Judul: Pemanfaatan dan Pengawetan Uwi Kelapa (Dioscorea alata L.) Sebagai Enyek-Enyek Serta Daya Terimanya
Abstrak: Tujuan penelitian ini adalah untuk mempelajari kemungkinan pemanfaatan uwi kelapa (Dioscorea alata L.) sebagai enyek-enyek. Enyek-enyek adalah sejenis bahan pangan kerupuk berasal dari bahan umbi-umbian singkong, yang dibuat melalui proses pengeringan.
Keyword: uwi kelapa

Judul: Produksi dan Karakteristik Tepung, Pati dan Lendir dari Umbi Uwi (Dioscorea alata).
Abstrak: Umbi uwi merupakan salah satu umbi-umbian yang sangat potensial di Indonesia namun belum dimanfaatkan secara optimal. Seperti umbi-umbian lainnya, umbi uwi dapat dimanfaatkan menjadi sumber pati dan tepung untuk meningkatkan nilai tambahnya. Namun, pemanfaatan pati dari uwi sedikit terhambat karena adanya kandungan lendir pada uwi yang ikut terekstrak saat mengekstrak pati sehingga mempengaruhi sifat kimia dan fungsional pati. Oleh karena itu, dilakukan desain percobaan ekstraksi sehingga sebisa mungkin memisahkan pati dan lendir. Desain percobaan yang dilakukan terdiri dari dua faktor yaitu jenis umbi uwi (uwi putih dan uwi ungu) dan suhu pelarut ekstraksi (suhu ±25ºC dan ±50ºC). Rendemen tepung uwi putih (25,26%) lebih besar dibandingkan tepung uwi ungu (23,03%). Ekstraksi pati pada suhu pelarut 50ºC memiliki rendemen (6,45-6,80%) yang lebih sedikit dibandingkan suhu pelarut 25ºC (8,26-8,59%) namun pada suhu pelarut 50ºC memiliki rendemen lendir (0,65-0,98%) yang lebih banyak dibandingkan suhu pelarut 25ºC (0,54-0,88%). Komponen protein, serat kasar, karbohidrat, amilosa dan daya cerna pati dipengaruhi oleh jenis umbi uwi sedangkan komponen air, serat kasar, pati, amilosa serta daya cerna pati dipengaruhi oleh suhu pelarut ekstraksi. Viskositas lendir uwi dipegaruhi jenis umbi dan suhu pelarut. Penggunaan suhu pelarut ekstraksi 50ºC pada pati memiliki sifat amilografi yang tidak jauh berbeda dengan pati yang diekstrak suhu pelarut 25ºC.
Keyword: Dioscorea alata, tepung, ekstraksi, lendir, pati, umbi uwi

Judul: Quantitative Trait Loci Mapping for Trait in Categorical Scale
Abstrak: Genes or regions on chromosome underlying a quantitative trait are called Quantitative Trait Loci (QTL). Characterizing genes controlling quantitative trait on their position in chromosome and their effect on trait is through a process called QTL mapping. In estimating the QTL position and its effect, QTL mapping basically utilize the association between QTL and DNA markers. However, many important traits are obtained in categorical scale, such as resistance from certain disease. From a theoretical point of view, QTL mapping method assuming continuous trait could not be applied to categorical trait. This research was focusing on the assessment of the performance of Maximum Likelihood (ML) and Regression (REG) approach employed in QTL mapping as well as the performance of Lander and Botstein (LB) and Piepho method in determining critical value in testing the existence of QTL for binary and ordinal trait by means of simulation study. The simulation study to evaluate the performance of ML and REG approach was conducted by taking into account several factors that may affecting the performance of both approaches. The factors are: (1) marker density; (2) QTL effect; (3) sample size; (4) shape of phenotypic distribution; (5) number of categories; and (6) number of QTL. Moreover, the simulation study for evaluating LB and Piepho method in determining critical value was conducted by generating distribution of the test statistic under null hypothesis. From simulation study, it was obtained that LB and Piepho method showing similar performance in determining critical value in testing the existence of QTL for binary and ordinal trait. The simulation study also indicating that both methods could be used in determining critical value in QTL mapping analysis for binary trait as well as for ordinal trait if the REG approach is used but not if ML approach is used due to their poor performance. In assessing the performance of ML and REG approach in QTL mapping analysis for binary trait, the two approaches showing comparable performance; whereas for ordinal trait REG approach showing poor performance compared with ML approach in estimating thresholds. As a result, in QTL mapping analysis, ML and REG approach could be used when dealing with binary trait, whereas ML approach is suggested when dealing with ordinal trait.
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