Pengaruh Variasi Waktu Perendaman Larutan NaCl 15% terhadap Kadar Formalin pada Tahu Putih di Kota Pematangsiantar Tahun 2023

Abstract

Formaldehyde is a type of chemical substance that is prohibited from being added as a preservative to food. Some tofu products are often found with formaldehyde as a food preservative that can preserve tofu products longer but is detrimental to the human body. Soaking white tofu in NaCl solution is one of the efforts to prevent formaldehyde poisoning in the community. The purpose of this study was to determine the effect of time soaking variation in 15% NaCl solution on formaldehyde levels in white tofu. This type of research is quasi experimental research with pretest and posttest design. This research used semi-quantitative test with colorimetric method with descriptive analysis and hypothesis testing. The sample studied was white tofu before and after soaking in 15% NaCl solution obtained by purposive sampling technique. In general, the average value of formaldehyde levels was highest in the duration of soaking for 20 minutes at 8.33 mg/l at a duration of 30 minutes at 7.00 mg/l and the lowest average value was in soaking for 40 minutes at 5.00 mg/l. The results of the Wilcoxon Signed Rank Test statistical analysis were obtained and the Asymp. Sig. (2-tailed) value of 0.000, then p < 0.05, meaning that there is a significant difference in mean value between formaldehyde levels before and after soaking in 15% NaCl solution with a duration of 20, 30, and 40 minutes.