Judul: Shelf Life and Vitamin C Content of Pohpohan (Pilea trinervia) Juice.
Abstrak: Penelitian ini bertujuan untuk menganalisis umur simpan, kandungan vitamin C dan perubahan organoleptik jus pohpohan yang disimpan dalam refrigerator (±4oC) selama 24 jam. Penelitian ini merupakan penelitian eksperimen dengan desain Rancangan Acak Lengkap. Jus pohpohan dibuat dari kombinasi 50% jus pohpohan yang berasal dari ekstraksi pohpohan dengan kadar 40%, 25% penambahan buah nanas dan 25% buah sirsak. Jus pohpohan dikemas menggunakan gelas plastik dan ditutup menggunakan cup sealer. Hasil analisis laboratorium menunjukkan jus pohpohan mengandung 85.78 g air, 0.38 g abu, 0.54 g protein, 0.53 g lemak, 12.76 g karbohidrat dan 17.06 mg vitamin C per 100 g produk. Jus pohpohan mencukupi 7.3% energi dan 47.4% vitamin C kebutuhan orang dewasa per serving size (250 g). Berdasarkan analisis mikorbiologi, total plate count jus pohpohan meningkat selama penyimpanan 24 jam dari 2.95x103 menjadi 2.9x104 koloni/ml. Jus pohpohan direkomendasikan untuk dikonsumsi kurang dari 8 jam. Waktu penyimpanan mempengaruhi perubahan vitamin C dan pH jus pohpohan (p<0.05), tapi tidak mempengaruhi total asam tertitrasi jus pohpohan (p>0.05). Tidak ada perubahan organoleptik yang signifikan antara jus pohpohan segar dan jus pohpohan yang disimpan 6 jam (p>0.05).
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB, pohpohan juice, shelf life, total plate count, vitamin c, Human ecology, Microbiological analysis, Organoleptic quality, Storage juice

Judul: Penyimpanan Suhu Rendah untuk Mempertahankan Mutu Daun Pohpohan (Pilea melastomoides (Poir.) Wedd.)
Abstrak: “Pohpohan” leaf is one of leafy vegetables generally used for salads. “Pohpohan” is leafy vegetable belonging to easily damaged. Cold storage is one of the methods to maintain the freshness of “Pohpohan” leaf. The objective of this research was to analyze the quality change of cold stored “Pohpohan” leaf. The storing temperatures were 5°C, 15°C, and room temperature. Respiration rate, weight loss, moisture content, colour, tensile test, vitamin C test, TPC, and total soluble solids of all samples were measured during storage period. The result showed that cold storage could hold down the respiration rate, reduce the weight loss, maintaining the moisture content of the leaves, delay the leaves brightening, increase the total soluble solid, reduce the decrease of vitamin C content, and also reduce the content of microbes until the 6th day of storage. Storage temperature 5°C shows decrease in lower quality compared to the other temperature treatments.
Keyword: Bogor Agricultural University (IPB), low temperature, storage, pohpohan, quality

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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