Acid hydrolysis

Pectin is a functional technology product by her rheological characteristics. In 2010 in Colombia, there were imported approximately 195 tons and its demand is increasing. The main goal of this research was to extract and characterize the pectin from ripe sugar mango peel. The isolation of pectin material was accomplished by acid hydrolysis, with hydrochloric acid to 0.5 N and ethyl alcohol to 96 % for precipitation and purification. For the extraction of pectin factorial arrangement 32 was used where the two factors evaluated were: pH and temperature, which took the levels 1, 2, 3 and 80, 90, 100 respectively, in a constant time of 60 minutes. There were 27 experimental units equivalent to 550 g of ripe, dry and ground sugar mango peel. The results were evaluated and it was stated that ideal variables (pH 1 and temperature 100 ºC) allow to extract major quantity of pectin, bringing a performance of 15.257±0.04%. The obtained pectin presented the following characteristics: humidity content (4.510 ± 0.80%), ashes content (1.351± 0.07%), alkalinity of the ashes (1.711±1.13%), free acidity (0.859±0.01 mEq free / g carboxyl), equivalent weight (2326.420±54.11 mg / mEq), methoxyl (11,801 ±0.03%), degree of esterification (81.688±024%), anhydrous acid content (82.380±0.17%) and the analysis by infrared spectrophotometry, showed the peaks of functional groups, typical of the obtained pectin and its similarity opposite to a standard pectin. The material studied is a potential source of quality pectin.

Paramyxoviruses are the leading cause of respiratory disease in children. Several paramyxoviruses possess a surface glycoprotein, the hemagglutinin-neuraminidase (HN), that is involved in attachment to sialic acid receptors, promotion of fusion, and removal of sialic acid from infected cells and progeny virions. Previously we showed that Newcastle disease virus (NDV) HN contained a pliable sialic acid recognition site that could take two states, a binding state and a catalytic state. Here we present evidence for a second sialic acid binding site at the dimer interface of HN and present a model for its involvement in cell fusion. Three different crystal forms of NDV HN now reveal identical tetrameric arrangements of HN monomers, perhaps indicative of the tetramer association found on the viral surface.

A water-soluble polysaccharide of an edible mushroom Calocybe indica var. APK2 showed immunoenhancing (macrophage, splenocyte, thymocyte, and bone marrow activation) and cytotoxic activity toward HeLa cell lines and found to consist of d-glucose, d-galactose, and l-fucose in a molar ratio of nearly 3:1:1. On the basis of acid hydrolysis, methylation analysis, and NMR studies (1H, 13C, DEPT-135, TOCSY, DQF–COSY, NOESY,

A method was developed for estimating the content in foods of the emulsifying additive E473, sucrose esters of fatty acids. The analytical approach taken to estimate the complex mixtures that comprise this additive involved, selective solvent extraction of the intact ...

The main toxic compound found in false morel (Gyromitra esculenta) is acetaldehyde-N-methyl-N-formylhydrazone (gyromitrin). This paper describes a method of determining the total hydrazones content based on acid hydrolysis of gyromitrin and other related hydrazones in air-dried false morel followed by derivatisation of methylhydrazine with pentafluorobenzoyl chloride. The derivative, tris-pentafluorobenzoyl methylhydrazine (tris-PFB-MH) is analyzed by gas chromatography–mass spectrometry. The overall precision

Organic-inorganic hybrid materials were synthesized by controlled hydrolysis of tetraethoxysilane (TEOS), methyltrimethoxysilane (MTES), synthetic wollastonite powders and polydimethylsiloxane (PDMS) in an ethanol solution. Aerogels were prepared from acid hydrolysis of TEOS and MTES with different volume ratio in ethanol, followed by addition of wollastonite powder and PDMS in order to obtain aerogels with 20 wt% of PDMS and 5 wt% of CaO of the total silica. Finally, when the wet gels were obtained, they were supercritically dried at 260 degrees C and 90 bar, in ethanol. In order to obtain its bioactivity, one method for surface activation is based on a wet chemical alkaline treatment. The particular interest of this study is that we introduce hybrid aerogels, in a 1 M solution of NaOH, for 30 s at room temperature. We evaluate the bioactivity of TEOS-MTES aerogel when immersed in a static volume of simulated body fluid (SBF). An apatite layer of spherical-shaped particles of uniform size smaller than 5 microns is observed to form on the surface of the aerogels after 25 days soaking in SBF.

Malto-dextrin, the mixture of glucose, maltose and dextrin is used in food industry, as bulking agent, fat replacer, and for medical/nutritional purpose. It is generally produced from cane sugar, maize (starch) etc. by acid or enzymatic hydrolysis. But presently its production rate is not so high. Malto-dextrin production from broken rice, a waste, is very beneficial because of its low cost and availability. In this paper, the objective of this study was to maximize the malto-dextrin production from rice starch by acid hydrolysis and also the effect of particle size on production of malto-dextrin. The rice starch was hydrolyzed by Hydrochloric acid (HCl). The range of the factors employed were particle mesh size, gelatinization pressure and time, saccharification time. The optimized gelatinization condition was 15psig for 30 minutes. The optimized acid hydrolysis condition was 67oC for 30 minutes. The optimized particle size was 18 meshes both for raw and parboiled rice. Maximum yie...