KOVALEN: Jurnal Riset Kimia
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Pengaruh Konsentrasi Asap Cair Terhadap Mutu, Total Bakteri, dan Waktu Simpan Ikan Cakalang (Katsuwonus pelamis) Asap: Effect of Liquid Smoke Concentration on Quality, Total Bacteria, and Shelf Life of Smoked Skipjack Fish (Katsuwonus pelamis)
Get PDFLiquid smoke contains acid, carbonyl, and phenolic compounds, so it is very appropriate to be used as a preservative. Traditional smoking can be replaced with liquid smoke because it is safer and more practical. The study of the use of coconut shell liquid smoke has been used in skipjack fish to determine the effect of liquid smoke concentration and storage time on dissolved protein content and total bacteria in smoked fish. The quality of smoked fish was determined by two treatments, namely the variation in the concentration of liquid smoke (2, 3, 4, and 5%) and storage time (2, 4, 6, 8, and 10 days). The results showed that the best concentration of liquid smoke to produce smoked skipjack fish is 3% with a water content of 62.41% and dissolved protein content of 17.58%. The maximum storage time of smoked skipjack tuna is 6 days with a total plate count (TPC) value or total bacteria 1.8 x 105
Pengaruh Waktu Hidrotermal terhadap Karakteristik Zeolite Socony Mobile-5 (ZSM-5) Tanpa Template Menggunakan Reaktor Autoclave: The Effect of Hydrotermal Time in Characteristics of Zeolite Socony Mobile-5 (ZSM-5) Without Template Using Autoclave Reactor
Get PDFZSM-5 is a synthetic zeolite which has a complex production process and is affected by operating conditions, such as temperature and time. In this study, synthesized ZSM-5 without template by hydrothermal method. An autoclave reactor was used for the hydrothermal process. The aim of this study was to investigate the effect of varied hydrothermal times of 24 and 48 hours with a hydrothermal temperature of 180oC on the characteristic of ZSM-5. The raw materials used were silica oxide and aluminum hydroxide as a source of silica and alumina. The synthesis results were characterized using X-Ray Diffraction (XRD). Based on XRD results, the best result was obtained in performed at 48 hours hydrothermal time indicating the formation of ZSM-5 material at the 22.2o position. The percentage crystallinity of the sample at the hydrothermal time of 48 hours was 51.3%
Ekstraksi Glukomanan dari Umbi Gembili (Dioscorea esculenta L.): Extraction of Glucomannan from Gembili Bulbs (Dioscorea esculenta L.)
Get PDFGembili bulbs (Dioscorea esculenta L.) have a fairly high carbohydrate content, so they can potentially be a new source of glucomannan compounds. This study aims to determine the yield and glucomannan characteristics of Gembili bulbs at different extraction times and temperatures. Glucomannan was obtained by extraction with water at temperatures of 45, 60, 75, 90, and 105oC for 45, 60, 75, 90, and 105 minutes, and precipitated with isopropyl alcohol. The results showed that the highest yield was obtained at the extraction time of 90 minutes and a temperature of 105oC of 53.09%. The glucomannan of Gembili bulb has a molecular weight of 1,865 x 104 g/mol with ash and water content values of 0.866% and 10.45%, respectively. The results of identification of functional groups with an FTIR spectrophotometer showed that there was a functional group stretching vibration of glucomannan compounds, including the –OH group at a wavenumber of 3431 cm-1 and -C-O-C (glycosidic bond) at a wavenumber of 1020.34 cm-1 and bending vibration of -CH functional groups on wavenumber of 850.61 cm-1
Kualitas Minyak Ikan Lele Dumbo (Clarias gariepinus) Selama Penyimpanan dengan Penambahan Likopen Kasar dari Buah Tomat: Quality of Dumbo Catfish Oil (Clarias gariepinus) During Storage with The Additing of Crude Lycopene from Tomatoes
Get PDFThe quality of Dumbo Catfish (Clarias gariepinus) oil can be maintained during storage with the addition of crude lycopene in tomatoes as an antioxidant. The purpose of this study was to obtain the best ratio between crude lycopene in tomatoes and Dumbo catfish oil during storage. The study was conducted using a variable ratio of crude lycopene: Dumbo catfish oil with 4 treatment levels (6:40, 8:40, 10:40, and 12:40 (w/v)) and storage time variables of 1, 2, 3, and 4 weeks. Lycopene levels in Dumbo catfish oil were analyzed using a UV-Vis spectrophotometer, while the quality of Dumbo catfish oil during storage was determined through peroxide value analysis. The results showed that the best ratio of crude lycopene of tomatoes: Dumbo catfish oil was 12:40 at the third week of storage with lycopene content of 0.257 grams and the peroxide value of Dumbo catfish oil was 3.45 meq/kg or had met IFOS standards.
Keywords: Crude lycopene, tomato fruit, dumbo catfish oil, peroxide value
Pembuatan Konsentrat Protein Ampas Kelapa (Cocos nucifera L.) Bebas Lemak pada Berbagai Konsentrasi NaOH: Production of Fat-Free Coconut Pulp (Cocos nucifera L.) Protein Concentrates at Various NaOH Concentrations
Get PDFCoconut pulp contains up to 18.2% protein which is one of the wastes from coconut oil processing. Protein from coconut pulp can be used in the manufacture of protein concentrates which are widely used in the food industry. The purpose of this research is to determine the concentration of NaOH that can produce the yield and protein content of coconut pulp protein concentrate. Coconut pulp protein was extracted with NaOH at various concentrations of 0.5, 1, 1.5, 2, and 2.5 M, then continued with salting out using salt (NH4)2SO4 with a saturation of 65%. The crude protein content of coconut pulp protein concentrate was determined by the Kjeldahl method. The results showed that the use of 0.5 M NaOH resulted in the highest protein content of coconut pulp protein concentrate, which was 71.30% with a yield of 14.42%
Ekstraksi dan Uji Stabilitas Zat Warna Alami dari Biji Buah Pinang (Areca catechu L.) sebagai Bahan Pengganti Pewarna Sintetik pada Produk Minuman: Extraction and Stability Test of Natural Dyes from Areca catechu L. as a Substitute for Synthetic Dyes in Beverage Products
Get PDFNatural dyes are an alternative dye that is not toxic, environmentally, friendly and easily degraded. Therefore, optimizing the use of body coloring sources is carried out. One of the natural dyes released is tannin from betel nuts. Tannins are polar pigments. This study aims to determine the results of natural dyes in betel nuts and find out the durability produced and known organoleptic results. Dyestuff extraction from betel nuts was carried out with 96% ethanol. Testing the color stability of betel nut seedlings was carried out on the effect of pH, temperature and storage time with the method UV-Vis Spectrophotometer. Then the application of betel nut dyes on beverage products was carried out. The results showed that betel fruit produced tannin dyes in brownish red color with an average tannin content of 28.002 mg/L. Dyes stabilized at pH of 6 by heating at 400C and storage for 2 days. The results of organoleptic tests showed that the extract of areca nut powder can be used as a natural dye in beverage products with a level of color, smell and flavor that emits at a concentration of 0.005 g/mL of dyes.
Keywords: Extraction, tannin, areca nuts, color stability, organolepti
Aktivitas Antioksidan Likopen Buah Tomat (Solanum lycopersicum L.) Terblending dalam Minyak Padat Ikan Lele (Clarias sp): Antioxidant Activity of Lycopene from Tomato (Solanum lycopersicum L.) Blended Into Frying Fat from Catfish Oil (Clarias sp)
Get PDFResearch on the antioxidant lycopene of tomato fruit (Solanum lycopersicum L.) blended in frying fat from catfish (Clarias sp) oil has been done. The purpose of this research is to determine the antioxidant activity of tomato lycopene before and after being grounded into frying fat and determine the quality of frying fat after being grounded with tomato lycopene. The antioxidant activity of tomato lycopene is determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Analysis of frying fat quality includes determination of pH, determination of FFA (free fatty acid) levels, determination of total fat content, measurement of water content, peroxide number and organoleptic observation. Antioxidant activity of tomato lycopen was very high, namely with inhibition value of 89.79%; 90.34%; 91.49% and 92.10%. Frying fat analysis showed high antioxidant activity of lycopene tomatoes with 50.67% inhibition; 51.63%; 51.39% and 51.23%. The results of the analysis of the quality of frying fat are nearly same with SNI quality standards, except for peroxide numbers.
Keywords: tomato, lycopene, antioxidants, frying fat, catfish, DPP
UJI AKTIVITAS ANTIOKSIDAN EKSRTRAK LUMUT HATI (Marchantia polymorpha)
Get PDFThe research is about antioxidant activity of the liverworts (Marchatia polymorpha) extract based on the level of a polar solvent. This research was done by maceration of liverworts by using n-hexane, ethyl acetate and ethanol solvent. The n-hexane, ethyl acetate, and ethanol fraction were tested the antioxidant activity by using DPPH method. The result was obtained for antioxidant activity (IC50) on n-hexane extract, ethyl acetate, ethanol, and vitamin C is 1065.33 ppm, 1326.52 ppm, 1876.11 ppm, and 13.45 ppm, respectively. The liverworts extract was identified contains secondary metabolites compounds of flavonoid, tannins, polyphenol, alkaloid, and steroid.
Keywords: Liverwort extract, antioxidant, IC5
Isolasi dan Identifikasi Steroid dari Ekstrak N-Heksana Daun Afrika (Vernonia amygdalina Del.): Isolation and Identification of Steroid from N-Hexane Extract of Vernonia amygdalina Del.
Get PDFIsolation and identification of steroids from the n-hexane fraction of Vernonia amygdalina Del. was carried out. Separation and purification were performed using flash chromatographic and gravity chromatography. Based on the results of phytochemical tests supported by UV and FT-IR data analysis, the isolate obtained was a steroid (sterol type). Toxicity test results using the Brine Shrimp Lethality Test (BSLT) were known that the steroid has moderate toxicity with an LC50 value of 48.39 ppm.
Keywords: Vernonia amygdalina Del., Toxicity, BSLT, Sterol, Steroi
Karakterisasi Nanokomposit Poly(Lactic Acid)-Spent Bleaching Earth Regenerasi Termodifikasi: Characterization of Nanocomposite of Poly(Lactic Acid)-Modified Regenerated Spent Bleaching Earth
Get PDFDevelopment of renewable resource-based polymers attracts attention to solve environmental problems due to the build up of polymer (plastic). Poly(lactic acid) (PLA) is one of the most widely used polymers which have good biodegradability and processability. The addition of fillers to the PLA matrix aims to improve the characteristics of the PLA, such as mechanical properties of nanocomposites of PLA. Thus, PLA can be use as substitution of fossil fuel-based polymer. Spent Bleaching Earth (SBE) can be used as a filler after regeneration process. SBE was extracted and oxidized to take its oil content. Then, SBE was modified with urea solution to increase the interlayer distance. In this study, structure of nanocomposites was characterized using X-Ray Diffraction and mechanical properties of nanocomposites were characterized using Universal Testing Machines. X-Ray Diffraction characterization results show that PLA-SBE nanocomposite and PLA-modified regenerated SBE nanocomposites do not form new peaks, so SBE and modified regenerated SBE is intercalated and partially exfoliated in the PLA matrix. The degree of intercalation/exfoliation is indicated by the results of characterization of mechanical properties. The mechanical properties of PLA-SBE nanocomposite are lower than neat PLA, whereas the mechanical properties of PLA-modified regenerated SBE nanocomposites are higher than neat PLA. The best mechanical properties of nanocomposites were obtained for PLA-5% modified regenerated SBE, with elongation and tensile strength, 3.26%, and 42.22 MPa, respectively.
Keywords: nanocomposites, poly(lactic acid), regeneration, spent bleaching eart