The pulp water as byproduct of cocoa beans fermentation is potential to be used as a raw material for making cocoa vinegar, but unfortunately the content of acetic acid is relatively low. So that, it is necessary to increase the content of acetic acid, by performed further fermentation method with several addition of carbon sources (sugar and alcohol) and fermentation time. The purposes of this research were: (1) to study the effect of the addition of sugar, alcohol and fermentation time on different urther fermentation method on the characteristics of cocoa vinegar and (2) to determine the optimal further fermentation method and fermentation time for the production of cocoa vinegar with the highest content of acetic acid. Several fermentation methods were conducted by using three different methods e.g.the alcoholic and acetic acid fermentation (2 stages), acetic acid fermentation (1 stage), and fermentation without inoculum (natural). The experimental design of this study was using a factorial BRD two factors on the 2 stages and the 1 stage fermentation method, as well as the simple RBD on the natural fermentation. The first factor on the 2 stages fermentation methods used two different inoculum e.g. Saccharomyces cerevisiae and Acetobacter aceti, 4 different concentration of sugar (4, 6, 8 and 10 %), while on the 1 stage fermentation method used inoculum Acetobacter aceti, is 4 different concentrations of alcohol addition (6, 8, 10, and 12 %), while the second factor is the same, namely 6 levels of fermentation time (0, 5, 10, 15, 20, and 25 days). Meanwhile, the treatment of fermentation time on the natural fermentation method was the same as the second factor. All methods of fermentation were performed at room temperature in 2 blocks/replications.The results showed that: 1) the characteristics of cocoa vinegar and OD660 of watery pulp were affected by : (1) the treatment of the sugar addition and fermentation time and their interaction on the 2 stages fermentation method by the treatment of the alcohol addition and fermentation time, their interaction on the 1 stage fermentation method, and by the treatment of fermentation time on the natural fermentation method, and (2) the cocoa vinegar with the highest content of acetic acid was produced on the 2 stages fermentation method by the addition of 6 % sugar within 25 days (2.35 %), on the 1 stage fermentation method by the ddition of 10 % alcohol within 20 days (3.37 %), and on the natural fermentation method within 15 days (2.65 %), respectively. Our result showed that the 1 stage fermentation method with the addition of 10 % alcohol using inoculum of Acetobacter aceti within 20 days is the most optimal further fermentation method for the production of cocoa vinegar.ABSTRAKCairan pulpa hasil samping fermentasi biji kakao berpotensi sebagai bahan baku pembuatan cuka kakao, tetapi kadar asam asetat yang dihasilkan relatif rendah. Untuk itu, perlu dilakukan upaya peningkatan kadar asam asetat antara lain dengan melakukan beberapa metode fermentasi lanjutan dengan variasi penambahan sumber karbon (gula dan alkohol) dan lama fermentasi. Tujuan penelitian ini adalah: (1) mengkaji pengaruh penambahan gula, alkohol dan lama fermentasi pada metode fermentasi lanjutan yang berbeda terhadap karakteristik cuka kakao dan (2) menetapkan metode fermentasi lanjutan dan lama fermentasi yang optimal untuk produksi cuka kakao dengan kadar asam asetat tertinggi. Metode fermentasi lanjutan yang dilakukan terdiri dari 3 metode yaitu: fermentasi alkohol dan asam asetat (2 tahap), fermentasi asam asetat (1 tahap), dan fermentasi tanpa inokulum (alami). Rancangan percobaan pada penelitian ini menggunakan Rancangan Acak Kelompok (RAK) faktorial 2 faktor pada metode fermentasi 2 tahap dan 1 tahap, serta RAK faktor tunggal pada fermentasi alami. Faktor I pada metode fermentasi 2 tahap yang menggunakan inokulum Saccharomyces cerevisiae dan Acetobacter aceti, adalah penambahan gula 4 konsentrasi (4, 6, 8, dan 10 %), dan pada metode fermentasi 1 tahap, yang menggunakan inokulum Acetobacter aceti, adalah penambahan alkohol 4 konsentrasi (6, 8, 10, dan 12 %), sedangkan faktor II lama fermentasi (0, 5, 10, 15, 20, dan 25 hari). Sementara itu perlakuan lama fermentasi pada metode fermentasi alami sama seperti pada faktor II. Semua metode fermentasi dilakukan pada suhu kamar dalam 2 kelompok. Hasil penelitian menunjukkan bahwa: (1) karakteristik cuka kakao dan OD660 cairan pulpa dipengaruhi oleh perlakuan penambahan gula dan lama fermentasi serta interaksinya pada metode fermentasi 2 tahap dan oleh perlakuan penambahan alkohol dan lama fermentasi serta interaksinya pada fermentasi 1 tahap, serta oleh perlakuan lama fermentasi alami, dan (2) cuka kakao dengan kadar asam asetat tertinggi masing-masing dihasilkan pada fermentasi 2 tahap dengan penambahan gula cenderung 6 % dalam waktu 25 hari (2,35 %), fermentasi 1 tahap dengan penambahan alkohol 10 % dalam waktu 20 hari (3,37 %), dan fermentasi alami dalam waktu 15 hari (2,65 %). Dengan demikian metode fermentasi 1 tahap dengan penambahan alkohol 10 % menggunakan inokulum Acetobacter aceti dalam waktu 20 hari merupakan metode fermentasi lanjutan yang paling optimal untuk produksi cuka kakao.
Effect of Different Regions and Ensiling Periods on Fermentation Quality and the Bacterial Community of Whole-Plant Maize Silage
