Available online at https://ejournal.unisayogya.ac.id/ejournal/index.php/ijhst International Journal of Health Science and Technology, 3 (1), 2021, 27-31 Doi: 10.31101/ijhst.v3i1.2168 This is an open access article under the CC–BY-SA license. Microbiological analysis on bone flour patin fish (Pangasius Hypophthalmus Sp.) biscuit is rich in calcium for children Dewi Sartika Siagian 1* , Wahyu Margi Sidoretno 2 , Sri Kartini 3 1 Program Studi Kebidanan Universitas Abdurrab, Jl. Riau Ujung no. 73 Pekanbaru, postcode 28291, Indonesia 2,3 Program Studi D-III Analis Farmasi dan Makanan Universitas Abdurrab, Jl. Riau Ujung no. 73 Pekanbaru, postcode 28291, Indonesia 1 dewi.sartika.siagian@univrab.ac.id*, 2 wahyu.margi@univrab.ac.id, 3 sri.kartini@univrab.ac.id *corresponding author Submission date: 16 April 2021, Receipt date: 3 Mei 2021, Publication date: 1 Juli 2021 Abstract Ikan Patin bones are a by-product of the fish processing industry which contains the most calcium from the fish body because the main elements of fish bones are calcium, phosphorus and carbonate. Biscuits are snack that have a water quality standard of less than 5% so that they have a crunchy texture. The purpose of this study was to see microbial contamination in biscuits using the ALT (Total Plate Number) method. The type of research carried out is experimental research. The results of microbial contamination meet the specified requirements and are included in the category of safe and normal standards according to SNI 2973:2011. The results of the identification of Coliform and E. coli bacteria, can be seen that the biscuits with or without the addition of Patin Fish bone meal contain less than the stipulated provisions. Keywords: patin bones, biscuits, microbial INTRODUCTION Patin fish bones are a by product of the fish processing industry which contains the most calcium from the fish body because the main elements of fish bones are calcium, phosphorus and carbonate (Kordi, 2010). Calcium absorption and retention in body is influenced by the quantity and quality of the dietary protein consumed. The interaction between calcium and protein is of special concern considering the fact that bone tissue is nearly 50 per cent protein by volume and other 50 per cent of bone is calcium (Agrahar- Murugkar et al. 2018). One of the easiest and cheapest food sources to obtain is fish, such as Patin fish. Patin fish is a fish that is classified as tasty, delicious and savory fish. In addition, Patin fish contains high protein and low cholesterol. Patin contains 68.6% protein, 5.8% fat, 3.5% ash, and 59.3% water (Kordi, 2010). Fish bone meal contains high levels of calcium and phosphorus which is high enough so that when used as a fortification materials in food products can be used as a source of calcium and from fish processing by fish bone separator machine. In 100 g of bone meal fish, contains 735 mg of calcium; 9.2 grams of protein; 44 mg fat; 345 mg phosphorus; 78 mg of iron; 24.5 grams of ash; and other minerals. High content fish bone calcium shows that fish bones has potential as a source