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Green tea and black tea are rich in antioxidants that have a beneficial effect on human health. The antioxidants in green tea and black tea are mainly polyphenols including catechin and its derivative epigallocatechingallate. The DPPH radical scavenging activity, IC50 value, total polyphenols, catechin and epigallocatechingallate content were analyzed throughout green and black tea processing. The DPPH radical scavenging activity, IC50 value, total polyphenols, catechin and epigallocatechingallate decreased during processing. The study confirms that the processing influences the antioxidant activity of green and black tea.

Epoxidized palm oil is an alternative source of bio polyol. The combination of temperature and time in epoxidation reaction is important to produce qualifying epoxidized palm oil. This study used a combination of the temperatures ranged from 50-80 °C and time ranged from 1-4 hours. The epoxidized palm oil parameters were Fourier-transform infrared spectroscopy (FTIR), density, oxirane oxygen content (OOC), and iodine value. The result of this study shows that an epoxidation temperature of 70 °C for 3 hours produced the highest OOC, while the epoxidation reaction temperature of 50 °C for 1 hour produced the lowest OOC. Epoxidized palm oil with high OOC is considered to be of better quality. The study also showed that the iodine values were getting lower. It indicates the epoxidation reaction was successful.

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Flexible polyurethane foams can be synthesized using polyols having a hydroxyl value of less than 100 mg KOH/g. The value of the hydroxyl value is affected by the temperature and time of the oxirane rings opening reaction. The purpose of this study was to examine the combination of temperature and time of the best oxirane rings opening reaction to produce polyols with a hydroxyl value of less than 100 mg KOH/g. Epoxidized palm oil was treated with temperature (50°C, 60°C, 70°C, and 80°C) and time (1 hour, 2 hours, 3 hours, and 4 hours). Parameters observed were hydroxyl value, hydroxyl content, density, viscosity, acid number, and color. The best treatment continued with the FTIR test. The oxirane rings opening reaction using a temperature of 50°C for 1 hour gave a hydroxyl value of 75.87 mg KOH/g.