Validations of Sensory Overall Acceptability Optimisations On Response Surface Methodology Through Just-About-Right Technique of Coffee Leaf Tea at Different Brewings Kiki Fibrianto*, Igoy Arya Bimo, Atika Muna Sofa, Azalea Putri, Devia Amelia, Ovirista Rachma Lailika, Irha Putri Genbrovit, Ahmad Izzul Haq
Departement of Food Science and Biotechnology, Faculty of Agricultural Technology, Universitas Brawijaya
*kiki.fibrianto[at]ub.ac.id
Abstract
Response Surface Methodology (RSM) has been widely employed for optimising process. However, implementation of RSM in sensory studies is still limited. Moreover, most of publications implementing RSM on sensory disregarded the validation stage as normaly apply for process optimisation. In this study, validating sensory overall acceptability with RSM was proposed by Just-About-Right (JAR) technique. Coffee leaf tea have great commercial potential as an ethnic beverage with unique sensory attributes while it is still underutilised. Optimising sensory acceptability level by modifying temperature and duration of brewing using the RSM was expected to obtain well accepted coffee leaf tea. Robusta coffee leaf herbal tea is brewed using combined Decoction - V60, French Press, combined French Press - V60, and V60 at 90oC to 100oC for 2 to 10 minutes. Evaluated by 110 untrained panellists, it was observed that the ideal brewing parameters for each technique were 96.6oC for 6.5 minutes for Decoction - V60, 96oC and 6.5 minutes for French Press, 90oC and 2 minutes for French Press - V60, and 90oC and 2 minutes for V60. All optimum brewing conditions based on RSM is successfully validated by overall acceptability on JAR (p-value 0.05). Thus, it can be recommended that overall sensory acceptability optimisations through RSM can be further validated by JAR technique.
