ANALYSIS OF TRADITIONAL TURKISH COFFEE AND DIFFERENT BRAND INSTANT COFFEES WITH DIFFERENTIAL SCANNING CALORIMETER

Abstract

The flavor and many beneficial properties of coffee make it the most consumed beverage in the world. Coffee is a complex beverage containing more than a thousand chemical compounds, including carbohydrates, lipids, nitrogenous compounds, vitamins, minerals, alkaloids and phenolic compounds. Caffeine content is one of the important issues that are emphasized as much as the aroma and taste of coffee. Recently consumers started to prefer instant coffee varieties sold in markets, started. In our study, we made comparative analyzes of Turkish coffee and some brands of instant coffees with the Differential Scanning Calorimetry (DSC). Shimadzu DSC60 Plus were used to take calorimetric measurements. Samples were weighted as 3 mg and sealed aluminum pans and heated from 14 oC to a final temperature 600 o C in a heating rate 10 oC min-1. Measurements were taken under nitrogen atmosphere (50 mL min-1). There are obvious differences between, Turkish coffee and granulated instant coffees (Figure 1). The peaks at 170.66 and 201.91oC is from melting of some constituents like amino acids, lipids and sugars, for example sucrose, glucose, fructose, arabinose, galactose, maltose and polysaccharides presents int the samples. The temperatures at 253.77, 266.17, 278.79, 278.81 oC are exothermic peaks and they involve breaking bonds and degradation of caffeine [1]. The endothermic curves at the beginning (39.92, 41.65 and 71.24 o C) are for pure coffee at three levels of roast [2]. The transitions are observed between 389.95 and 494.94 o C due to degradation of cellulose fractions [3]. DSC is a complementary technique that can offer a reproducible fingerprint for adulteration detection and quantification purposes of coffee. Our results showed us that instant coffees contain more additives than filtered types. For this reason, we think that filter coffees are healthier and we recommend that they be preferred instead of instant coffee. Keywords: Turkish Coffee, caffeine, instant coffees, Differential Scanning Calorimeter.