Judul: The Combined Application of Active Packaging Oxygen Scavenger and Vacuum to Extend the Shelf Life of Galamai
Abstrak: Galamai dikenal sebagai salah satu jajanan khas yang berasal dari daerah Payakumbuh, Sumatera Barat. Berbahan dasar tepung beras ketan, gula aren dan santan, makanan ini juga dikenal sebagai ‘dodol’ atau ‘jenang’ di berbagai daerah Pulau Jawa. Galamai merupakan makanan yang umumnya dipilih oleh wisatawan untuk dibawa pulang ke kampung halaman sebagai oleh-oleh. Dengan demikian diperlukan masa simpan yang panjang agar galamai dapat dikonsumsi oleh konsumen yang jaraknya jauh sekalipun. Salah satu teknik untuk memperpanjang umur simpan dan menjaga stabilitas mutu galamai adalah teknik kemasan aktif. Kemasan aktif yang diaplikasikan dalam penelitian ini adalah kemasan oxygen scavenger dan vakum. Penelitian ini bertujuan membandingkan kinerja dan efektivitas aplikasi kemasan aktif oxygen scavenger dan kemasan vakum (vacuum packaging) dalam mempertahankan stabilitas mutu dan memperpanjang umur simpan produk galamai dengan metode langsung (direct method). Penelitian juga mengkaji tentang laju penurunan mutu setiap teknik pengemasan untuk menentukan teknik pengemasan mana yang memiliki laju penurunan mutu paling rendah. dapat tiga perlakuan kemasan yaitu kemasan kontrol (pabrik), teknik pengemasan vakum, dan teknik pengemasan vakum dengan penambahan oxygen scavenger. Parameter mutu produk galamai yang diamati selama 14-21 hari pada suhu ruang antara lain : kadar air, kadar abu, kadar lemak, kadar protein, kadar asam lemak bebas, bilangan peroksida, angka lempeng total (ALT), angka kapang khamir (AKK) dan uji organoleptik. Penerapan kemasan aktif vakum dan oxygen scavenger pada gelamai dinilai mampu mempertahankan stabilitas mutu lebih baik dibandingkan kemasan kontrol. Hal ini dapat dibuktikan dengan laju penurunan mutu yang lebih tinggi pada kemasan kontrol dibandingkan dengan kemasan aktif vakum dan oxygen scavenger. Urutan teknik pengemasan yang memberikan umur simpan terbaik pada galamai pada suhu penyimpanan 27 ± 1°C adalah teknik pengemasan vakum dengan umur simpan 14.89 hari, teknik pengemasan kombinasi vakum dan oxygen scavenger dengan umur simpan 14.85 hari, dan teknik pengemasan kontrol dengan umur simpan 14.41 hari., Galamai is known as one of the typical snacks originated from Payakumbuh area, West Sumatra. Made from glutinous rice flour, palm sugar and coconut milk, also known as 'dodol' or 'jenang' in various parts of Java. Galamai commonly preferred by tourists as souvenirs they carried to their hometowns. One of the techniques to extend shelf-life and maintain the quality of galamai is active packaging. The active packaging that applied in this study are oxygen scavenger and vacuum packaging. This study aims to compare the performance and effectiveness of active oxygen scavenger and vacuum packaging applications in maintaining quality stability and extending the shelf life of galamai products using the direct method. The study also examined the rate of quality deterioration of each packaging technique to determine which packaging technique has the lowest rate of quality deterioration. three packaging treatments were obtained, namely factory packaging, vacuum packaging technique, and vacuum packaging technique with the addition of oxygen scavenger. Quality parameters of galamai that observed for 14-21 days at room temperature include: moisture content, ash content, fat content, protein content, free fatty acid, peroxide number, total plate count (TPC), yeast mold number (AKK) and organoleptic test. This study shows that the application of active vacuum and oxygen scavenger packaging on galamai is considered capable to maintain
Keyword: galamai, active packaging, shelf-life, rate of quality deterioration

Judul: Pengaplikasian Proses Termal dan Pengemasan Vakum untuk Memperpanjang Umur Simpan Produk Wingko Babat
Abstrak: Wingko babat is an intermediate moisture food made from grated coconut, glutinous rice flour and sugar baked in an oven. It is well known as an indigenous food from Semarang, Central Java. Unfortunately, its shelf life is only 2-4 days at room temperature. The objective of this research was to extend the shelf life of wingko babat in room temperature using combination of thermal process and vacuum packaging. Wingko babats were packed in aluminum foil, in vacuum or non vacuum condition, then heated in a waterbath at 65 °C, 75 °C and 85 °C for certain time that met the concept of 6D and 12D for mold and yeast. Differences in treatment didn’t promote any significant differences on sensory attributes of the products (p>0.05). By considering efficiency of the process, the thermal process at 85 °C for 10 min (12D) was chosen. The application of this thermal process on vacuum packed wingko babat showed that total plate count (4.6 x 103 CFU/g), mold & yeast count (3.0 x 102 CFU/g) and free fatty acid level (0.66%) of the sample still met the SNI 01-4311-1996 for wingko babat at week 4. However, sample’s sensory were already unacceptable at week 2 due to texture hardening
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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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