Roasting and Colouring Curves for Coffee Beans with Broad Time-Temperature Variations

Farm to Consumer: Factors Affecting the Organoleptic Characteristics of Coffee. II: Postharvest Processing Factors

“…So, recently, a broader and inevitable research study, further supporting and elucidating the roasting data discussed above, was published by Pramudita et al. () who pointed out the relationship between the dehydration process, roasting time, and roasting temperature. This study denoted that a reduction in mass started even before the start of the dehydration process, but a major reduction in mass was seen when the moisture content dropped to 2%.…”

“…Production of aromatic and flavoring compounds mostly occurs in the second stage of roasting. The generation of flavoring and aromatic compounds follows path‐dependent biochemical reactions which are greatly under the influence of roasting settings/levels (roasting time, roasting temperature, hot air flow speed, and so on) In industry, roasting settings are a function of dedicated artisanal/personal expertise from hit and trial methods, and there is much literature disclosing the effects of different roasting settings on the physical, chemical, structural, mechanical, and compositional changes to coffee beans during roasting (Bicho, Leitão, Ramalho, deAlvarenga, & Lidon, ; Franca, Oliveira, Oliveira, Agresti, & Augusti, ; Moon & Shibamoto, ; Petisca et al., ; Pittia, Dalla Rosa, & Lerici, ; Pramudita, Araki, Sagara, & Tambunan, ; Summa, dela Calle, Brohee, Stadler, & Anklam, ; Wang & Lim, ). For physical changes, color, bulk density, apparent density, roast volume, and roast loss are important features.…”

“… Note : Data were compiled from Akiyama et al., , 2003; Baggenstoss et al., ,b; Craig et al., ; Czerny et al., , 2008; Czerny & Grosch, ; Dawidowicz & Typek, ; Dorfner et al., ; Gloess et al., ; Gonzalez‐Rios et al., ,b; Grosch et al., , 2001a,b; Hertz‐Schünemann et al. , ; Lee et al., ,b; Mayer & Grosch, ; Moon and Shibamoto et al., ; Nebesny et al., ; Pramudita et al., ; Ribeiro et al., 2010; Rousi et al., 2012; Santos et al., ; Schenker et al., 2002; Steen et al., 2017; Toledo et al., ; Wang & Lim, .…”

“…Although unreliable, color is still considered a useful tool to determine quality parameters and roasting degree. Despite the fact that different temperatures give different colorations, a longer time at a lower temperature is required for the same level of color generation as that at a higher temperature, except for 260 and 360 °C where the final dark color is the same (Pramudita et al., ; Wang & Lim, ). The exact reasons for these differences in color generation still need to be investigated, but 2 possible reasons are given in the literature.…”

“…At/after that temperature, beans become overroasted and dark. This is due to the fact that beans tend to darken faster at temperatures at which there is a rapid loss of solid mass due to pyrolysis (that is, 260 to 300 °C) (Pramudita et al., ).…”