Arabica coffee beans

Robusta coffee has a somewhat higher phenolic content than Arabica (see Table 7). The feruloylquinic and dicaffeoylquinic acid content in Robusta is higher than in Arabica coffee beans.71 72... 

Chrysanthemum indica, Helianthus annuus (Asteraceae) [flower], Coffea arabica (coffee bean) (Rubiaceae), Theobroma cacao (cocoa bean) (Sterculiaceae), Camellia sinensis (tea) (Theaceae) [leaf]... 

Of course, not all bad food is a different colonr from good food. It has been found that certain non-visible defects (bacteria for example) fluoresce when irradiated with ultraviolet light (350 mn), and this property may be used as a basis for sorting. This technique was originally developed for removing stinkers from green Arabica coffee beans, but has found applications in sorting peanuts, almonds and cranberries. However, the fluorescence effects can be short lived and may also depend on the circumstances and time elapsed since the product was harvested. 

Figure 14. Detection of some volatiles emitted during roasting of 6 coffee beans. Six green Arabica coffee beans were roasted at 185°C, and headspace VOCs were monitored by PTR-MS the ions monitored and the corresponding VOCs are indicated. Data replotted from Ref. [30]. 

Mendonca et al. have used an electrospray ionization mass spectrometry (ESI-MS) method to identify the CGA profile, which allowed the discrimination of green Arabica and Robusta coffee beans [22]. This method also allowed discrimination between defective and nondefective coffee beans (ESI-MS positive mode). For this kind of identification and discrimination, they used principal component analysis and hierarchical cluster analysis [22]. Alonso-Salces et al. also used a linear discriminant analysis and a partial least-squares discriminant analysis based on HPLC and UV spectra of phenolic (CGAs) and methykanthine contents for a number of green Robusta and Arabica coffee beans from different geographical origins [9]. 

Synonyms Coffea arabica Coffee bean extract... 

Gas Chromatography Mass Spectrometry Analyses of Volatile Compounds in Arabica Coffee Beans with Different Roast Degrees... 

The DH-SPME sampling method was applied to different roast degrees of different Arabica coffee beans, including Ethiopia coffee beans (L23), to investigate changes in the contents of volatile compounds. Compounds identified and their peak areas under the same GCMS conditions are shown in Table 2. 

The dry method produces green coffee beans much less expensively than the wet method. A high proportion of Brazilian Arabica coffee is processed in this way, and almost all Robusta coffees are treated in this way. The final beverage produced from dry-processed coffee has a full flavor that is often described as hard and sometimes is characteristic of a region, for example Rio coffees. 

Decaffeination of green coffee beans is most usually carried out with a water/solvent partition system. The green coffee beans are first steamed until they are hot, wet, and swollen, to make the caffeine available. Solvent is then used to extract the caffeine out of the aqueous phase of the beans. Finally, the beans are steamed to drive off residual solvent. The coffee beans lose their wax surface covering in the process, as well as some flavor components. For this reason, the Robusta and Brazilian Arabica coffees that are dry-processed and have the most powerful flavors are usually the types that are decaffeinated. They become milder in the process. Mechanical polishing is used to improve the appearance of decaffeinated green coffee beans if they are not to be roasted immediately. Extra care is required, however, to store these decaffeinated beans since the loss of wax covering as well as caffeine renders them much more susceptible to fungal attack. 

Yet another consideration is the fact that the sugar content of the beans causes roast variation. For example, high-grown Arabica coffees have the... 

The coffee beans with the most desirable flavor to many tastes are the highest grown Arabicas prepared by the wet method. Coffee beverages need to be prepared within 8 h of grinding the freshly roasted coffee beans if the volatile flavor and aroma compounds are to be retained. Brew... 

Methods for the decaffeination of green coffee beans, mainly with solvents after a steaming, have already been described. Even with the selective adsorption techniques to remove only caffeine, it is unlikely that the full character of the starting beans can be realized in a final decaffeinated beverage the result is that Robusta coffees are generally used to prepare decaffeinated coffee. The cost is kept down and the treatment, anyway, reduces any harsh or bitter flavor that the Robusta coffee may have had. The resulting beverage will be relatively caffeine-free, but Robusta coffee will contribute more soluble carbohydrates, phenols, and volatile fatty acids, and much less of the diterpenes found in Arabica coffees. 

The characteristic earthy and harsh flavor and aroma of roasted Ro-busta coffees is largely attributed to 2-methylisoborneol. Amounts found in green Robusta coffee beans were 0.03 to 0.3 ppb, and this could be completely removed by steam heating or roasting.26 There is approximately ten times as much 2-methylisoborneol in roasted Robusta coffee beans than in similarly treated Arabica coffee.27... 

Coffee oil is generally described as the petroleum ether-soluble fraction from green coffee beans. Arabica coffees contain 11.1 to 13.6% oil, whereas Robusta coffees contain only 4.4 to 4.8% oil.106 Triglycerides constitute 79% of this oil, terpene esters 17%, and the remaining 4% is contributed by sterols, free terpenes, tocopherols, and as yet unknown... 

The world s coffee supply comes primarily from two major types of coffee beans, Arabica (Coffea arabica) and Robusta (Coffea canephora), which differ in several characteristics as well as caffeine content. Arabica is favored for its finer aroma, flavor, and body, and contains 1% caffeine. Robusta is neutral and contains twice as much caffeine.1 The ratio of... 

Arabica/Robusta beans used in different countries ranges from 1.5 1 in Italy, 4 1 to 3 1 in the U.S., and 20 1 in Sweden and Norway.2 As described in Chapter 6, coffee contains a number of physiologically active components, including caffeine, diterpene alcohols, sterols, hydrocarbons, squalene, and others. 

The failure to find an effect in the American trial above was confirmed in a study conducted in the Netherlands, which also used paper-filtered, drip-brewed coffee.14 In that 12-week experiment, 23 women and 22 men who habitually drank 4 to 6 cups of coffee per day were assigned to consume 5 cups/day of either caffeinated (417.5 mg caffeine/day) or decaffeinated coffee (15.5 mg caffeine/day) for six weeks, and then switch for another six weeks. The blend of coffee beans was 71% Arabica and 29% Robusta for the caffeinated coffee, and 58% Arabica and 42% Robusta for the decaffeinated coffee. Lipid values at the end of both six-week study periods were almost identical. Total cholesterol was 5.47 vs. 5.48 mmol/ L (212 vs. 212 mg/dL), LDL-C was 3.41 vs. 3.40 mmol/L (132 vs. 131 mg/ dL), HDL-C was 1.52 vs. 1.52 mmol/L (59 vs. 59 mg/dL), and TG were 1.17 vs. 1.20 mmol/L (104 vs. 106 mg/dL) for the caffeinated vs decaffeinated coffee periods, respectively. Further, a small study of 12 Finnish men also failed to find an effect of caffeinated coffee on serum cholesterol levels.15 However, the study period was only three weeks which may have been insufficient. 

To identify further which substance, cafestol or kahweol, or both, was inducing changes in serum cholesterol, the investigators attempted, but failed due to technical limitations, to separate the two chemical compounds. Alternatively, they compared coffee oil from Arabica vs. Robusta coffee beans. Arabica beans contain both cafestol and kahweol, while Robusta beans contain cafestol, but almost no kahweol. The investigators found that Arabica and Robusta oils both increased serum cholesterol and triglyceride levels comparably. They thus concluded that cafestol is, and kahweol might be, a serum cholesterol raising factor. 

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