Nutritional and Technological Properties of Selected Kinds of Coffee

Abstract

All the chemicals used were of analytical grade and were purchased from Sigma-Aldrich (St. Louis, MO, USA) and CentralChem (Slovakia). The aim of the study was to evaluate the quality indicators (moisture content, fat, ash, polyphenols and antioxidant activity) of seven samples of green coffee. The coffee samples were subsequently roasted, using the cinnamon roasting style. In the prepared roasted coffee, the same measurements were made as in the green coffees, in order to compare the samples and point out the changes taking place during roasting. In addition, oxidative stability was determined after the roasting process. The moisture content of the green coffee ranged from 7.4 % to 9.08 %, the ash content ranging from 2.53 % to 2.97 %, the fat content from 2.19 % to 6.33 %. The DPPH antioxidant activity ranged from 45.36 to 55.81 mg TEAC.l-1 (TEAC-Trolox equivalent antioxidant capacity) and total polyphenols from 511.44 to 618.11 mg GAE.l-1 (GAEgallic acid equivalent). After the roasting process, the amount of dry matter (97.88-98.54 %) and fat (3.38-12.76 %) increased, the ash content did not change significantly. The most pronounced was the decrease in polyphenols, which is not surprising due to thermolabile substances. Overall, their values decreased of about 80 % compared to green coffee samples. Despite these losses, the samples showed a high antioxidant activity after the roasting process-42.56 to 55.63 mg TEAC.l-1 , which can be explained by the fact that during the roasting the Maillard reaction takes place, whereby new bioactive substances with antioxidant effect arise, on activity it also participates in vitamin B3, which is produced by thermal breakdown of trigonelline. The oxidative stability evaluated by the Rancimat method ranged from 1.2 to 10 minutes, suggesting that roasted coffee is susceptible to oxidation, therefore it should be milled just before preparation and serving. ARTICLE INFO

A meta analysis: the effects of types, roasting degrees and origins on antioxidant properties of coffee

“…We collected 189 data points separated into two groups, that is, database 1 presenting complete data and database 2 presenting data with no information about temperature and roasting time, which was merged with data from database 1, as presented in Table S1. The data in Table S1 were extracted from 12 articles (Somporn et al ., 2011; Margarita et al ., 2012; Moreira et al ., 2013; Pokorná et al ., 2015; Liang et al ., 2016; Odžakovic et al ., 2016; Kurniawan et al ., 2017; Herawati et al ., 2019; Ivanisovà et al ., 2019; Bobková et al ., 2020; Schouten et al ., 2021; Chindapan et al ., 2022). The antioxidant test was expressed in different units as follows: FRAP 1 (mg Fe 2+ per g coffee beans), FRAP 2 (mg Trolox per g coffee beans), FRAP 3 (mg Trolox per g soluble solid), ABTS 1 (mg Trolox per g coffee beans), ABTS 2 (mg Trolox per g soluble solid), DPPH (% inhibition), DPPH 1 (mg Trolox per g coffee beans), DPPH IC 50 (mg soluble solid per mL), DPPH IC 50 (%) and ORAC (mg Trolox per g soluble solid).…”

“…Coffee consumption is also increasing, from 164.2 million bags in 2019-2020 to 166.3 million tonnes in (ICO, 2021. The global production of coffee primarily comes from the top 10 coffee-producing countries in 2020: Brazil, Vietnam, Columbia, Indonesia, Ethiopia, Honduras, India, Uganda, Peru and Guatemala (ICO, 2021). The two main coffee species are Coffea arabica and Coffea canephora var.…”

“…According to the International Coffee Organisation (ICO) in 2021, coffee production was 175.3 million tonnes worldwide in 2020. Coffee consumption is also increasing, from 164.2 million bags in 2019-2020 to 166.3 million tonnes in (ICO, 2021. The global production of coffee primarily comes from the top 10 coffee-producing countries in 2020: Brazil, Vietnam, Columbia, Indonesia, Ethiopia, Honduras, India, Uganda, Peru and Guatemala (ICO, 2021).…”