Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties

Cassava and banana starch modified with maleic anhydride-poly (ethylene glycol) methyl ether (Ma-mPEG): A comparative study of their physicochemical properties as coatings

This study proposes a simple route to obtain starch grafted copolymers from cassava and banana starches chemically modified with amphiphilic maleic anhydride-poly (ethylene glycol) methyl ether (Ma-mPEG). The starches were extracted from cassava (StC) and banana (StB) pulp and characterized by FTIR spectroscopy, amylose content, scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and average molecular weight. Starches were chemically modified with amphiphilic Ma-mPEG in three mass ratios 1:1, 1:2 and 1:3. Thermal behavior and interactions of Ma-mPEG/starch in the St-g-(Ma-mPEG) copolymers were studied by DSC and TGA. The T_g values showed a higher plasticizer effect in the copolymers obtained from StC. Films were formed from StC-g-(Ma-mPEG) and StB-g-(Ma-mPEG) copolymers, thermal and morphological properties were studied. An increase in the mass ratios of Ma-mPEG and the absence of the glycerol in the formulations formed homogeneous films. StC-g-(Ma-mPEG) 1:3 with 2% concentration showed a potential use as coating in strawberries, presenting a lower weight loss (15.5 ± 5.7%) than the control sample (18.6 ± 3.3%).

Crystalline polysaccharides: A review

The biodegradability and mechanical properties of polysaccharides are dependent on their architecture (linear or branched) as well as their crystallinity (size of crystals and crystallinity percent). The amount of crystalline zones in the polysaccharide significantly governs their ultimate properties and applications (from packaging to biomedicine). Although synthesis, characterization, and properties of polysaccharides have been the subject of several review papers, the effects of crystallization kinetics and crystalline domains on the properties and application have not been comprehensively addressed. This review places focus on different aspects of crystallization of polysaccharides as well as applications of crystalline polysaccharides. Crystallization of cellulose, chitin, chitosan, and starch, as the main members of this family, were discussed. Then, application of the aforementioned crystalline polysaccharides and nano-polysaccharides as well as their physical and chemical interactions were overviewed. This review attempts to provide a complete picture of crystallization-property relationship in polysaccharides.

Effect of the Esterification of Starch with a Mixture of Carboxylic Acids from Yarrowia lipolitica Fermentation Broth on Its Selected Properties

Potato starch was esterified with carboxylic acids contained in the fermentation broth from Yarrowia lipolitica yeast production. Various acid concentrations and various roasting temperatures were used to determine effects of process conditions on ester properties, including the number of acid residues attached to starch chains, starch susceptibility to amylolysis, and thermal characteristics of starch phase transitions. Study results demonstrated the effect of both the composition and the dose of the fermentation broth and of roasting temperature of starch on the number of acid residues attached to starch chains. Citric acid was more susceptible to esterification with starch (DS = 5.65%) compared to the α-ketoglutaric acid (DS = 0.12%). In the case of the latter, a higher degree of substitution was determined in the esters produced at higher roasting temperatures. The lowest digestibility (RS = 20%) was demonstrated for the starch esters with the highest degree of substitution with citric acid, whereas all starch esters showed decreased values of the thermal characteristics of pasting.

Structural and rheological properties of pectic polysaccharide extracted from Ulmus davidiana esterified by succinic acid

The present study was carried out to investigate the physicochemical and structural properties of pectic polysaccharide extracted from Ulmus davidiana (UDP) and to determine the physicochemical, structural, and rheological properties of esterified UDP with succinic acid (ES-UDP). The results indicated that UDP had high amounts of galacturonic acids and various neutral sugars, such as galactose, rhamnose, and glucose. UDP was identified as a low methoxyl pectin, consisting of 1,4-linked α-d-GalpA (the main backbone chain), supported by the results of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, and 1D Nuclear magnetic resonance (NMR) spectroscopy. In the FT-IR and XRD, no difference was detected between UPD and ES-UDPs. However, ¹H and ¹³C NMR spectra revealed that the new ester bonds were formed between a hydroxyl group of UDP and a carboxyl group of succinic acid during esterification. In the steady shear rheological analysis, the consistency index (K) of ES-UDP was significantly higher than that of UDP and increased significantly with increasing concentration of succinic acid. In the dynamic rheological analysis, the tan δ values of all ES-UDP solutions were significantly lower than those of the UDP solution.

Starch Modification by Organic Acids and Their Derivatives: A Review

Starch has been an inexhaustible subject of research for many decades. It is an inexpensive, readily-available material with extensive application in the food and processing industry. Researchers are continually trying to improve its properties by different modification procedures and expand its application. What is mostly applied in this view are their chemical modifications, among which organic acids have recently drawn the greatest attention, particularly with respect to the application of starch in the food industry. Namely, organic acids naturally occur in many edible plants and many of them are generally recognized as safe (GRAS), which make them ideal modification agents for starch intended for the food industry. The aim of this review is to give a short literature overview of the progress made in the research of starch esterification, etherification, cross-linking, and dual modification with organic acids and their derivatives.