Judul: Sensory Aroma Profiles and Hedonic Preference of Processed Andaliman (Zanthoxylum acanthopodium DC.) Produced by Different Methods
Abstrak: Andaliman (Zanthoxylum acanthopodium DC.) is a native Indonesian spice with limited usage due to its short shelf life. Several processing methods have been conducted to prolong the shelf life of andaliman, along with preserving its flavor characteristics, such as drying, extraction, and encapsulation. This study aimed to evaluate andaliman after those processing methods to obtain its sensory aroma profile by Quantitative Descriptive Analysis (QDA) and aroma acceptance through hedonic ranking and rating tests. A descriptive test was conducted with ten trained panelists and generated nine attributes to describe andaliman, including citrus peel, menthol, herb, spice, woody, orange, green, floral, and pungent. Extraction increased the intensity of all aroma attributes in andaliman, with a significant difference in citrus peel, spice, and green aroma. Drying of andaliman and encapsulation of andaliman extract with two combinations of wall materials resulted in an insignificant difference in aroma intensity to fresh andaliman. Hedonic test performed with 70 panelists showed that the preference for dried andaliman was not significantly different from fresh andaliman. The rest of the processing methods (extraction and encapsulation) resulted in a lower preference for processed andaliman. In general, processing methods to prolong the shelf life of andaliman yielded processed andaliman with an acceptable aroma profile and quality., Andaliman (Zanthoxylum acanthopodium DC.) merupakan salah satu rempah Indonesia yang masih terbatas penggunaannya dikarenakan umur simpannya yang singkat. Beberapa metode pengolahan telah dilakukan dalam upaya memperpanjang umur simpan serta mempertahankan kualitas flavor pada andaliman, antara lain pengeringan, ekstraksi, dan enkapsulasi. Penelitian ini bertujuan mengevaluasi andaliman dari berbagai metode pengolahan tersebut untuk memperoleh profil aroma melalui evaluasi sensori dengan metode Quantitative Descriptive Analysis (QDA) dan tingkat kesukaan aroma melalui metode hedonik rating dan ranking. Uji deskriptif telah dilakukan oleh 10 orang panelis terlatih dan menghasilkan sembilan atribut aroma untuk mendeskripsikan andaliman segar dan hasil pengolahan, yaitu citrus peel, menthol, herb, spice, woody, orange, green, floral, dan pungent. Pengeringan menghasilkan aroma herb yang lebih kuat pada andaliman. Proses ekstraksi meningkatkan intensitas seluruh atribut aroma andaliman dengan perbedaan signifikan pada aroma citrus peel, spice, dan green. Pengeringan andaliman dan enkapsulasi pada ekstrak andaliman dengan dua jenis kombinasi bahan penyalut menghasilkan produk andaliman dengan keseluruhan aroma yang tidak berbeda nyata terhadap andaliman segar. Uji hedonik dilakukan oleh 70 orang panelis menunjukkan andaliman hasil pengeringan memiliki nilai kesukaan yang tidak berbeda nyata terhadap andaliman segar, sedangkan proses lainnya (ekstraksi dan enkapsulasi) menghasilkan andaliman dengan nilai kesukaan yang lebih rendah. Akan tetapi secara umum, ketiga proses pengolahan untuk memperpanjang umur simpan andaliman masih dapat menghasilkan produk dengan kualitas aroma dan penerimaan yang baik.
Keyword: andaliman, aroma profile, drying, encapsulation, extraction

Judul: Perubahan Senyawa Volatil dan Mati Rasa Andaliman (Zanthoxylum acanthopodium) oleh Berbagai Teknik Pengeringan
Abstrak: Andaliman (Zanthoxylum acanthopodium DC) is an endemic plant from North Sumatera, commonly used as spices and folk medicines. Andaliman has a robust citrus aroma and numbing trigeminal sensations. Unfortunately, the research, usage, and popularity of andaliman are much behind its related species, such as Z. piperitum (Japanese pepper) and Z. bungeanum (Sichuan pepper). The main hurdles in fresh andaliman usage are the fast rotting and rapid flavor degradation. Proper processing techniques by farmers and industries will be crucial to expand its usage. Drying could prevent andaliman from degradation by reducing the moisture content; however, its effects on volatiles, numbing compound, and aroma profile have not been fully understood. Unsaturated alkylamides (sanshools) have been reported to be responsible for the unique numbing sensation. Analysis of sanshools is usually conducted using column chromatography or High Pressure Liquid Chromatography; however, these methods tend to be time-consuming and requires a large amount of costly solvent. On the other hand, aroma analysis is conducted using Gas Chromatography-Mass Spectrometry (GC-MS), which requires researchers to use two types of analytical methods to get the complete picture of both the aroma and taste of andaliman. However, three studies managed to analyze sanshools by GC-MS, which will shorten the research timeline and reduce research costs. This research was composed of three main stages: drying of andaliman (sun, sunshade, shade, oven, and freeze drying), confirmation of the GC-MS parameter, analysis of the volatiles, sanshools, sensory and physical characteristics. The volatiles and sanshool analysis were conducted with GC-MS, while the sensory analysis used the Rate All That Apply-Hedonic method. Physical characteristics such as moisture, water activity, yield, bulk density, and color were analyzed. Statistical data analysis using Principal Component Analysis (PCA), one-way ANOVA, Duncan posthoc, Pearson’s correlation, and Partial Least Square regression analysis were conducted to evaluate the impact of drying on volatiles, numbing, and sensory profile as well as to determine the volatiles responsible for andaliman aroma quality. The logarithmic thin-layer drying model best-described andaliman drying kinetics. The drying process significantly altered andaliman appearance, aroma profile and physical properties. No significant difference was found in the yield of each drying method; however, shade drying resulted in the highest moisture and water activity, while sun drying and freeze drying resulted in the lowest moisture content and water activity. Freeze drying resulted in the lowest bulk density. All drying methods managed to produce andaliman with less than 17.90% moisture content and 0.6 water activity, indicating the drying targets have been achieved. Generally, drying increased the a*, indicating green color degradation, however, no significant difference was observed in the a* values of dried samples. GC-MS analysis of all chloroform andaliman extract managed to detect total of 67 peaks while identifying 42 compounds. However, 25 unidentified peaks could comprise of other sanshool isomers. Fresh and dried andaliman generally had similar total relative content of volatiles and chromatogram pattern, differing mostly in the individual compound quantities. The content of limonene, (E)-2-hexenal, geranial, α-pinene, sabinene, and β-myrcene as well as the intensities of citrus and green aroma tended to decrease. In contrast, the content of geranyl acetate, citronellal,
Keyword: Zanthoxylum, andaliman, drying, aroma, sanshool

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model