KOVALEN: Jurnal Riset Kimia
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Analisis Formalin Secara Kualitatif pada Bakso dan Mie Basah di Kecamatan Sukarame, Wayhalim, dan Sukabumi: Qualitative Formaline Analysis on Meatball and Wet Noodle in Sukarame, Wayhalim, and Sukabumi
Get PDFMeatballs and wet noodles are foods that are favored by the community. The high water content causes these two types of food to be vulnerable and easily damaged in storage. The addition of chemicals such as preservatives in the manufacture of food products is carried out by producers so that the products are more durable, economical, and produce maximum profit. One chemical that is often misused for food preservatives is formaldehyde. Formalin is a dangerous chemical that is carcinogenic, mutagenic, corrosive, and irritating. This study aims to determine whether there is formalin content in meatballs and wet noodles that are sold in the districts of Sukarame, Wayhalim, and Sukabumi. This research was conducted in a qualitative analysis using Schiff's reagent on 30 samples of meatballs and 30 samples of wet noodles which were sold in Sukarame, Wayhalim, and Sukabumi. The results showed that 10 samples of meatballs and 2 wet noodles showed positive results containing formaldehyde. This shows that around 33.3% of the meatball sample and 6.66% of the wet noodles sample analyzed were identified to contain formaldehyde so that they are not safe for consumption in the long term and people must be careful in selecting meatballs and wet noodles for consumption.
Keywords: Qualitative analysis, formalin, meatballs, wet noodle
Sintesis Metil Ester Asam Lemak dari Biji Alpukat (Parsea americana Mill) Menggunakan Polimer Penyangga Katalis Berbahan Dasar Eugenol: Synthesis of Fatty Acid Methyl Ester from Avocado Seeds (Parsea americana Mill) using Polymer Support Catalyst Based on Eugenol
Get PDFResearch on the manufacture of methyl esters from avocado seeds (Parsea americana Mill) with eugenol-based catalysts has been conducted. The aim is to determine the catalyst concentration used to produce methyl esters with the highest rendement and determine the composition of fatty acid methyl ester in avocado seeds. This study was used variations in concentrations of 0.25%, 1%, 1.75%, 2.25%, and 3%. The results of this study showed that the best concentration is 2.25% with the calculation of the results of 24.8% methyl esters in avocado seeds, namely lignoceric and octadecenoic acid methyl ester.
Keywords: Avocado seeds, fatty acid methyl ester
Kinerja Elektroda Platina Terlapis Enzim Butirilkholinesterase-Selulosa Asetat-Glutaraldehida untuk Deteksi Diazinon: Performance of Platina Electrode Coated by Butyrylcholinesterase-Cellulose Acetate-Glutaraldehyde for Diazinon Detection
Get PDFDiazinon (o, o-diethyl-o [2-isopropyl-6-methyl pyrimidynyl] phosphorotioate) is one of the organophosphate group pesticides widely used to protect cabbage plants (Brassica olarecea). Pesticide residues left in plants can bind to the cholinesterase enzyme and cause system disruption nerve. Analysis of diazinon residues in cabbage plants needs to be done to determine the level of toxicity caused. The electrochemical biosensor method as an electrochemical sensor uses a working electrode of platinum wire coated with the enzyme butybholchesteresterase (BChE) and cellulose acetate (SA) membrane and glutaraldehyde (GA) can be used for the analysis of pesticide residues. The test results of the SA electrode composition of the 10% GA 20% membrane obtained Nernst factor prices 28.1 µV / decade with a measurement range of 10-9 - 10-6 M, detection limit value of 1.29 x 10-7 M response time of 30 - 300 seconds.
Keywords: biosensor, butylochholesterase, membrane, electrochemistr
Analisis Kadar Vitamin C Bawang Putih dan Hitam dengan Metode Spektrofotometri UV-Vis: Analysis of Vitamin C Levels of Garlic and Black Garlic by UV-Vis Spectrophotometric Method
Get PDFAn analysis of vitamin C levels of garlic and black garlic was done by UV-Vis spectrophotometric method. Garlic and black garlic contain a variety of nutrients and vitamins. Single and plural garlic is widely used as a medicine, besides garlic is currently also popular with garlic which is processed at temperatures between 60-80̊C with an environmental humidity of around 70-90% for 10-40 days. One of the vitamins contained in garlic includes vitamin C which acts as an antioxidant and is effective in dealing with free radicals. Vitamin C analysis was performed by the spectrophotometric method on the maximum wavelength is 250 nm with an absorbance value of 3.994. Results of analysis of vitamin C levels single garlic by 0.28% content of plural garlic by 0.27%. Vitamin C levels of single black garlic 0.29% (10 days), 0.31% (20 days), and 0.32% (30 days), plural black garlic Vitamin C levels 0.28% (10 days), 0.29% (20 days) and 0.31% (30 days).Based on ANOVA test results obtained there are differences in levels of vitamin C in single black garlic over several variations of time (days)and there are differences in levels of vitamin C in plural black garlic over several variations of time (days) because of Fcount ≥ Ftable.The coefficient of variation (KV) value is needed to test the level of accuracy of the analysis results. KV value in single garlic is 0.68% and plural garlic is 1.24%. KV value of single black garlic 0.3% (10 days), 0.25% (20 days), and 0.7% (30 days), KV of black garlic 0.55% (10 days), 0.61% (20 days), and 0.43% (30 days).
Keywords: Single garlic, garlic plural, black garlic, fermentation, vitamin C level
Studi Perbandingan Aktivitas Antioksidan Xantofil dan Karoten Kapang Oncm Merah pada Berbagai Waktu Inkubasi: Comparison Study of Antioxidant Activity of Xanthophyll and Carotene from Red Oncom Mold In Various Incubation Times
Get PDFResearch on a comparative study of antioxidant activity of xanthophyll and carotenoids from red oncom, mold in various incubation times has been studied. This study aims to determine the antioxidant activity of xanthophyll and carotene at various incubation times of red oncom cultured in corn cob medium. This study used a Completely Randomized Design (CRD) at variations in incubation time: 2, 3, 4, 5, 6, and 7 days. The results showed that the best antioxidant activity of xanthophyll and carotene was on the second day with antioxidant activity of 82.27% and 65.80%, respectively.
Keywords: antioxidant activity, xanthophyll, carotene, carotenoids, red onco
Efisiensi Mikroenkapsulasi Ekstrak Kulit Buah Naga Super Merah (Hylocereus costaricensis) Tersalut Maltodekstrin Berdasarkan Kecepatan Pengadukan: Microencapsulation Efficiency of Super Red Dragon Fruit (Hylocereus costaricensis) Peel Extract Coated with Maltodextrin Based on Stirring Speed
Get PDFExtract of super red dragon fruit peel has an antioxidant activity that can prevent free radicals from outside and its activity can be maintained by the coating of super red dragon fruit peel extract with maltodextrin The coating efficiency of super red dragon fruit peel extract with maltodextrin can be controlled with the speed of stirring during microencapsulation experiment. In order to obtain the highest microencapsulation efficiency and compare the antioxidant activity of super red dragon fruit peel extract before and after microencapsulation experiment. The study of coating efficiency has been done with microencapsulation that was carried out using the freeze-drying technique. During the microencapsulation of super red dragon fruit peel extract with freeze-drying technique, stirring speed in the microencapsulation process was 600 rpm, 800 rpm, 1000 rpm, 1200 rpm, and 1400 rpm respectively. From the microencapsulation process of super red dragon fruit peel extract coated with maltodextrin, it was obtained the highest microencapsulation efficiency at stirring speed of 800 rpm, which was 66.85% and had a particle size of 14.24 µm. It can be concluded that the antioxidant activity before and after encapsulation included a very weak category with IC50 values of 205.42 ppm for extracts and 246.32 ppm for microcapsules.
Keywords: Super red dragon fruit peel, freeze-drying, microencapsulation, maltodextri
Retensi Ekstrak Karoten pada Olahan Mie Wortel (Daucus carrota L.): Retention of Carotene Extract on Carrot (Daucus carrota L.) Noodles
Get PDFCarotene extract from carrots (Daucus carrota L.) can improve the quality of processed noodles. Determining of carotene retention in processed carrot noodles during the storage period that has been done aims to know the reaction kinetics and shelf life of the noodles. Carrot noodles were stored for 8 weeks at room temperature and analyzed its carotene content by using a UV-Vis spectrophotometer every 7 days. The result showed that the retention of carrot noodles during storage of 0, 1, 2, 3, 4, 5, 6, 7, and 8 weeks was 53.64%, 53.19%, 52.49%, 51.68%, 51.07%, 46.30%, 45.96, 45.88, and 44.93%, respectively. The retention kinetics of carrot noodles during storage followed a zero-order reaction and had a shelf life of up to 30 weeks, 4 days, 4 hours.
Keywords: carrot noodles, retention, self lif
Sintesis Nanopartikel Perak Menggunakan Ekstrak Daun Eceng Gondok (Eichornia crassipes) Sebagai Bioreduktor: Synthesis of Silver Nanoparticles Using Leaves Extract of Water Hyacinth (Eichornia crassipes) As a Bioreductor
Get PDFNanoparticles was done by adding water hyacinth leave extract to AgNO3 2mM solution with a ratio of 1:40. Formed silver nanoparticles were analyzed using UV-Vis spectrophotometer, SEM, XRD, PSA, and FTIR to determine its characteristics. Results showed that absorbance value increased if reaction time is increased. Maximum absorption was obtained at wavelength 432-446 nm by using UV-Vis spectrophotometer. Result of PSA analysis shows that the average size of silver nanoparticles formed is 93.2 nm while XRD analysis shows that the average crystal size of silver nanoparticles is 50.11 nm, with round shape and amorphous. Result of FTIR analysis to determine functional group that contributes to nanoparticle synthesis shows the contribution of OH group.
Keywords: reduction method, silver nanoparticles, Eichornia crassipes, bioreducto
Analisis Kadar Glukomanan Dari Biji Durian (Durio zeibethinus Murr) dengan Metode Spektrofotometri pada Berbagai Waktu dan Suhu Hidrolisis: Analysis of Glucomannan Content From Durian Seeds (Durio zeibethinus Murr) Using Spectrophotometry Methods in Several Hydrolysis Times and Temperatures
Get PDFDurian seeds are one type of seed that contains glucomannan. The aim is to determine glucomannan levels in the durian seed. The study was designed using a completely randomized design (CRD). The extracted glucomannan was determined by the spectrophotometry method at various temperature and hydrolysis time. The crude extract of glucomannan was hydrolyzed using 3 M HCl for 70, 80, 90, 100, and 110 minutes at 70, 80, 90, 100, and 110°C. The highest glucomannan concentration of 39.60% was obtained at a hydrolysis temperature of 100°C for 100 minutes. The analysis of the FTIR spectrophotometer shown that the vibration of the C-O-C functional group (glycoside bond) was obtained at the wavelength number of 1020.34 cm-1 which is a characteristic of glucomannan.
Keywords: glucomannan, durian seed, hydrolysis, spectrophotometr
Perubahan Bilangan Peroksida pada Blending VCO-Ekstrak Likopen Buah Tomat Berdasarkan Perbandingan Rasio dan Lama Penyimpanan: Peroxide Value Changes on Blending of VCO and Extract of Tomato Lycopene Based on Ratio Comparison and Storage Time
Get PDFUtilizing of lycopene extract in VCO has serve as antioxidant agent that protected VCO from oxidation process during storage. Belnding of VCO and tomato lycopene extract has been done that purpose to determine changes in peroxide number in the mixture of VCO-lycopene extract tomatoes based on comparison of ratios and length of storage. Peroxide contents from the mixture of tomato extract with VCO were determined using a spectrophotometric method at a wavelength of 500 nm. The results showed that the best results were obtained at a ratio of 40: 3 (v/w) with peroxide numbers 0.08 meq O2/ kg, 1.38 meq O2/ kg, 1.84 meq O2/ kg, 3.21 meq O2/ kg, 3.46 meq O2/ kg and 3.83 meq O2/ kg respectively. Peroxide numbers increased with increasing storage time, the highest increase occurred at week 3 at a ratio of 40: 1 (v/w) which was equal to 9.62 meq O2/ kg. The addition of lycopene was better at reducing the VCO oxidation process than without the addition of lycopene.
Keywords: peroxide value, VCO, lycopene, duration of storage, ratio compariso