This study explored the optimization of extraction condition of total polyphenols and flavonoids from dried coffee cherry pulp (Cascara) by response surface methodology. The effect of varying the extraction conditions such as solvent (water)-to-material ratio (X1); temperature (X2) and time (X3) were studied. The results demonstrated that the best combination of extraction conditions for dried coffee cherry pulp was at 1:40.77 solid-solvent ratio, 71.59 oC and 48.39 min. At optimal extraction conditions, the total polyphenols content achieved 23.816 mg GAE/g and total flavonoids achieved 11.365 achieved mg QE/g, on a dry basis.
the parameters affect recovery of TFC However, the quadratic coefficient of solvent, temperature and time had relative in inverse ratio to flavonoid content If continued to increase, TFC yield tended to decrease at higher extraction parameters Two-dimensional contour plots and three-dimensional response surface plots are presented in Fig Regression coefficient is R2 = 0.992 and virtual variation coefficient Q2 = 0.953 The value of R and Q2 were nearly close to 1, indicating a degree of correlation between the observed and predicted values, hence suggesting that the model was significant [5] Optimal extraction conditions are found by RSM The optimal results of the optimization model verification are in Table 3: Table Predicted and experimental values under optimum conditions based on the multiple responses of TPC and TFC Predicted value Solvent-tomaterial ratio Temp Time 1: 40.7733 71.5914 48.3857 Experimental value TPC (mg GAE/g) TFC (mg QE/g) TPC (mg GAE/g) TFC (mg QE/g) 23.8703 11.3831 23.816 23.816 Experimental results show that the average TPC (p = 0.479 > 0.05) and TFC (p = 0.489 > 0.05) when tested by student test (n = 5) there are no significant difference between the predicted value and the experiment 3.2 The result of sensory evaluation of drinking water product from cascara after applying optimization conditions in the extraction process The results evaluated of final product with two healthy herbal tea lines, Dr Thanh and Oolong tea plus, as shown in the Figure Average score 4.7125b 5.025b a b 5.7875a c Figure Graph of the degree of consumer acceptance by sensory evaluation, final product (a), Dr Thanh (b) and Oolong tea plus (c) 31 Do Mai Nguyen Phuong, Hoang Thi Truc Quynh, Le Thi Hong Anh With an average score of 4.7125 on a scale of 7, drinking water from Cascara is receiving positive reviews from consumers At the same time, there is no difference in priority between final product and Dr Thanh tea product (α = 0.05), showing that the product has been accepted by the consumer as a refreshing drink that are healthy CONCLUSIONS Research results showed that three factors: the ratio of materials: solvent (water), temperature and time affect the extraction from coffee cherry pulp (cascara) The optimization process offers optimal conditions: the ratio of solvent material 1:40.7733, the extraction temperature of 71.5914 oC, the extraction time of 48.39 minutes After the control experiment was performed, the total polyphenols and flavonoids content were 23.816 mg GAE/g dry basis and 11.365 mg QE /g dry basis, respectively Applying the optimization conditions of extraction process to drinking water products from coffee cherry pulps and implementing sensory methods according to the ranking test method to determine the mixing formula: syrup ratio 9oBx, citric acid content is 0.01 % Acknowledgements The research funding from the Research Foundation of Ho Chi Minh University of Food Industry was acknowledged REFERENCES Heeger A., Kosińska-Cagnazzo Cantergiani E., and Andlauer W - Bioactives of coffee cherry pulp and its utilisation for production of Cascara beverage, Food chemistry 221 (2017) 969-975 Geremu M., Tola Y B., and Sualeh A - Extraction and determination of total polyphenols and antioxidant capacity of red coffee (Coffea arabica L.) pulp of wet processing plants, Chemical and Biological Technologies in Agriculture (2016) 25 Sulaiman C and Balachandran I - Total phenolics and total flavonoids in selected Indian medicinal plants, Indian journal of pharmaceutical sciences 74 (2012) 258 Al-Farsi M A and Lee C Y - Optimization of phenolics and dietary fibre extraction from date seeds, Food Chemistry 108 (2008) 977-985 Duc C T and Van K - Finding optimal conditions for hydrophilic polymer polymerization process based on acrylic acid using ammonium sulfate initiator by experimental planning method, Journal of Science and Technology 49 (4) (2011) 95-99 32 ... mg GAE/g dry basis and 11.365 mg QE /g dry basis, respectively Applying the optimization conditions of extraction process to drinking water products from coffee cherry pulps and implementing sensory... Geremu M., Tola Y B., and Sualeh A - Extraction and determination of total polyphenols and antioxidant capacity of red coffee (Coffea arabica L.) pulp of wet processing plants, Chemical and Biological... the ratio of materials: solvent (water) , temperature and time affect the extraction from coffee cherry pulp (cascara) The optimization process offers optimal conditions: the ratio of solvent