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 Lama Penyeduhan Teh Hitam (Camellia sinensis) serta Proses Pencernaan secara In Vitro terhadap Penghambatan Aktivitas Enzim Alfa Amilase dan Alfa Glukosidase secara In Vitro
Abstrak: 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. Natural alpha amylase and alpha glucosidase inhibitors from food-grade plants offer an attractive strategy to eather manage or prevent type 2 diabetes by controlling of starch breakdown and intestinal glucose absorption. Black tea is the second most widely consumed beverage in the world after water. A lot of researches about bioactive compounds in tea related have been done. In this study, six extracts treated with different combination of temperature and brewing time were investigated for alpha amylase and alpha glucosidase inhibitory potential. Furthermore, the influence of the digestion condition in vitro to the activity of the enzymes was also performed in this study. The enzymes inhibitory and total phenol was measured by spectrophotometric while tannin content was measured by gravimetric method. Results showed that tea brewed by 70oC 15 minutes, 70oC 30 minutes, 100oC 5 minutes, 100oC 15 minutes can optimally inhibit amylase at initial extract (as an estimation of salivary alpha amylase), 70oC 15 minutes and 100oC 5 minutes can optimally inhibit pH digestion-controlled extract (pancreatic amylase), 70oC 30 minutes and 100oC 30 minutes can optimally inhibit alpha glucosidase at initial extract, also 70oC 15 minutes, 100oC 15 minutes, and 100oC 30 minutes can optimally inhibit at pH digestion-controlled extract. Alpha amylase inhibitory has a positive correlation with tannin content but not with total phenol. While alpha glucosidase inhibitory showed no correlation with tannin and showed a negative correlation with total phenol.
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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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