Upadi, Alwan and Djufri, Mohamad Rifandi (2017) Pengaruh Pretreatment Ampas Tebu Menggunakan Kalsium Hidroksida Dan Hidrotermal Pada Produksi Asam Sitrat Metode Ssf. Sarjana thesis, Universitas Brawijaya.
Abstract
Asam sitrat merupakan produk fermentasi yang banyak digunakan di industri pangan, minuman, deterjen, farmasi, dan kosmetik. Teknik yang berkembang untuk memproduksi asam sitrat diantaranya solid state fermentation (SSF) dengan mikroorganisme A.niger. Teknik ini memanfaatkan limbah agro-industri sebagai substratnya. Substrat potensial dalam produksi asam sitrat salah satunya ampas tebu. Namun, sebelum digunakan perlu dilakukan proses perlakuan awal (pretreatment) yang bertujuan merusak kompleks selulosa-hemiselulosa-lignin didalam substrat padat untuk meningkatkan selulosa siap cerna bagi proses hidrolisis berikutnya menjadi gula siap fermentasi. Beberapa metode yang berpotensi untuk pretreatment substrat padatan adalah proses hidrotermal dan kalsium hidroksida (Ca(OH)2). Penelitian ini dilakukan untuk mengetahui pengaruh adanya pretreatment dan lama waktunya terhadap yield asam sitrat yang diproduksi dengan metode SSF. Pada penelitian ini, pretreatment substrat ampas tebu dibedakan atas kondisi kontrol (tanpa pretreatment), hidrotermal, dan kalsium hidroksida. Waktu yang digunakan untuk proses pretreatment dibedakan atas tiga, yaitu 10, 30, dan 60 menit. Setelah itu, dilakukan proses fermentasi SSF dengan berat substrat ampas tebu 50 g. Proses fermentasi SSF dilakukan selama 5 hari pada kondisi kadar air awal 60-75%, pH awal 5, suhu 25-30oC, dan laju aerasi 0,75±0,25 L/menit. Massa ampas tebu terfermentasi kemudian di-recovery melalui proses leaching dengan aquades dan filtrasi untuk memperoleh produk asam sitrat dalam bentuk cairan supernatant. Supernatant yang diperoleh kemudian dianalisis secara kualitatif dengan pengukuran pH, spektrofotometri UV, dan FT-IR. Sementara untuk analisis kuantitatif dilakukan dengan metode titrimetri asam basa. Hasil penelitian menunjukkan bahwa yield asam sitrat pada variabel tanpa pretreatment sebesar 1,792% (berat asam sitrat per berat ampas tebu awal). Yield asam sitrat pada variabel pretreatment hidrotermal untuk waktu 10, 30, dan 60 menit berturut-turut sebesar 0,980%, 1,216%, dan 0,696%. Yield asam sitrat pada variabel pretreatment kalsium hidroksida untuk waktu 10, 30, dan 60 berturut-turut sebesar 1,512%, 1,938%, dan 0,340%. Waktu optimum bagi produksi asam sitrat pada masing-masing pretreatment hidrotermal dan kalsium hidroksida terjadi pada menit ke 30. Pada kondisi waktu optimum, pretreatment hidrotermal menurunkan produksi asam sitrat dengan yield sebesar 1,22% (0,608 g asam sitrat/ 50 g ampas tebu awal) dibandingkan kondisi tanpa pretreatment, sedangkan pretreatment kalsium hidroksida meningkatkan produksi asam sitrat dengan yield sebesar 1,94% (0,969 g asam sitrat/ 50 g ampas tebu awal) dibandingkan kondisi tanpa pretreatment. Dari hasil ini, penggunaan kalsium hidroksida dalam fase larutan pada proses pretreatment perlu dipertimbangkan untuk menghindari terikatnya asam sitrat sebagai Ca-sitrat selama proses fermentasi berlangsung. Disamping itu, proses recovery asam sitrat juga perlu dirancang agar persentase produk yang dapat diambil lebih tinggi.
English Abstract
Citric acid is the fermentation product that is widely used in food, beverage, detergent, pharmaceutical, and cosmetic industries. One of technique for producing citric acid is solid state fermentation (SSF) with Aspergillus niger microorganism. This technique utilizes agro-industrial waste as its substrate. One of the potential substrate in the production of citric acid is sugarcane bagasse. However, before using it a pretreatment process may required for destroying the cellulose-hemicellulose-lignin complex inside the solid substrate to increase the digestible cellulose for the next subsequent hydrolysis converting to fermentable sugars. Some of the methods that potential to pretreat solid substrates are hydrothermal and calcium hydroxide (Ca(OH)2) processes. This research was conducted to determine the effect of pretreatment and time pretreatment to the yield of citric acid produced by SSF method. In this study, pretreatment of bagasse substrate was distinguished (without pretreatment), hydrothermal, and calcium hydroxide. The time used for the pretreatment process is divided into three times, 10, 30, and 60 minutes. Thereafter, SSF fermentation process was carried out with a weight of 50 g of bagasse substrate. The SSF fermentation process is carried out for 5 days under initial moisture conditions about 60-75%, initial pH was 5, temperature was 25-30oC, and aeration rate was 0.75 ± 0.25 L/min. The fermented bagasse mass is then recovered through a leaching process with aquades and filtration to obtain the citric acid product in the form of a supernatant. The supernatant obtained was then analyzed qualitatively by measurement of pH, UV spectrophotometry, and FT-IR. While for the quantitative analysis is done with acid-base titrimetric method. The results showed that the yield of citric acid on the variable without pretreatment was 1.792% (weight of citric acid per weight of the initial bagasse). The citric acid yield with the hydrothermal pretreatment variable for 10, 30, and 60 minutes respectively was 0.980%, 1.216%, and 0.696%. The citric acid yield for calcium hydroxide pretreatment variables for 10, 30, and 60 were 1.512%, 1.938%, and 0.340%. The optimum time for the production of citric acid in each hydrotthermal and calcium hydroxide pretreatment at 30 minutes. At the optimum conditions, hydrothermal pretreatment decreased citric acid production with yield of 1.22% (0.608 g citric acid / 50 g of initial bagasse), while calcium hydroxide pretreatment increased citric acid production by a yield of 1.94% (0.969 g citric acid / 50 g of initial bagasse) compared to without pretreatment condition. From this result, the use of calcium hydroxide in the solution phase in the pretreatment process should be considered to avoid the bonding of citric acid as Ca-citrate during the fermentation process. In addition, the citric acid recovery process also needs to be designed to make the percentage of products higher.
| Item Type: | Thesis (Sarjana) |
|---|---|
| Identification Number: | SKR/FT/2017/530/051706223 |
| Uncontrolled Keywords: | Asam sitrat, Aspergillus niger, ampas tebu, pretreatment, solid state Fermentation |
| Subjects: | 600 Technology (Applied sciences) > 660 Chemical engineering and related technologies > 660.2 General topics in chemical engineering > 660.28 Specific types of chemical plant and specific activities in chemical plants |
| Divisions: | Fakultas Teknik > Teknik Kimia |
| Depositing User: | Nur Cholis |
| Date Deposited: | 05 Sep 2017 07:25 |
| Last Modified: | 28 Dec 2020 10:57 |
| URI: | http://repository.ub.ac.id/id/eprint/2109 |
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