Judul: Karakterisasi sifat fisikokimia dan fungsional fraksi pati dan tepung umbi lima kultivar uwi (Dioscorea alata)
Abstrak: Yam (Dioscorea alata), as a bulbous plant, was rich in starch content. Yam starch pastes naturally had a character that was resistant to high temperatures, and this character was needed in food processing. A fairly high diversity, quitely high plant productivity and easily in cultivation of yam plant indicated the potential utilisation of yam tuber as raw material in food industry. Starch in food processing applications would result in the final product that was affected by refined starch physicochemical properties. As for food processing, information about the starch physicochemical characteristics was necessary, which was typical characteristic to the type (source) of starch. Physicochemical character was influenced by several factors such as the type (source) of starch, granule size, amylose content and starch crystallization. Starch with different on its granules sizes had different chemical composition that was contribute to the different pasting character and paste viscoelastisity. Pasting characters and paste viscoelastisity themselve were important functional characters of the starch in food processing applications as thickeners. In relation to that and for the development usage of yam tuber, this study was aimed to observe and to study the physicochemical characteristics and functional properties of starch granules and flour particle size fractionation from several yam cultivars, especially in the paste formation and paste viscoelastisity profile. The chemical composition of starch was specific for each yam cultivar which influenced the nature of the starch physical and functional properties. It was found that yam starch had unimoda asymmetrical distribution of its granule size with a higher portion on the large size, and the size ranged 7-100 μm. The morphology of yam starch granules was round disc-shaped, elliptical, oval and round with smooth wavy surfaces. The chemical composition of yam starch had lipid content ranged 16-30 % db, amylose ranged 23.44-26.99 % db and phosphorus ranged 268.15- 365.36 ppm db. Yam starch crystallinity structure had type-B pattern with low crystallinity which was ranged 20.6-30.4 %. Based on the viscoelastisity profile of its cold paste, yam starch had strong resistance to high friction up to =107 rad/s. of the sweep test frequency Fractionation of yam starch was achieved by dry sieving Retsch Siever with 400 and 500 meshes, and was resulted in unperfectly separated of the size fractions. The fractionation was provided a significantly different on average value among the fractions for all cultivars with the range of average of 20.89- 27.93 μm as smaller fraction, 22.41-28.82 μm as medium size fraction and 25.00- 34.80 μm as large size fraction. Based on the average value of the fraction, the larger the granule size contributed to the increase of amylose and phosphorus content and reduced starch crystallinity. The difference in the granule size fraction was not enough to produce any significant effect of size on gelatinization character. In the paste formation, the starches showed type-B profile and higher paste stability could be found in the bigger granule size. The viscoelastisity character showed that the value of storage modulus (G') was increase as the granule size increase which was lead to the stronger gel formation of the paste from small granule
Keyword: yam starch, size fractionation, pasta profile, gelatinization, viscoelastisity

Judul: Physicochemical Characterization of Starch from Several Types of Tubers
Abstrak: Salah satu tanaman alternatif sumber karbohidrat berasal dari tanaman umbi-umbian. Pati merupakan sumber karbohidrat terbesar pada tanaman. Tujuan dari penelitian ini adalah mempelajari karakteristik fisikokimia pati dari beberapa jenis umbi, seperti singkong, ubi jalar, talas bogor, talas beneng, dan anuwun sehingga dapat diketahui potensi pemanfaatannya. Karakterisasi fisikokimia yang dilakukan pada penelitian ini yaitu analisis proksimat, kadar pati, amilosa dan amilopektin, serat kasar, bentuk dan ukuran granula pati, kristalinitas pati, profil gelatinisasi pati, dan kestabilan panas pati. Kelima jenis pati umbi memiliki kadar pati basis kering yang tinggi, seperti pati singkong yaitu 96,04%; ubi jalar yaitu 89,98%; talas bogor yaitu 89,86%; talas beneng yaitu 87,45%; dan anuwun yaitu 90,11%. Kadar amilosa basis kering pati singkong yaitu 35,45%; ubi jalar yaitu 36,88%; talas bogor yaitu 15,33%; talas beneng yaitu 27,15%; dan anuwun yaitu 32,84%. Kelima jenis pati umbi memiliki kadar serat kasar basis kering yang rendah. Pati singkong, ubi jalar, dan anuwun memiliki bentuk granula hampir bulat dan berukuran sedang. Sementara itu pati talas bogor dan talas beneng memiliki bentuk poligonal dan berukuran kecil. Kelima jenis pati memiliki profil gelatinisasi pati tipe A dan kristalinitas pati tipe A. Kristalinitas pati singkong yaitu sebesar 10,21%; ubi jalar yaitu 10,92%; talas bogor yaitu 12,89%; talas beneng yaitu 12,86%; dan anuwun yaitu 10,14%. Analisis kestabilan panas dari kelima jenis pati menunjukkan puncak endotermik sekitar 59,45 – 66,89°C dan entalpi transisi sekitar 145,4284 - 191,8308 J/g. Berdasarkan analisis multivariat menggunakan Principle Component Analysis (PCA) pati singkong dan pati ubi jalar memiliki karakteristik fisikokimia yang mirip. Sementara itu pati talas bogor, talas beneng, dan anuwun memiliki karakteristik fisikokimia yang berbeda., One of the alternative sources of carbohydrates comes from root crops. Starch is the largest source of carbohydrates in plants. The purpose of this study was to study the physicochemical characteristics of starch from several types of tubers, such as cassava, sweet potato, bogor taro, beneng taro, and anuwun so that their potential utilization can be identified. The physicochemical characterizations carried out in this study were proximate analysis, starch content, amylose and amylopectin, crude fiber, starch granule shape and size, starch gelatinization profile, starch heat stability, and starch crystallinity. The five types of tuber starch have high dry base starch content, such as cassava starch which is 96.04%; sweet potato is 89.98%; taro bogor is 89.86%; taro beneng is 87.45%; and anuwun is 90.11%. The dry base amylose content of cassava starch was 35.45%; sweet potato is 36.88%; taro bogor is 15.33%; taro beneng is 27.15%; and anuwun is 32.84%. The five types of tuber starch have low dry base crude fiber content. Cassava, sweet potato, and anuwun starch have almost round granule shape and medium size. Meanwhile, bogor taro and beneng taro strach have a polygonal shape and are small in size. The five types of starch have a starch gelatinization profile type A and starch crystallinity type A. The crystallinity of cassava starch was 10.21%; sweet potato is 10.92%; taro bogor that is 12.89%; taro beneng is 12.86%; and anuwun is 10.14%. Heat stability analysis of the five types of starch showed endothermic peaks around 59.45 –
Keyword: Karakteristik fisikokimia, Pati, Principle Component Analysis (PCA), Physicochemical characteristics, Principle Component Analysis (PCA), starch

Judul: Portofolio Arbitrase Pada Capital Market Line Dan Security Market Line
Abstrak: sekuritas atan portofolio. Salah satu asumsi yang digunakan dalam model ini adalah tidak diperbolehkan terjadinya arbitrase. Arbitrase adalah tindakan yang memanfaatkan terjadinya perbedaan harga sekuritas P<lda w'.. . ktu yang bersamaan pada dua pasar yang berbeda atau lebih. Ketika tidak diperbolehkan adanya arbitrase, semua investor akan memilih portofolio pasar yaitu portofolio yang terdiri atas semua sekuri(HS yang ada di pasar. Portofolio pasar ini merupakan portofoJio sekurilas berisiko yang oplimaL Portofolio optimal ini jika digambarkan pada SML dan CML akan berada tepat pacta garis-garis tersebut. Faktanyd dalam dunia nyata saa! ini arbitrase dapat terjadi. Apabila arbitrase terjadi maka investor tidak akan memilih portofolio pasar melainkan memilih portofolio arbitrase karena lebih menguntungkan. Portofolio arbitrase ini menguntungkan karena nilai harapan returnnya lebih besar daripada nilai hardpan return portofolio pasar dengan risiko yang
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