Judul: Pengaruh Fermentasi Natural dan Fermentasi Lactobacillus casei Terhadap Karakter Fisikokimia Tepung Ubi Jalar (Ipomea batatas) Varietas Jago
Abstrak: Sweet potato (Ipomea batatas) has considerable potencies to be developed to support food diversification in Indonesia. One of sweet potato variety is Jago. Jago variety has high yields with high starch content, and suitable to be used in flour and starch production. Fermentation can be done to increase physicochemical and functional quality of sweet potato flour. In this research, sweet potato Jago was fermented for 1, 2 and 3 days using natural fermentation and controlled fermentation with Lactobacillus casei. Then the physicochemical properties were analyzed. Analysis showed that the sweet potato flour with best functional quality was the flour which fermented using L. casei during 3 days (L3). This flour contained 11.42% moisture, 0.41% ash, 0.20% fat, 1.72% protein, and 86.24% carbohydrate. The water absorption index of this flour was 2.78 gr/gr, the water solubility index was 0.0009 gr/ml, swelling power was 10.36%, solubility was 0.21%, whiteness index was 88.30% and freeze-thaw stability was 59.64%. The RVA analysis showed that peak viscosity of L3 flour was 6395 cP, breakdown viscosity was 3931 cP, final viscosity was 4030 cP, setback viscosity was 1566 cP, pasting temperature was 75.75⁰C and the peak time was 6.93 minute.
Keyword: Lactobacillus casei, fermentation, Jago variety, sweet potato flour

Judul: Karakterisasi sifat fisikokimia tepung ubi jalar (Ipomea batatas)
Abstrak: Ubi jalar (Ipomoea batatas) merupakan salah satu tanaman pangan tropis yang banyak terdapat di Indonesia. Ubi jalar memiliki potensi yang sangat layak untuk dipertimbangkan dalam menunjang program diversifikasi pangan yang berbasiskan pada produk tepung dan pati. Metode pengeringan yang digunakan akan mempengaruhi mutu tepung ubi jalar yang dihasilkan. Menyangkut hal tersebut, perlakuan awal dan berbagai teknik pengeringan pada pembuatan tepung ubi jalar diperkirakan mempunyai pengaruh besar terhadap perubahan karakteristik fisikokimia tepung ubi jalar. Penelitian ini bertujuan untuk mempelajari pengaruh perlakuan teknik pengolahan terhadap karakteristik fisikokimia tepung ubi jalar yang dihasilkan. Penelitian diawali dengan analisis proksimat ubi jalar kemudian pembuatan tepung ubi jalar dengan enam teknik proses yang berbeda yaitu teknik 1 (disawut-tanpa dikukus-sinar matahari), teknik 2 (disawut-tanpa dikukus-oven), teknik 3 (diiris-tanpa dikukus-drum dryer), teknik 4 (disawut-dikukus-sinar matahari), teknik 5 (disawut-dikukus-oven), dan teknik 6 (kupas utuh-dikukus-drum dryer), dilanjutkan dengan analisis tepung ubi jalar yang dihasilkan serta aplikasi tepung ubi jalar pada pembuatan roti manis. Analisis fisikokimia yang dilakukan pada tepung ubi jalar yang dihasilkan tersebut adalah analisis fisik dan kimia meliputi analisis kadar air, densitas kamba, warna, sifat mikroskopis granula pati, indeks penyerapan air (IPA) dan indeks kelarutan air (IKA), derajat gelatinisasi, sifat amilografi tepung, stabilitas terhadap pembekuan dan thawing. Roti manis yang dihasilkan dianalisis secara visual dan organoleptik meliputi pengembangan roti, warna, rasa, tekstur, dan aroma. Hasil analisis karakteristik ubi jalar varietas sukuh menunjukkan bahwa rata-rata kadar air sebesar 61.48 % bb atau 159.83 %bk, kadar abu 0.72 %bb atau 1.87 %bk, kadar protein 1.29 %bb atau 3.35 %bk, kadar lemak 0.19 %bb atau 0.49 %bk, dan kadar karbohidrat 36.32 %bb atau 94.29 %bk. Tepung hasil pengolahan teknik 1 memiliki rata-rata kadar air sebesar 7.04 %bb, densitas kamba 0.40 g/ml, kecerahan 64.30, intensitas warna 6.48, derajat hue 5.87, IPA 2.89, IKA 0.0084 g/ml, absorbansi pati tergelatinisasi 0.010, suhu awal gelatinisasi 77.20C, viskositas puncak 451.6 BU, viskositas balik 96.3 BU, viskositas jatuh 109.7 BU, stabilitas pasta -84.0 BU, serta sineresis 30.03-38.60%. Tepung hasil pengolahan teknik 2 memiliki rata-rata kadar air sebesar 7.47 %bb, densitas kamba 0.40 g/ml, kecerahan 64.69, intensitas warna 4.67, derajat hue 14.53, IPA 3.35, IKA 0.0131 g/ml, absorbansi pati tergelatinisasi 0.007, suhu awal gelatinisasi 76.60C, viskositas puncak 466.0 BU, viskositas balik 96.0 BU, viskositas jatuh 55.0 BU, stabilitas pasta -45.6 BU, serta sineresis 26.82-39.49%. Tepung hasil pengolahan teknik 3 memiliki rata-rata kadar air sebesar 9.00 %bb, densitas kamba 0.37 g/ml, kecerahan 62.64, intensitas warna 4.60, derajat hue 26.55, IPA 7.90, IKA 0.0375 g/ml, absorbansi pati tergelatinisasi 0.861, viskositas puncak 710.0 BU, viskositas balik 56.0 BU, viskositas jatuh 705.0 BU, stabilitas pasta -16.0 BU, serta sineresis 50.31-70.20%...
Keyword: tanaman pangan tropis, diversifikasi pangan, fisikokimia tepung, ndeks penyerapan air (IPA), indeks kelarutan air (IKA)

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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