IDENTIFIKASI SENYAWA TANIN PADA SAWI HIJAU (Brassica rappa var. parachinensis L.) DAN KUBIS (Brassica oleracea L) DARI KABUPATEN MALANG SEBAGAI SUMBER BELAJAR BIOLOGI

Tannins are secondary metabolite compounds commonly found in plants and possess various biological activities such as antioxidant and antibacterial properties. This study aims to identify tannin content in mustard greens (Brassica rapa var. parachinensis) and cabbage (Brassica oleracea L.) from Malang Regency, and to evaluate the potential of the findings as a contextual biology learning resource. The methods used include qualitative testing through phytochemical screening and quantitative testing using UV-Vis spectrophotometry. The screening results showed that both types of vegetables did not exhibit a positive reaction to the FeCl₃ test, indicating that tannins were not detected qualitatively. However, quantitative tests revealed that mustard greens contained 12.332 mg TAE/g extract of tannins, while cabbage contained 9.483 mg TAE/g extract. These findings indicate the presence of tannins in low concentrations, detectable only through quantitative methods. The results of this research also have potential as teaching materials in biodiversity lessons for grade X (phase E), by linking the concept of secondary metabolites and the use of local plants in real-life contexts. Incorporating these findings into the learning process may encourage students to explore the potential of local plants and enhance their scientific thinking skills.