FOOD PRESERVATIVE TOOLS AND HARMFUL HEAVY METAL REDUCERS ON VEGETABLES AND FRUITS Emas Agus Prastyo Wibowo*, Heru Setiawan aProdi Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Negeri Semarang Gedung D6 lantai 2, Semarang Indonesia bProdi Pendidikan Biologi, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Negeri Semarang Gedung D6 lantai 1, Semarang Indonesia *Email:
[email protected] ABSTRACT Vegetables and fruits are the primary food of the Indonesian people. The food that unclean and polluted by some substances would be harmful for human health. But the fact showed that vegetables and fruits Indonesia has polluted by harmful heavy metals. When heavy metals such as Pb, Hg, Cd, Cu and Zn are toxic. Based on this problems it is needed for innovative research in order decreased levels of heavy metals in food. The aim of this research is to analyze the decreased levels of heavy metals in the pickling system based reduction of heavy metals in foods that more energy efficient based on the photocatalytic reaction by visible light from the sun as a solution to providing safe food. The method of this research was experimental method: preparation of tools and materials, develop the tools, and application. The results showed that N-doped TiO2 innovation can reduce levels of heavy metals in food, that can be used as consideration as a food preservative. The food preservative tool using TiO 2 material. TiO2 is a photocatalyst material that has antibacterial activity and can reduce the heavy metals. With the innovation of the N-doped TiO2 photocatalyst reaction can also be initiated with visible light and photocatalytic reactions so it would be more effectively. The work system of this tools is Photocatalyst N-doped TiO2 can be generate as the superoxide compounds through fotocatalics reaction that kill bacteria and reduce dangerous heavy metals. Keywords: food preservatives tools, N-doped TiO2, Heavy Metal Reducers, Photocatalysis ABSTRAK Sayuran, buah-buahan merupakan makanan pokok masyarakat Indonesia. Bahan makanan tersebut apabila tidak dijaga kebersihannya akan membahayakan kesehatan. Namun faktanya sayuran dan buah-buahan di Indonesia sudah banyak tercemar, pencemaran ini terutama diakibatkan logam berat berbahaya. Bila logam berat seperti Pb, Hg, Cd, Cu dan Zn yang bersifat toksik, karena itu diperlukan adanya penelitian inovatif dalam rangka penurunan kadar logam berat pada makanan. Tujuan dari penelitian ini yaitu menganalisis penurunan kadar logam berat pada sistem pengawetan berbasis reduksi logam berat yang hemat energi pada makanan akibat adanya reaksi fotokatalis oleh cahaya tampak dari cahaya matahari sebagai solusi penyediaan makanan yang aman bagi masyarakat Indonesia. Metode yang digunakan adalah metode eksperimental yang meliputi tahap persiapan alat dan bahan, pembuatan alat, dan penerapan. Hasil penelitian menunjukkan bahwa inovasi N-doped dapat menurunkan kadar logam berat pada makanan sehingga dapat dijadikan sebagai bahan pertimbangan bagi masyarakat sebagai alat pengawet makanan. Alat pengawet makanan ini menggunakan material . merupakan material fotokatalis yang memiliki aktivitas antibakteri dan dapat mereduksi logam berat. Dengan inovasi N-doped reaksi fotokatalis juga dapat diinisiasi dengan sinar tampak dan reaksi fotokatalis sehingga bisa berjalan lebih efektif. Sistem kerjanya yaitu Fotokatalis N-doped dapat menghasilkan senyawa superoksida melalui reaksi fotokatalik yang dapat membunuh bakteri dan mereduksi logam berat berbahaya. Kata kunci: Alat Pengawet, Fotokatalis, N-doped TiO2 ,Pereduksi Logam Berat
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INTRODUCTION Four of five perfectly healthy motto proclaimed as an invitation to make a balance of nutrition in daily consumption, which consists of staple food, side dishes, vegetables, fruits and milk. Vegetables are important food in health. However, vegetables can cause illness when contaminated by heavy metals or microorganisms. In 1994 data showed that vegetables grown on the roadside contain contaminants tetra ethyl lead at 28.78 ppm originating from motor vehicle fumes (Winarno, 1994). Dissertation research in 1997 against cadmium contamination at kale, basil, and calsim in the Supreme Lenteng obtained content of 1.56 ppm; 1.04 ppm; and 1.86 ppm. Fruits and vegetables are foods that are very easily available in Indonesia, even each region has a fruit and vegetable as typical for the area. Fruits and vegetables with various types and colors can be complementary nutritional needs required by our body. In addition, one of the foodstuffs that contain lots of fiber found in fruits and vegetables (Jahari, 2001). Vegetables and fruits are a source of vitamins and minerals that the body needs to regulate processes in the body. Although the need for a relative small, but the function of vitamins and minerals can hardly be replaced so that the requirement for the consumption of these substances is essential. If the consumption of vitamins and minerals does’nt meet the requirements, then the body will experience a deficiency of vitamins and minerals which may result in reduced endurance. According to research conducted, the type of foods that contain vegetables and fruits in the school cafeteria not meet enough criteria to be consumed. Nanotechnology in the world is growing so rapidly. One example is the nanomaterial TiO (Titanium dioxide) is a photocatalyst substance economically valuable (Burgess, 2007). The working principle photocatalyst TiO is a nano-sized titanium dioxide when exposed to UV rays will form a super-oxide compounds which can oxidize a variety of organic compounds so as to carbon dioxide CO and water H O (Samal et al, 2010). TiO that can oxidize organic compounds such as bacteria (antibacterial) and economical price makes the nano (1 nm- 100 nm) TiO as a suitable material in the manufacture of preservatives and reducing harmful metals on vegetables and fruits.
Based on its utilization as a means of curing and reducing harmful heavy metals in fish and shellfish photocatalyst TiO has some weaknesses that can only be initiated by UV light (Liu et al, 2011), whereas the UV light can damage the protein content in fish and shells so necessary modifications to the material in order to work on a range of visible light. One solution of this problem is the coat TiO and Nitrogen (Rani et al, 2010). Coating TiO with nitrogen gas to raise the activity of organic compounds hinggga pendekomposisian wavelength of 550 nm (Ashahi et al, 2001) or can be said to be N-doped TiO as a visible light photocatalyst. With these modifications, the activity TiO as a photocatalyst as an antibacterial and reducing heavy metal becomes more effective. Bacteria and harmful heavy metals are compounds that can be reduced by n-doped photocatalyst TiO . N-doped TiO can reduce bacteria up to 98.7% by using visible light (Wang, 2011). In addition photocatalyst with N-doped TiO can reduce dangerous heavy metals such as Cr (VI) 2
to 80% (Slamet, 2003). From these data it can be concluded when the n-doped TiO superimposed on the glass, the N-doped TiO may provide antibacterial effect resulting in vegetables and fruits to avoid the decay process and reduce metal harmful heavy on vegetables and fruits so that it would be safe to eat. Based on the facts above, one of the innovations that will be the solution to the problem solving preservation system and harmful heavy metals in vegetables and fruits is to create a tool preservatives and reducing heavy metals be deadly in food (vegetables, fruits) with N-doped TiO . The tool serves to preserve vegetables and fruits with their high antibacterial activity and can reduce dangerous heavy metals in vegetables and fruits. Tools of N-doped TiO is also energy efficient because of the preservation system only needs energy from sunlight usual, another advantage of this tool also does not spoil the taste, texture and nutrition because vegetables and fruits will only be illuminated by visible light. In addition the tool preservatives and reducing harmful heavy metals is easily applied and is not harmful to the environment because it will only produce byproduct CO and H O. MATERIALS AND METHODS Material Materials used are TiO Degussa P-25, ethanol, HCl, urea, and distilled, plate glass, plywood and wooden formwork. Synthesis method
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The initial process of making tools preservatives and reducing harmful heavy metals in vegetables and fruits have started from TiO − N synthesis process. The nanomaterial-making process is as follows (Saragih, 2011): 1. Mixing 5 grams of TiO Degussa P-25 in 70 mL of absolute ethanol and proceed with the process of sonication for 10 minutes 2. Mix 10 mL of absolute ethanol, 10 mL of distilled water and 2 M HCl to achieve pH 2. Stir the mixture with magnetuc stirrer for 30 minutes to form sol 3. Stirring the mixture TiO Degussa P-25 and ethanol with a magnetic stirrer for 30 minutes 4. Incorporating urea into TiO sol mixture and followed by the stirring with a magnetic stirrer for 60 minutes. 5. Evaporating the sol at a temperature of 70 ℃ under the hood for 1 hour 6. Heating the sol in the furnace at a temperature of 500 ℃ for 1 hour.
TiO - N derived from this method is the basic material that will be used to coat a glass plate on the appliance preservatives and reducing harmful heavy metals in vegetables and fruitbuahan.Setelah obtained TiO - N is then performed with a glass plate making system using the method of spray coating , Spray method is intended that the glass is coated with TiO - N equitably. Spray method can create a thin layer of TiO - N on the glass plate. This method can also save on the use of TiO - N so that this method can be produced TiO -coated glass plate - N with a relatively low cost (Laksono, 2014) . After obtained TiO -coated N glass plate is then performed making tools preservatives and reducing hazardous wastes on vegetables and fruits with the outer frame design tool using metal or plastic polymers. But in order to minimize the cost of these tools can be made using waste such as straw and wood plank formwork. 3
RESULT AND DISCUSSION
Fig 1. Preservative Tool Vegetables and Fruits Use wooden plank formwork on the device not only reduces the cost of production tools but also make the tool becomes lighter and unique. The design of the tool preservatives and reducing harmful heavy metals can still continue to evolve and is still need for improvements to address weaknesses in these tools. Preservation mechanism with this tool is when the glass plate coated yangg N-doped TiO irradiated by sunlight then there will be storage diruang super oxide compound. Super oxide compound will oxidize bacteria that are in the storage room so that the bacteria will die. N-doped material TiO is catalyst so that the photocatalytic reaction can continue to take place continuously (Laksono, 2014). Senyawa super oksida yang dapat membunuh bakteri
Bakteri
Plat kaca N-Doped TiO2
Sumber Cahaya Tampak
Fig 2. Work Systems Coated Glass Plate N-doped TiO
Tools preservatives and reducing harmful heavy metals in vegetables and fruits is economically valuable. In addition, this tool does not produce by products that are harmful to the environment and this tool requires low energy. So with the innovation and design of the device is expected to deal with issues regarding the preservation system and dangerous problem of heavy metals in vegetables and fruits in Indonesia.
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CONCLUSION 1. Preparation of preservative tool framework and reducing harmful heavy metals in vegetables and fruits can be done by utilizing the waste straw and wood plank formwork so as to reduce the price on the device manufacturing process. 2. The solution to the provision of vegetables and fruits is a functional utilization of N-doped TiO2 photocatalyst which is a material that is suitable for use in tool preservatives and reducing harmful heavy metals in vegetables and fruits because of their antibacterial activity and can reduce dangerous heavy metals. TiO2 nano materials can be made using the initial material TiCl4 with sol gel method. Method of N-doped TiO2 coating on glass plates using the method of spray in order to get a thin layer and evenly N-doped TiO2 on a glass plate. REFERENCES Ashahi, T. Ohwaki, K. Aoki, Y. Taga, Science 293 (2001) 269–271 Burgess, Kevin David. 2007. Self-Cleaning Titania-Polyurethane Composites. Liu, Xu; Liu, Zhongqing; Jian Zheng, Xin Yan, Dandan Li, Si Chen, Wei Chu, 2011,Characteristics of N-doped TiO2 nanotube arrays by N2-plasma for visible lightdriven photocatalysis, College of Chemical Engineering, Sichuan University: China Jahari.2001. Epidemiologi Konsumsi Serat di Indonesia. PUSLITBANG Gizi DepKes RI. Laksono,F.B. 2014. Alat Pengawet dan Pereduksi Logam Berat Berbahaya pada Ikan dan Kerang Hemat Energi Berbasis nano N-Doped . Semaran : Universitas Diponegoro Rani, S.C. Roy, M. Paulose, O.K. Varghese, G.K. Mor, S. Kim, S. Yoriya, T.J.LaTempa, C.A. Grimes, Phys. Chem. Chem. Phys. 12 (2010) 2780–280 Samal, S.S.; Jeyaraman, P.; Vishwakarma, V, 2010, Sonochemical Coating of Ag-TiO2 Nanoparticles on Textile Fabrics for Stain Repellency and Self-Cleaning- TheIndian Scenario: A Review. Sathyabama University: India Saragih, Winda J. 2011. Degradasi Polutan Udara Ruanagn Menggunakan Lampu Hias dengan Penutup Berlapis Katalis Termodifikasi. Skripsi. Depok : Universitas Indonesia Wang, H.; Tang, B.; Li, X.; Ma, Y., 2011, Antibacterial Properties and Corrosion Resistance of Nitrogen-doped TiO2 Coatings on Stainless Steel. Taiyuan University of Technology: China Winarno, F.G, 2004. Kimia Pangan dan Gizi. Jakarta : Gramedia
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