BIOFARMASI J NAT PROD BIOCHEM Volume 16, Number 2, August 2018 E-ISSN: 2580-2550 Pages: 64-68 DOI: 10.13057/biofar/f160202 The hydroxyproline content of fish bone gelatin from Indonesian Pangasius catfish by enzymatic hydrolysis for producing the bioactive peptide YONI ATMA 1,♥ , HANIFAH NURYANI LIOE 2,♥♥ , ENDANG PRANGDIMURTI 2 , HERMAWAN SEFTIONO 1 , MOH. TAUFIK 1 , DITA FITRIANI 1 , APON ZAENAL MUSTOPA 3 1 Department of Food Science and Technology, Faculty of Bioindustry, Universitas Trilogi. Jl. Taman Makam Pahlawan Kalibata, Jakarta 12760, Indonesia. Tel./fax.: +62-21-7980011,  email: yoniatma@trilogi.ac.id 2 Department of Food Science and Technology, Faculty of Agricultural Engineering, Institut Pertanian Bogor. Jl. Raya Dramaga, Bogor 16680, West Java, Indonesia.  email: hanifahlioe@apps.ipb.ac.id 3 Research Center for Biotechnology, Indonesian Institute of Sciences. Jl. Raya Jakarta-Bogor Km 46, Cibinong, Bogor 16912, West Java, Indonesia Manuscript received: 24 June 2018. Revision accepted: 21 August 2018. Abstract. Atma Y, Lioe HN, Prangdimurti E, Seftiono H, Tahufik M, Fitriani D, Mustopa AZ. 2018. The hydroxyproline content on fish bone gelatin from Indonesian Pangasius catfish by enzymatic hydrolysis for producing of bioactive peptide. Biofarmasi J Nat Prod Biochem 16: 64-68. Gelatins has been widely used in food, medicines, cosmetics, photography industries. In the food industry, gelatin used as food additives and functional foods. The applications of gelatin as a functional food due to their bioactivity in a form of peptides. Bioactive peptides from gelatin are mostly obtained through enzymatic hydrolysis processes. This study was conducted to measure the hydroxyproline content of gelatin bone of Indonesian Pangasius catfish ( Pangasius sutchi) before and after enzymatic hydrolysis. The hydroxyproline is one of the dominant amino acids in gelatin. Gelatin hydrolysis was carried out using a flavourzyme at concentration of 6% and the incubation series of 0, 4, 6 and 8 hours. The standard concentration of hydroxyproline was used in range of 0-1 μg. The results showed that the linear curve of the hydroxyproline standard solution was y=0.0554x+0.0406, with the coefficient of determination (R²) = 0.9435. The incubation time of enzymatic hydrolysis (6% enzyme concentration) affected the hydroxyproline content. The hydroxyproline from fish bone gelatin was 18.91±2.87 mg/mL, 63.81±1.28 mg/mL, 46.21±1.28 mg/mL and 37.64 ± 0.64 mg/mL respectively during 0, 4, 6 dan 8 h incubation time. This hydroxyproline content was significantly different at 95% confidence level from each treatment time. Keywords: Bioactive peptide, enzymatic hydrolysis, fishbone gelatin, hydroxyproline INTRODUCTION Gelatin is a collagen hydrolysate with molecular weight ranging from 97 kDa until >250 kDa in which it is produced in acid or alkaline condition. It has been used in various industries including food, medicines, cosmetic and photographs (Mariod and Fadul 2013). In food industries, gelatin was used as food additives and functional food. As food additive, gelatin was used as emulsifier, stabilizer, gelling former, thickener, adhesive agent and biofilm. While as functional food, gelatin has been developed in form of peptide for antidiabetic, antimicrobial, antioxidant and antihypertensive (Gómez-Guillén et al. 2011). The research regarding on gelatin as a functional food has been growing rapidly especially about fish-based gelatin utilization (Aleman et al. 2011; Koli et al. 2014; Nikoo et al. 2014). It is because the fish based gelatin could be potential to replace the mammalian gelatin, which is the most source of gelatin however unacceptable due to religion, sociocultural and health aspect consideration (Nurul and Sarbon 2015). Many previous studies have been reported that the fish gelatins have their bioactivities, for example, the gelatin from salmon, hake, halibut, nila tilapia, pangasius catfish and etc (Li-Chan et al. 2012; Mahmoodani et al. 2014a; Wang et al. 2015). Fortunately, most of fish based gelatin comes from by-product or waste of fish processing (Karayannakidis and Zotos 2016). Therefore, the utilization of this source could be promising in the future especially in Indonesia. Indonesia is a country with wide area of water so that it provides the biodiversity in fisheries. There are two types of fish based on their habitat including warm-water fish and cold-water fish. In cases for gelatin source, it has been known that the gelatin from warm-water fish having superiority characteristic compared to the other one (Gómez-Guillén et al. 2009). One of the warm-water fish, which have the high production yield in Indonesia, is Pangasius catfish (Pangasius sutchi). In Indonesia, Pangasius catfish spread out in Sumatera and Kalimantan. In addition, the consumption and production rate of this fish has been increased every year. The Ministry of Marine Affairs and Fisheries targets the Pangasius catfish production in 2018 reaching 604.587 ton. It will inflict to the waste especially bone of fish, which contribute about 12.44% of the total fish weight. Based on previous studies, it concluded that gelatin from bone of Pangasius catfish was better compared to another fish based on gelatin in physicochemical characteristic. The gelatin from this