Background: The evaluation of coffee quality before and after the roasting process is a determining factor for defining and evaluating coffees. Among the parameters analysed, physical and chemical characterisation are considered extremely important, since from them the quality of the beverage from these coffees can be predicted.
Aim: This chapter focuses on the comprehensive analysis of the
physical and chemical parameters of coffee samples categorised as soft, hard,
and rio beverages.
Methods: The physical evaluation considers key attributes such as
bean type, sieve size, and colour. In addition to the physical assessment, a
detailed chemical analysis was conducted to evaluate essential compositional
factors that impact the coffee’s overall quality and flavour profile. This
includes determining the moisture content, ethereal extract, and protein
levels, which are essential for Maillard reactions during roasting.
Furthermore, the study examines ash content, soluble solids, and total
titratable acidity. The coffee samples were roasted at different roasting
levels specific to each beverage category to evaluate how varying roasting
intensities influence their physical and chemical properties. During the
roasting process, critical parameters such as colour development and mass loss
were carefully monitored utilising the free software Scilab®.
Results: The results obtained for the Rio beverage coffees
presented lower physical classifications compared to other coffee types, with
these coffees exhibiting a lighter colour and, regarding the sieve, showed a
higher percentage of larger, flat beans, which may influence the texture and
extraction characteristics of the brewed coffee. The moisture content was found
to be in compliance with current regulations, ensuring proper storage and
roasting conditions.
The ether extract, protein levels, and ash content were all within
the expected ranges, indicating that the chemical composition of the Rio coffee
samples was consistent with standard quality expectations. The Rio beverage
coffees exhibited the lowest soluble solids content and the highest total
titratable acidity compared to the other types of coffee. Upon roasting, the
colour parameters -L* (lightness), b* (yellow-blue chromaticity), C* (chroma,
or colour saturation), and H* (hue angle) - decreased as the roasting level
increased, indicating that the coffee beans darkened and became less vibrant in
color. Additionally, mass loss increased with higher roasting levels, which is
consistent with the typical reduction in moisture content and other volatile
compounds during the roasting process. But no difference was observed between
the beverages. The compiled graphs illustrated a clear distinction among the
samples, within the scope of each roast. This suggests that the roasting
process produced consistent and distinguishable changes in the physical
properties of the beans, reinforcing the effectiveness of the analytical
methods used.
Conclusion: Among the various parameters analysed, the L* colour
parameter (lightness) was the most effective in differentiating the samples.
Its strong correlation with roasting intensity highlights its significance in
determining the roasting point.
Author
(s) Details
Emanuelle Morais de
Oliveira
Instituto Federal de Educação, Ciência e Tecnologia do Sul de Minas
Gerais/IFSul de Minas, Poços de Caldas, MG, Brasil, e Faculdade de Engenharia
de Alimentos/FEA, Universidade Estadual de Campinas/Unicamp, Campinas, SP,
Brasil.
Helena Teixeira Godoy
Faculdade de Engenharia de Alimentos/FEA, Universidade Estadual de
Campinas/Unicamp, Campinas, SP, Brasil.
Itallo Dirceu Costa
Silva
Faculdade de Engenharia Agrícola/FEAGRI, Universidade Estadual de
Campinas/Unicamp, Campinas, SP, Brasil.
José Teixeira Filho
Faculdade de Engenharia Agrícola/FEAGRI, Universidade Estadual de
Campinas/Unicamp, Campinas, SP, Brasil.
Please see the book here:- https://doi.org/10.9734/bpi/fsarh/v2/5235
No comments:
Post a Comment