Mackerel tuna (Euthynnus affinis) is one of the most popular foods in the community since it is affordable and has complete nutritional content. It is a frozen fish food product so the storage period of which is relatively short. In addition, it is possible to add formalin on which. Formalin is a substance that is prohibited from being used due to its dangerous effects. The content of saponin compounds found in red onions (Allium cepa L) can be used to reduce formalin levels. This study aimed to determine the effect of variations in the soaking time of red onion extract on the formalin level in mackerel tuna and the optimal soaking time for reducing formalin levels. This study used an experimental method with a posttest control group design. The treatment was given by soaking red onion extract at a concentration of 10% in mackerel tuna containing formalin with variations in soaking time of 1 hour, 2 hours, and 3 hours which were tested quantitatively using a UV-Vis spectrophotometer. Then, the data were analyzed using a one-way ANOVA statistical parametric test and a post hoc test using Duncan's test (DMRT). The decrease of the formalin levels by soaking the onion extract for 1 hour, 2 hours, and 3 hours was 10.61%, 41%, and 73%, respectively. The result showed that there was an effect of the soaking time of red onion extract on formalin levels (p-value 0.05), and the optimal time of soaking onion extract to reduce the formalin content of the samples was 3 hours.

Anglania, Shintya Rara, And Galuh Ratmana Hanum. 2019. “Pengaruh Filtrat Bawang Merah (Allium Cepa) Terhadap Kadar Formalinformalin Pada Ikan Kembung ( Rastrelliger Sp ).” 2(1):18–21. Doi: 10.21070/Medicra.V2i1.1654.

Hanum, Galuh Ratmana, Syahrul Ardiansyah, And Puspita Handayani. 2019. “Efektivitas Pandan (Pandanus Amarilifolius Roxb) Sebagai Pereduksi Alami Kadar Formalin Pada Cincau Hitam The Effectiveness Of Pandan (Pandanus Amarilifolius Roxb) Leaves For A Natural Reducted Formalin Level Of Black Grass.” Journal Of Pharmacy And Science 4(2):61–65.

Jannah, M., W. Ruf, And T. Surti. 2014. “Efektivitas Lengkuas (Alpinia Galanga) Sebagai Pereduksi Kadar Formalin Pada Udang Putih (Penaeus Merguiensis) Selama Penyimpanan Dingin.” Jurnal Pengolahan Dan Bioteknologi Hasil Perikanan 3(1):70–79.

Juliadi, Debby., Yuliasih, Wayan. 2016. “The Influence Test Of Soaking Concentration Variance Solution Of Tamarind To Reduce Levels Of Formaldehyde On Sausage.” Medicamento 4(2):71–77.

Juliadi, Debby, Ni Wayan Yuliasih, Dewa Ayu Ika Pramitha, And Ni Putu Dewi Agustini. 2018. “Uji Pengaruh Variasi Konsentrasi Perendaman Larutan Asam Jawa Terhadap Penurunan Kadar Formalin Pada Sosis.” Jurnal Ilmiah Medicamento 4(2):71–77. Doi: 10.36733/Medicamento.V4i2.853

Mayasari, Eva, And Suko Priyono. 2022. “Dalam Mereduksi Kandungan Formalin Dan Kualitas Fillet Ikan Nila ( Oreochromis Niloticus ) Effectiveness Of African Leaf Extract ( Vernonia Amygdalina Del ) In Reducing Formaldehyde Concentration And Quality Of Tilapia ( Oreochromis Niloticus ) Fillet.” 23(1):1–8.

P, Annisa Fadhilah, Widodo Farid Ma’ruf, And Laras Rianingsih. 2013. “Efektivitas Lidah Buaya (Aloe Vera) Di Dalam Mereduksi Formalin Pada Fillet Ikan Bandeng (Chanos Chanos Forsk) Selama Penyimpanan Suhu Dingin.” Jurnal Pengolahan Dan Bioteknologi Hasil Perikanan 2(4):21–30.

Sitompul, Yemima Maria Lasmaroha, I. Made Sugitha, And Agus Selamet Duniaji. 2020. “Pengaruh Lama Perendaman Dalam Air Perasan Buah Belimbing Wuluh (Averrhoa Bilimbi Linn) Dan Lama Penyimpanan Terhadap Karakteristik Ikan Tongkol (Euthynnus Affinis) Pada Suhu Ruang.” Jurnal Ilmu Dan Teknologi Pangan (Itepa) 9(1):71. Doi: 10.24843/Itepa.2020.V09.I01.P09.

Wahyudi, Jatmiko. 2017. “Mengenali Bahan Tambahan Pangan Berbahaya : Ulasan.” Jurnal Litbang: Media Informasi Penelitian, Pengembangan Dan Iptek 13(1):3–12. Doi: 10.33658/Jl.V13i1.88.

Zamhariroh, And Galuh Ratmana Hanum. 2018. “Efektivitas Temu Kunci (Boesenbergia Rotunda) Terhadap Penurunan Kadar Formalin Pada Ikan Tuna (Thunnus Sp.).” Journal Of Medical Laboratory Science/ Technology) 1(2):68–76.