Wine testing

The complicated olfactory system in humans and animals can detect and differentiate the presence of an odour even at trace levels [187]. Sensory evaluation is one of the important parameters for environmental monitoring, quality assessment for food, wine and beverages, and clinical diagnosis, as well as for the control of many cosmetics and fermentation processes [188-190]. Typically, sensory evaluation in odour as well as food/ wine testing is performed by a panel of well-trained professionals based upon their sense of smell, taste, experience and mood. However, the human olfactory system is very sensitive but not selective. 

Wine was analyzed by Hughes and Johnson (1983) and carbohydrates and alcohols were determined. Cation-exchange chromatography with a water mobile phase was used for the separation, and postcolumn addition of NaOH was necessary for PAD detection. Both dry and sweet wines were analyzed, and as expected, the dry wine had much less fructose and dextrose than the sweet wine. A peak for sorbitol was not observed for any of the wines tested. Because sorbitol is not naturally present in grapes, its presence in wine would indicate adulteration of the wine with other fruit juices. 

Alcohol. The number of driving under the influence of alcohol (DUl) cases reflects the enormity of the dmnken driving problem in the United States (9). Tests to measure blood alcohol concentration are conducted on blood, urine, or breath (10). In the case of urine and breath, the alcohol concentration measured is reported in terms of the equivalent blood alcohol concentration. Most states in the United States presume that a person is under the influence of alcohol with respect to driving a motor vehicle at a blood alcohol concentration of 0.10%, ie, an ethanol concentration >10 g/100 mL of blood. Some states maintain a lower necessary concentration of 0.08%. In some European countries levels are as low as 0.05%. A blood alcohol concentration of 0.10% in a 68-kg (150-lb) person is the equivalent of about four drinks of 80 proof alcohoHc beverage or four 340-g (12-oz) beers in the body at the time of the test (see Beer Beverage spirits, distilled Wine). Ethanol is metabolized at the equivalent rate of about one drink per hour. 

In the most frequently used test the sample is placed between two electrodes and the voltage is increased from zero at a uniform rate until breakdown occurs. When an insulated wine is available, the voltage can be placed between the inner conductor and a conductive medium, such as an outside metallic shield or even water. 

The PVC formulations shown in Table 2 represent typical compounds used by the wine and cable industry. PVC compounders have developed new PVC-based formulations with very good fire and smoke properties (can pass the UL 910 Steiner Tunnel test) that compete with the more expensive fluoropolymers. These can be used in fabricating telecommunication cables usable for plenum area appHcations. 

Freeze Crystallization. Freezing may be used to form pure ice crystals, which are then removed from the slurry by screens sized to pass the fine sohds but to catch the crystals and leave behind a more concentrated slurry. The process has been considered mostly for solutions, not suspensions. However, freeze crystallization has been tested for concentrating orange juice where sohds are present (see Fruit juices). Commercial apphcations include fmit juices, coffee, beer, wine (qv), and vinegar (qv). A test on milk was begun in 1989 (123). Freeze crystallization has concentrated pulp and paper black hquor from 6% to 30% dissolved sohds and showed energy savings of over 75% compared with multiple-effect evaporation. Only 35—46 kJ/kg (15—20 Btu/lb) of water removed was consumed in the process (124). 

Pipette 25 mL of an aluminium ion solution (approximately 0.01 M) into a conical flask and from a burette add a slight excess of 0.01 M EDTA solution adjust the pH to between 7 and 8 by the addition of ammonia solution (test drops on phenol red paper or use a pH meter). Boil the solution for a few minutes to ensure complete complexation of the aluminium cool to room temperature and adjust the pH to 7-8. Add 50 mg of solochrome black/potassium nitrate mixture [see Section 10.50(C)] and titrate rapidly with standard 0.01 M zinc sulphate solution until the colour changes from blue to wine red. 

Despite the fact that phloem is rich in catechins the amount of these ingested daily in our phloem study was rather small when compared to previously conducted studies. In similar studies the amount of catechins ingested in the form of tea or red wine per day has varied from 81 mg to as high as 2490 mg (de Rijke et al., 1996 Carbormeau et al., 1997 Nigdikar et al., 1998 Princen et al., 1998). It would be interesting to test in the future whether increasing the ingested amount of phloem would further reduce the inhibition of lipid peroxidation. 

Immobilization is the technique of choice in many food industry processes and especially in beverage production. Many immobilization technologies have already been tested and some are applied in the production of beer, wine, vinegar, and other food products using a traditional approach with cultme adhesion (i.e., Acetobacter in vinegar production) or more modem approaches with entrapment of yeast biomass (i.e., sparkling wines, cheeses, and yogurts). 

Fig. 2.10. Composition of a test sample of wine (schematic representation in the middle the size of each area symbolizes the relative amount of the respective component or sort of constituents) and of the measuring samples of inorganic and organic components, respectively (left and right diagrams)...

Sometimes it is necessary to apply two (or more) variants of sample preparation to get different measuring samples from only one test sample. This is the case if various problems have to be solved, e.g. determination of major- and ultra trace constituents, comparison of depth- and surface profiles, or analysis of inorganic and organic trace components in the same test sample. An example is shown in Fig. 2.10 where in a test sample of wine both inorganic and organic trace constituents have to be determined and, therefore, different measuring samples must be prepared. 

Statistical experimental design is characterized by the three basic principles Replication, Randomization and Blocking (block division, planned grouping). Latin square design is especially useful to separate nonrandom variations from random effects which interfere with the former. An example may be the identification of (slightly) different samples, e.g. sorts of wine, by various testers and at several days. To separate the day-to-day and/or tester-to-tester (laboratory-to-laboratory) variations from that of the wine sorts, an m x m Latin square design may be used. In case of m = 3 all three wine samples (a, b, c) are tested be three testers at three days, e.g. in the way represented in Table 5.8 ... 

The cyclic voltammetry method has been used for testing fruit and vegetable samples including Iryanthera juruensis fruits (Silva and others 2001), prickly pear (Butera and others 2002), orange juice (Sousa and others 2004), and wine (Roginsky and others 2006). 

Do the results of oxidizability tests of LDL in the Cu2+ system correlate with the results of PCL examinations after treatment with wine ... 

Three different types of white wines and four red wines were compared after PCL testing in an ex vivo model system of the influence of oxidation resistance on LDL. 

Table 2 Antiradical Activity of Red and White Wines (ACWw) and Their Antioxidative Protective Effectiveness in the Test System of the Cu2+-Initiated LDL Oxidation...

Possible industrial applications include screening of substances with antiradical activity, quality testing of raw materials, pharmaceuticals, cosmetic products, fruit juices, wines, beers, edible oils, detection of food irradiation, and many more. 

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