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Clarifying Agents (clarifying + agent)

Distribution by Scientific Domains

Polymers and Materials Science	75%

Selected Abstracts

Fining of red wines with gluten or yeast extract protein

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2010
Nerea Iturmendi
Abstract Due to a growing interest in alternatives to substitute gelatin as clarifying agent, this work investigates the use of yeast extracts and glutens. Physico-chemical characteristics of proteins were analysed. Fining experiments were carried out on young red wines. Turbidity reduction, lees volume and effects on polyphenolic content and colour characteristics were determined. The results indicated that glutens and yeast extracts turbidity reduction is comparable to gelatin. Lees production was considerably reduced by non-animal proteins: yeast extracts produced 44%, wheat glutens 60% and maize gluten 92% less than gelatin. Lees volume is highly correlated (R = ,0.720) with the absolute superficial charge density value (SCD) and with the pI (0.936) when clarifier was used in combination with bentonite. Treatments with glutens reduced less the polyphenolic content (between 0.6 and 8.7 units) than gelatin did. There were slight differences on the modification of colour intensity. [source]

Haze of polyethylene films,effects of material parameters and clarifying agents

POLYMER ENGINEERING & SCIENCE, Issue 5 2002
Erik Andreassen
Effects of material parameters on the haze of blown films were analyzed. Four linearlow-density polyethylenes (two metallocene grades and two Ziegler-Natta grades) were studied in combination with three additives (two sorbitol-based clarifying agents and a low-molecular-weight long-chain branched polyethylene). One of the sorbitol-based additives reduced the haze of both the metallocene materials in this study, but did not have any positive effect on the two Ziegler-Natta materials. The variation in haze among the four base materials was directly related to the root-mean-square surface roughness (,). When considering all 16 material/additive combinations, the link between haze and surface topography was not a simple ,-haze relationship, but the haze was correlated with the average distance between adjacent surface profile peaks, the average slope, and the power spectral density at high lateral frequencies. Both of the mechanisms referred to in the literature, extrusion-induced haze and crystallization-induced haze, were probably active for the films in this study. [source]

Advanced nucleating agents for polypropylene,

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2007
Dima Libster
Abstract The present short review aims to summarize advanced nucleating agents for polypropylene (PP). Reviewing the relevant literature, we focused on powerful nucleators that are capable of significantly increasing the crystallization temperature of the polymer at very low working concentrations and also serving as clarifying agents. The nucleation mechanism and efficiency of these compounds are discussed in detail. The nucleating agents were divided into groups according to their tendency to induce monoclinic (,), hexagonal (,), or orthorhombic (,) PP cell geometries. The major , -nucleators and clarifiers are sorbitol-based compounds that speed-up the polymer crystallization due to gelation phenomena and induction of epitaxial crystallization by the metal salts of substituted aromatic heterocyclic phosphate. Among , -nucleators, N,N,-dicyclohexyl-2,6-naphthalene dicarboxamide was found to be very efficient and its nucleation ability was highly concentration dependent. In addition, it was shown that nucleation efficiency of a nucleator can be significantly increased by a new dispersion method comprising its solubilization in a microemulsion. Moreover, the nucleator (HPN-68) increased the , -modification present in the polymer. Copyright © 2007 John Wiley & Sons, Ltd. [source]