant and iron(III) tetrasulfophthalocyanine (FePcS) as a catalyst, with properties in the same range as those for commercial oxidized starches prepared using NaOCl. Herein, we performed an in-depth study on the oxidation of potato starch focusing on the mode of operation of this green catalytic system and its fate as the reaction progresses. At optimum batch reaction conditions (H₂O₂/FePcS molar ratio of 6000, 50 °C, and pH 10), a high product yield (91 wt %) was obtained with substantial degrees of substitution (DS_COOH of 1.4 and DS_CO of 4.1 per 100 AGU) and significantly reduced viscosity (197 mPa·s) by dosing H₂O₂. Model compound studies showed limited activity of the catalyst for C6 oxidation, indicating that carboxylic acid incorporation likely results from C-C bond cleavage events. The influence of the process conditions on the stability of the FePcS catalyst was studied using UV-vis and Raman spectroscopic techniques, revealing that both increased H₂O₂ concentration and temperature promote the irreversible degradation of the FePcS catalyst at high pH. The rate and extent of FePcS degradation were found to strongly depend on the initial H₂O₂ concentration where also the rapid decomposition of H₂O₂ by FePcS occurs. These results explain why the slow addition of H₂O₂ in combination with low FePcS catalyst concentration is beneficial for the efficient application in starch oxidation.

Cationic oxidized microporous rice starch: Preparation, characterization, and properties

The combination of enzymolysis of compound enzyme, oxidation of sodium hypochlorite, and cationic etherification of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTMA) was selected for the functionalization of rice starch (RS) to better raise the performances. The results showed that the oxidation and etherification could improve the acid and alkali resistance of RS, and enhanced its thermal stability. The crystalline structure of RS was an A-type, the enzymolysis, oxidation, and etherification did not change the structural type, while the crystallinity degree of RS derivatives was all reduced. The enzymolysis, oxidation, and etherification altered the pasting properties of RS, and could effectively decrease the setback and breakdown of RS. The oxidation of sodium hypochlorite not only damaged RS particles containing no micropores, but also destroyed the particles containing the micropores. The enzymolysis and oxidation more seriously destroyed the crystalline region than cationic etherification. The oxidation could increase the enthalpy change of RS, whereas the enzymolysis and etherification decreased its enthalpy change. In addition, the enzymolysis and oxidation could lead to the evident increase in average size of RS. The cationic etherification was able to improve the adsorption of Cu²⁺ on RS, whereas the low oxidation could only slightly ameliorate the adsorption of Cu²⁺ . PRACTICAL APPLICATION: Cationic oxidized microporous rice starch as an adsorbent, slow-release agent, and flocculant will be well used in food, medicine, pesticide, papermaking, waste water treatment, and so on owing to its abundant micropores, anionic groups, and cationic groups as well as small particle size and narrow size range.

Nutritional and functional properties changes during facultative submerged fermentation of gadung (Dioscorea hispida Dennst) tuber flour using Lactobacillus plantarum

This work aims to examine the influence of flour concentrations (5%–25% w/v), inoculum loading (2.5%–15% v/v), and fermentation time (0–144 h) on the nutritional and functional properties of gadung (Dioscorea hispida Dennst) tuber flour. The flour was microbiologically treated through facultative submerged fermentation using Lactobacillus plantarum. The carbohydrate, lipid, protein, fiber and ash contents were reduced by fermentation, while moisture content was increased. In general, the swelling power and the solubility of fermented flour were below those of the native flour. Carboxyl group content increased with fermentation time, whereas no clear trend was found for carbonyl group. The amylose content of the fermented flour was larger than that of the native flour, which most probably was due to the depolymerization of amylopectin branches to form new amylose-like molecules. The best fermentation conditions were flour concentration of 10% (w/v), inoculum loading of 5% (v/v), and fermentation for 48 h.

Structural, Physicochemical, and Functional Properties of Electrolyzed Cassava Starch

Cassava starch was oxidized using the electrolysis system. Sodium chloride was added to this system at various concentrations from 0.5 to 5.0 % (w/v). The whiteness of modified starches proportionally increased based on the NaCl concentration and human eyes could recognize the difference of color. Under treatment, dents occurred on the surface of starch granule. Concentration of carbonyl and carboxyl groups was increased compared to native starch. Based on X-ray diffraction pattern, oxidized starch kept its A-type. Besides, the ratios of alpha-helix/amorphous regions remained indicating oxidation reaction mainly subjected on amorphous region. Intrinsic viscosity was used to indirectly calculate the average molecular weight of sample. Furthermore, results showed that average molecular weight was significantly reduced (from 2.09-fold to 13.22-fold) based on the reacting NaCl concentration. The increase of NaCl content related to the increase of retrogradation of treated starches. At various temperatures (30-95°C), swelling factor and clarity reflected negative and positive correlations to NaCl concentration.

Kithul palm (Caryota urens) as a new source of starch: Effect of single, dual chemical modifications and annealing on the physicochemical properties and in vitro digestibility

The objective of this study was to determine the effect of physical and chemical modifications on the physicochemical and in vitro digestibility of kithul starch. Starch isolated from kithul flour (Caryota urens) was subjected to physical and chemical modifications. The starch modification was verified by the presence of functional groups using Fourier transform Infrared spectral analysis (FT-IR). X-ray Diffraction (XRD) pattern revealed that the kithul starch is A- type and the modifications did not change the crystalline pattern. However, the relative crystallinity showed significant changes. Chemical modifications increased the swelling and solubility. Pasting and thermal parameters of all modified starches showed significant changes as compared to native starch (NS). Acetylated oxidised starch (AOS) showed highest paste viscosities. Higher enthalpy of gelatinization (∆H_gel) and paste viscosity attributed to perfection and ordering of amorphous regions in annealed starch (ANS). All modifications significantly increased the resistant starch (RS) content than native starch (NS), which indicates its lower digestibility. The current study showed the single, dual chemical modifications and annealing, effectively modified the physicochemical and in vitro digestibility of kithul starch.

Functional and thermal properties of flour obtained from submerged fermentation of durian (Durio zibethinus Murr.) Seed chips using Lactobacillus plantarum

Durian (Durio zibethinus Murr.) is one of the most popular seasonal fruits in South East Asia, mainly Thailand, Indonesia, Malaysia and the Philippines. After consuming of the fruit pulp, the abundant durian seeds are usually disposed. However, they can be eaten after being boiled, roasted, baked, fried or cooked. Unfortunately, there is no sufficient information on the innovative utilizations of the durian seeds as raw materials in the preparation of modern foods. This study aims to characterize the functional and thermal properties of native and fermented durian seed flour obtained from submerged fermentation of durian seed chips using Lactobacillus plantarum, so that this information can be used as the basis in the development of functional foods. The effect of solid consistency (5 - 25% w/v), inoculum size (2.5 - 15% w/v) and time (0 - 40 h) on the swelling power, water solubility, water absorption capacity, oil absorption capacity, carbonyl and carboxyl content, degree of substitution and gelatinization temperature of the flour were investigated. Fermentation was found to alter all of the functional and thermal properties of durian seed flour. Although fermentation increased the gelatinization temperature and oil absorption capacity of durian seed flour, their value were still lower than that of wheat flour. Based on the carboxyl group content and degree of substitution, the fermented durian seed flour obtained from fermentation of durian seed chips at 15% w/v solid consistency and 5% v/v inoculums size for 24 h is safe for consumption. Fermented durian seed flour exhibits similar functional properties to that of wheat flour and offers its superiority and high potential applications in the food industry over wheat flour due to its high fiber content (8.50 ±0.26%), but low fat content (0.63 ±0.03%). However, rigorous research should be conducted to ensure the acceptability and practical implementation of fermented durian seed flour as raw material for the manufacture of bread, cookies, cake and noodle.

Calcium content mediated hemostasis of calcium-modified oxidized microporous starch

Blood coagulates are closely related to calcium ions (coagulation factor IV), and calcium-doped biomaterials have been reported to be effective in hemostasis. However, the effects exerted by calcium on hemostatic agents have not been previously investigated. The aims of this work were to develop calcium-modified oxidized microporous starch (CaOMS) with controllable calcium contents and to explore the relationship between calcium content and hemostatic effects. The results showed that low calcium content promoted coagulation, while high calcium content inhibited coagulation. CaOMS3 with 2.2 mg/g calcium content was optimal because of its excellent water absorption performance that enhanced physical coagulation, the rapid initiation of coagulation cascade reactions, and the enhanced chemical coagulation by RBC aggregation and platelet activation. The synergistic effects of chemical activation and physical absorption endowed CaOMS with the potential to control internal organ bleeding. These results suggested that CaOMS may be a promising hemostatic agent with wide spread applications.

Non-starch contents affect the susceptibility of banana starch and flour to ozonation

The properties of native flour and starch were compared and the changes in their properties were evaluated following ozonation at 100 and 200 ppm. X-ray diffraction analysis indicated that crystallinity index of both ozonated banana flour and starch decreased by 1.6%, B-type pattern of native banana flour and starch did not change following ozonation. The presence of higher amounts of non-starch components decreased the sensitivity of flour to the oxidation, as indicated by the lower carboxyl content compared to that of starch. The flour also required higher ozone concentration than starch to alter its properties, particularly pasting properties. Ozonation tended to increase peak, hold and final viscosity of both. A prominent change in the freeze thaw stability of both flour and starch following ozonation was the most encouraging result. Ozonation also improved the solubility of flour which was important to reduce cooking loss when applied in a range of food products. The solubility improvement in the flour might be linked to the formation of new binding following ozonation presumably involving protein present in the granule surface.

Emerging opportunities in exploring the nutritional/functional value of amaranth

Amaranthusspp. is a highly nutritive pseudocereal, rich in macronutrients and micronutrients, including vitamins and minerals.

Impact of acid and oxidative modifications, single or dual, of sorghum starch on biodegradable films

The objective of this study was to evaluate the effects of acid and oxidation modifications on sorghum starch, as well as the effect of dual modification of starch on the physical, morphological, mechanical, and barrier properties of biodegradable films. The acid modification was performed with 3% lactic acid and the oxidation was performed with 1.5% active chlorine. For dual modification, the acid modification was performed first, followed by oxidation under the same conditions as above. Both films of the oxidized starches, single and dual, had increased stiffness, providing a higher tensile strength and lower elongation when compared to films based on native and single acid modified starches. However, the dual modification increased the water vapor permeability of the films without changing their solubility. The increase in sorghum starch concentration in the filmogenic solution increased the thickness, water vapor permeability, and elongation of the films.

Effect of Ozone Treatment on Deoxynivalenol and Wheat Quality

Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium fungi, which is found in a wide range of agricultural products, especially in wheat, barley, oat and corn. In this study, the distribution of DON in the wheat kernel and the effect of exposure time to ozone on DON detoxification were investigated. A high concentration of toxin was found in the outer part of the kernel, and DON was injected from the outside to the inside. The degradation rates of DON were 26.40%, 39.16%, and 53.48% after the samples were exposed to 75 mg/L ozone for 30, 60, and 90 min, respectively. The effect of ozonation on wheat flour quality and nutrition was also evaluated. No significant differences (P > 0.05) were found in protein content, fatty acid value, amino acid content, starch content, carbonyl and carboxyl content, and swelling power of ozone-treated samples. Moreover, the ozone-treated samples exhibited higher tenacity and whiteness, as well as lower extensibility and yellowness. This finding indicated that ozone treatment can simultaneously reduce DON levels and improve flour quality.