journal homepage: www.elsevier.com/locate/fbio Available online at www.sciencedirect.com Characteristics and antioxidative activity of carotenoprotein from shells of Pacific white shrimp extracted using hepatopancreas proteases Theeraphol Senphan a , Soottawat Benjakul a,n , Hideki Kishimura b a Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand b Laboratory of Marine Products and Food Science, Research Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan article info Article history: Received 15 May 2013 Received in revised form 6 September 2013 Accepted 15 November 2013 Keywords: Carotenoprotein Pacific white shrimp Carotenoid Hydrolysis Protease Antioxidant abstract Carotenoprotein from shells of Pacific white shrimp (Litopenaeus vannamei) was extracted with the aid of proteases from hepatopancreas of the same species at various levels (5–30 units/g shrimp shell) for different times (0–180 min). Recovery of carotenoprotein increased with increasing protease levels and hydrolysis times, but mainly reached the plateau at 120 min of hydrolysis. Carotenoprotein contained astaxanthin and astaxanthin- diester as major carotenoids. Carotenoids extracted from carotenoprotein showed increas- ing ABTS, DPPH radical scavenging activities, FRAP and metal chelating activity when the concentrations increased up to 5 mg/ml (po0.05). Carotenoprotein consisted of 73.58% protein, 21.87% lipids and 2.63% ash contents. It was rich in essential amino acids and Asp/ Asn and Glu/Gln were found as dominant amino acids. Therefore, carotenoprotein from shell of Pacific white shrimp could be successfully extracted using shrimp hepatopancreas proteases and could serve as the value-added nutritive food ingredients or as the animal feed. & 2013 Elsevier Ltd. All rights reserved. 1. Introduction Pacific white shrimp (Litopenaeus vannamei) accounts for 90% of the global aquaculture shrimp production. Thailand has been the world's leading exporter of cultivated shrimp since the mid-90s, (Lebel, Mungkung, Gheewala, & Lebel 2010). Pacific white shrimp and its products have become economically important for Thai- land. By the year 2010, frozen Pacific white shrimp and products were manufactured and exported totally for 407,978 metric tons, particularly to USA and Japan ( Lebel, Mungkung, Gheewala, & Lebel 2010; Senphan & Benjakul, 2012). During shrimp processing, a large amount of by-products including cephalothorax, shell, etc. is generated. To exploit those left-over, cephalothoraxes have been used as raw material for production of shrimp hydrolysate, shrimp flavorant, carotenoid and chitin/chitosan (Armenta-López, Guerrero, & Huerta 2002; Bueno-Solano et al., 2009; Gildberg & Stenberg, 2001; Ravi Kumar, 2000; Sowmya, Rathinaraj, & Sachindra, 2011). Shrimp shell has been intensively used for carotenoprotein extraction (Armenta & Guerrero-Legarreta, 2009; Babu, Chakrabarti, & Surya Sambasivarao, 2008; Cano-Lopez, Simpson, & Haard, 1987; Chakrabarti, 2002; Klomklao et al., 2009; Sila, Nasri & Bougatef, 2012; Sowmya et al., 2011). Carotenoid and carotenoproteins have been recognised as the natural colourant. Furthermore, they have been reported 2212-4292/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.fbio.2013.11.004 n Corresponding author. Tel.: þ66 7428 6334; fax: þ66 7455 8866. E-mail address: soottawat.b@psu.ac.th (S. Benjakul). FoodBioscience 5 (2014)54–63