Judul: Pengaruh Fermentasi dan Penambahan Gula dalam Proses Pembuatan Selai Belimbing Wuluh (Averrhoa bilimbi. L.).
Abstrak: The ability of bilimbi tree (Averrhoa bilimbi. L.) to produce fruits annually is not proportional with the utilization so that many fresh fruits were fallen and spoiled on the soil. The sour taste makes this fruit is not edible straight away. Fruit jam is thought as an alternative processing product. Bilimbi is fermented before it is processed into jam, because the fermentation process is expected to be better in aroma and taste as well. The purpose of this research is to clarify the effect of fermentation process to the taste and flavour of the product. This bilimbi jam is fermented in three parts or periods, namely two days, three days, and four days in addition to without fermentation as the control. Besides that, there are three different of composition fruit and sugar portion, those are 55:45, 50:50, and 45:55. That formula are tested afterwards by organoleptic test and yield the best formula was that with four days fermentation and composition of fruit: sugar (55:45). The chemistry and physic analysis showed that bilimbi jam has pH 2.76- 3.06, with score aw 0.68-0.74, moisten content of 19.47%-27.72% (wet basis) and the total soluble solids of 68.75% until 73.13%. The result of analysis stated that all parameters which have been tested are match with the product standard. The outcome of this research also showed that fermentation process impacts to the taste produced, yet not influenced the flavor of the jam. This can be seen from the organoleptic tests of the product.
Keyword: organoleptic, jam, fermentation, bilimbi

Judul: Mempelajari pengaruh cara pembuatan sari buah belimbing wuluh (Averrhoa bilimbi L.) terhadap nilai gizi dan daya terimanya
Abstrak: Penelitian ini bertujuan untuk mempelajari pengaruh cara pembuatan sari buah belimbing wuluh (Averrhoa bilim- bi L.) terhadap nilai gizi maupun daya terimanya. Sedang- kan tujuan khususnya adalah untuk mengetahui pengaruh pemblansiran (merendam dalam air panas 80°C selama 3 menit), cara ekstraksi buah dengan blender dan juicer serta lama penyimpanan terhadap nilai gizi dan daya terimanya. Selain itu penelitian ini juga bertujuan untuk mengetahui adanya kandungan zat aktif kalium dan asam oksalat dari sari buah belimbing wuluh. Metode penelitian dilakukan dalam dua tahap, yaitu penelitian pendahuluan dan penelitian lanjutan. Penelitian pendahuluan bertujuan menentukan proses pembuatan sari buah, menentukan komposisi bahan seperti buah, air, gula pasir, dan essence (aroma nanas), menentukan taraf perlakuan lama penyimpanan dan juga untuk mengetahui kandungan zat gizi buah segar belimbing wuluh. Sedangkan pada penelitian lanjutan dilakukan proses pembuatan sari buah dan analisis zat gizi serta uji organoleptik untuk melihat pengaruh perlakuan terhadap nilai gizi serta daya terima sari buah.
Keyword: nilai gizi

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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