Judul: Profil Komponen Bioaktif dan Aktivitas Inhibitor  α-Amilase Kombucha Rumput Laut Sargassum sp. dan Ulva sp.
Abstrak: Rumput laut merupakan tumbuhan yang hidup di lautan dan banyak digunakan sebagai alternatif sumber pangan fungsional karena kaya akan senyawa fitokimia. Di sisi lain, kombucha adalah minuman fungsional yang diproduksi dengan memfermentasi ekstrak tumbuhan bergula dengan Symbiotic Cultures of Bacteria and Yeast (SCOBY). Penelitian ini bertujuan untuk mengevaluasi senyawa fitokimia dan aktivitas inhibitor α-amilase, serta profiling senyawa bioaktif pada ekstrak dan kombucha terbaik rumput laut Sargassum sp. dan Ulva sp. Perlakuan yang digunakan adalah masing-masing jenis rumput laut Sargassum sp. dan Ulva sp., serta kombinasi dari keduanya. Hasil penelitian menunjukkan bahwa Sargassum sp. dan Ulva sp. rumput laut mengandung fenol hidrokuinon, steroid, triterpenoid, tanin, dan saponin. Ekstrak rumput laut kombinasi memiliki aktivitas penghambatan α-amilase tertinggi dengan nilai IC50 4,04±0,09 ppm. Lama fermentasi rumput laut berpengaruh nyata terhadap pH, total keasaman, dan kadar alkohol kombucha. Profil senyawa bioaktif kombucha rumput laut berbeda dengan ekstrak rumput laut., Seaweed is a plant that lives in the ocean and is widely used as an alternative functional food source due to its rich phytochemical compounds. On the other hand, kombucha is a functional beverage produced by fermenting sweet plant extracts with Symbiotic Cultures of Bacteria and Yeast (SCOBY). This research aims to evaluate the phytochemical compounds and α-amylase inhibitor activity, as well as profiling the bioactive compounds in the best seaweed extracts and kombucha of Sargassum sp. and Ulva sp. seaweeds. The treatments used were individual Sargassum sp. and Ulva sp. seaweeds, as well as a combination of both. The results of the study showed that Sargassum sp. and Ulva sp. seaweeds contain hydroquinone phenols, steroids, triterpenoids, tannins, and saponins. The combined seaweed extract exhibited the highest α-amylase inhibition activity with an IC50 value of 4.04±0.09 ppm. The duration of seaweed fermentation significantly affected the pH, total acidity, and alcohol content of the kombucha. The bioactive compound profile of seaweed kombucha differed from that of seaweed extract.
Keyword: Antidiabetic, Bioactive, Fermentation, Seaweed, Tea

Judul: Sensory Profile and Flavour of Kombucha  Sargassum sp. with Different Types of Sugars and Fermentation Times
Abstrak: Salah satu cara untuk memperbaiki cita rasa yang pada teh Sargassum yaitu dengan dilakukannya proses fermentasi menjadi teh kombucha. Penelitian ini bertujuan untuk menentukan pengaruh lama waktu fermentasi dan jenis gula yang berbeda terhadap profil sensori kombucha Sargassum, serta karakteristik fisiko-kimia dan profil flavour pada perlakuan jenis gula dan lama fermentasi terbaik. Sampel kombucha Sargassum diberikan perlakuan dengan gula yang berbeda (sukrosa, sorbitol, dan steviol) dan lama waktu fermentasi selama 9 hari dengan waktu pengambilan sampel hari ke 0, 3, 5, 7, 9. Karakteristik kombucha Sargassum dapat dilihat dari parameter pH, alkohol, warna, total gula, dan uji sensori. Berdasarkan uji sensori hedonik sampel terbaik kombucha Sargassum yaitu kombucha Sargassum dengan perlakuan gula steviol dan waktu fermentasi selama 3 hari. Profil flavour sensori kombucha Sargassum dapat dilihat dengan pengujian CATA dan GC-MS. Sampel kombucha Sargassum terbaik memiliki profil senyawa volatil dari golongan asam, alkohol, keton, heterosiklik dan lainnya., One way to improve the taste of Sargassum tea is by fermenting it into kombucha tea. This research aims to determine the effect of fermentation time and different types of sugar on the sensory profile of Sargassum kombucha, as well as the physico-chemical characteristics and flavor profile of the best type of sugar and fermentation time. Sargassum kombucha samples were treated with different sugars (sucrose, sorbitol, and steviol) and a long fermentation time of 9 days with sampling times of days 0, 3, 5, 7, 9. The characteristics of kombucha Sargassum can be seen from the parameters of pH, alcohol, color, total sugar, and sensory tests. Based on the hedonic sensory test, the best sample of Sargassum kombucha was Sargassum kombucha with steviol sugar treatment and fermentation time for 3 days. The sensory flavor profile of Sargassum kombucha can be displayed by CATA and GC-MS testing. The best Sargassum kombucha samples had a volatile compound profiles from acids, alcohols, ketones, heterocyclics and other groups.
Keyword: Fermentation, flavour profile, Sargassum kombucha, sensory

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
Keyword: