Ropiness

In low-acid, dry wines, growth of pediococci and lactobacilli may result in formation of extracellular polysaccharides. Many appear to be P-D-glucans (Llauberes et al., 1990) but other monosaccharides may be present (Manca de Nadra and Strasser de Saad, 1995). Described as ropi-ness or oiliness by winemakers, this fault is commonly detected as an increase in viscosity. 

damnosus and P. pentosaceus have been implicated in this defect in wines (Manca de Nadra and Strasser de Saad, 1995 Lonvaud-Funel, 1999 Walling et al., 2005) while Lactobacillus spp. have been reported to cause ropiness in ciders (Duenas et al., 1995). Factors that affect bacterial growth also impact ropiness. For instance, exopolysaccharide production by P. damnosus is enhanced above pH 3.5 (Walling et al., 2005). Although ropy strains of pediococci are thought to be more tolerant of alcohol, acid, and SO2 than other strains of Pediococcus (Lonvaud-Funel and Joyeux, 1988 Walling et al., 2005), synthesis of these polysaccharides is not a response to ethanol stress (Walling et al., 2005). 

Early research by Krumperman and Vaughn (1966) reported five species of Lactobacillus, including L. brevis and L. plantarum, that can utihze tartaric acid. Apparently, pathways to metabohze tartaric acid differ between heterofermentative and homofermentative bacteria. As described by Radler and Yaimissis (1972), L. brevis (heterofermentative) converts tartaric to oxaloacetic acid and through a series of intermediates, succinic acid, acetic acid, and GO2. By comparison, L. plantarum (homofermentative) decarboxylates oxaloacetic acid to pyruvic acid, which is subsequently reduced to lactic acid or decarboxylated to acetic acid and GOj. More recently, a novel species of Candida has been isolated from wine lees that can degrade tartaric acid (Fonseca et al., 2000), but it remains unknown if this yeast causes spoilage in wines. 

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It is recognized that a truly reversible process does not exist in the real world. II it is further recognized that real processes result in an increase in enl ropy, the second law can be stated. 

Fig. 4.2. Temperalure-en(ropy diagram for single-step cooling—equivalent two cycles (after Ref. [5 ).

J ropi ) fics.- Vhc, acid, nhich contains i molecule of water, crystallises in prisms soluble in water, alcohol, and also mo-cleralely soluble in ether m. p. looA The anhydrous acid melts at 153—154. ... 

S-Benzyl Thiocarbamate, 548 Butynyl, 548 p-Cyanobenzyl, 548 Cyclobutyl, 548 Cyclohexyl, 548 Cyclopentyl, 548 Cyclop ropy I methyl, 548 p-Decyloxybenzyl, 548 Diisopropylmethyl, 548 2,2-Dimethoxycarbonylvinyl, 548... 

Strick-lava, /. ropy lava, -waren, f.pl. knitted goods. 

Ziehen, n. drawing, etc. (see ziehen) draft, traction (of liquids) ropiness move twinge, twitch, -lassen, n. drawing, infusion (as of tea) allowing (a vessel) to fill, filling. Zieh-fkhigkeit, /. capability of being drawn, pulled, etc. (see ziehen) (Metal.) draw-... 

Phorone (Di iso p ropy lidene acetone, 2,6-dimethyl-2,5-heptadien-4-one). 

This class of polysaccharide was well known in sugar refineries as the causative agent of ropiness it was formed from cane or beet sugar by bacteria of the Leuconostoc genus. Over many years, numerous papers were published, mainly with E. J. Bourne [Adv. Carbohydr. Chem. Biochem., 34 (1977) 1-22] and S. A. Barker as co-authors, describing the isolation, purification, properties, and structural features of dextrans. 

The Structure of a Polysaccharide Synthesized by a Streptococcus Isolated from a Ropy Fermentation, The Value of Infrared Spectroscopy in Polysaccharide Studies, S. A. Barker, F. Pautard, I. R. Siddiqui, and M. Stacey, Chem. Ind. (London), (1955) 1450-1451. 

Ketose-polyol Interconversions by a Ropy-cider Organism, S. A. Barker, E. J. Bourne, E. Salt, and M. Stacey, J. Chem. Soc., (1959) 593-598. 

If inhomogeneous broadening of the EPR linewidth is primarily due to unresolved hyperfine couplings (hfc), at higher frequencies the g-an iso (ropy will dominate over the hyperfine interactions, i.e., the condition (Ag/gIS0H0) > AHhk must be fulfilled. 

Pasteur had found that acid wines, ropy wines, hitter wines, sour beer and so oh were caused by the growth in them of undesirable contaminating organisms which produced these so-called diseases. 

When the C=S bond is conjugated with double or triple bonds, thioketones can also behave as heterodienes93 104 towards dienophiles. If thioketone contains an aromatic ring, the [4+2] cycloaddition can be followed by 1,3-protot-ropy to restore the ring aromaticity,105 108 forming lH-2-benzothiopyrans as shown in Scheme 13, where 4,4 dimethoxythiobenzophenone reacts with the dienophile dimethyl acetylenedicarboxylate (DMAD).105... 

Roofies, Rophies, Ruffies, Roche, Roach, Rope, Ropies, Rib, Circles, Mexican Valium, R-2, Date Rape Pill, Forget-Me Pill. 

Ethyl-l,3-hexanediol,2- Ethyl-3-p ropy 1-1,3-propanediol or Ethohexadiof... 

Solubility. When 35g of the sample is added to 100ml water and allowed to stand, with occasional shaking for 18—24 hours, the resulting liquid shall be free-flowing, unifcim in 3ppssr2fiC gnA without siny indi cation of ropiness... 

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