Judul: Pengaruh Suhu dan Lama Penyeduhan Teh Hijau (Camellia sinensis) serta Proses Pencernaan secara In vitro terhadap Penghambatan Aktivitas Enzim Alfa Amilase dan Alfa Glukosidase secara In vitro
Abstrak: Tea is one of the major product in food industries. One type of its product is green tea. Diabetes is a chronic disease that occurs either when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin. Green tea has an active compound which inhibits α-amylase and α-glucosidase enzyme performance. Natural alpha-amylase and alpha-glucosidase inhibitors from food-grade plants offer an attractive strategy either to prevent or manage type 2 diabetes via controling starch breakdown and intestinal glucose absorption. The research focuses on evaluating the correlationship between tea’s anti diabetic activity and brewing’s time and temperature. In this study, six different extracts based on combination of temperature (in 70 and 100oC) and brewing time (in 5, 15, and 30 minutes) were investigated for alpha-amylase and alphaglucosidase potential inhibitor. Furthermore, the influence of the in vitro digestion condition to the activity of the enzyme was also performed in this study. The enzyme inhibitory and total phenol were measured by spectrophotometric while tannin content was measured by gravimetric method. Results showed that green tea brewed by 100oC 5 minutes and 100oC 15 minutes can optimally inhibit alphaamylase at initial extract (as an estimation of salivary alpha-amylase), 70oC 5 minutes, 70oC 30 minutes, 100oC 5 minutes, and 100oC 15 minutes inhibit alpha-amylase at pH digestion-controlled (as an estimation of pancreatic amylase) higher than another green tea extracts. Green tea brewed by 70oC 30 minutes can optimally inhibit alpha-glucosidase enzyme, both at initial extract and pH digestion-controlled extract. After passed through the in vitro digestion, green tea extracts showed decreasing of inhibition values both of alpha-amylase and alpha-glucosidase.
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Judul: Pengaruh Suhu Dan Waktu Penyeduhan Teh Hijau (Camellia Sinensis) serta Proses Pencernaan In Vitro terhadap Aktivitas Inhibisi Lipase
Abstrak: Obesity will lead to many other degenerative diseases. One of the alternative solutions to prevent obesity is by inhibiting the digestion of lipids. Green tea extract has anti-lipase activity. This research aims to determine the effect of time (5, 10, and 15 minutes) and temperature (70, 85, and 100˚C) of green tea brewing and in vitro digestion on lipase inhibition. The research method is divided into two stages, green tea brewing and in vitro gastrointestinal pH simulation. Green tea extract is analyzed for anti-lipase activity, total phenol, and condensed tannin level. The results showed that the temperature and time of brewing influence the level of lipase inhibition, total phenol, and condensed tannin of green tea extract. The total phenols and condensed tannin level have a strong correlation with the lipase inhibition. The green tea initial extract (before in vitro digestion) in 85˚C for 5 min and 100˚C temperature in all the time showed the highest inhibition activity. But, after in vitro digestion, only green tea which brewed in 100˚C for 5 minutes and 10 minutes which had the best inhibition of lipase. There are no difference in significant level for inhibition activity between green tea brewed in 100˚C brewing temperature for 5 minutes and 10 minutes.
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Judul: Rantai Markov Pada Bilangan Biner
Abstrak: Ranlai Markov {Xn} yang didefinisikan pada ruang peluang (n, P, P) dilllana n = (O,I],dan 'Fadalah cr-lapangan Borel, lllelllpunyai ekspansi biner X n = 0, dl(n) din).. n = I, 2, ... Mengkonstruksi rantai Markov ini diawali dengan memilih sembarang bilangan ..Y o di (0,1], nyatakan bilangan Xo dalam ekspansi biner Xo =0, diD) diD) ... d~O) ... dimana { d~O) ,n = 1,2, ... } adalah barisan nol dan satu. Peubah acak XI ditentukan oleh .Xo dan asumsi berikut.
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