Background and Aim: The authentication of honey is important to protect industry and consumers from such adulterated honey. However, until now, there has been no guarantee of honey's authenticity, especially in Indonesia. The classification of honey is based on the bee species (spp.) that produces it. The study used honey from sting bee Apis spp. and stingless bee Tetragonula spp. based on the fact that the content off honey produced between them has differences. Authenticating honey with currently available rapid detection methods, such as 13C nuclear magnetic resonance analysis, is costly. This study aimed to develop an inexpensive, fast, precise, and accurate classification method for authenticating honey. Materials and Methods: In this study, we use attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy with wavelengths ranging between 550 and 4000 cm-1 as an alternative analysis method, which is relatively less expensive. The spectra of authentic and fake honey samples were obtained using ATR-FTIR and plotted using chemometric discriminant analysis. The authentic honey samples were acquired from a local Indonesian breeder of honey bees, while the fake honey samples were made from a mixture of water, sugar, sodium bicarbonate, and authentic honey. Data were collected using Thermo Scientific's OMNIC FTIR software and processed using Thermo Scientific's TQ Analyst software. Results: Our method effectively classified the honey as authentic or fraudulent based on the FTIR spectra. To authenticate the honey, we formed two classes: Real honey and fake honey. The wavelengths that can best differentiate between these two classes correspond to four regions: 1600-1700 cm-1; 1175-1540 cm-1; 940-1175 cm-1; and 700-940 cm-1. Similarly, for classification purpose, we formed two classes: Apis spp. and Tetragonula spp. The wavelength region that can best classify the samples as belonging to the Apis spp. or Tetragonula spp. class is explicitly within the range of 1600-1700 cm-1. Conclusion: This study successfully demonstrated a method to rapidly and accurately classify and authenticate honey. ATR-FTIR is a useful tool to test the authenticity of honey. Keywords: Apis spp., attenuated total reflectance Fourier transform infrared, discriminant, spectrum, Tetragonula spp.
Adsorption-crosslinking is one of the immobilization methods to improve the reusability of lipase. It requires amino groups to reduce cross-link immobilization risk so that lipase–support interaction increases and the immobilization is attainable. Also, the amino group on the support is expected to increase lipase performance. This study aimed to analyze the effect of amino group addition on immobilized Aspergillus niger lipase by the adsorption-crosslinking using MP-64 macroporous anion resin and XAD-7HP macroporous nonionic resin that has been treated with chitosan. The chitosan-coated resin was characterized by Fourier transform infrared spectrometry (FTIR) and scanning electron microscope (SEM). Lipase immobilization was carried out by adding 10 ml lipase solution containing 0.75 g resins and shaken at 25°C for 150 rpm. Adsorption was achieved for 4 h, followed by cross-linking separately (adding 0.5% (v/v) glutaraldehyde and re-reacting for 20 min). Lipase activity was measured with the titrimetric of olive oil emulsion; mixed with Aspergillus niger lipase, emulsion, and a buffer solution (pH 6.5, ionic strength of 0.7); and incubated for 30 min at 37°C. The effect of amino-functional groups was investigated based on lipase loading and lipase activity. The best lipase loading and lipase activity of 83.79% and 29.41 U/g support were achieved in the adsorption-crosslinking using MP-64 resin coated with chitosan. After four cycles, biodiesel synthesis was maintained at 70.61% of the initial yield. These results indicated that chitosan as an affordable and readily available source of amino groups could be used to modify support for Aspergillus niger lipase immobilization.
This research suggests that AP-PLA2 has the potential to develop as an antiviral agent because in vitro experiment showed its ability to decrease HIV infection in PBMC and the number of HIV ribonucleic acid in culture
Background:In the previous research propolis and curcumin have been reported to have biological activity as antibacterial. Both of those herbs can be developed as anti-oral biofilm mouthwash oral hygiene. Mouthwash is produced as nanoemulsion that promotes wide distribution throughout oral biofilm and effectively penetrates to target cell. Objective: This study aims to create the best mouthwash formulation with great physical characteristics and stability, and also proved as an anti-biofilm agent. Methods: Each propolis A.mellifera and curcumin Curcuma domestica Val. was formulated into a mouthwash using the combined method of homogenization, mixing and ultrasonication. There was a variation amount of Tween-80 and glycerin in each formulation to investigate its effect on stability. The proven formula with the greatest stability was continued to undergo antibiofilm assay. Results: Result of this study showed that formula with a ratio of Tween-80 and glycerin 2:1 (v/v) was found to be the best. Tween-80 and glycerin can’t work as a single surfactant to produce stable nanoemulsion. Propolis and curcumin mouthwash showed in vitro antibiofilm activities against Streptococcus mutans, the primer colony in the biofilm. Propolis mouthwash reported has better effectiveness with the MIC of biofilm formation was 5% v/v and % inhibition of 48,54%, respectively. Conclusion:Nanoemulsion propolis mouthwash is proven to have the higher effectiveness in inhibiting biofilm formation than curcumin mouthwash. It suggested nanoemulsion propolis can be developed as good oral hygiene mouthwash that cansignificantly reduce the number of oral bacteria and inhibit their proliferation.
Conventionally, biodiesel is produced by using the homogeneous catalyst which has difficulty in high cost of the separation process. The heterogeneous catalysts ion exchange resin by its Solid phase can make an easier separation process, able to be reactivated and used repeatedly. In this research, the heterogeneous catalyst from various source such as Lewatit macro porous resin, Amberlite gel resin and natural zeolite bayah was investigated their performance to produced biodiesel from used cooking oil. Initially, the preparation of the ion exchange process with variations in time, temperature, the concentration of HCl and NaOH solution was investigated. Then, the activity of heterogeneous catalyst to produced biodiesel under the variation of stirring rate, zeolite particle size, and comparison of different ion exchange catalysts were also investigated. Finally, the stability test and regeneration treatment were also investigated. The optimum operating conditions of biodiesel synthesis process is at the temperature of 60 °C for 2 h with a stirring speed of 700 rpm. Natural zeolite Bayah with 6 M of NaOH solution produced 16.19%, Amberlite gel with 6 M HCL produced 65.22% of biodiesel yield and material Lewatit macro porous with 6 M of NaOH solution produced 85.94% as the maximum result. As the best result, Material Lewatit macro porous selected as the material which was used in the variation of stirring speed, temperature, and reaction time, the concentration of base and stability test. According to the results of analysis, calculations yield methyl oleic HPLC produced by Lewatit macro porous with 6 M NaOH at 62.95%.
Reliability data are very important for probabilistic safety assessment by fault tree analysis. Due to the limitations of historical failure data of the system being evaluated, generic data have been occupied. However, generic data comes with uncertainties and, hence, cannot represent its real performance. To overcome this limitation, fuzzy probability has been integrated into conventional fault tree analysis to evaluate the performance of nuclear reactors’ safety systems. In fuzzy fault tree analysis, the qualitative judgments of experts are collected to assess the failure possibility of basic events. Furthermore, the membership functions of fuzzy numbers are used to convert those qualitative judgments into quantitative data. The assessment made by experts is a subjective judgment. Each expert has varying levels of expertise, so assessment of the same basic event will provide different judgments. The experts who are involved in the assessment process should be selected properly, because expert judgment is very influential on the final outcome of analysis. This study proposes a four stage expert selection process. Through the implementation of the proposed approach, five groups of experts has been selected. The five groups consisted of (1) head of division (reactor maintenance division, reactor operation division, and occupational and operation safety division); (2) head of subdivision (mechanical system subdivision, electrical system subdivision, instrumentation and control subdivision, operation reactor subdivision, and operation safety subdivision); (3) supervisor of reactor and supervisor of maintenance; (4) operator of reactor and maintenance technician; (5) radiation protection officer and staff of operation safety subdivision.