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Journal : TEKNIK

Perbaikan Proses Produksi Antosianin dari Kelopak Bunga Rosella dengan Ekstraksi Berbantuan Ultrasound Triyastuti, Meilya Suzan; Djaeni, Mohamad
TEKNIK Vol 40, No. 2 (2019): Agustus 2019
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (529.416 KB) | DOI: 10.14710/teknik.v39i3.23258

Abstract

Kelopak bunga rosella mengandung senyawa bioaktif diantaranya Antosianin. Kelopak bunga rosella mempunyai pigmen berwarna ungu yang berpotensi sebagai zat pewarna alami untuk menggantikan pewarna sintetis Violet GB. Pigmen warna ungu ini berasal dari senyawa antosianin. Namun senyawa antosianin ini mudah terdegradasi pada temperatur diatas 70°C, sehingga diperlukan metode ekstraksi yang tepat pada kondisi optimum. Metode yang digunakan yaitu ekstraksi dengan bantuan gelombang ultrasonik (Ultrasound Assisted Extraction) dan dioptimasi menggunakan software Design Expert. Hasil penelitian menunjukkan bahwa kondisi optimum ekstraksi pada waktu ekstraksi 15 menit, rasio sampel dan pelarut 15 gr/ml dan temperatur ekstraksi 50°C dengan kadar antosianin sebesar 206,996 ppm
Peningkatan Kecepatan Proses dan Mutu Minyak Bekatul melalui Proses Ekstraksi Berbantukan Ultrasonik Djaeni, Mohamad; Listyadevi, Yuniar Luthfia
TEKNIK Vol 40, No. 1 (2019): Mei 2019
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (697.703 KB) | DOI: 10.14710/teknik.v39i3.22826

Abstract

Rice bran oil is one of the oils that has been widely used in the chemical, pharmaceutical and food industries considering the high essential content such as antioxidants, vitamins that are good for the body. Extraction of ultrasonic assisted bran oil is one of many method used to reduce extraction time. The purpose of this study was to examine the effect of extraction methods on mass transfer of bran oil, antioxidant quality, and the quality of bran oil during the extraction process at the temperature, extraction time, and the right solvent ratio. Mass transfer of bran oil was evaluated based on the effect of various temperatures, extraction times, and solvent ratios to predict the right tim e to get a lot of bran oil. Chemical quality (antioxidant content of α-tocopherol) and physical quality (oil color) of bran oil were studied so that they were able to predict temperature, extraction time, and relatively good solvent ratio. The results showed that yield increased with increasing temperature and extraction time. However the antioxidant value of α-tocopherol will decrease with increasing temperature, extraction time and solvent. The recommended operating conditions for obtaining yields and antioxidant values at 40ºC, material to solvent ratio 1: 5 and extraction time for 51 minutes.
PENINGKATAN KECEPATAN PROSES PENGERINGAN KARAGINAN MENGGUNAKAN PENGERING ADSORPSI DENGAN ZEOLIT Djaeni, Mohamad
TEKNIK Volume 33, Nomor 1, Tahun 2012
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (117.323 KB) | DOI: 10.14710/teknik.v33i1.3786

Abstract

Drying carrageenan product still deals with low product quality and energy efficiency. The drying with airdehumidified by activated natural zeolite has a potential for drying the product. In this concept, air as dryingmedium was contacted with zeolite to reduce its relative humidity. Hence, the driving force of drying increasesand the process can be conducted at moderate temperature (40-60oC) to retain the quality. This research looksinto the effectiveness of adsorption dryer with zeolite for drying carrageenan. The natural zeolite is activated byheating 300-400oC for 2-3 hours. The zeolite is then used to dehumidify the ambient air as drying medium. Inthis work, the effect of drying temperature and carrageenan thickness on water content in carrageenan duringthe drying were studied. Results showed with air velocity 3.0 m/sec, thickness of carrageenan 1-2 mm,operational drying time 3 hours and air temperature 40-60oC, water content in carrageenan can be reducedfrom 82.0% to 25%. This result is very promising for industrial application.
Pemodelan Pupuk Rilis Lambat Dengan Fly Ash sebagai Matriks Inert yang Dilapisi oleh Ethylcellulose Djaeni, Mohamad; Maulana, Kemal
TEKNIK Vol 41, No. 1 (2020): May 2020
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1074.216 KB) | DOI: 10.14710/teknik.v41i1.25053

Abstract

Pupuk lambat rilis memiliki peranan yang penting dalam mencegah hilangnya nutrisi tanaman serta meningkatkan efisiensi penyerapan. Penelitian ini bertujuan untuk memperoleh nilai koefisien difusivitas ethylcellulose melalui perbandingan antara laju rilis pellet urea eksperimen dengan laju rilis pellet urea simulasi. Penelitian ini menggunakan metode elemen hingga 2D dengan software Comsol Multiphysics. Melalui perbandingan menggunakan hasil eksperimen dengan simulasi diperoleh hasil difusivitas pada lapisan ethylcellulose bervariasi antara 6 x 10-3 - 9 x 10-3 cm2/hari dengan Root Mean Square Error (RSME) sebagai indikator error perhitungan memiliki nilai antara 0.675 - 1.791. Hasil tersebut menunjukkan bahwa model cukup baik untuk menggambarkan karakteristik difusi urea dari matriks ke air.