Article Per Year (5 Year)
p-Index From 2021 - 2026
4.704
P-Index
This Author published in this journals
All Journal Jurnal Riset Kimia Jurnal Kimia Mulawarman Indonesian Journal of Chemistry Warta Pengabdian Andalas: Jurnal Ilmiah Pengembangan Dan Penerapan Ipteks REACTOR : Journal of Research On Chemistry And Engineering Andalasian International Journal of Agricultural and Natural Sciences Andalasian International Journal of Applied Science, Engineering, and Technology AJARCDE (Asian Journal of Applied Research for Community Development and Empowerment) Jurnal Abdi Inovatif : Pengabdian kepada Masyarakat Jurnal Katalisator Jurnal Kimia Unand
Yefrida -
Universitas Andalas
Agriculture, Biological Sciences & Forestry Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Medicine & Pharmacology Social Sciences Other

Published : 38 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 38 Documents
Search

 1   2   3   4 
VALIDASI METODA PENENTUAN ANTIOKSIDAN TOTAL (DIHITUNG SEBAGAI ASAM SITRAT) DALAM SAMPEL JERUK SECARA SPEKTOFOTOMETRI DENGAN MENGGUNAKAN OKSIDATOR FeCl3 DAN PENGOMPLEKS ORTO-FENANTROLIN Yefrida -; Mega Ulfaningsih; Umiati Loekman
Jurnal Riset Kimia Vol. 7 No. 2 (2014): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v7i2.187

Abstract

ABSTRACTAntioxidant is a compound that can be used to obstruct species oxygen reactive, speciesnitrogen, and other free radicals so it can be used degenerative illnesses inhibition. Citric acid isa natural antioxidant that can be found in some kind of oranges. There are some methode thatusually used to determination the antioxidant, such as CUPRAC, DPPH, and FRAP. Objectiveof this research is studied about alternative method to determine total antioxidant that is countedas citric acid by using FeCl3 as an oxidator and o-phenantroline as a complexant reagent. Instudied of appropriateness of this method, validation has been done with parameter linearity,LoD, LoQ, SDR, and recovery with samples orange, kaffir lime, and lime. Base on the research,the regression equation is Y = 0,066 + 117.35 X and R2 = 0.990 with value of LoD is1.15x10-3M and LoQ is 3.86x10-3 M. The value of SDR and recovery in samples orange, kaffir lime, andlime are 1.64%, 0.53% 2.14%, and 100.47%, 93.58%, 93.78%, respectively. Base on validationmethod data, can be concluded that this method appropriate to be used to determination of totalantioxidant for samples orange, kaffir lime, and lime.Keywords : Antioxidant, Validation Method, Spectrophotometry
VALIDASI METODA FRAP MODIFIKASI PADA PENENTUAN KANDUNGAN ANTIOKSIDAN TOTAL DALAM SAMPEL MANGGA DAN RAMBUTAN Yefrida -; Nor Ashikin; Nor Ashikin; Refilda -; Refilda -
Jurnal Riset Kimia Vol. 8 No. 2 (2015): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v8i2.236

Abstract

Validation of modified FRAP method to determine total antioxidant content in mango and rambutan sample have been done. Total antioxidan content in sampel is presented as Gallic Acid Equivalent (GAE). Modified FRAP method using FeCl3asoxidizing agent and ortho-phenantroline as complexan, which produce complex compounds of [Fe (C12H8N2)3]+2 sorrel coloured. Validation parameters are obtained in this research are r = 0.999, R2 = 0.998, LoD 3.13 x 10-6 M and LoQ 1.04 x 10-5 M. While RSD and recovery in the sample mango and rambutan were 1.15%, 1.34% and 96.31%, 97.72%, respectively. Based on the value of the validation parameters, it can be concluded that this method can be used for determination of total antioxidant content in the mango and rambutan samples.
Validasi Metode MPM untuk Penentuan Kandungan Antioksidan dalam Sampel Herbal serta Perbandingannya dengan Metode PM, FRAP dan DPPH Yefrida Yefrida; Hamzar Suyani; Hermansyah Aziz; Mai Efdi
Jurnal Riset Kimia Vol. 11 No. 1 (2020): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i1.342

Abstract

The Modified Phenanthroline Method (MPM) has been validated for determination of antioxidant content in herb samples. Validation was done using Relative Standard Deviation (RSD) and percentage of recovery. The RSD and percentage of recovery for herb samples are 3.13% and 98.6%, respectively. Based on these values, MPM method is valid for determining antioxidant content in herb samples. T test shows no significant differences of antioxidant content using any of these methods, MPM, PM, FRAP or DPPH, at a 95% confidence level. MPM method shows a very strong correlation with PM and FRAP method.  While with DPPH and TPC shows is strong.
Penentuan Kandungan Antioksidan Total pada Infusa Selada Hijau (Lactuca sativa L.) Hidroponik dan Konvensional secara Spektrofotometri dengan Modified Phenantroline Method (MPM) Yefrida Yefrida; Refilda Refilda; Nofi Hamidah; Widuri Rosman
Jurnal Riset Kimia Vol. 13 No. 1 (2022): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i1.492

Abstract

Green lettuce is a vegetable that is widely consumed in Indonesia. These vegetables come from conventional and hydroponic farming. This study aims to compare the antioxidant content of these two types of vegetables. This vegetable is extracted by the infundation method. The extract obtained was determined for its antioxidant content by the MPM method. This method was validated by using parameter LoD, LoQ, linearity, precision and accuracy. The results showed that this method was valid for determining the total antioxidant content in conventional and hydroponic green lettuce samples. The total antioxidant content in conventional and hydroponic green lettuce samples was 2.68 ± 0.65 mg aa/g FW and 1.67 ± 0.40 mg AA/g FW, respectively. T test stated that the antioxidant content of the two samples was significantly different.
Budidaya Ikan Lele untuk Menunjang Kelancaran Biaya Operasional TPQ dan RTQ Raudhatul Adzkia Jorong Dalam Koto Kabupaten Agam Refilda Refilda; Rahmiana Zein; Yefrida Yefrida; Zilfa Zilfa; Upita Septiani; Syukri Syukri; Diana Vanda Wellia; Syafrizayanti Syafrizayanti; Matlal Fajri Alif; Elida Mardiah; Refinel Refinel; Admi Admi; Emil Salim; Fitratul Ilahi; Dwi Syukur Phameswari
Warta Pengabdian Andalas Vol 28 No 3 (2021)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat (LPPM) Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jwa.28.3.206-214.2021

Abstract

The Qur'an Education Park (TPQ) and Tahzhul Qur'an House (RTQ) of the Raudhatul Adzkia Jorong Dalam Koto Nagari Koto Tangah, Tilatang Kamang, and District of Agam have been launched since 2015. The students who study here are free of charge. The operational costs of education and the honorarium for educators come from donations from their community and some nomads. However, this contribution is not sufficient for operational costs. The Department of Chemistry's community service team, Andalas University, collaborated with partners to start a business to solve this problem. The business was carried out using vacant land owned by partners for catfish cultivation. Surveys, program socialization and assisting activities were carried out online using virtual media, while Partners carried out the implementation in the field. Activities carried out were pond preparation, the release of catfish seeds, feeding, sorting, maintenance, harvesting, and marketing cultivated catfish. Based on the evaluation, 5000 seedlings from the released catfish developed well. About 99% of catfish typically growth to a large and even size, while the other 1% growth relatively slowly. Harvested catfish were sold for IDR 18,000/kg for wet fish and IDR 100,000/kg for dried fish. This business has been carried out sustainably by partners, and the profits have been used to support the operational costs of TPQ and RTQ Raudhatul Adzkia.
Teknik Edible Coating dengan menggunakan Campuran Gel Lidah Buaya dan Ekstrak Daun Psidium guajava L. untuk Mempertahankan Sifat Fisikokimia Buah Jambu Biji Refilda Refilda; Riga Habib Ngestu; Emil Salim; Yefrida
Jurnal Riset Kimia Vol. 13 No. 2 (2022): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i2.501

Abstract

The synthetic chemicals is a common substance used to extend the shelf life of postharvest fruit. But it can have health impact. The use of edible coatings from natural ingredients has begun to be developed. Modification of aloe vera gel by guava leaf extract as the edible coating to increase guava fruit shelf life has not been reported yet. Guava fruit coated by several compositions of aloe vera gel and guava leaf extract have been carried out. Observations on physichochemical in fruit on the days 0, 3, 6, 9, 12 and 15 were evaluated. The best quality found on guava fruit treated with the compotition of aloe vera gel:ethanol guava leaf extract: CMC:glycerol (90: 5:0.25: 0.5) on the day 15. It had a weight loss of 9.88%, a spoilage of 3.33%, the decrease of water content 11.61%, titratable acidity 0.5%, total antioxidant 1.08 mg AA/g FW, total phenolic 0.51 mg GAE/g FW, and increase of total dissolved solids 3.01 oBrix. This result was significantly better than the uncoated fruit. It can be concluded that guava leaf extract can be used to maintain the physicochemical properties during storage.
Pengembangan Usaha Akuaponik di Kolam Ikan TPQ & RTQ Raudhatul Adzkia Dalam Koto, Kabupaten Agam Refilda Refilda; Rahmiana Zein; Hermansyah Aziz; Yefrida Yefrida; Zilfa Zilfa; Syukri Syukri; Matlal Fajri Alif; Yulizar Yusuf; Admi Admi; Raihan Hanif Aulia; Nurul Afifah
Warta Pengabdian Andalas Vol 29 No 4 (2022)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat (LPPM) Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jwa.29.4.436-442.2022

Abstract

The Community Service Team of the Chemistry Department has worked closely with the Taman Pendidikan Qur'an (TPQ) and Rumah Tahzhul Qur'an (RTQ) Raudhatul Adzkia Jorong Dalam Koto Nagari Koto Tangah in solving problems faced by partners. The pond catfish farming business supports smooth operational costs and has been running for over a year, but these results still need to be improved for TPQ and RTQ. This activity aims to develop a catfish farming business accompanied by an aquaponic cultivation business to increase income from TPQ and RTQ. The benefit of this activity is that the partners have an Aquaponics business which is cultivating catfish and vegetable plants in the fish pond. The Community Service Team transferred knowledge to partners, especially in cultivating aquaponic plants through entrepreneurship. The activities of the Community Service Team in helping partners are a form of the Andalas University Higher Education Tri Dharma. The method applied to support the realization of this community service program was through supervision, program socialization, and implementation of activities. The result of this activity was that partners could run an aquaponics business to increase income to meet the operational costs of education and teacher salaries.
Pelatihan Praktikum Kimia Sederhana di SMAN 16 Padang Imelda Imelda; Refinel Refinel; Refilda Refilda; Yefrida Yefrida; Hermansyah Aziz; Yulizar Yusuf; Suryati Suryati; Zulkarnain Chaidir; Sumaryati Syukur; Rahmiana Zein; Novesar Jamarun; Safni Safni; Zilfa Zilfa; Yetria Rilda; Norman Ferdinal; Tommi Hermansyah; Fivi Mona Bareno
Warta Pengabdian Andalas Vol 30 No 3 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat (LPPM) Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jwa.30.3.562-568.2023

Abstract

Chemistry is one of the subjects taught in State Senior High Schools (SMAN), especially in Natural Sciences (IPA). The problem with chemistry subjects is that it is difficult to practice in the laboratory because laboratory facilities such as space, equipment and chemicals are expensive. As a result, chemical laboratory practices were only sometimes carried out. Several lecturers and students from the Department of Chemistry, FMIPA Unand Kimia Unand, carried out service activities at SMAN 16 Padang through laboratory practice using materials and equipment that were cheap and readily available in the surrounding environment. This community service aims to train teachers and students to carry out chemistry practicums using simple materials and equipment available around them. The training was given to chemistry subject teachers and students in the science laboratory at SMAN 16 on 17 and 21 November 2022. The material was practised in oxidation and reduction (redox) and electrolysis reactions. The activity went smoothly; the students enthusiastically carried out the practicum. Through the results of this simple chemistry practicum, students can design and carry out chemical experiments using simple tools and materials, conduct direct observations of chemical processes, practice scientific thinking, attitude and work skills and analyze and solve various scientific processes using scientific methods. SMAN 16 hopes that this activity will continue with different topics.
Penentuan Kandungan Antioksidan dan Fenolik Total dari Infusa Daun Tanaman Famili Myrtaceae Secara Spektrofotometri Yefrida; Hayatul Isra; Refilda
Jurnal Kimia Unand Vol. 11 No. 1 (2022): May 2022
Publisher : Departemen Kimia Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jku.11.1.6-11.2022

Abstract

Myrtaceae family plants are widely distributed in the tropics. The leaves of this plant have been widely used by the community as a traditional medicine. This study aims to determine the total antioxidant and total phenolic content of the infusion of five types of leaves of the Myrtaceae family, namely bay leaves (Syzygium polyanthum), jambak leaves (Syzygium malaccense), guava leaves (Psidium guajava), water guava leaves (Syzygium aqueum). and duwet leaves (Syzygium cumini). Total antioxidant content was determined using the MPM method and total phenolic content using the Folin Ciocalteau method. The highest total antioxidant content was found in jambak leaf infusion of 122.73 ± 3.10 mg AA/g DW, while the highest total phenolic content was found in guava leaf infusion of 58.84 ± 1.86 mg GAE/g DW.
A mixture of Aloe Vera Gel (Aloe vera. L) and Sungkai Leaf Extract (Peronema canescens. Jack) as Edible Coating to Increase Tomato (Solanum lycopersicum) Storage Life Yefrida Yefrida; Fella Krisna Boneta; Refilda Refilda
Andalasian International Journal of Applied Science, Engineering and Technology Vol. 4 No. 2 (2024): July, 2024
Publisher : LPPM Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/aijaset.v4i2.122

Abstract

Tomatoes are climacteric fruits, are well-known for containing lycopene is an antioxidant. The post-harvest shelf life of harvested tomatoes is only 4-5 days. This research aims to optimize previous methods such the use of plastic packaging and cold storage methods were found to be inefficient and produced waste, so it is necessary to renew them by using the edible coating method, a natural ingredient from Aloe vera. L gel, while sungkai leaf extract (Peronema canescans. Jack) shows the effectiveness of edible coating could potentially provide a protective barrier against external factors, helping to maintain the quality of tomatoes and waste reduction. Edible coating material from aloe vera gel added with sungkai leaf extract of various compositions (C, EC1, EC2, EC3, EC4, and EC5) was prapare and applied to tomatoes. Fourier Transform Infrared (FTIR) testing was carried out to determine the functional groups in all edible coating materials. Physicochemical properties tests were carried out on tomatoes. The results obtained by EC5 the lowest weight loss 11.14%, while EC4 was the best edible coating material in percent decay 8.89%, total dissolved solids 1.00oBrix, total antioxidant 0.024 mg AA/g FW, and total phenolic 0.224 mg GAE/g FW for 15 days compared to aloe vera gel coating (EC1), which only lasted for 9 days, and uncoated (C), which only lasted for 6 days. Keywords: Edible coating, physicochemical properties, FTIR
Co-Authors Admi Admi Admi Admi Afdhal Muttaqin Ainun Nasution Aldini, Tasya Ardiani, Ajeng Putri Ashikin, Nor Boneta, Fella Krisna Deliza, Deliza Dheasy Gustira Dheasy Gustira Dini Hanifa Dwi Syukur Phameswari EFENDI Elida Mardiah Elinda Fithriana Emil Salim Etriyanto Arman Farrah Aprilina Fella Krisna Boneta Fivi Mona Bareno Fuji Astuti Febria Hamidah, Nofi Hamzar Suyani Harsita, Wanda Dwi Harza Dipajana Umardi Harza Dipajana Umardi Hayatul Isra Hayatul Isra Hermansyah Aziz Hermansyah Aziz Humaira, H Ilahi, Fitratul Imelda Imelda Imelda Imelda Indrawati - Indrawati Indrawati Indri Ticel Leone Irma Yanti Siregar Irmanida Batubara Isra, Hayatul Jihanul Khaira Jihanul Khaira Mahdivan Syafwan Mai Efdi Matlal Fajri Alif Mega Ulfaningsih Mildawati Mildawati Muhammad Samudra Ilham Mutia Ramadani Narwen Narwen ndrawati - Nindi Rahmi Amelia Nofi Hamidah Nor Ashikin Nor Ashikin Norman Ferdinal Novesar Jamarun Novita Lucia Nurjannah El Firsti Nurul Afifah Rahmiana Zein Raihan Hanif Aulia Refilda Refilda Refilda Refilda Refilda Refilda Refinel - Richi Silvianti Riga Habib Ngestu Rosman, Widuri Safni Safni Salim, Emil Sepriyaldi Silvia Detri Susanti Solfiyeni Solfiyeni Sumaryati Syukur Suryati Suryati Syafrizayanti Syafrizayanti Syukri Syukri Tommi Hermansyah Umiati Loekman Umiati Loekman Upita Septiani Wellia, Diana Vanda Widuri Rosman Y.T. Putri Yani Kasuma Putri Yetria Rilda Yola Tsurayya Putri Yulizar Yusuf Zilfa Zilfa Zulfi Zulfi Zulkarnain Chaidir