Judul: Pembuatan Permen Jelly dari Karagenan dan Konjak dengan Aplikasi Prebiotik Xilo-Oligosakarida
Abstrak: The functional food’s consumption is growing rapidly. One of the functional ingredients is Xilo-oligosaccharides (XOS). In this study XOS was added to jelly candy which used carrageenan and konjac as gelling agent. Carrageenan and konjac was used as alternative gelatin substitute. The objective of this research is to study the influence of gelling agent (carrageenan, konjac, mixture of carrageenan and konjac), ratio of carragenan and konjac (1:1, 2:1, 3:1) and concentration of xilooligosaccharide used (3%,4%, 5%) to the physical and sensory characteristics of jelly candy. This research is divided in two steps, preliminary and main research. Preliminary research consists of formulation and selection of the best formula for the main research. The best formula is formula with 1.5% gelling agent, 20% sugar, 5% glucose, 0.2% citric acid, 0.1% flavor, 0.001% colorant, 73.2% water and sugar coating. Main research consists of texture, sensory, proximate, and XOS content analysis. The optimum jelly candy from texture and sensory analysis is jelly candy with mixture of carrageenan and konjac (1:1) and 5% XOS. The jelly candy has the hardness of 166.28 gf, elasticity 1.00, and stickiness 132.95 gf. The result of proximate analysis showed that jelly candy has 10.37% water content, 0.35% ash content, 1.00% fat content, 0.96% protein content, and 87.32% carbohydrates content (by difference). The XOS anlalysis show that the jelly candy contain 15.17% XOS.
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Judul: Karakterisasi Jelly Drink dari Jelly Powder Menggunakan Alat Texture Analyser dengan Metode Compression-Extrusion Test
Abstrak: Characterization needs to be done to determine the consistency of product quality. Appropriate methods are needed to characterize jelly drink. This is due to jelly drink is a gel product that is different from other types of gel products in terms of consumption. Jelly drink products consumed by aspirated (flow) and immediately swallowed like drinks. This research used compression extrusion test method because this method uses the principle of emphasis to an existing product extruded under the probe (flow), which is suitable for semisolid material like gel. Raw materials used in this study were jelly powder, carrageenan 0,4% + 0,05% konjac, carrageenan 0,4% + konjac 0,1%, carrageenan 0,4 % + LBG 0,05%, and karaginan 0,4% + 0,1% LBG. The results of characterization by using texture analyser and compression extrusion test method showed that the jelly powder 0,33 % (as control) has gel fracture and firmness values lower than carrageenan 0,4%+konjac 0,05%, carrageenan 0,4%+ konjac 0,1%, and carrageenan 0,4%+LBG 0,1%, and the brittleness and gel strength max, higher than carrageenan 0,4% + konjac 0,05% , and carrageenan 0,4% + LBG 0,1%. Based on sensory test and statistical test were using univariate models and continued test were using Duncan with 95% confidence level, showed that all samples have the brittleness were not significantly different with jelly powder o,33%, except carrageenan 0,4% (without the addition of LBG or konjac), and the firmness of samples carrageenan 0,4% + 0,05% LBG, carrageenan 0,4% + 0,05% konjac, and carrageenan 0,4% + 0,1% LBG was not significantly different with jelly powder 0,33%. Graphically, the addition of konjac with the same concentration with the addition of LBG up to 0,1%, rise in influence gel fracture, gel max strength, and firmness value was higher in carrageenan 0,4%.
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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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