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Indriana Lestari
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PENGARUH JENIS ASAM DAN SUHU EKSTRAKSI TERHADAP KARAKTERISTIK PEKTIN DARI KULIT PISANG KEPOK yuli ristianingsih; Indriana Lestari; Wibiana Wulan Nandari
Eksergi Vol 18, No 2 (2021)
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v18i2.5400

Abstract

Pectin is structurally and functionally the most complex polysaccharide in plant cell walls. Pectin is widely used as an adhesive and emulsifier in the food, pharmaceutical industry and also as an adsorbent in waste water treatment. This research used banana peels as a raw material. The purpose of this study was to study the effect of temperature and solvent (acetic acid and hydrochloric acid) on the characteristics of pectin (ash content, methoxyl and galacturonic content). This research was carried out in a stirred tank reactor for 90 minutes with various types of solvents (hydrochloric acid and acetic acid) and extraction temperatures (60, 70, 80 and 90) 0C. Based on the research, it was found that the optimum pectin yield with 0.25 N HCl at a temperature of 800C was 24.93%. The characteristics of pectin which include galacturonic acid, methoxyl content, ash content and equivalent weight at an extraction temperature of 800C with a concentration of 0.25 N HCl were 79,56%; 2.65; 6,72% and 3846
Polymerization Styrene dengan Solven Toluena Sri Wahyu Murni; Wasir Nuri; Indriana Lestari; Ani Saraswati
Eksergi Vol 9, No 1 (2009): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v9i1.7579

Abstract

Polystyrene is the result of free radical-addition polymerization of styrene monomer with the initiator benzoyl peroxide. This research aims to study the effect of variable temperature and ratio of toluene-styrene (T / S) against the conversion and reaction kinetics of polymerization of styrene with toluene solvent and initiator benzoyl peroxide. This research was conducted in two stages, ie preliminary experiments with test FTIR (Fourier Transform Infra-Red) to prove that the manufacture of polystyrene was successful. Manufacture of polystyrene begins with purifying styrene monomer, and then enter a toluene-styrene (5:1 volume ratio, 5:2, 5:3, 5:4) and 0.2 gram of benzoyl peroxide into a three-neck flask and heated to the desired temperature (60, 70, 80, 90 and 100)oC. Samples were taken every 15 minutes. Each sample is added 0.01 grams of hydroquinone in 10 ml of ethanol and shaken gently to precipitate the polystyrene, then wet samples were weighed, put in oven at 200oC for 1.5 hours. Dried sample was cooled in eksikator then weighed to determine the weight of polystyrene formed. From the experimental results at optimum condition of reaction time of 120 minutes, the temperature of 100oC and toluene-styrene ratio of 5:4, obtained by conversion of 58.75%. The global rate reaction according to equation k' = 5963 exp (-8901 / T).
Edible Oil sebagai Pelarut Ekstraksi Karotenoid dari Kulit Labu Kuning (Cucurbita moschata) Perwitasari Perwitasari; Heni Anggorowati; Susanti Rina Nugraheni; Indriana Lestari
Eksergi Vol 20, No 2 (2023)
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v20i2.10003

Abstract

Carotenoids are pigments found in various types of fruits and vegetables that provide yellow, orange, and red colors. This study aimed to extract yellow pumpkin skin using edible oil solvents. The extraction process was carried out using ultrasound-assisted extraction (UAE) method with virgin coconut oil (VCO) and palm kernel oil (PKO). Yellow pumpkin peel powder with sizes of 40 mesh and 100 mesh were extracted with variations in extraction time (30 minutes, 60 minutes, and 90 minutes) and variations in solid-to-solvent ratio (1:10, 1:20, 1:30, 1:40, and 1:50). UV-Vis spectrophotometer analysis was used to determine the concentration of the extraction results. According to the research results, the best carotenoid concentration of 2513.44 ppm was obtained using PKO solvent with a powder size of 100 mesh, extraction time of 30 minutes, and powder-to-solvent ratio of 1:10.