Peningkatan kesadaran tentang gaya hidup sehat memicu pertumbuhan tren pangan fungsional di kalangan masyarakat. Anemia merupakan salah satu masalah gizi utama di Indonesia yang disebabkan oleh defisiensi zat besi. Salah satu pangan lokal sumber zat besi adalah cangkang kepiting bakau. Dalam rangka menciptakan pangan fungsional kaya zat besi sekaligus pemanfaatan limbah pangan, penelitian ini dilakukan untuk mengetahui pengaruh penambahan tepung cangkang kepiting bakau terhadap kandungan gizi proksimat dan zat besi cookies. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan perlakuan penambahan tepung cangkang kepiting bakau dengan konsentrasi yang berbeda (0%, 3%, 6%, 9%, 12%, 15%). Data dianalisis menggunakan metode ANOVA dan uji lanjut Duncan. Hasil penelitian menunjukkan bahwa penambahan tepung cangkang kepiting bakau memberikan pengaruh yang sangat nyata terhadap kandungan proksimat dan zat besi cookies. Semakin tinggi konsentrasi penambahan tepung cangkang kepiting bakau, maka kadar air, kadar lemak, dan kadar karbohidrat cookies menurun, sedangkan kadar abu, kadar protein, dan kadar zat besi cookies meningkat. Kata Kunci: Cookies, cangkang kepiting bakau, zat besi, proksimat

Increased awareness of healthy lifestyles has spurred the growth of functional food trends among communities. Iron deficiency causes anemia, a major nutritional problem in Indonesia. Mangrove crab shells are a local source of ironrich food waste. The purpose of this study was to determine the effect of adding mangrove crab shell powder on the proximate composition and iron content of cookies. This study employed an experimental design using a Complete Randomized Design (CRD), with treatments of adding different concentrations of mangrove crab shell powder (0%, 3%, 6%, 9%, 12%, 15%). The data were analyzed using ANOVA and Duncan’s multiple range test. Findings indicated that adding mangrove crab shell powder significantly affected cookies' proximate composition and iron content. Increasing the powder concentration decreased moisture, fat, and carbohydrate levels, while increasing ash, protein, and iron content. Keywords: Cookies, mangrove crab shell powder, iron content, proximate composition