Judul: Effects of Inlet Temperature and Feed Concentration on Quality of Spray Dried Instant Green Tea Powder
Abstrak: Tea is a popular drink because of its unique aroma and characteristic flavor which is controlled by key chemical components which are volatile terpenes, teaine, organic acids, and polyphenols. Currently, the quality ofinstant green tea powder has been improved. It has some advantages like increase solubility, shelf life, and flavor. Instant green tea powder is produced trough drying method like spray drying.This process, unfortunately, potentially has deleterious effects on some component in green tea, like polyphenol compounds and volatile compounds. The objective of this research is to study effect of inlet air temperature and feed concentration in feed on quality of green tea powder. Main material used in this research was green tea leaf which was supplied by Boonrod Tea Factory. The drying method used in this research was spray drying. There are three level of inlet temperature used in this research, which were 180 oC, 200 oC, and 220 oC. This research also used three level of feed concentration which were 3%, 6%, and 9%. Parameters studied in this research were volatile compounds, chemical compound, and physical properties of green tea powder. The result shows that inlet temperature and feed concentration significantly affected (p<0.05) the quality of green tea powder. Generally, increased temperature (up to 200 oC inlet temperature) decreases amount and type of volatile compound, particularly ketone, total polyphenol, teaine content, solubility, and bulk density (p<0.05). On the other hand, increased feed concentration increases L value, b value, gallic acid, teaine, and catechin content (p<0.05). The best green tea powder is the one with 6% total solid in feed and 180 0C inlet temperature. It has highest amount of terpene and also contains hydrocarbon and aldehide.It also has low moisture content (4.17 ± 0.02 %), high total polyphenol content (26.42 ± 0.07 %), high teaine content (7.06 ± 0.01 %), and highest catechin content (26.16 ± 0.13 %). Physical properties analysis shows it has low water activity (0.21 ± 0.02), lowest a value (3.80 ± 0.35) low b value (18.87 ± 0.14) high hygroscopicity (9.09 ± 0.94 %) high solubility (98.79 ± 0.53 %) and low bulk density (0.51 ± 0.18 g / mL).
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Judul: Effect of Spray Drying Conditions on Physical and Chemical Properties of Dried Green Tea Extract (Camellia sinensis var. Oolong No 12).
Abstrak: The effect of spray drying conditions on physical and chemical dried green tea (Camellia sinensis var. Oolong No 12) extract were observed. Tea extract was prepared from milled dried tea, dissolved in hot water at temperature 90°C and ratio of dried tea to water 1: 20 (w / v). The time of extraction used was 60 minutes, and pH value was 5.0. Then, tea extract was concentrated with ice maker machine until reached 3, 6 and 9% of total solid, and dried with spray drier with condition inlet air temperatures were 180, 200, 220°C, outlet air temperatures was controlled 75°C, blower speed was adjusted in 2500 rpm. The physical analysis, such as bulk density, color, solubility, hygroscopicity, and the chemical analysis, such as moisture content, total polyphenols content, antioxidant activity (DPPH assay), catechins, and caffeine content were determined. Results showed that different solid concentration of 3, 6, 9% in feed and inlet air temperatures of 180, 200, and 220˚C affected the variation of physical and chemical properties of green tea powder. An increase inlet air temperature, resulted in a significant decrease (p<0.05) in bulk density, hygroscopicity, total polyphenols and antioxidant activity. An increase of solid concentration in feed gave an increase in tea powder solubility, L, a, b value, and antioxidant activity. However, the total polyphenols contents were not affected by the increase. The condition of feed concentrated to 3% and inlet temperature at 220˚C was evaluated with the highest of physical, chemical results and the highest of kg water removal/hour by spray dryer.
Keyword: Green tea, tea powder, freeze concentration, spray dryer

Judul: Embriogenesis ikan buta (Astyanax fasciatus)
Abstrak: Ikan buta Astyanax fasciatus adalah spesies ikan unik dari famili Characidae yang menempati perairan dalam gua di Wilayah La Cueva Chica-San Luis Potasi-Mexico. Ikan ini memiliki mata yang tereduksi (Blind Cavefish) dan warna kulit merah muda, pucat serta mengkilap.
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