cover
Contact Name
Eko Didik Widianto
Contact Email
rumah.jurnal@live.undip.ac.id
Phone
-
Journal Mail Official
jvsarvokasiundip@gmail.com
Editorial Address
Vocational School of Diponegoro University Jl. Prof. H. Soedarto, S.H. Tembalang, Semarang 50275
Location
Kota semarang,
Jawa tengah
INDONESIA
Journal of Vocational Studies on Applied Research
Published by Universitas Diponegoro
ISSN : -     EISSN : 26848090     DOI : -
Core Subject : Engineering,
Journal of Vocational Studies on Applied Research [e-ISSN 2684-8090] is an open access peer reviewed journal published by Vocational School Diponegoro University Semarang Central Java Indonesia. Journal of Vocational Studies on Applied Research is an Journal publishing academic and industrial topics which covers area of interest on applied research as well as vocational studies. Research papers on Engineering, Science and Vocational Studies are welcomed. The Journal is double-blind reviewed which accepts Original Research Paper, Short Communication and Review Articles.
Articles 75 Documents
The Effect of Differences in the Use of Flour and Plasticizers in Making Biodegradable Plastic on the Physical Characteristics of Beeswax Yustianto, Ahmad Hadi; Sully, Diah Amara; Fauzi, Ahmad Dzakky; Amalia, Rizka
Journal of Vocational Studies on Applied Research Volume 6, Issue 2, Year 2024 (October 2024)
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jvsar.v6i2.24257

Abstract

Plasticis is one of the objects that is necessary in daily activities. This is because plastics makes it easier for humans to package goods. Its elastic and easy-to-use properties make plastic widely used by humans. However, on the other hand, plastic has properties that are difficult to decompose (non-degradable) so it is one of the biggest generators of waste that pollutes the environment. Biodegradable plastic or commonly called bioplastic can be an alternative product to reduce plastic waste because it is easily decomposed and more environmentally friendly. This research examines the influence of the type of starch (avocado seed flour, manga seed flour, banana peel flour, cassava peel flour) and plasticizers (glycerol, sorbitol, and polyvinyl alcohol) with beeswax additives on the characteristics of the resulting bioplastic. The best tensile strength value was found in a sample of mango seed flour, PVA type plasticizer, 0.04 gram beeswax, namely 11.35 MPa. The best elongation value was found in samples of mango seed flour, glycerol type plasticizer, 0.04 gram beeswax, namely 67%. The best percentage degradation value is bioplastic using cassava peel starch. The best swelling index value was found in samples of avocado seed flour, sorbitol type plasticizer, 0.1 gram beeswax, namely 20.16%. In terms of water content values, all samples are in accordance with SNI, namely below 20%.
Optimizing Microwave-Assisted Extraction Parameters for Delignification of Water Hyacinth Stems Mario, Abraham; Fahira, Lala Firdha; Wulansari, Tiara; Amalia, Rizka
Journal of Vocational Studies on Applied Research Volume 6, Issue 2, Year 2024 (October 2024)
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jvsar.v6i2.24429

Abstract

Water hyacinth (Eichornia crassipes) is an aquatic plant that grows very quickly in Indonesian waters and is classified as an invasive weed, so it can cause ecological problems. Water hyacinth stems have a high cellulose content of 28-39%. Extraction of cellulose from water hyacinth needs to be done to remove lignin content. The microwave delignification method has the advantage of a rapid increase in temperature so that the extract yield is greater. This study aims to determine the optimal operating conditions in the delignification process of water hyacinth stems using the Microwave Assisted Extraction (MAE) method by examining the process variables: extraction time (5,10,15 minutes) and microwave power (400, 5000 and 600 watts). Based on the results of the study, the optimal operating conditions at a transmission time of 11.5 minutes and a transmission power of 530.5 watts, which were obtained in 20.25% of water hyacinth stems.
The Role of Acid Catalysts in Optimizing Iron Adsorption: Mechanistic Insights and Applications Resi, Nadyn Amalia; Ichwan, Muhammad Maulana; Hapsari, Fatimah
Journal of Vocational Studies on Applied Research Volume 6, Issue 2, Year 2024 (October 2024)
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jvsar.v6i2.25113

Abstract

This research aims to evaluate the influence of acid catalysts HCl and H2SO4, on the adsorption efficiency of Fe (Iron) using silica extracted from rice husk ash. The synthesis process employs the sol-gel method, including the initial treatment of rice husk ash, sodium silicate extraction, and the formation of silica gel with acid catalysts. The research results show that acid catalysts affect the structure and adsorption efficiency, with the highest efficiency obtained using 0.5M HCl catalyst with an adsorption efficiency of 62.3% and 0.5M H2SO4 catalyst with an adsorption efficiency of 24.85%. FTIR analysis to identify functional groups revealed siloxane (Si-O-Si) and silanol (Si-OH) contain on silica, which support the metal adsorption capability. The results of the morphological observation using SEM show that the amorphous silica structure has diverse pores based on the type of catalyst.
Optimization Extraction of Anthocyanin from Roselle as a Natural Colorant using Natural Deep Eutectic Solvent with Microwave Assisted Extraction Method Kurnianto, Ade; Prasetyaningrum, Aji; Paramita, Vita
Journal of Vocational Studies on Applied Research 2025: Just Accepted Manuscript and Article In Press 2025
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jvsar.v0i0.26556

Abstract

Roselle (Hibiscus sabdariffa L.) contains high levels of anthocyanins with significant antioxidant properties. However, conventional extraction methods often result in low efficiency and degradation of bioactive compounds. This study aims to optimize the extraction of anthocyanins from roselle using Microwave Assisted Extraction (MAE) with Natural Deep Eutectic Solvent (NADES) combination of sodium acetate and glycerin then examine the effect of optimum anthocyanin content. The variables applied were microwave power (200, 400, 600 Watt) and extraction time (4, 6, 8 min), optimized using Response Surface Methodology (RSM) with 12 experimental runs. Analysis included antioxidant content (anthocyanins, vitamin C, tannins, and total phenolics) and stability tests (density and viscosity). The RSM results have shown that the optimization value of anthocyanin content is 0.3217%, which will be achieved at an extraction time of 6.02 min, and microwave assisted extraction power at 323.77 Watt. The result of the optimum anthocyanin variable shows anthocyanin content is 0.3072% confirming the model's accuracy. MAE combined with NADES provides an efficient and environmentally friendly method for extracting natural colorants with high antioxidant activity from roselle.
Multi-Response Optimization of Mangosteen Peel Extraction Using Natural Deep Eutectic Solvent and Microwave Assisted Extraction for Anti-Aging Berkah, Fitroh Bawa; Paramita, Vita
Journal of Vocational Studies on Applied Research 2025: Just Accepted Manuscript and Article In Press 2025
Publisher : Vocational College of Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jvsar.v0i0.26555

Abstract

The peel of mangosteen (Garcinia mangostana L.) is rich in bioactive compounds, including xanthones, phenolics, flavonoids, anthocyanins, and vitamin C, which have been associated with antioxidant, anti-inflammatory, and anti-aging properties. This study aimed to optimize the extraction of these compounds, particularly xanthones, using Microwave-Assisted Extraction (MAE) in combination with a Natural Deep Eutectic Solvent (NADES) consisting of lactic acid, sodium acetate, and distilled water in a 3:1:2 volume ratio. The extraction process was carried out under varying microwave power levels (300, 375, and 450 Watt) and extraction times (2, 4, and 6 min). Optimization was conducted using Response Surface Methodology (RSM), and the resulting bioactive compound contents were analyzed by UV-Vis spectrophotometry. The optimal extraction conditions were determined at 300 Watt and 4.46 min, resulting in xanthone (1.40%), phenolics (42.43%), flavonoids (1.22%), anthocyanins (1.20%), and vitamin C (2.94%). These findings indicate that NADES-MAE is an effective green extraction technique for maximizing bioactive compounds from mangosteen peel, supporting its potential use in anti-aging product formulations.