Investigating the Effect of Ultrasonication on the Molecular Structure of Potato Starch Using Synchrotron-based Infrared Spectroscopy

For the first time, in this paper, synchrotron-based Fourier transform infrared spectroscopy characterized the changes in the short-order range of potato starch after ultrasonication. Ultrasonic treatment caused cracks and fissures on potato starch granules. Simultaneously, size exclusion chromatography revealed that the ultrasonic treatment having 53 kHz did not induce scissoring of the glycosidic bond of starch. Differential scanning calorimetry showed decreased thermal parameters (To, Tp and ΔH) of potato starch, indicating a disorder in the starch molecule. Furthermore, synchrotron-based FTIR gives insights on the loosening of short-range order of potato starch as reported by the disruption of the crystalline region of potato starch.

Synthesis of a novel arginine-modified starch resin and its adsorption of dye wastewater

In the side reaction, the two aldehyde groups in the glutaraldehyde molecules should undergo an aldol condensation reaction with the hydroxyl group in the starch molecule, which has been corrected.

Effect of Alkali Treatment on Structure and Properties of High Amylose Corn Starch Film

Alkali treatment is used for melt extrusion film formation with corn starch, but optimal conditions for this procedure are still unknown. In this study, the changes in properties and structure of high amylose corn starch (70%) films with different concentrations of sodium hydroxide (NaOH), prepared by melting extrusion, were investigated. With increasing sodium hydroxide concentrations, the tensile strength of the high-amylose starch film decreased gradually, while the elongation at break increased. The tensile strength of the high amylose starch (HAS) film with 2% NaOH-treatment was 10.03 MPa and its elongation at break was 40%. A 2% NaOH-treatment promoted the orderly rearrangement of starch molecules and formed an Eh-type crystal structure, which enlarged the spacing of the single helix structure, increased the molecular mobility of the starch, and slowed down the process of recrystallization; a 10% NaOH-treatment oxidized the hydroxyl groups of the high amylose corn starch during extrusion, formed a poly-carbonyl structure, and initiated the degradation and cross-linking of starch molecule chains.

Starch nanoparticles – two ways of their preparation

Starch nanoparticles (SNP) originate from the disruption of the semi-crystalline structure of starch granules. They are very useful in food packaging technology because they increase the mechanical and water vapour resistance of the matrix as well as hinder its recrystallisation during storage in high humidity atmospheres. In medicine, SNP are suitable as carriers in modulated drug delivery for immobilized bioactive or therapeutic agents. Depending on the method of preparation, nanoparticles with different physicochemical, technical or mechanical properties can be obtained. Two different methods of preparation were characterized and compared in this work: the first involving acid hydrolysis of the amorphous part of a starch molecule and the second focusing on the debranching of starch by enzymatic treatment with pullulanase.

Experimental and Theoretical Studies of Inhibitive Behaviour of Millet Starch on the Corrosion of Aluminium in Sulphuric Acid Environment

The corrosion inhibition of aluminium in 2 M H2SO4 by millet starch was investigated using gravimetric technique at 35-65OC and theoretical quantum chemical computations. The results indicate that millet starch functioned as a good inhibitor for acid induced corrosion of aluminium. It was found that increase in inhibition efficiency of the inhibitor was concentration dependent and also addition of potassium iodide increased inhibitive performance of the inhibitor synergistically. Furthermore, the mode of adsorption process of the inhibitor was best modeled using Langmuir adsorption isotherm at all inhibitor concentrations and temperatures studied. The trend of inhibition efficiency with temperature, calculated values of free energy, activation energy and enthalpy of adsorption was used to propose the inhibition mechanism. Theoretical chemical quantum computations were carried out using density functional theory to underscore the relationship existing between the inhibitive performance of millet starch and electronic properties of millet starch. Finally, Molecular dynamic simulations were performed using Forcite quench molecular dynamics to model lowest energy adsorption configurations of the starch molecule on Al surface and to determine the binding energy of adsorption

Bacillus Spp. Amylase: Production, Isolation, Characterisation and Its Application

Amylase is one of the leading enzymes used in industry from decades. The preliminary function of this enzyme is the hydrolysis of the starch molecule into glucose units and oligosaccharides. Amylases have spectacular application in broad spectrum of industries such as food, detergent, pharmaceutical and fermentation industries. Among different type of amylases α- amylase is in utmost demand because of its striking features. This particular enzyme is a good substitute over the chemicals catalyst used in industries. α- amylases can be acquired from different sources such as microorganism, animals and plants. Microorganisms are the major source of production of amylase because of the ease of availability, manipulation and operation. The starch converting enzymes is basically generated using submerged fermentation. Some of the prominent characteristics of amylase are its mode of action, substrate specificity and operating condition (temperature and pH). Amylases from different bacterial sources contribute differently to the particular trait of the enzyme. Bacillus amylases have been studied and applied so far because of their robustness in nature and easy accessible pure form of it. Thus this makes it more specific and fit for distinct application in the industry. The purpose of this manuscript was the comparative analysis of the physical and chemical features of α amylases from Bacillus species. It also focuses on the unique characteristics of this enzyme and their industrial applications.Int J Appl Sci Biotechnol, Vol 4(1): 3-14

Purification and characterization of a thermostable glucoamylase from the thermophilic fungus Thermomyces lanuginosus

Glucoamylase (1,4-alpha-D-glucan glucohydrolase, EC 3.2.1.3) was purified from the culture filtrates of the thermophilic fungus Thermomyces lanuginosus and was established to be homogeneous by a number of criteria. The enzyme was a glycoprotein with an average molecular weight of about 57 000 and a carbohydrate content of 10-12%. The enzyme hydrolysed successive glucose residues from the non-reducing ends of the starch molecule. It did not exhibit any glucosyltransferase activity. The enzyme appeared to hydrolyse maltotriose by the multi-chain mechanism. The enzyme was unable to hydrolyse 1,6-alpha-D-glucosidic linkages of isomaltose and dextran. It was optimally active at 70 degrees C. The enzyme exhibited increase in the Vmax. and decreased in Km values with increasing chain length of the substrate molecule. The enzyme was inhibited by the substrate analogue D-glucono-delta-lactone in a non-competitive manner. The enzyme inhibited remarkable resistance towards chemical and thermal denaturation.

Sugars and Starches in a Non-Sweet Sweet Potato Compared to those of Conventional Cultivars

Sweet potatoes that varied from a typical high suqar dessert through various degrees of sweet tropical type, and a new type of non-sweet staple were cooked by three methods, and sugar contents were compared with controls. Starch grain size was measured, and percent amylose was determined. Reducing power and intrinsic viscosity of extracted starches were determined to estimate molecular size and possible structure. Reducing sugar content increased on cooking except in one cultivar, the staple type "Ninety-nine". Low reducing power and high intrinsic viscosity might be indicative of a large, unbranched starch molecule.