Trigonelline in coffee

Viani, R., Horman, I., Determination of trigonelline in coffee, Coll. Int. Chim. Cafes 7, 273, 1975. (CA85 190824x)... 

Lehmann G. and Hahn H.G. (1968) Quantitative determination of chlorogenic acid and trigonellin in coffee 3rd. Int. Colloq. Chem. Coffee (Trieste, 2-9.6.1967) (ASIC, 1968), 115-20. 

Stennert A. and Maier H.G. (1994) Trigonelline in coffee. II. Content of green, roasted and instant coffee. Z. 

Niacin is released from trigonelline in coffee beans by the roasting process. 

About 50—80% of the trigonelline is decomposed during roasting. Trigonelline is a probable source for niacin [59-67-6] but also a source of some of the aromatic nitrogen compounds such as pyridines, pyrroles, and bicycHc compounds found in coffee aroma (16). Certain acids, such as acetic, formic. 

Determinations of nicotinamide in green and roasted Robusta coffee are indicative of its much increased content in coffee roasted at or below 240°C. The values are 3 and 46 mg/100 g for green and roasted coffee, respectively.183 At least part of this increase is from trigonelline as it decomposes on roasting. 

Many pyrroles have been identified in roasted coffee. Regarding their formation in coffee pyridine, pyrrole and N-methyl-2-formylpyrrole are trigonellin derivatives 3 and 4 typical pyrroles from primary amino acids and 6 to 8 hydroxyproline derived Maillard products ( 26 ). ... 

It was formed in the pyrolysis of proline and 4-hydroxyproline (Merritt et al., 1970) and is one of the pyrolysis products of trigonelline (Viani and Horman, 1974). Baltes and Bochmann (1987b) found 1-methylpyrrole in all their serine/threonine/sucrose reactions as well as in coffee. 

Ouweland et al., 1978) or directly by the pyrolysis of amino acids (Fujimaki et al., 1969). Another important, if not the main, precursor of pyridines in roasted coffee is trigonelline (see Section 2.1.1.2), a product isolated by Goi ter (1910), identical to the product isolated from the seeds of Trigonella foenum-graecum. Viani and Horman (1974, 1976) identified 12 pyridinic compounds after pyrolysis of trigonelline, six of which have now been identified in roasted coffee (4-methylpyridine is noted as identified in coffee, but it is not present in the lists of quoted publications, and to our knowledge its identification has not yet been reported in the literature). The presence of four other alkyl derivatives and of two N-methylnicotinamides have not yet been confirmed in the flavor. The authors have also isolated two piperidylpyridines, 3-phenylpyridine and two of its methyl derivatives, as well as four unsubstituted and dimethyl-substituted dipyridyl compounds. 

For Viani and Horman (1974), pyridine represents 25% of the pyrolysis products of a trigonelline monohydrate sample. Pyridine has been found in model reactions between glucose and amino acids (Kato et al., 1973b), when heating serine and/or threonine with or without sucrose under coffee-roasting conditions (Baltes and Bochmann, 1987d who found it also in coffee). Mottram (1991) explained the possible formation of pyridine by reaction of ammonia on 2,4-pentadienal. 

Casal S., Oliveira M.B. and Ferreira M.A. (2000b) HPLC/diode-array applied to the thermal degradation of trigonelline, nicotinic acid and caffeine in coffee. Food Chem. 68 (4), 481-5. 

Nakabayashi T. and Masano M. (1986a) Changes of the trigonelline and caffeine contents in coffee beans during roasting. Nippon Shokuhin Kogyo Gakkaishi (J. Jpn. Soc. Food Sci. Techno ) 33(10), 725-8 (Chem. Ahstr. 106, 66103). 

Trigonelline, C7H7O2N, was discovered in the seeds of Trigonella foenum-graecum L. (63) but it has since been found in a wide variety of plants such as the seeds of Pisum satimm L. and Cannabis saliva L. (64) in the seeds of Strophanthus kombe Oliver (65), and in coffee (66, 67) also in the soybean (69), in potatoes (70) and in the tubers of Dahlia variabilis Des. and Scorzonera hispanica L. (73). The content of the base in known coffees is fairly constant (0.228-0.245%) (68). 

Plants produce various pyridine alkaloids derived from nicotinic acid. Trigonelline, the major component in coffee seeds, and ricinine, the toxic alkaloid produced by Ricinus communis, are formed from nicotinic acid originating from the NAD catabolism [20, 25, 26], Quinolinic acid was found to be an efficient precursor in the biosynthesis of nicotine [27]. 

Any effect of coffee on neurodegenerative disease risk therefore requires further evaluation, and the phytochemicals in coffee that might contribute to such an effect would also need to be assessed. Trigonelline (60) is a pyridine alkaloid that occurs in coffee, and it increases neurite outgrowth, inhibits AChE in vitro, and it improves memory retention in vivo [193, 194] (Scheme 42.16). 

Pyridine is formed from trigonelline during roasting.3 It is presumed to contribute to the flavor, especially in the darker coffee roasts.15... 

Trigonelline is present in green coffee (1 %),15 but it is rapidly decomposed on roasting so that only about 0.1% trigonelline is present in a deeply roasted coffee.161 The products of trigonelline breakdown are evident in roasted coffee and include nicotinic acid and its methylester, pyridine, and p-picoline (Figure 17).3... 

The products from trigonelline seen in roasted coffee.3... 

Anti-adhesive effect. Green and roasted coffee, used in a treatment mixture and as a pretreatment on beads, inhibited the Strep tococcus mutans sucrose-independent adsorption to saliva-coated hydroxyapatite beads. The inhibition of Salmonelb mutans adsorption indicated that coffee-active molecules may adsorb to a host surface, preventing the tooth receptor from interacting with any bacterial adhesions. Among the known tested coffee components, trigonelline and nicotinic and chlorogenic acids are very... 

In general, niacin is widespread in foodstuffs (93,94). Cereals, seeds, meat, and fish are good food sources of niacin. The niacin content of coffee beans is primarily a product of the roasting process, which converts trigonelline (1-methylnicotinic acid) to nicotinic acid (95). 

High-performance gel filtration chromatography was used to separate trigonelline, chloro-genic acid (CGA), and CF in green coffee by De Maria et al. (281). The method has the advantage, with respect to RP-HPLC, of an aqueous eluent. 

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