Judul: Extending the Shelf Life of Mandarins (Citrus  nobilis Lour) with Palm Oil Coating.
Abstrak: Jeruk siam (Citrus nobilis Lour) memiliki karakteristik yang khas, yakni kulit berwarna hijau meskipun telah matang dan daging buahnya lunak dengan rasa manis dan harum. Edible coating merupakan lapisan tipis yang terbuat dari bahan yang dapat dikonsumsi, dibentuk untuk melapisi makanan atau produk. Tujuan dari penelitian ini mengetahui pengaruh konsentrasi emulsi minyak kelapa sawit dalam memperpanjang umur simpan buah jeruk siam. Penelitian dilaksanakan di Laboratorium pascapanen Agonomi dan Hortikultura IPB. Jeruk Siam yang digunakan berasal dari mitra yang berada di Sumatera Utara. Penelitian ini menggunakan rancangan percobaan Rancangan Kelompok Lengkap Teracak (RKLT) faktor tunggal, yaitu konsentrasi bahan pelapisan. Perlakuan konsentrasi minyak kelapa sawit yang diuji adalah 0% (kontrol), 3, 6, 9, dan 12%. Hasil penelitian perlakuan emulsi minyak kelapa sawit berpengaruh nyata terhadap nilai citrus color index, dapat mengurangi susut bobot, kilap warna. Emulsi minyak kelapa sawit berpengaruh nyata terhadap PTT, namun perlakuan emulsi minyak kelapa sawit tidak mempengaruhi kekerasan buah dan kualitas internal buah seperti, asam total, dan vitamin C. Perlakuan pelapisan dengan emulsi minyak kelapa sawit konsentrasi 3% merupakan perlakuan paling efektif dalam masa simpan dibandingkan perlakuan yang lainnya selama penyimpanan 21 hari pada suhu ruang., Mandarins (Citrus nobilis Lour) have distinctive characteristics, namely green skin even when ripe and soft flesh with a sweet and fragrant taste. Edible coatings are thin layers made of edible materials, formed to coat food or products. The purpose of this study is to determine the effect of palm oil emulsion concentration on extending the shelf life of mandarins fruit. The research was conducted at the Agronomy and Horticulture IPB postharvest laboratory. The mandarins used are originated from partners in North Sumatra. This study used a single-factor namely the concentration of coating material. Completely randomized group design experimental design is used. The palm oil concentration treatments tested were 0% (control), 3, 6, 9, and 12%. The results of palm oil emulsion treatment significantly affect the citrus color index, can reduce weight loss, color glossyness. Palm oil emulsion had a significant effect on total soluble solid, but did not affect fruit firmness and internal fruit quality such as total acid and vitamin C. Coating treatment with 3% of palm oil emulsion was the best treatment in terms of shelf life compared to the other treatments during 21 days of storage at room temperature.
Keyword: Edible coating, susut bobot, Citrus color index, Warna kulit

Judul: Shelf Life Extension of Cayenne Pepper (Capsicum frutescens L. cv. Bonita) with Palm Oil Emulsion Coating
Abstrak: Cabai rawit (Capsicum frutescens L.) merupakan komoditas sayur yang sering mengalami permasalahan terkait mutu dan umur simpannya. Hal tersebut karena cabai rawit mempunyai karakteristik yang lunak dan berair sehingga mudah mengalami kerusakan. Edible coating menjadi sebuah teknologi dalam memperpanjang masa simpan produk pertanian segar. Pelapisan yang dilakukan pada cabai rawit menggunakan senyawa organik yang aman untuk dikonsumsi manusia sehingga tidak menyebabkan adanya efek samping setelah mengonsumsi. Penelitian bertujuan menganalisis pengaruh konsentrasi minyak sawit dari emulsi minyak kelapa sawit dalam air sebagai pelapis yang digunakan dalam memperpanjang umur simpan cabai rawit pada suhu ruang. Penelitian menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) faktor tunggal, yaitu konsentrasi bahan pelapisan. Pelapisan menggunakan emulsi minyak kelapa sawit dengan konsentrasi 0% (kontrol), 3%, 6%, 9%, dan 12%. Pelapisan dengan emulsi minyak kelapa sawit konsentrasi 12% berpengaruh nyata dalam mempertahankan warna cabai rawit setelah dipanen. Perlakuan pelapisan menggunakan emulsi minyak kelapa sawit menyebabkan munculnya keriput pada buah dan meningkatkan persentase munculnya cendawan, serta pembusukan buah. Perlakuan pelapisan emulsi minyak kelapa sawit pada cabai rawit menghasilkan tampilan buah yang mengkilap, tetapi tidak mampu memperpanjang umur simpan melebihi perlakuan kontrol (15 HSP)., Cayenne pepper (Capsicum frutescens L.) is vegetable commodity that often experience problems related to quality and shelf life. This is because cayenne pepper has soft and juicy characteristics that are easily damaged. Edible coating becomes a technology to extend the shelf life fresh farm product. The coating carried out on cayenne pepper uses organic compounds that are safe for human consumption so that is does not cause any side effects after consume. The study aims to analyze the effect of palm oil concentration of palm oil emulsion in water as coating used in extending the shelf life of cayenne pepper at room temperature. The study used a single factor randomized complete block design (RCBD), namely the concentration of coating material. Coating was using palm oil emulsion at concentrations of 0% (control), 3%, 6%, 9%, and 12%. The treatment with 12% palm oil emulsion concentration had a significant effect on mantaining the color of cayenne pepper after harvest. Palm oil emulsion coating causes wrinkles to appear on the fruit and increases the percentage of fungi appearing and fruit rot. The palm oil emulsion coating treatment on cayenne pepper produced a shiny fruit appearance, but was unable to extend the shelf life beyond the control treatment (15 days after application).
Keyword: Edible coating, kilap buah, kualitas visual, umur simpan, fruit shine, shelf life, visual quality

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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