Jurnal Akademika Kimia
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Antioxidant Activity Tests of Extract of Principle Crafts (Phaleria macrocarpa)
Get PDFoai:ojs.pkp.sfu.ca:article/23Phaleria macrocarpa contains secondary metabolite compounds such as alkaloids, terpenoids, saponins, polyphenols, tannins, sterols, and coumarins. Those metabolites are antioxidants and can be efficacious in the healing of various degenerative diseases such as cervical cancer and diabetes. This plant is widely grown in Tindaki Village, Parigi Mautong, Central Sulawesi. The aim of this study was to determine the antioxidant power of those phaleria macrocarpa fruit extract. This study was conducted by using maceration extraction technique with ethanol as solvent, and compound 2,2-difenil-1-picrilhidrazil (DPPH) as source of free radical, and vitamin C as the positive control. The UV-Vis spectrophotometer was used to measure the absorbance of the extract. Various concentrations of the extract used were 5 ppm, 15 ppm, 25 ppm, and 35 ppm. The results showed that the IC50 value of the fruit extract was 28.242 ppm, while the IC50 value of vitamin C was 19.302 ppm. These IC50 values show that vitamin C was a stronger antioxidant activity than the fruit extract, but the fruit extract was still as a very strong natural antioxidant category
Analysis of Vitamin C and Calcium in Jongi Fruits (Dillenia serrata Thunb) Based on Their Maturity Level
Get PDFJongi plant (Dillenia serrata Thunb) is one of the plants that found Poso District. The characteristics of this fruit are mainly on the refreshing sour taste and attractive color which is yellow. This study aims to determine the levels of vitamin C and calcium in this fruit based on the level of maturity. The fruit of jongi used as a sample was categorized into there type of maturity namely mature, ripe, and overripe. The method used for vitamin C analysis was iodimetry and for calcium, analysis using spectrophotometry (λ: 422.7 nm). From the results of the analysis, it was obtained that the levels of vitamin C in fruit jongi successively were 81.84, 114.40, and 70.40 mg/100 g, while the calcium levels obtained in the fruits were 5.91, 5.65, and 6.46 mg/100 g. The data above showed that the maximum vitamin C content in jongi fruit when the fruit was in ripe type, while the highest calcium content in jongi fruit was when the fruit in overripe type
The Implementation of Blended Learning Based on MOODLE on Student’s Chemistry Learning Outcome at Class X in SMA Negeri 3 Poso
Get PDFThe growth of technology has encouraged learning toward blended learning which combines e-learning-based learning with the conventional face-to-face learning system. The use of MOODLE software to created web-based virtual class and the benefits of social interaction, making blended learning to has a more flexible and efficient time with more varied learning media. This research aimed to determine the effect of the implementation of blended learning based on MOODLE on student chemistry learning outcomes at class X in SMA Negeri 3 Poso. The research was conducted by giving treatment to the experiment class 1 (n = 32) and repeating the same treatment to the experiment class 2 (n = 33). The average pretest value in experiment class 1 was 19.06 and in experiment class 2 was 20.30. While the average of posttest value in experiment class 1 was 76.50 and in experiment class 2 was 73.00. The test of hypotheses was conducted using the Wilcoxon Signed Rank Test with criteria is, if –Ztable ≤ Zcalculate ≤ +Ztable then H0 is accepted. The value of Zcalculate in experiment class 1 was -4.93 and in experiment class 2 was -5.01. Based on the data, it been concluded that there was an effect of the implementation of blended learning based on MOODLE on student’s chemistry learning outcomes at class X in SMA Negeri 3 Poso