Identification of nutritional descriptors of roasting intensity in beverages of Arabica and Robusta coffee beans

Abstract

Arabica and Robusta coffee beans were roasted at 220 ± 10°C for 7, 9 and 11 min to identify chemical descriptors in the beverages. The pH of the beverages showed the lowest value in the medium roasting level. In each degree of browning, the soluble solids content remained slightly higher in Arabica drinks. The contents of caffeine did not vary, but trigonelline decreased with burning up intensity. Chlorogenic acids also decreased with increasing roasting time. The 5-O-caffeoylquinic acid prevailed in Arabica and Robusta beverages, but the isomers of dicaffeoylquinic and feruolilquínic acids remained higher in Robusta. It was concluded that trigonelline and total caffeoylquinic, fatty dicaffeoylquinic and fatty feruolilquínic acids detached the beverages according to roasting intensity. Caffeine and pH allowed drinks separation between both species. Soluble solids take apart Arabica and Robusta drinks in each degree of roasting. All the individual groups of chlorogenic acids also explained 90% of the variance among samples.

Application of colour parameters for assessing the quality of Arabica and<br>Robusta green coffee

“…In this context, the residual silverskin of the surveyed samples had a reddish-brown colour, being almost absent in the groove of the green coffee beans, which is also an indicator of a dry primary processing. The green coffee samples had still predominantly flaky bean with round shape, according to the classification of Esteves and Oliveira (1970), further supported by Bicho et al (2011b).…”

“…In this context, it was also found that Arabica and Robusta green coffee beans had a normal odour (Table 1), showing no deterioration from chemical or microbiological origin, as well as any contamination with foreign substances or defective beans that could have an impact in the olfactory characteristics. Thus, these results further become favourable indicators of the quality of the analysed samples (Bicho et al, 2011b).…”

“…Coffee beans quality depends on moisture content, defects, bean size, some chemical compounds and preparation of a sample to perform cup tasting (Bicho et al, 2011b). To perform such physical quality analysis, standard methods are being used to characterize technological quality of green coffee, namely particle size, medium sieve, most frequent sieve, share split, cumulative calibration, trade homogeneity, mass of 1000 coffee beans, apparent densities, strange bodies and defects, mass losses on drying and olfactory and visual parameters.…”

Chemical descriptors for sensory and parental origin of commercialCoffeagenotypes

“…Among the cultivated species, C. arabica, C. canephora, Coffea liberica Bull ex-Hiern and Coffea dewevrei Wild and Durand cv. Excelsa represent Arabica, Robusta, Liberica and Excelsa coffee types (Carvajal 1984;Smith 1989;Ramalho 2002;Davis et al 2006), which display multiple heterogenic chemical and/or sensory characteristics (Bicho et al 2011a(Bicho et al , 2011b. In some of these species (and their several cultivars), the interaction of caffeine with some alkaloids promotes bitterness in coffee beverages that becomes unpleasant if the levels of caffeine surpass 60 -200 mg cm 23 (Clifford 1989).…”

Use of colour parameters for roasted coffee assessment

“…Sampling of Coffea arabica (Brazil) and Coffea canephora (India) was carried out according to the Instrução Normativa Nº 8 (BRASIL, 2003), NP 1666(PORTUGAL, 1980 and ISO 4072 (INTERNATIONAL ORGANIZATION FOR STANDARDIZATION, 1982), as described in Bicho et al (2011). Briefly, the sampling process began with the selection of green coffee bags, following PSCB Nº 36/02 (INTERNATIONAL COFFEE ORGANIZATION, 2002), at random (a minimum of 10% of the lot, with ca.…”