Judul: Effetcs of Pretreatment and Drying Temperature on Quality of Dried Bamboo Shoots (Dendrocalamus membranaceus Munro)
Abstrak: Whole bamboo shoots (Dendrocalamus membranaceus Munro) freshly harvested in Doi Tung were blanched at 90-100 ⁰C in various concentrations of sodium metabisulfite solution (0, 0.5%, 1.0%, and 1.5%) for ten minutes, as pretreatment, and then dried at various temperatures (50 ⁰C, 60 ⁰C, and 70 ⁰C) using a laboratory scale hot air drier. Effects of both pretreatment and drying temperature on quality of dried bamboo shoots were evaluated. There were seven parameters observed: drying time, aw, color, rehydration ratio, shrinkage, firmness, and total residual sulfites. Results showed that drying time decreased with increase in the drying temperature (p<0.01) while both pretreatment and drying temperature had no significant effect (p>0.05) on aw and shrinkage of dried bamboo shoots. Moreover, L* value, b* value, and rehydration ratio increased with increase in concentration of sodium metabisulfite and decrease in drying temperature, whereas a* value increased. The higher b* value and rehydration ratio (p<0.01) were found in samples blanched in 1.5% Na2S2O5 solution and dried at 50 ⁰C and samples blanched in 1.0% Na2S2O5 solution and dried at 60 ⁰C. It was also observed that total residual sulfites in dried-sulfited sample was quite high, ranged from 1250 to 3378 ppm SO2 while the sample blanched in 1.5% Na2S2O5 solution had higher residual sulfites than the other concentrations. Based on the parameters, sample blanched in 1.0% Na2S2O5 solution and then dried at 60 ⁰C was chosen to be the best sample. Results of rating hedonic test confirmed that the rehydrated of the best sample was more preferrable than the rehydrated-commercial dried bamboo shoots. It is suggested that blanching in 1.0% Na2S2O5 solution and then drying at 60 ⁰C is a better drying condition to produce dried bamboo shoots with a desired quality and applicable in Doi Tung.
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Judul: Physical Properties and Drying Characteristics of Tamiang Bamboo using Oven, Steam Drying, and Air Drying Methods
Abstrak: Bambu merupakan tanaman cepat tumbuh yang termasuk kedalam komoditas hasil hutan bukan kayu. Salah satu jenis bambu yang potensial dimanfaatkan sebagai sedotan bambu adalah bambu tamiang (Schizostachyum blumei). Namun dalam proses pengeringannya terdapat beberapa permasalahan. Tujuan penelitian ini adalah pengaruh berbagai metode pengeringan terhadap sifat fisis dan sifat pengeringan bambu tamiang serta mengidentifikasi serangan dan jenis organisme perusak yang menyerang bambu tamiang pada saat proses pengeringan. Bambu tamiang dikeringkan dengan metode pengeringan oven, uap panas, dan alami. Pengujian sifat fisis yang dilakukan meliputi kadar air, perubahan warna, perubahan dimensi, serta penurunan berat selama proses pengeringan. Sifat pengeringan meliputi laju, waktu, dan cacat pengeringan. Metode pengeringan memberikan pengaruh yang nyata terhadap perubahan warna, perubahan kecerahan, penyusutan dimensi dan laju pengeringan. Sebanyak 17 sampel bambu tamiang yang dikeringkan alami mengalami serangan kumbang (Dinoderus minutus) dan 16 sampel diserang jamur pada bagian ujungnya. Deformasi diameter terjadi pada 9 sampel pengeringan oven, 4 sampel pengeringan uap panas, dan 3 sampel pengeringan alami., Bamboo is a fast-growing plant that falls under the category of non-timber forest products. One type of bamboo that is potentially useful for making bamboo straws is tamiang bamboo (Schizostachyum blumei). However, there are several issues in the drying process. The aim of this research is to study the effect of various drying methods on the physical properties and drying characteristics of tamiang bamboo and to identify the types of organisms that attack tamiang bamboo during the drying process.Tamiang bamboo was dried using oven drying, steam drying, and natural drying methods. The physical properties tested include moisture content, color change, dimensional change, and weight loss during the drying process. The drying characteristics studied include the rate, time, and defects of drying. The drying method has a significant effect on color change, brightness change, dimensional shrinkage, and drying rate. A total of 17 naturally dried tamiang bamboo samples were attacked by beetles (Dinoderus minutus), and 16 samples were attacked by mold at the ends. Diameter deformation occurred in 9 oven-dried samples, 4 steam-dried samples, and 3 naturally dried samples.
Keyword: bamboo straws, Dinoderus minutus, drying, moisture content, Schizostachyum blumei

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular