Pengaruh Lama Penyimpanan Buah Kopi Arabika (coffea arabica L.) Petik Merah terhadap Kinerja Mesin Pulper Pengupas Kulit Daging Buah secara Basah: The Effect Of Storage Duration Of Red Picked Arabica Coffee (Coffea Arabica L.) On The Performance Of Wet Fruit Skin And Flesh Pulper Machine - Ni Made Tuhu Yuliani; Yohanes Setiyo; I Wayan Widia (Program Studi Teknik Pertanian dan Biosistem, Fakultas Teknologi Pertanian, Universitas Udayana, Badung, Bali, Indonesia, 2025)
ABSTRAK Lama penyimpanan buah kopi Arabika petik merah mempengaruhi karakteristik fisik buah sebelum pengupasan secara basah. Penyimpanan menyebabkan perubahan kadar air dan sifat reologi buah, yang mempengaruhi koefisien gesek dan efektivitas mesin pulper. Penelitian ini bertujuan mengevaluasi pengaruh lama penyimpanan terhadap kinerja mesin pulper dan mutu biji kopi hasil pengupasan. Penelitian menggunakan Rancangan Acak Lengkap dengan empat perlakuan yaitu, tanpa penyimpanan (P0), penyimpanan tiga hari (P1), lima hari penyimpanan (P2), dan tujuh hari penyimpanan (P3). Setiap perlakuan dilakukan ulangan 5 kali dan setiap sampel percobaan menggunakan 5 kg buah kopi Arabika petik merah. Buah kopi dengan kadar air awal 55% disimpan hingga kadar air 45–50% sebelum dikupas menggunakan mesin pulper berkapasitas 300 kg/jam. Hasil penelitian menunjukkan bahwa kapasitas kerja mesin menurun dari 290 kg/jam (P0) menjadi 204 kg/jam (P3), dengan efisiensi 68,0–96,7%. Semakin lama disimpan, kadar air berkurang, meningkatkan gesekan dan memperlambat pengupasan. Buah kopi Arabika petik merah yang disimpan 3 hari menghasilkan karateristik hasil pengupasan yang optimal yang dicirikan oleh persentase biji terkelupas sempurna 99,16%, persentase buah kulit kopi 42,4%, biji tercampur kulit 0,77%, dan biji pecah 0,26%, memenuhi batas maksimum biji pecah 1% menurut SNI 01-2907-2008. Sementara penyimpanan tujuh hari (P3) meningkatkan persentase biji pecah menjadi 1,15%, melebihi batas standar. Semakin lama penyimpanan, kadar air menurun, kulit mengeras, dan gaya gesek meningkat, menyebabkan kinerja mesin menurun dan kualitas hasil pengupasan memburuk. Disimpulkan bahwa penyimpanan selama tiga hari merupakan perlakuan optimal untuk mempertahankan kualitas biji kopi Arabika serta efisiensi kerja mesin pulper. ABSTRACT The storage period of red-picked Arabica coffee cherries affects the physical characteristics of the cherries before wet pulping. Storage causes changes in the moisture content and rheological properties of the cherries, which affect the friction coefficient and effectiveness of the pulper machine. This study aims to evaluate the effect of storage period on the performance of the pulper machine and the quality of the peeled coffee beans. The study used a Completely Randomized Design with four treatments: no storage (P0), three days of storage (P1), five days of storage (P2), and seven days of storage (P3). Each treatment was replicated five times, and each experimental sample used 5 kg of red-picked Arabica coffee cherries. Coffee cherries with an initial moisture content of 55% were stored until they reached 45–50% moisture content before being peeled using a pulper machine with a capacity of 300 kg/hour. The results showed that the machine's working capacity decreased from 290 kg/hour (P0) to 204 kg/hour (P3), with an efficiency of 68.0–96.7%. The longer the storage period, the lower the moisture content, increasing friction and slowing down the pulping process. Red picked Arabica coffee cherries stored for 3 days produced optimal peeling characteristics characterized by a percentage of perfectly peeled beans of 99.16%, a percentage of coffee skinned fruit of 42.4%, beans mixed with skin of 0.77%, and broken beans of 0.26%, meeting the maximum limit of broken beans of 1% according to SNI 01-2907-2008. Meanwhile, seven days of storage (P3) increased the percentage of broken beans to 1.15%, exceeding the standard limit. The longer the storage period, the water content decreased, the skin hardened, and the friction force increased, causing machine performance to decrease and the quality of the peeling results to deteriorate. It was concluded that three days of storage was the optimal treatment to maintain the quality of Arabica coffee beans and the efficiency of the pulper machine