Coffee between

Product liability is also a major concern for many companies. The McDonald s coffee award is a good example. In this case, a woman placed a cup of McDonald s coffee between her legs in a car. The coffee spilled and the woman was severely burned. McDonald s was found liable for the injuries, even though McDonald s cups contain a warning stating the contents are hot. 

The principal CGA isomers identified in green coffee include three caffeoylquinic acid isomers, 3-CQA [327-97-9], 4-CQA [905-99-7], and 5-CQA [906-33-2], three dicaffeoylquinic acid isomers, 3,4-diCQA [14534-61-3], 3,5-diCQA [2450-53-5], and 4,5-diCQA [57378-72-0], and three feruloylquinic acid isomers, 3-FQA [1899-29-2], 4-FQA, and 5-FQA [40242-06-6]. The total CGA level is somewhat higher in robustas compared to arabicas. The 5-CQA is the predominant isomer both in arabicas, ie, 4—5% dry basis (db), and in robustas, 5—6% db, and is known to form in vitro and possibly in vivo complexes with caffeine [58-08-2]. Greater compositional differences between robustas and arabicas are found in the minor CGA isomers, eg, 3,4-diCQA, 5-FQA,... 

NB There is some evidence of an inverse relationship between coffee drinking and cancer of the large bowel coffee drinking could not be classified as to its carcinogenicity to other organs)... 

Anyone who has worked for some time in the pharmaceutical industry has a story of how a successful drug was developed after a fortuitous coffee machine encounter between two or more scientists, or how a problem was not discovered until late-stage development because an important piece of information was missed. 

How would you describe the differences between a cup of coffee and a cup of hot water What probably come to mind are the aroma, the dark color, and the taste of a good cup of coffee. Coffee s action as a stimulant is another obvious difference. These properties come from the chemical compounds that hot water dissolves from ground coffee beans. These compounds are molecules constructed from different atoms bound together in veiy specific arrangements. The molecule that makes coffee a stimulant is caffeine. Our background photo is a magnification of crystals of pure caffeine, and the inset is a ball-and-stick model of this molecule. 

Ironically, coffee does need relatively acidic soil, with pH between 5 and 6. Conifers and shmbs such as azaleas and rhododendrons thrive on soils with this acidity, as do tea, potatoes, rice, and rye. The vast majority of crop plants, including most vegetables, need soils just on the acidic side of neutral, pH between 6 and 7. Only a few crops—barley, sugar beets, cotton, and sugarcane—like soils on the mildly basic side, between pH 7 and 8, and only desert plants can cope with soils whose pH is greater than 8. 

A number of handbooks and monographs are available with detailed descriptions of a variety of plant products and their use (Shahidi and Naczk, 1995). From a more practical point of view, an interlaboratory comparison between six university and industry laboratories of 17 extracts of spices, teas, coffees, and grape skin and of tomato peel slurry established within the framework of an EU sponsored programme, would be of interest (Schwarz et al, 2001). In this collaboration, detailed chemical analysis of the content of different phenolic compounds is compared with six antioxidant assays for the 17 extracts including different extraction procedures. 

The NMR spectra using PCA and Linear Discriminant Analysis (LDA) obtained for instant spray dried coffees from a number of different manufacturers demonstrated [8] that the concentration of the extracted molecules is generally high enough for clear detection. The compound 5-(hydroxymethy)-2-furaldehyde was identified as the primary marker of differentiation between two groups of coffees. This method may be used to determine whether a fraudulent retailer is selling an inferior quality product marked as being from a reputable manufacturer [8]. 

The measurement of viscosity is important for many food products as the flow properties of the material relate directly to how the product will perform or be perceived by the consumer. Measurements of fluid viscosity were based on a correlation between relaxation times and fluid viscosity. The dependence of relaxation times on fluid viscosity was predicted and demonstrated in the late 1940 s [29]. This type of correlation has been found to hold for a large number of simple fluid foods including molten hard candies, concentrated coffee and concentrated milk. Shown in Figure 4.7.6 are the relaxation times measured at 10 MHz for solutions of rehydrated instant coffee compared with measured Newtonian viscosities of the solution. The correlations and the measurement provide an accurate estimate of viscosity at a specific shear rate. 

Fig. 4.7.6 The relationship between spin-spin relaxation time and viscosity for a concentrated coffee solution (32-46%-w/w).

Coffee is grown in countries situated between the Tropics of Capricorn and Cancer. C. arabica is the most widely grown, but regions where temperature and humidity are rather high have been replanted with C. canephora var. robusta. Robusta coffees are thus the major species grown in the less mountainous regions closest to the equator. 

One of the most significant differences between Arabica and Robusta coffees is in the caffeine content. Robusta coffees contain almost twice the caffeine found in Arabica coffees. There are some other differences recognized thus far Robustas contain almost no sucrose and only very small amounts of the kaurane and furokaurane-type diterpenes they contain higher proportions of phenols, complex carbohydrates (both soluble and hydrolyzable), volatile fatty acids on roasting, and sulfur compounds, all in comparison with Arabicas. References to these distinctions can be found in Chapter 6 of this book. 

Model systems indicate that aldehydes may also be produced by the action of polyphenoloxidases on amino acids in the presence of catechin, all of which are present in coffee beans at some stage between green and roasted. For example, valine yields isobutanal, leucine yields isopentanal, and isoleucine yields 2-methyl-butanal.14 Some of these aldehydes probably undergo condensation reactions in the acidic medium of the roasted bean when moisture is present.15 Some dienals in green coffee beans have recently been identified as (E,E)-2,4- and (E,Z)-2,4-nonadienal and (E,E)-2,4- and (E,Z)-2,4-decadienal.18... 

Some particular proteins, recognizable thus far by little more than their biological effect, have been documented. An allergen in the green coffee bean of between 18,000 and 40,000 da is probably a heterogeneous glycoprotein it can be precipitated out at pH 4.0 to 4.5.92 93... 

Monosaccharides are probably involved in the browning reactions that occur during the roasting of coffee. Caramelization involving the sugars alone, and Maillard reactions, between sugars and free amino acids, produce polymeric yellow to dark brown substances, known as melanoidins. These melanoidins can be extracted into hot water, separated and characterized.105... 

Wajda, P., Walczyk, C., Relation between acid value of extracted fatty matter and age of green coffee beans, J. Sci. Food Agric., 29, 377, 1978. (CA89 145281q)... 

De Menezes, H. C., The relationship between the state of maturity of raw coffee beans and the isomers of caffeoylquinic acid, Food Chem. 50(3),293, 1994. (CA121 33749w)... 

Daglia, M., Cuzzoni, M. T., Dacarro, C., Antibacterial activity of coffee relationship between biological activity and chemical markers, J. Agric. Food Chem., 42(10), 2273, 1994. (CA121 203869e)... 

Overall tea production between 1990 and 1994 has increased only 4%, which is down from the dramatic rise in production of 30% during the years of 1980 to 1989.1114 As a widely consumed beverage, the percentage exported from all tea produced was 49% in 1990 and 46% in 1991.15 This pattern indicates that tea, compared to coffee and cocoa, is often domestically produced and consumed. Most worldwide production (91.4%) in 1991 occurred in developing countries.15... 

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