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Journal : Reaktor

EFFECT OF TEMPERATURE AND PARTICLE SIZE ON THE ALKALINE EXTRACTION OF PROTEIN FROM CHICKEN BONE WASTE Andri Cahyo Kumoro; Sofiah Sofiah; Nurul Aini; Diah Susetyo Retnowati; Catarina Sri Budiyati
Reaktor Volume 13, Nomor 2, Desember 2010
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (255.999 KB) | DOI: 10.14710/reaktor.13.2.124-130

Abstract

Chicken bone is a waste of chicken meat processing industry and restaurants that has not been used widely, even though it contains valuable organic compounds that are functionals, such as collagenous and non collagenous protein. This research was conducted to investigate the effect of temperature and particle size on the protein extraction from chicken bones using dilute sodium hydroxide solution. Controlled parameters in this study were the solvent in the form of sodium hydroxide solution, extraction time for 1 hour, pH 10.5, the ratio of chicken bone powder: solvent (1:4 w/v), and stirring speed 200 rpm. While the operating variables included the extraction temperature of 30oC, 55oC, and 80oC, and particle size of 150 and 250 μm. Experiments were carried out by heating of 300 mL of sodium hydroxide solution with pH 10.5 in a three-necked flask equipped with Leibig condenser, thermometer, mechanical agitator and sampling device to reach the desired temperature (30oC, 55oC, and 80oC). Then, a total of 75 g of chicken bone powders with desired particle size (150μm and 250μm) was introduced into the sodium hydroxide solution and the stirrer was operated at speed of 200rpm. At every 10 minutes interval, as much as 10 mL samples were withdrawn for total protein analysis using Lowry-Folin method. The experiment was terminated after 1 hour. The results show that both increase in temperature and particle size caused an increase in the amount of extracted protein. Highest concentration of protein extracted was achieved at 630.99 mg/L, when the extraction was carried out using 250mm bone particles and temperature 80oC.
PEMUTIHAN ENCENG GONDOK MENGGUNAKAN H2O2 DENGAN KATALISATOR NATRIUM BIKARBONAT Diah Susetyo Retnowati
Reaktor Volume 12, Nomor 1, Juni 2008
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (311.059 KB) | DOI: 10.14710/reaktor.12.1.33-36

Abstract

Batang enceng gondok (Eichornia crasipess) dapat digunakan sebagai bahan baku kerajinan seperti tas, atau digunakan sebagai pengganti rotan dalam industri mebel.Untuk mendapatkan warna yang lebih cerah, umumnya batang  enceng gondok kering yang berwarna coklat diputihkan  dengan perendaman dalam larutan yang mengandung oksidator. Pada penelitian ini, oksidator yang dipakai adalah hidrogen peroksida, suatu oksidator yang lebih ramah lingkungan dibandingkan dengan oksidator lainnya. Oksidator ini dilarutkan dalam pelarut yang berupa campuran etanol-air. Untuk lebih mempercepat proses pemutihan, juga ditambahkan katalisator NaHCO3 yang dapat bereaksi dengan hidrogen peroksida membentuk peroksidamonokarbonat yang lebih reaktif. Hasil enceng gondok yang putih dan cerah, serta mempunyai kuat tarik cukup tinggi, diperoleh  pada proses pemutihan selama 3 jam dalam larutan etanol-air dengan perbandingan volume 0,36 yang mengandung H2O2 dan NaHCO3 dengan konsentrasi 4 % berat dan 1,95 g/L.
Nutritional Characteristics and Potential Applications of Flour Prepared from Indonesian Wild White Yam (Dioscorea esculenta L.) Diah Susetyo Retnowati; Ratnawati Ratnawati; Andri Cahyo Kumoro
Reaktor Volume 19 No. 2 June 2019
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (228.632 KB) | DOI: 10.14710/reaktor.19.2.43-48

Abstract

Gembili or wild white yam (Dioscorea esculenta L.) is one of underutilized tubers that can be found during dry season in Indonesia and other Southeast Asian countries. Although it has been consumed as staple food by people for centuries during famine, no further studies have been conducted to explore its potentials in food applications. This work aims to study the preparation, characterization and potential analysis of Gembili flour for use as raw material in novel foods development. Creamy white flour was obtained from white yam tuber from milling and sieving of dried tuber chips. The flour has water content about 12.08%, which is acceptable for storage. No lipid was detected. In addition, the protein, ash, and fiber content of the flour were respectively 3.00%, 1.27%, and 9.04%. The carbohydrate and amylose contents of the flour were 86.69% and 29.92% indicating its suitability for energy source. As expected, the cyanide content is very low of about 1.688 ppm suggesting that it is safe for consumption. Refer to those properties, Gembili flour can be a promising raw material for the preparation of bakery, cookies, noodle and confectioneries.Keywords: proximate composition, flour, white yam, food, preparation
MANNAN PRECIPITATION FROM ALOE VERA LEAF PULP JUICE USING METHANOL AND ISOPROPYL ALCOHOL AS ANTI-SOLVENT: EXPERIMENTAL AND EMPIRICAL MODELLING APPROACH Diah Susetyo Retnowati; Andri Cahyo Kumoro
Reaktor Volume 14, Nomor 1, April 2012
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (74.848 KB) | DOI: 10.14710/reaktor.14.1.46-50

Abstract

Precipitation of mannan from Aloe vera leaf pulp juice was investigated using anti-solvent precipitation process under room temperature condition. The aims of this work were to study the effects of types (methanol and isopropyl alcohol) and amount of anti-solvent on the precipitation phenomena and to propose a simple mathematics model for evaluating the precipitation rate of mannan (Rβ). The experiments were carried out using a semi batch system; where continuous drop wise addition of anti-solvent to the Aloe vera leaf pulp juice was kept constant at 50.4 mL/min, while the speed of stirring was maintained at 675 rpm. At every run of the experiments, the time at which the precipitation began was recorded and the experiment was terminated when no further precipitation occurred. The samples were withdrawn from the system at every 25 min after the first precipitation for mannan analysis. The results of this work showed that isopropyl alcohol acted as a more effective anti-solvent to precipitate mannan from Aloe vera leaf pulp juice than methanol. The mathematics model represented the precipitation phenomena fairly well with average relative deviation only 11.73%, and finally suggested that the precipitation rate obeyed the zero order.  PENGENDAPAN MANNAN DARI JUS DAGING DAUN LIDAH BUAYA (ALOE VERA) MENGGUNAKAN METANOL DAN ISOPROPIL ALKOHOL SEBAGAI ANTI SOLVEN: PERCOBAAN DAN PEMODELAN DENGAN PENDEKATAN EMPIRIK. Pengendapan mannan dari jus daun lidah buaya (Aloe vera) dengan teknik pengendapan menggunakan anti-pelarut dikaji pada suhu kamar. Tujuan dari penelitian ini adalah untuk mempelajari pengaruh jenis anti-pelarut (metanol dan isopropil alkohol) dan massa anti-pelarut terhadap fenomena pengendapan mannan, serta mengembangkan model matematik dengan pendekatan empiric untuk mengevaluasi laju pengendapan mannan (Rβ). Percobaan dilakukan dalam sistem yang bekerja secara semi-batch, dengan anti-pelarut diumpankan secara terus menerus dalam bentuk tetesan-tetesan dengan laju 50,4 mL/men dan pengadukan dijaga tetap pada 675 putaran per menit (ppm). Pada setiap percobaan, waktu yang diperlukan sejak pengumpanan anti-pelarut hingga saat endapan pertama kali terbentuk dicatat, dan percobaan dihentikan jika tidak ada lagi endapan yang terbentuk. Cuplikan cairan diambil setiap 25 menit sejak endapan pertama terbentuk dan dianalisis kandungan mannannya. Hasil penelitian menunjukkan bahwa isopropil alkohol merupakan anti-pelarut yang lebih efisien dibandingkan dengan metanol untuk mengendapkan mannan dari jus daun lidah buaya. Dari pemodelan matematik diketahui bahwa laju pengendapan mannan mengikuti order nol. Model matematik yang diusulkan dapat mewakili fenomena pengendapan mannan dengan baik yang ditunjukkan dengan ralat rata-rata sebesar 11,73%.
Anaerobic Fermentation of Mixed Fruits Peel Waste for Functional Enzymes Production Employing Palm Sugar and Molasses as The Carbon Source Retnowati, Diah Susetyo; Kumoro, Andri Cahyo; Haryani, Kristinah
Reaktor Volume 23 No.2 August 2023
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.23.2.71-76

Abstract

The daily abundant generation of fruit peel waste potentially triggers environmental problems if no appropriate management is performed. Besides, fruit peel waste can be a valuable source for functional enzyme production. This study aims to investigate the use of molasses and palm sugar as sugar source during anaerobic fermentation of banana and papaya peel waste to produce functional enzymes. The fermentation was subjected to biomass at various banana peels to papaya peels mass ratio for 3 months. The feed consisted of sugar:biomass:water, and their mass ratio was kept constant at 1:3:10. Both brown functional enzyme cocktails obtained from the fermentation using palm sugar and molasses as carbon source were acidic with pH of 3.7 and 4.4, respectively. The amylase, protease, and lipase activities of the functional enzyme cocktails was maximum when the biomass mixture contained four portions of banana peel and one portion of papaya peel. In addition, molasses was found to be the better sugar source than palm sugar for producing functional enzymes from aerobic fermentation peel fruits comprises banana and papaya peels. This study proved that fruit peel waste can be converted to valuable functional enzymes as one of the solutions of fruit peel waste management Keywords: anaerobic fermentation; carbon source; enzyme activity; functional enzyme; organic waste