Pengaruh suhu pirolisis, proses redestilasi dan perlakuan mekanik terhadap rendemen dan kualitas asap cair tempurung kelapa

RAHMAH, Sitti, Ir. Moh. Fahrurrozi, M.Sc.,Ph.D

2007 | Tesis | S2 Teknik Mesin (Magister Sistem Teknik)

Metode pengasapan bahan makanan pada beberapa daerah di Indonesia tergolong pengasapan langsung yang membahayakan kesehatan, karena mengandung senyawa hidrokarbon polisiklis aromatik, salah satunya adalah benzo (a) pirena. Pengawetan bahan makanan menggunakan asap cair dapat menurunkan senyawa benzo (a) pirena. Dalam penelitian ini bahan baku yang digunakan adalah tempurung kelapa, karena mudah diperoleh dengan areal perkebunan yang luas dan masa produksi yang relatif singkat. Tujuan penelitian untuk mengetahui pengaruh suhu pirolisis terhadap rendemen asap cair dan pengaruh redistilasi terhadap kualitas asap cair. Penelitian ini menggunakan alat pirolisis yang terbuat dari plat stainless steel. Proses pirolisis dilakukan dengan variasi suhu. Uji sifat fisik terhadap destilat yang diperoleh, meliputi: berat jenis asap cair dan tar, proses pemisahan, menentukan rendemen asap cair dan tar. Uji GC dilakukan sebelum dan sesudah redestilasi untuk mempelajari pengaruh proses redestilasi terhadap jumlah senyawa asap cair. Berdasarkan hasil penelitian, suhu pirolisis berpengaruh terhadap rendemen asap cair, sebaliknya suhu pirolisis tidak berpengaruh terhadap berat jenis asap cair dan tar. Pada pemusingan distilat pirolisis, asap cair berada di lapisan atas sedangkan tar mengendap. Rendemen asap cair terbesar diperoleh pada suhu pirolisis 500oC sebesar 37,90 %, sedangkan rendemen tar terbesar diperoleh pada suhu 300oC sebesar 7,80 %. Berdasarkan hasil uji GC sebelum dan sesudah redestilasi terdapat perbedaan pada jumlah komponen penyusun asap cair. Sebelum redestilasi terdapat 22 senyawa asap cair hasil pirolisis 285oC, 42 senyawa asap cair hasil pirolisis 554oC dan 37 senyawa asap cair hasil pirolisis 450oC. Setelah redestilasi dengan suhu redestilasi 150 oC tinggal 17 senyawa penyusun asap cair, atau terdapat 20 senyawa yang hilang.

Smoking is a commonly used food preservation method in Indonesia. Directly smoked food products may contain harmful compounds such as polycyclic aromatic hydrocarbons. Some of those polycyclic aromatics such as benzo (a) pirena are suspected to be carcinogenic. The advantage of natural preservation of smoking can be obtained while avoiding the bad effects of benzo (a) pirena by using liquid smoke instead of direct smoking. This research dealt with the production of quality liquid smoke from coconut shell. The main objective of the research was to study effects of pyrolisis temperature to yields and compositions of liquid smoke. The research also studied the effect of centrifugation and redistillation to the quality and composition of the refined liquid smoke. The experiment was carried in a small scale (about 10 kg capacity) pyrolysis unit which was constructed from stainless steel. Pyrolysis temperatures were varied from 285oC to 554 oC. The distillate which comprised of liquid smoke and tar was then separated into liquid smoke and tar fractions and then analyzed separately. Selected liquid smoke samples were then subjected to mechanical and redistillation processes to obtain refined liquid smoke. Redistillation product were also analyzed analogous to the pyrolysis product. Experimental results show that pyrolysis temperature affect liquid smoke yields as well as its quality and composition. Temperature however does not have significant influence on densities of liquid smoke and tar. The highest liquid smoke yield (about 37.9 %) was obtained at pyrolysis temperature of 500oC while the highest tar yield (8.10 %) was obtained pyrolisis temperature of 300o C. GC analyses showed that the higher pyrolysis temperature the more number of compounds existed in the pyrolysis products, i.e. 22, 37 and 42 compounds when pyrolysis temperatures were 285o C, 450 o C and 554 o C respectively. Redistillation reduced number of compounds by about 20 and improve the color and clarity of the liquid smoke

Kata Kunci : Asap Cair,Tempurung Kelapa,Kualitas,Suhu Pirolisis dan Redestilasi,Pirolysis, Liquid Smoke, Temperature, Reedmen, Redestilation