Potential of Beetroot (Beta vulgaris L.) and Purple Sweet Potato (Ipomoea batatas L.) as Natural Indicators of Formalin in Food. J. Ilmu Kesehat. Bhakti Setya Med. [Internet]. 2019 Sep. 1 [cited 2026 May 25];4:7-13. Available from: http://jurnal.poltekkes-bsi.ac.id/index.php/bsm/article/view/67