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All Journal Jurnal Riset Kimia Jurnal Kimia Mulawarman Warta Pengabdian Andalas: Jurnal Ilmiah Pengembangan Dan Penerapan Ipteks Andalasian International Journal of Applied Science, Engineering, and Technology
-, Yefrida
Departemen Kimia FMIPA Universitas Andalas
Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Electrical & Electronics Engineering Energy Industrial & Manufacturing Engineering Mechanical Engineering Medicine & Pharmacology Social Sciences Other

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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.
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.
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
Determination of Total Antioxidant and Phenolic Content from Malvaceae Family Leaves Infusion by Spectrophotometry Yefrida Yefrida; Silvia Detri Susanti; Refilda Refilda
JURNAL KIMIA MULAWARMAN Vol 21 No 1 (2023)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/jkm.v21i1.1007

Abstract

The use of plants as a source of medicine has been increasing lately. The plants used generally have bioactivities such as anti-bacterial, antioxidant, and others. Plants that contain antioxidants are widely used because of their ability to capture free radicals so that they can protect the body from various diseases. One of the plants that is often used is plants from the Malvaceae family. In this study, the antioxidant and total phenolic contents of five types of plants were determined. These plants were extracted by infundation method and analyzed using MPM (Modified Phenanthroline Method) and Folin-Ciocalteu methods. The highest antioxidant and total phenolic contents were found in kapok randu and waru leaves.
Training on Postharvest Guava Fruit Processing in KWT Jambu Biji, VII Koto Sungai Sariak, Pariaman Yefrida Yefrida; Refilda Refilda; Imelda Imelda; Refinel Refinel; Rahmiana Zein; Safni Safni; Admi Admi; Dheasy Gustira; Jihanul Khaira; Harza Dipajana Umardi
Warta Pengabdian Andalas Vol 31 No 3 (2024)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat (LPPM) Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jwa.31.3.510-517.2024

Abstract

Red guava fruit is one type of fruit that quickly changes colour, texture and spoilage. This is of course a problem for farmers. At harvest time, not all of the fruit is marketable. So sometimes farmers just leave the fruit on the tree, because if harvested it will only increase operational costs. The KWT Jambu Biji Bengke Sakato, VII Koto Sungai Sariak, Pariaman is a group of red guava farmers. They tried to find a solution to this problem by discussing with TIM PPM KIMIA UNAND of the Department of Chemistry, FMIPA, Universitas Andalas. Finally it was agreed that the solution was to make products from red guava. The products made in this program are dodol and red guava ice cream. The KWT members and the Tim PPM KIMIA UNAND together made these two types of products. The results obtained, dodol and ice cream made are quite delicious and have an attractive appearance. This product can be an alternative to red guava processing that has economic value.
Co-Authors Admi Admi Dheasy Gustira Etriyanto Arman Fella Krisna Boneta Hamzar Suyani Harza Dipajana Umardi Hayatul Isra Hermansyah Aziz Imelda Imelda Jihanul Khaira Mai Efdi Nofi Hamidah Nor Ashikin Nor Ashikin Rahmiana Zein Refilda Refilda Refinel - Riga Habib Ngestu Safni Safni Salim, Emil Silvia Detri Susanti Widuri Rosman