The effects of heating time on physical changes (weight, volume, texture and colour) of coffee beans (Outspan and Guaxupe coffee) were investigated. The roasting temperature of both samples was 170°C and samples for analysis were taken at the intervals of 7 minutes during 40 minutes of roasting. Total weight loss at the end of the roasting process was 14.43 % (light roasted) and 17.15 % (medium to dark roasted) for Outspan and Guaxupe coffee beans, respectively. Significant (P < 0.05) changes in the coffee bean breaking force values were noted between the 7th and 14th minutes, and statistically not significant (P > 0.05) between the 35th and 40th minutes of the roasting. According to the L* colour parameter as a criterion for the classification of roasted coffee colour (light, medium, dark), the Outspan sample was medium and Guaxupe sample was dark roasted

Background. Coff ee is one of the most widely consumed beverages in the world, because of its unique sensory properties and physiological properties. Coff ee beverages represent a signifi cant source of antioxidants in the consumers' diet and contribute signifi cantly to their daily intake. The aim of this research was to investigate the eff ect of diff erent roasting degrees on the content of biologically active compounds and antioxidant activity in diff erent quality classes of Arabica coff ee. Materials and methods. Samples of green Arabica coff ee (Rio Minas) of two quality classes from two production batches were used for the research. Roasting was carried out at temperatures of 167, 175 and 171°C. The total phenol content (TPC), total fl avonoid content (TFC), fl avonol content (FC) and antioxidant activity (DPPH, ABTS) in the coff ee extracts was determined.Results. This research shows that TPC was signifi cantly higher (P < 0.05) in green coff ee compared to TPC in roasted coff ee, and TPC decreases as the roasting temperature increases. TFC and FC were signifi cantly lower (P < 0.05) in green coff ee than in roasted coff ee. Diff erences in TPC between the 1 st and 2 nd classes of Arabica coff ee were not signifi cant (P > 0.05), while diff erences in TFC were signifi cant (P < 0.05) only for green coff ee from the second production batch and diff erences in FC were signifi cant (P < 0.05) for green coffee and for coff ee roasted at 175°C. Roasting temperatures have diff erent infl uences the antioxidant activity (DPPH, ABTS) of coff ee and the highest antioxidant activity was determined in coff ee roasted at 171°C. An exception was 1 st class Arabica coff ee roasted at 167°C (ABTS). All samples of 1 st class Arabica coff ee had higher antioxidant activity (DPPH, ABTS) compared to 2 nd class Arabica. Conclusions. This research shows that the bioactive compounds content and antioxidant activity of diff erent quality classes of Arabica coff ee are dependent on the degree of roasting. TPC decreases when the roasting temperature increases, while TFC and FC also increase. These results indicate that the antioxidant activity of coff ee depends on a variety of bioactive components in coff ee beans. Antioxidant activity largely depends on the class of coff ee. The coff ee samples of 1 st class quality (maximum 8 black beans/300 g from the sample and large bean size) had higher antioxidant activity compared to samples of 2 nd quality class (maximum 19 black beans/300 g in the sample and medium-sized beans).

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The contents of polyphenolic components (total polyphenols, flavonoids, and monomeric anthocyanins) and vitamin C, and the bioactive potential (antioxidant, antiproliferative, and antihyperglycemic activities) of wild cornelian cherry were determined. Samples were collected from four different locations in Bosnia and Herzegovina. Sample CC3 from Drinić had the highest monomeric anthocyanin content (1.40 mg CyGE/g FW) and the highest inhibition of free radicals (IC50 DPPH = 262.19 mg/ml; IC50 ABTS = 76.78 mg/ml; IC50 OH˙ = 102.31 mg/ml) and inhibition of breast adenocarcinoma cell line growth (IC50 MCF-7 = 1.37 mg/ml). Sample CC4 from Drvar showed the highest total polyphenol (55.92 mg GAE/g DW) and vitamin C (88.74 mg/g FW) contents. Sample CC4 significantly inhibited the growth of cervix epithelioid carcinoma (IC50 HeLa = 0.62 mg/ml) and lung adenocarcinoma (IC50 A549 = 0.48 mg/ml) cell lines, and αglucosidase (IC50 AGHA = 0.466 mg/ml). Wild cornelian cherry could be used as a functional food with beneficial pro-health properties.

The influence of different roasting temperatures on the physical properties of Arabica and Robusta coffee was investigated. Arabica (Rio Minas) of two quality classes and Robusta coffee samples, roasted at 167, 171 and 175 °C, were used for this research. Bulk density, total weight loss, water activity , texture and colour of coffee were determined. Total weight loss increased, and bulk density of coffee beans decreased with increasing of roasting temperature. Arabica 1 st class with the highest weight and volume also had the highest total weight loss and Robusta had the highest bulk density. Coffee samples roasted at 175 °C had significantly lower (P<0.05) water activity values than samples roasted at 167 °C and those changes mostly affected mechanical properties of beans. The highest breaking force values had Arabica 1 st class, with lower share of black beans, roasted at 167 °C and Arabica 2 nd class roasted at 171 and 175 °C, compared to other samples roasted at the same temperatures. Robusta beans had the most brittle and fragile texture. It can be concluded that texture of coffee depends on the roasting temperature, type and class of coffee as well. L*, a*, and b* colour parameters decreased as the roasting temperature increased, which affected on coffee beverage colour defined as brown (167 °C) and dark brown (171 °C and 175 °C) with different share of yellowish, orange, reddish and grey shades. Sensory analysis can be used as a good tool for a detailed description of coffee colour, as an important indicator of quality, especially in industrial conditions of coffee production.