scholarly journals Pengaruh Paparan Medan Magnet Extremely Low Frequency (ELF) terhadap Perubahan pH Pada Proses Fermentasi Biji Kopi Lanang (Peaberry) Kering

2021 ◽  
Vol 4 (2) ◽  
pp. 129-136
Author(s):  
Mamik Purbawati ◽  
Sudarti Sudarti ◽  
Firdha Kusuma A A
Keyword(s):  
Magnetic Field ◽  
Fermentation Process ◽  
Low Frequency ◽  
Control Group ◽  
Extremely Low Frequency ◽  
Coffee Beans ◽  
Post Test ◽  
Frequency Magnetic Field ◽  
Group Variation ◽  
Elf Magnetic Field

ABSTRAK Kopi lanang (Peaberry) merupakan jenis kopi yang mempunyai biji berkeping satu (monokotil) dengan kafein yang kadarnya lebih tinggi jika dibandingkan dengan kopi jenis lain. Kadar kafein yang tinggi pada biji kopi bisa diturunkan dengan proses fermentasi kopi. Penelitian ini mempunyai tujuan untuk mengetahui pengaruh paparan medan magnet ELF (Extremely Low Frequency) terhadap perubahan pH pada proses fermentasi biji kopi lanang (Peaberry) kering jenis robusta dengan penambahan enzim -amilase. Jenis penelitian yang digunakan yaitu penelitian eksperimen dengan desain Rancangan Acak Lengkap (RAL) bertujuan mengkaji pengaruh perlakuan dengan pengulangan percobaan. Penelitian ini memiliki tujuh kelompok sampel meliputi kelompok kontrol dan kelompok eksperimen variasi intensitas paparan medan manet ELF sebesar 200 µT dan 300 µT dan variasi lama pemaparan 30 menit, 60 menit dan 90 menit. Pengukuran data hasil penelitian diambil setelah pemaparan yaitu pada hari ke-1 sampai hari ke-5 selama proses fermentasi berlangsung. Hasil penelitian menyatakan bahwa paparan medan magnet ELF berpengaruh terhadap perubahan pH pada proses fermentasi biji kopi lanang (Peaberry) kering jenis robusta yang ditunjukkan dengan variasi bentuk grafik. Pemaparan medan magnet ELF dengan intensitas 200 µT dan lama pemaparan 30 menit dapat menurunkan pH secara signifikan, sedangkan intensitas 200 µT dan lama waktu paparan 90 menit dapat menaikkan pH secara signifikan pada proses fermentasi biji kopi lanang (Peaberry) kering jenis robusta. Kata  kunci : Medan magnet ELF, Fermentasi, Kopi Lanang (Peaberry), pH ABSTRACT Peaberry coffee is a type of coffee that has a single bean (monocotyle) with a higher levels of caffeine if compared whith other types of coffee. High levels of caffeine in coffee beans can be reduced by the coffee fermentation process. The study aims to examine the effect of exposure to the ELF (Extremely Low Frequency) magnetic field on changes of pH in the fermentation process of robusta peaberry dray coffee beans with the addition of -amylase enzyme. The type of research that use in the experimental reseacrh with a randomized subject post test only control grup design, it aiming to examine the effect of treatment by repeating the experiment. This study include seven sample groups covering the control group and the experimental group variation in the intensity of ELF magnetic field with 200 µT and 300 µT and variation of a length 30, 60, 90 minutes. Meansurement of the data research taken after exposure that is on the day one to day five during the fermentation process. The result of the study suggest that exposure to ELF magnetic field has an effect on the pH fermentation prosess of dried peaberry coffee beans, which was shown variations of the shape of the graph. Exposure to the ELF magnetic field with an intensity of 200 µT and the length of 30 minutes can significantly decrease the pH, while the intensity of 200 µT and the length of 30 minutes can significantly increase the pH in the fermentation process of dried robusta paberry coffee beans. Keywords : ELF magnetic field, Fermentation, Peaberry Coffee, pH

scholarly journals PENGARUH PAPARAN MEDAN MAGNET EXTREMELY LOW FREQUENCY (ELF) TERHADAP pH DAN DAYA HANTAR LISTRIK PADA PROSES FERMENTASI BASAH KOPI LIBERIKA (Coffea liberica) DENGAN PENAMBAHAN α-AMILASE

2020 ◽  
Vol 6 (2) ◽  
pp. 315
Author(s):  
Nanda Rizky Fitrian Kanza ◽  
Sudarti Sudarti ◽  
Maryani Maryani
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Fermentation Process ◽  
Low Frequency ◽  
Control Group ◽  
Control Group Design ◽  
Extremely Low Frequency ◽  
Post Test ◽  
Wet Fermentation ◽  
Elf Magnetic Field

ABSTRAKPenelitian ini bertujuan untuk mengkaji pengaruh paparan medan magnet Extremely Low Frequency (ELF) terhadap pH dan daya hantar listrik pada proses fermentasi basah kopi liberika dengan penambahan α-amilase. Jenis penelitian ini merupakan penelitian eksperimen dengan randomized subjects post test only control group design. Pada penelitian ini terdapat 7 perlakuan yang terdiri dari kelompok kontrol dan kelompok eksprimen yang dipapar medan magnet ELF dengan variasi intensitas 300 µT dan 400 µT dan variasi lama paparan 30 menit, 60 menit, dan 90 menit. Pengambilan data dilakukan pada jam ke-24, jam ke-48, hari ke-3, hari ke-4, dan hari ke-5 setelah proses fermentasi. Hasil penelitian menunjukkan bahwa paparan medan magnet Extremely Low Frequency (ELF) berpengaruh terhadap pH dan daya hantar listrik pada proses fermentasi basah kopi liberika dengan penambahan α-amilase yang ditunjukkan dengan bervariasinya grafik. Pengukuran kopi liberika dengan paparan medan magnet ELF intensitas 400 µT selama 30 menit paling berpengaruh terhadap pH kopi liberika. Sedangkan, pengukuran kopi liberika dengan paparan medan magnet ELF intensitas 300 µT selama 30 menit dan 90 menit paling berpengaruh terhadap daya hantar listrik kopi liberika yang telah difermentasi secara basah dengan penambahan α-amilase. Kata kunci: medan magnet ELF; pH; daya hantar listrik; fermentasi; kopi. ABSTRACTThe purpose of the research is to examine the effect of Extremely Low Frequency (ELF) magnetic field to pH and electrical conductivity in the wet fermentation process of liberica coffee with the addition of α-amylase. Type of the research is an experimental research with randomized subjects post test only control group design. There is seven treatments consist of control group and experimental group exposed to ELF magnetic field with 300 µT and 400 µT intensity variation and for 30, 60, and 90 minutes for long variations. For hours 24, 48, day 3, day 4, and day 5, can make data retrieval after fermentation process. The result explain is effect of Extremely Low Frequency (ELF) magnetic field to pH and electrical conductivity in the wet fermentation process of liberica coffee with the addition of α-amylase was take effect to indicated by the variation of the graph. The process ELF magnetic field with 400 µT intensity for 30 minutes most influential on pH of liberica coffee. Meanwhile, the process ELF magnetic field with 300 µT intensity for 30 and 90 minutes most influential on electrical conductivity of liberica coffee in the wet fermentation with the addition of α-amylase. Keywords: ELF magnetic field; pH; electrical conductivity; fermentation; coffee.

Effect of 50 Hz magnetic field on chicken embryo development and course of hatching

2019 ◽  
Vol 5 (2) ◽  
pp. 44-49
Author(s):  
Marcin Lis
Keyword(s):  
Magnetic Field ◽  
Chick Embryo ◽  
Chicken Embryo ◽  
Low Frequency ◽  
Quality Analysis ◽  
Control Group ◽  
Control Groups ◽  
Extremely Low Frequency ◽  
Helmholtz Coils ◽  
Elf Magnetic Field

The effect of additional extremely low frequency (ELF) magnetic field (50 Hz) on the development of chick embryo was investigated. The experiment was carried out in three variants for induction values 15 μT, 10 μT and 5 μT. Magnetic field (MF) in the experimental incubator was generated by a set of three Helmholtz coils. The following analyses were performed: embryopathological analysis; evaluation of the hatched chicks for quality; analysis of the course and synchronization of hatching. Increased embryo mortality was found between 1 and 6 days of incubation in 15 μT MF and between 18 and 20 days of incubation in 5 μT MF. In each group exposed to MF, the principal stage of hatching was completed earlier. Increased degree of chick hatching synchronization was observed in MF of 5 μT and 10 μT. Hatching results in the control group were higher than in MF exposed groups. Statistically significant (p≤0.05) differences were found for chick malpositions in the groups incubated with exposure to additional MF of 10 μT and 5 μT compared to the control groups.

scholarly journals PENGARUH PAPARAN MEDAN MAGNET EXTREMELY LOW FREQUENCY (ELF) TERHADAP pH ROTI TAWAR

2021 ◽  
Vol 7 (2) ◽  
pp. 299
Author(s):  
Yuyun Setyawati ◽  
Sudarti Sudarti ◽  
Albertus Djoko Lesmono
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Control Group ◽  
White Bread ◽  
Extremely Low Frequency ◽  
Randomized Design ◽  
Analysis Technique ◽  
Research Type ◽  
Experimental Group ◽  
Elf Magnetic Field

ABSTRAKRoti tawar adalah sumber karbohidrat memiliki umur simpan yang sangat pendek yakni empat sampai enam hari terhitung dari proses masa produksi. Penelitian ini bertujuan menyelidiki pengaruh paparan medan magnet Extremely Low Frequency (ELF) intensitas 500 µT dan 700 µT selama 60, 90, dan 120 menit terhadap pH roti tawar. Jenis penelitian yang digunakan yaitu eksperimen dengan desain penelitian Rancang Acak Lengkap (RAL). Ada dua kelompok dalam penelitian ini, yakni kelompok kontrol dan kelompok eksperimen dimana kelompok kontrol yang tidak dipapari medan magnet dan kelompok eksperimen diberi paparan medan magnet. Sampel yang digunakan dalam penelitian ini adalah roti tawar sari roti kupas sebanyak 126 sisir dimana kelompok kontrol sebanyak 18 sisir roti tawar dan kelompok eskperimen sebanyak 108 sisir roti tawar yang dibagi menjadi enam kelompok yang diberi perlakukan berupa paparan medan magnet ELF dengan intensitas 500 µT dan 700 µT selama 60, 90 dan 120 menit. Teknik analisis data dilakukan menggunakan SPSS 22 dengan uji Kruskal-Wallis.  Berdasarkan hasil penelitian yang diperoleh paparan medan magnet ELF berpengaruh terhadap perubahan pH pada roti tawar. Dengan memaparkan medan magnet intensitas 500 µT lama paparan 60 menit dan 700 µT lama paparan 60 menit dapat menghambat penurunan pH roti tawar. Kata kunci: Medan Magnet ELF; Roti Tawar; pH. ABSTRACTBread is a source of carbohydrates that has a very short shelf life of four to six days from the production process. This study aims to examine the effect of exposure to an Extremely Low Frequency (ELF) magnetic field with an intensity of 500 µT and 700 µT for 60, 90, and 120 minutes on the pH of white bread. This research uses an experimental research type with the research design used is Completely Randomized Design (CRD). There were two groups in this study, namely the control group and the experimental group where the control group was not exposed to a magnetic field and the experimental group was exposed to a magnetic field. The samples used in this study were 126 combs of peeled white bread, where the control group consisted of 18 white bread combs and the experimental group consisted of 108 white bread combs which were divided into six groups which were treated in the form of exposure to the ELF magnetic field with an intensity of 500 µT and 700 µT for 60, 90 and 120 minutes. The data analysis technique was carried out using SPSS 22 with the Kruskal-Wallis test. The results of the study stated that exposure to the ELF magnetic field had an effect on changes in pH in white bread as shown by a graphic diagram. Exposure to a magnetic field intensity of 500 µT with an exposure time of 60 minutes and 700 µT with an exposure duration of 60 minutes can inhibit the decrease in the pH of white bread. Keywords: Magnetic Field; White Bread; pH.

Intracellular Ca2+levels in rat ventricle cells exposed to extremely low frequency magnetic field

2011 ◽  
Vol 30 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Cemil Sert ◽  
Sevda Söker ◽  
Mustafa Deniz ◽  
Yusuf Nergiz
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Extremely Low Frequency ◽  
Frequency Magnetic Field ◽  
Rat Ventricle

scholarly journals Temperature and magnetic field effects on the activity of protocerebral neurosecretory neurons and corpora allata in Cerambyx cerdo L. larvae

2005 ◽  
Vol 57 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Vera Nenadovic ◽  
Marija Mrdakovic ◽  
Jelica Lazarevic ◽  
D. Mircic ◽  
Dajana Todorovic ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Constant Temperature ◽  
Low Frequency ◽  
Corpora Allata ◽  
Control Group ◽  
Magnetic Field Effects ◽  
Neurosecretory Neurons ◽  
Cerambyx Cerdo ◽  
Frequency Magnetic Field ◽  
A1 Neurons

The effects of constant temperature and an extremely low-frequency magnetic field (ELFMF, 50 Hz and average induction of 20 mT) on the activity of medial protocerebral neurosecretory neurons (A1 and A2) and corpora allata were investigated in Cerambyx cerdo L. larvae after 30 days of exposure. Both constant temperature of 23?C and the ELFMF led to decrease in activity of A1 and A2 neurosecretory neurons and increase in activity of corpora allata compared to the control group (larvae from natural conditions). The changes are more pronounced in A2 than A1 neurons.

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