Judul: Evaluation of Heat Adequacy in Pasteurization  Process of Mini Jelly in Cup Packaging at PT XYZ
Abstrak: Mini jelly merupakan produk jeli agar yang memiliki pH kesetimbangan 4,0 – 4,5. Proses termal yang digunakan adalah pasteurisasi dengan target untuk mereduksi mikroba patogen dan pembusuk agar menghasilkan makanan yang berkualitas dan aman untuk dikonsumsi. Mini jelly dipasteurisasi menggunakan sistem continuous batch pasteurizer pada suhu 80 ± 2 ℃. Tahapan ini merupakan titik kendali kritis yang telah ditetapkan namun belum memiliki acuan dan belum dievaluasi kecukupan panasnya. Penelitian ini bertujuan untuk mengevaluasi kecukupan panas pada proses termal pasteurisasi mini jelly yang dikemas dalam cup (polipropilena). Kecukupan panas proses pasteurisasi ditentukan dengan membandingkan nilai pasteurisasi standar (P85 standar) dan nilai pasteurisasi proses (P85 proses) untuk siklus reduksi 5D. Hasil penelitian menunjukkan bahwa proses pasteurisasi mini jelly cukup untuk mereduksi Esherichia coli, Staphylococcus aureus, kapang dan khamir. Hal ini didukung oleh hasil analisis angka lempeng total, kapang, khamir, dan Esherichia coli yang telah memenuhi standar untuk mini jelly. Namun, proses pasteurisasi tidak cukup untuk mengurangi bakteri yang toleran terhadap asam dan panas yaitu Bacillus polymyxa, Bacillus macerans, dan Clostridium pasteurianum. Bakteri pembusuk ini berpotensi merusak mini jelly selama penyimpanan., Mini jelly is an agar jelly product which has an equilibrium pH of 4.0 – 4.5. The thermal process applied is pasteurization with the target to reduce pathogenic and spoilage microbes to produce quality and safe food for consumption. Mini jelly was pasteurized using continuous batch pasteurizer system at 80 ± 2 oC. This step is critical control point that was established without any references and heat adequacy has not been evaluated. This research aims to evaluate heat adequacy in thermal process of mini jelly pasteurization packaged in cup (polypropylene). Heat adequacy of the pasteurization process was determined by comparing the standard pasteurization value (P85 standard) and the process pasteurization value (P85 process) for 5D reduction cycle. The results revealed that pasteurization process of mini jelly was sufficient to reduce Esherichia coli, Staphylococcus aureus, mold and yeasts. This was supported by the analysis results of total plate count, Esherichia coli, mold and yeast that had complied to the standard for mini jelly. However, pasteurization process was not sufficient to reduce the acid tolerance and heat-resistant bacteria i.e. Bacillus polymyxa, Bacillus macerans, and Clostridium pasteurianum. These spoilage bacteria are potential to deteriorate mini jelly during storage.
Keyword: kecukupan panas, mini jelly, nilai pasteurisasi, proses termal

Judul: Evaluasi Mutu Fisik, Mikrobiologi, dan Sifat Fungsional Gel Cincau Hijau (Premna Oblongifolia Merr.) dalam Kemasan dengan Perlakuan Pasteurisasi
Abstrak: Green grass (Premna oblongifolia Merr.) jelly is one of functional food, that has been widely studied for it’s beneficial effect. The purposes of this study are to design pasteurization condition of green grass jelly and to study the effect of pasteurization on the jelly properties. Thermal schedule based on 6D concept targetting S. aureus were applied on the product in three combinations of time and temperature. The combinations were 36 minutes in 75°C, 25 minutes in 85°C, and 22 minutes in 95°C. Pasteurization reduced pH value, L value, a value, b value, rate of syneresis, gel strenght, rupture point, and rigidity. Pasteurization also decreased the total of chloropyll, a chlorophyll, b chlorophyll, phenol, and capacity of antioxidant. But, pasteurization increased the total dietary fiber (TDF, SDF, dan IDF). The results showed that the best pasteurization condition was 22 minutes in 95°C based on the physical and functional properties. Physical characteristics of the selected product were 8.24 of pH value, 22.64 of L value, -0.60 of a value, 4.20 of b value, 2.84% of syneresis rate, 493.7105 g/cm2 of gel strength, 3.13 cm of rupture point, and 1.9955 g/cm of rigidity. Moreover, the functional characteristics were 1.2220 mg/L of total chloropyhll , 1.0385 mg/L of a chlorophyll, 0.1838 mg/L of b chlorophyll, 36.1220 mg GAE/L of total phenol, 19.1591 mg AEAC/L of antioxidant capacity, 3.0275% of TDF, 2.1743% of SDF, and 0.8532% of IDF. The product was organoleptically acceptable and microbiologically safe.
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Judul: Tree berdiameter lima adalah graceful
Abstrak: This manuscript presents some proofs that every tree of diameter five is graceful. A graceful tree is a graph which has a graceful labelling. This labelling assigns absolute difference of connected vertices, such that the resulting edge labels are mutually distinct. There are three theorems to be considered. First theorem proves that every tree of diameter four is graceful. Second theorem proves that every tree of diameter five is graceful or nearly graceful. The third theorem improves the second theorem and shows that every tree of diameter five is nearly graceful, which can be transformed into graceful using some certain patterns.
Keyword: Graf, Pelabelan graceful, Bogor Agricultural University, Institut Pertanian Bogor, IPB