Judul: Application of Vapor Heat Treatment to Reduce Chilling Injury Symptoms and Maintain Quality of Papaya (Carica papaya).
Abstrak: Papaya (Carica papaya) is a perishable fruits with has limited postharvest shelf-life because of its high metabolic activities during storage. Low temperature storage is common method to extend shelf-life of papaya fruits. However, long term storage at low temperature (below 10 oC) are susceptible to chilling injury (CI). One of the effort can be applied to reduce chilling injury symptoms is heat treatment. Heat treatment not only reduce the chilling injury symptoms but also control pests and diseases and maintain postharvest fruit quality. There are three methods of heat treatment i.e hot water treatment (HWT), hot air treatment (HAT) and vapor heat treatment (VHT). The objective of this study was to examine the effect of vapor heat treatment in alleviating chilling injury and maintaining quality of papaya fruits at different temperature storage. This research used papaya fruits cultivar Calina (IPB-9) with average weight of 0.8-1.0 kg. Papaya fruits were sourced from farmer orchad in Semplak, Bogor. Papaya fruits were treated in vapor heat at 46.5 oC for 15 and 30 minutes and following VHT, papaya fruits were cooled with water dip to adjust the temperature. After the treatment, papaya fruits were stored at 5 oC, 13 oC and room temperature (26-30 oC). Parameter measure involved chilling injury index, respiration rate, weight loss, peel and flesh yellowing, firmness, total soluble solids and Vitamin C contents. The result showed that VHT at 46.5 oC for 15-30 minutes decreased chilling injury symptoms and accelerated climacteric peak two days earlier. Vapor heat treatment at 46.5 oC for 30 minutes decreased weight loss, maintained lightness of peel and flesh and its firmness, accelerated peel yellowing, but decreased total soluble solids and Vitamin C contents. Low temperature storage delayed climacteric peak, peel yellowing, maintained firmness and decreased peel lightness, however it did not affect total soluble solids and Vitamin C contents. The interaction of VHT and temperature storage accelerated peel yellowing, maintained flesh yellowing and firmness but reduce total soluble solids and Vitamin C contents. It was concluded that VHT at 46.5 oC for 30 minutes was the best treatment to reduce chilling injury and maintain the papaya quality for three weeks.
Keyword: chilling injury, papaya fruits, vapor heat treatment

Judul: The Effect of Methyl Jasmonate on the Quality of Papaya Fruit (Carica papaya L)
Abstrak: Pepaya adalah buah klimakterik yang mengalami puncak respirasi dan produksi etilen pada fase pematangan setelah panen. Umumnya, pepaya menghadapi kendala pascapanen seperti masa simpan yang singkat, kemudahan mengalami luka mekanis, tingkat respirasi yang tinggi, kehilangan kandungan air, serangan penyakit serta hama, dan chilling injury. Aplikasi metil jasmonat (MeJA) pada pascapanen telah umum dipraktikkan untuk meningkatkan masa simpan buah, meningkatkan kualitas buah, mengurangi chilling injury, dan meningkatkan resistensi buah terhadap penyakit yang disebabkan oleh fungi. Penelitian ini bertujuan mempelajari pengaruh aplikasi metil jasmonat pascapanen terhadap kualitas buah pepaya. Penelitian dilaksanakan di Laboratorium Pascapanen Departemen Agronomi dan Hortikultura, Fakultas Pertanian, Institut Pertanian Bogor yang berlangsung di bulan Juni 2023. Rancangan percobaan yang digunakan adalah Rancangan Acak Lengkap (RAL) satu faktor. Faktor tersebut adalah konsentrasi metil jasmonat yang terdiri atas empat taraf konsentrasi yaitu 0 mM (kontrol, penyimpanan suhu ruang), 0 mM (kontrol, penyimpanan suhu dingin), 0,1 mM (penyimpanan suhu dingin) dan 1 mM (penyimpanan suhu dingin). Hasil dari penelitian ini menunjukkan bahwa perlakuan metil jasmonat berpengaruh nyata terhadap pengurangan susut bobot buah pada 8 HSP, pengurangan pelunakan kulit buah pada 5 dan 8 HSP, pengurangan ATT, dan peningkatan rasio ATT/PTT jika dibandingkan dengan kontrol suhu ruang, tetapi tidak berbeda nyata jika dibandingkan dengan kontrol suhu dingin. Aplikasi metil jasmonat 1 mM memiliki persentase kulit buah berwarna hijau paling tinggi dan tingkat kematangan daging buah paling rendah berdasarkan warna daging buah pada 17 hari setelah panen., Papaya is a cilmacteric fruit which undergoes peak respiration and ethylen produuction during postharvest ripening and commonly face postharvest obstacles such as short shelf life, ease of mechanical injury, high respiration rate, loss of water content, disease & pest attack, and chilling injury. Application of methyl jasmonate (MeJA) in postharvest handling is commonly used to raise shelf life, increase fruit quality, reduce chilling injury, and boost fruit resistence against fungal attack. The objective of this study is to understand the effect of methyl jasmonate postharvest application on papaya fruit quality. This study was conducted at Postharvest Laboratory, Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University in June 2023. Completely Randomized Design (CRD) with one factor was applied. The factor was methyl jasmonate concentration ranging from 0 mM (control, room temperature), 0 mM (control, cold storage), 0,1 mM (cold storage), and 1 mM (cold storage). The result showed that application of methyl jasmonate significantly reduce fruit weight loss on 8 days after harvest, reduce peel softening on 5 and 8 days after harvest, reduce total titratable acid, and increase total soluble solid/total titratable acid ratio if compared to room temperature control treatment, but showed no significant effect if compared to cold temperature control treatment. Fruits with methyl jasmonate 1 mM treatment showed highest percentage of green peel color and lowest maturity level based on fruit flesh color on 17 days after harvest.
Keyword: chilling injury, chemical content, color scale, physical quality, postharvest

Judul: Rantai Markov Pada Bilangan Biner
Abstrak: Ranlai Markov {Xn} yang didefinisikan pada ruang peluang (n, P, P) dilllana n = (O,I],dan 'Fadalah cr-lapangan Borel, lllelllpunyai ekspansi biner X n = 0, dl(n) din).. n = I, 2, ... Mengkonstruksi rantai Markov ini diawali dengan memilih sembarang bilangan ..Y o di (0,1], nyatakan bilangan Xo dalam ekspansi biner Xo =0, diD) diD) ... d~O) ... dimana { d~O) ,n = 1,2, ... } adalah barisan nol dan satu. Peubah acak XI ditentukan oleh .Xo dan asumsi berikut.
Keyword: