Judul: Pengaruh Pelapisan Kitosan terhadap Daya Simpan Buah Pisang Ambon
Abstrak: The banana needs post harvest treatment to be not decay quickly. One of the way is by coating. Chitosan is a substance that can be used to coat the fruit, which is a polysaccharide derived from shrimp and crab shell waste. The aims of the research was to study the effect of chitosan coating on post harvest of bananas, and find out the optimal concentration of chitosan as a natural coating materials. This research used the completely randomized design (CRD) method with one factor. The factor was the chitosan coating by three level treatments with different concentrations. First concentration was 0%, second was 1%, and the last was 2% w/v. Each treatment was repeated four times. The results showed that treatment with concentration of chitosan couldn’t inhibit loss of. There is no consistent effect of chitosan on acid titration, vitamine C content and no significant effect on total soluable solute. From organoleptic test that was conducted in 12 day after treatment indicated that respondent still like bananas on 2% concentration of chitosan treatment.
Keyword: weight loss, banana, self life, total soluable solute, total titration acid

Judul: Maintaining the Quality of Cavendish Bananas through the Application of Chitosan Edible Coating Using the Dip and Spray Methods
Abstrak: Penerapan teknologi pascapanen seperti edible coating diperlukan dalam memperpanjang umur simpan pisang. Kitosan merupakan bahan edible coating yang dapat melapisi permukaan kulit buah dengan baik sehingga menghambat respirasi dan memperpanjang umur simpannya. Jenis metode pelapisan menjadi faktor yang penting dalam aplikasi edible coating. Penelitian ini bertujuan mengevaluasi susut bobot, rasio bobot daging terhadap kulit, kekerasan, pH, padatan terlarut total, konversi pati menjadi gula, warna kulit, dan keparahan penyakit buah pisang cavendish yang dilapisi coating kitosan (1,25 %) dengan metode celup dan semprot. Penyimpanan pisang dilakukan pada suhu ruang (26 ± 2oC) dengan RH 80±5% selama 11 hari. Sprayer gendong bermotor digunakan untuk menyemprotkan larutan coating. Uji kinerja alat sprayer dilakukan untuk mengevaluasi efektivitasnya. Hasil uji menunjukkan tekanan semprot sebesar (4 ± 0,00) kgf/cm2, tinggi penyemprotan sebesar (58,5 ± 0,71) cm, diameter droplet sebesar (78,50 ± 12,02) μm, dan kerapatan droplet sebesar (733,5 ± 20,51) droplet/cm2. Pelapisan kitosan berpengaruh signifikan terhadap rasio bobot daging:kulit, kekerasan, padatan terlarut total, pH, nilai a* warna, dan keparahan penyakit buah pisang. Pisang coating metode semprot tidak mengalami kemunculan bintik coklat selama penyimpanan dan memiliki nilai keparahan penyakit terendah pada hari ke-11 penyimpanan yaitu sebesar 3,33 ± 0,00 dibanding metode celup sebesar 4,17 ± 0,71 dan tanpa pelapis sebesar 5,00 ± 0,00. Penghambatan susut bobot hanya terjadi pada pisang coating metode semprot, dengan nilai susut bobot pada hari ke-11 penyimpanan sebesar (14,51 ± 0,28)%, dibanding metode celup sebesar (15,32 ± 0,64)%, dan tanpa pelapis sebesar (15,25 ± 0,26)%. Pisang coating metode semprot memiliki nilai kekerasan pada hari ke-5 penyimpanan sebesar (29,11 ± 0,25) mm/50g/50dtk, lebih rendah dibanding metode celup sebesar (34,81 ± 0,43) mm/50g/50dtk, dan tanpa pelapis sebesar (37,58 ±0 ,01) mm/50g/50dtk. Pisang tanpa pelapis telah mengalami konversi pati seluruhnya pada hari ke-5 penyimpanan, sedangkan pati pisang coating metode semprot terkonversi sebesar 45%, lebih rendah dibanding metode celup sebesar >65%. Hal ini menunjukkan metode semprot menghasilkan sebaran larutan kitosan lebih merata dan mampu mempertahankan mutu buah pisang dibanding metode celup., Applying postharvest technology such as edible coating is needed to extend the shelf life of bananas. Chitosan is an edible coating material that has an excellent ability to coat the surface of fruit so that it inhibits respiration and extends its shelf life. The coating method is an essential factor in the application of edible coating. This study aims to evaluate the weight loss, pulp-to-peel ratio, firmness, pH, total soluble solids, starch-to-sugar conversion, peel color, and disease severity of cavendish bananas coated with chitosan solution (1.25 %) using the dip and spray method. A knapsack power sprayer was used to spray the coating solution. The sprayer performance test was carried out to evaluate its effectiveness. The result of the tests shows spray pressure (4 ± 0.00) kgf/cm2, spray height (58.5 ± 0.71) cm, droplet diameter (78.50 ± 12.02) μm, and droplet density (733.5 ± 20.51) droplet/cm2. Chitosan coating significantly affects the pulp:peel ratio, firmness, total soluble solids, pH, a* color value, and disease severity of bananas. Spray coated bananas do not experience the appearance of brown spots during storage and have the lowest disease severity value on the
Keyword: cavendish banana, chitosan, dip method, edible coating, spray method

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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