DEVELOPMENT OF HIGH-QUALITY SURIMI AND SURIMI BASED PRODUCTS FROM LOW-COST JEWFISH

Abstract

Jewfish (Otolithes ruber), is an underutilized marine species with firm, white flesh and excellent gel-forming ability, holds promise for surimi-based value-added products such as fish ball. This study evaluated the proximate composition, biochemical parameters (TVBN and NPN), microbiological quality (TPC and pathogenic bacteria identification), and sensory attributes of O. ruber fish ball prepared with different binding agents sticky rice, corn flour, wheat flour, and their combinations compared to a control (surimi only). Samples were vacuum-packaged and stored under chilled (4 °C, up to 15 days) and frozen conditions (−8 °C and −25 °C, up to 100 and 120 days, respectively). Throughout storage, gel strength declined over time, particularly under chilled conditions. The control (S) exhibited the lowest gel strength (2.20 to 0.46 N at 4 °C), while the sticky rice, corn flour formulation (S3) maintained the highest strength (11.63 to 10.90 N at 4 °C, 11.63 to 10.64 N at −8 °C and 11.63 to. and 9.50N at -25ºC). Moisture content significantly decreased (p < 0.05) during chilled storage, with the most notable reduction observed in S (79.15% to 78.03%) and the least in S3 (67.72% to 67.22%). Similar trends were observed under frozen conditions, with more gradual changes. As moisture declined, ash and carbohydrate contents increased, while protein and lipid contents decreased. Biochemical parameters such as total volatile base nitrogen (TVBN) and non-protein nitrogen (NPN) increased during storage. The control showed the highest TVBN at 4 °C (6.99 to 45.26 mg N/100 g), while S4 had the lowest (4.16 to 37.86 mg N/100 g). NPN values followed similar patterns. Microbial spoilage exceeded acceptable limits (>6 log CFU/g) by 12 days at 4 °C, whereas all samples remained microbiologically acceptable at frozen temperatures up to 120 days. Sensory evaluation revealed that fish ball with sticky rice (S1) had the highest overall acceptability across all temperatures, particularly when vacuum-packaged. Optimal shelf lives were 14–16 days at 4 °C, 80–100 days at −8 °C, and 80–120 days at −25 °C.