Food Science and Biotechnology
→ Food Science and Biotechnology 2019 ; 28(1): 7-14
Critical roasting level determines bioactive content and antioxidant activity of Robusta coffee beans
Dian Herawati1,2, Puspo Edi Giriwono1,2, Fitriya Nur Annisa Dewi3, Takehiro Kashiwagi4, Nuri Andarwulan1,2
1Department of Food Science and Technology, Faculty of Agricultural Engineering and Technology, Bogor Agricultural University (IPB), IPB Dramaga Campus, Bogor 16680, Indonesia, 2Southeast Asian Food and Agricultural Science and Technology Center, Bogor Agricultural University (IPB), Jl. Ulin No.1 IPB Dramaga Campus, Bogor 16680, Indonesia 3Primate Research Center, Bogor Agricultural University (IPB), Jl. Lodaya II No. 5, Bogor, Indonesia, 4Department of Agricultural Chemistry, Faculty of Agricultural and Marine Science, Kochi University, B200, Monobe, Nankoku, Kochi 7838502, Japan
Indonesian Lampung Robusta coffee green beans were roasted at eight roasting levels (green bean, early yellow, brown, 1st crack done, very light, light, medium, and dark), followed by grinding and brewing. The physical properties of ground coffee and chemical properties of brewed coffee were analyzed. The resulting data were mapped in order to investigate the critical roasting level. It was observed that major alterations for physicochemical properties of coffee happened after ‘‘first crack’’ roasting level (when water activity (Aw) of bean decreased from 0.22 to 0.15). This cracking is defined as popping sound of the bean during roasting. Continuous formation of melanoidins under low Aw (.15) was followed by slow degradation of chlorogenic acid (5-CQA) and total phenolic compounds. Caffeine was stable during roasting, while antioxidant activity slightly decreased. The ‘‘first crack’’ was determined to be the critical roasting level to produce roasted coffee beans containing high concentrations of phenolics.
Roasted coffee, Roasting, Water activity, Bioactive compounds, Antioxidant activity
Food Science and Biotechnology 2019 ; 28(1): 7-14