Characterization of waxy starches phosphorylated using phytic acid

Structural features, physiological functions and digestive properties of phosphorylated corn starch: A comparative study of four phosphorylating agents and two preparation methods

Phosphorylation is an important modification to modulate functional and digestive properties of starches. We systematically investigated starch phosphorylation process parameters by using two different preparation methods (slurry and semi-dry conditions) and four commonly used phosphorylating agents, namely sodium tripolyphosphate (STPP), sodium trimetaphosphate (STMP), STMP/STPP (99: 1), and sodium phytate (SP). The effects of phosphorylation on physicochemical characteristics, techno-functionalities, digestive properties and structural features of corn starch were analyzed. Phosphorylation with the semi-dry method resulted in higher phosphorus content, degree of double helix, and degree of starch aggregation and lower amylose content and relative crystallinity than with the slurry method. Phosphorylation using semi-dry conditions, irrespective of the used phosphorylating agent, furthermore decreased the gelatinization temperature, enthalpy, the temperature corresponding to the maximum starch mass loss rate and estimated glycemic index of corn starch, and increased solubility, swelling power, peak viscosity, transmittance, and resistant starch content. Of the phosphorylating agents, independent of the used preparation method, STMP and STMP/STPP resulted in the highest degrees of starch phosphorylation and therefore modulated the physiochemical, functional and digestive properties of corn starch more than STPP and SP. The findings of this systematic comparison provide important information to tailor phosphorylated corn starches to meet specific food requirements.

Improvement of pasting behavior and retrogradation inhibition of normal corn starch treated with phytic acid and malic acid

Phytic acid (PA) and malic acid (MA), as environmentally friendly, plant-based water-soluble acids, were applied to normal corn starch during dry heating at mildly acidic pH to improve its gelatinization and retrogradation behaviors. A significant increase in peak viscosity (5011-6338 mPa·s) was observed in starch treated with MA compared to native corn starch (1162 mPa·s). The treatment with PA and MA further increased the peak viscosity (8140-8621 mPa·s). The interactions of PA and MA with starch were analyzed using ICP-OES, FTIR, and 13C CP/MAS NMR. Swelling power and solubility increased in MA and PA + MA starches. After storage at 4 °C for 14 d, MA and PA + MA starches produced transparent and fluid gels without forming B-type crystals, which indicated inhibition of starch retrogradation by PA and MA treatments. In conclusion, dry heating with PA and MA produced starch with remarkably superior paste viscosity, swelling, and inhibition of retrogradation.

Phytic Acid-Functional Cellulose Nanocrystals and Their Application in Self-Healing Nanocomposite Hydrogels

Cellulose nanocrystals (CNCs) have garnered significant attention as a modifiable substrate because of their exceptional performances, including remarkable degradability, high tensile strength, high elastic modulus, and biocompatibility. In this article, the successful adsorption of phytic acid (PA) onto the surface of cellulose nanocrystals @polydopamine (CNC@PDA) was achieved. Taking inspiration from mussels, a dopamine self-polymerization reaction was employed to coat the surface of CNCs with PDA. Utilizing Pickering emulsion, the CNC@PDA-PA nanomaterial was obtained by grafting PA onto CNC@PDA. An environmentally friendly hydrogel was prepared through various reversible interactions using poly(acrylic acid) (PAA) and Fe3+ as raw materials with the assistance of CNC@PDA-PA. By multiple hydrogen bonding and metal-ligand coordination, nanocomposite hydrogels exhibit remarkable mechanical properties (the tensile strength and strain were 1.82 MPa and 442.1%, respectively) in addition to spectacular healing abilities (96.6% after 5 h). The study aimed to develop an innovative approach for fabricating nanocomposite hydrogels with exceptional self-healing capabilities.

Phosphorylation and citration of normal corn starch by dry heating with phytic acid and citric acid

Normal corn starch was subjected to dry heating in the presence of phytic acid (PA, 2 %, starch basis) and citric acid (CA, 5 % and 10 %) for modification. Dual treatment with PA and CA induced structural and physicochemical changes in normal corn starch. Phosphorus concentration, degree of substitution, FTIR, and ³¹P NMR analyses confirmed esterification of starch by dry heating with PA and CA. Both phosphorylation and citration by esterification with PA and CA were observed in PA + 5CA starch, but high CA concentration inhibited covalent interaction between PA and starch in PA + 10CA starch. The degree of phosphorylation and citration resulted in different physicochemical properties in starch treated with PA and CA. The treatment with only PA did not change the crystalline regions of PA starch, but CA treatment induced the disruption of the crystalline structure of PA + 5CA and PA + 10CA starch. PA starch showed high solubility (46.41 %) and transmittance (90.51 %), but dual treatment of PA and CA induced significant decrease in solubility (3.23 %) and transmittance (2.18 %) of PA + 10CA starch. CA treatment increased the fraction of resistant starch in non-cooked (72.44 %) and cooked PA + 10CA starch (42.76 %). Therefore, dual treatment with PA and CA had potential to control physicochemical and functional properties of starch by phosphorylation and citration of starch.

A green approach to starch modification by solvent-free method with betaine hydrochloride

In this study, a novel simple and eco-efficient, semi-dry method with a spray system for starch modification has been developed. Compared to conventional semi-dry methods, this method does not use solvents so that no slurry or semi-liquid mixture is obtained, the material is in a moisted/semi-moisted state. The modification of starch was performed using betaine hydrochloride (BHC) as the cationic reagent, and the characteristics of such starch derivates were compared with cationic starches obtained using glycidyltrimethylammonium chloride (GTMAC). Due to the instability, toxicity, and high cost of the most commonly used GTMAC, it should be replaced with more eco-friendly reagents, such as BHC, which is derived from betaine found in most green plants (e.g., spinach - Spinacia oleracea, beets - Beta vulgaris). The influence of processing conditions such as temperature, concentration of cationic reagents, presence and concentration of natural plasticizers/catalyst on physico-chemical and structural properties of cationic starches have also been studied. The cationic degree varied from 0.045-0.204 for the starch-BHC samples and within the range of 0.066-0.245 for the starch-GTMAC samples. The modification of starch with cationic reagents resulted in an increased solubility and swelling capacity, followed by decreased viscosity of the modified starches.

Flame Retardant Functionalization of Microcrystalline Cellulose by Phosphorylation Reaction with Phytic Acid

The functionalization of microcrystalline cellulose (MCC) is an important strategy for broadening its application fields. In the present work, MCC was functionalized by phosphorylation reaction with phytic acid (PA) for enhanced flame retardancy. The conditions of phosphorylation reaction including PA concentration, MCC/PA weight ratio and temperature were discussed, and the thermal degradation, heat release and char-forming properties of the resulting PA modified MCC were studied by thermogravimetric analysis and pyrolysis combustion flow calorimetry. The PA modified MCC, which was prepared at 90 °C, 50%PA and 1:3 weight ratio of MCC to PA, exhibited early thermal dehydration with rapid char formation as well as low heat release capability. This work suggests a novel strategy for the phosphorylation of cellulose using PA and reveals that the PA phosphorylated MCC can act as a promising flame retardant material.

Preparation and properties of phosphate starches from tuberous roots

The diversification of raw materials in the starch industries is a current strategy. However, the production of native starches does not meet market demand, and it is essential to expand the knowledge about chemical modifications in the same production line for different sources of starch. Phosphate starches are one of the most abundantly produced and widely used chemically modified starches. However, the effects of this modification may vary with the starch source and the reaction conditions. In this study, arrowroot, cassava and sweet potato starches were modified with sodium trimetaphosphate (STMP)/sodium tripolyphosphate (STPP) mixture under same conditions. The reaction time ranged from 7.5 to 120 min. Unmodified and modified starches were analyzed for phosphorus, amylose, morphology, X-ray diffraction pattern, crystallinity, swelling power, solubility, pasting and thermal properties. Phosphorus content linked to the starches increased with the reaction time, which affected the physicochemical properties of the three starches. The changes were more significant in all reaction times for cassava starch, followed by arrowroot. Due to its intrinsic characteristics, longer reaction times were necessary for more significant changes in sweet potato starch. Regardless of the starch source, as the reaction time increased, the average starch granule diameter, swelling power, solubility and peak viscosity increased. There was a decrease in setback in the longer reaction times for cassava and arrowroot starches. The changes in the reaction times allowed obtaining phosphate tuberous starches with different properties which can meet the demands of the food and non-food industries.

Novel Biodegradable Starch Film for Food Packaging with Antimicrobial Chicory Root Extract and Phytic Acid as a Cross-Linking Agent

The aim of the study was to obtain and evaluate the properties of biodegradable starch film with the addition of phytic acid (0.05%) as a cross-linking agent and chicory root extract (1-5%) as an antimicrobial agent. To prepare biodegradable film, extracts from chicory root obtained with water or methanol were used. The content of bioactive compounds (sesquiterpene lactones and total polyphenols) was evaluated in chicory extracts. The antibacterial activity of the extracts was tested against Gram-negative bacteria (Pseudomonas fluorescens, Escherichia coli) and Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) using the microculture method. The extracts acted as bacteriostatic agents, decreasing the growth rate (µ_max), and extending the lag phase (t_lag). The most sensitive bacterium in terms of film bacteriostatic activity was P. fluorescens; all extracts, irrespective of the solvent used, decreased its µ_max value. S. aureus was the least sensitive. The obtained films were tested for their properties as food packaging (color, thickness, permeability, mechanical strength). Phytic acid improved the tensile strength and barrier properties of the films. The antimicrobial activity of the films was studied by the disk diffusion method against Gram-negative (P. fluorescens, E. coli) and Gram-positive (B. subtilis, S. aureus) bacteria, as well as fungi (Candida albicans, Aspergillus niger). The growth-inhibiting activity of each obtained film was observed for all tested microorganisms, and the most beneficial effect was observed for films with the 5% level of added extracts obtained with water. The growth-inhibiting activity for fungi, in particular for the yeast C. albicans, was low.