ASSESSMENT OF QUALITY AND HANDLING PROCEDURES OF IMPORTED FROZEN FISH IN OYO STATE, NIGERIA

ABSTRACT

The deficit of domestic fish supply necessitates importation of frozen fish to supplement protein intake of Nigerians. Adequate quality standards and control measures are in place for frozen fish at the point of entry to the country. However, there is dearth of information on quality control along the distribution chain to the final consumer. Therefore, quality and handling procedures of imported frozen fish within Oyo State were investigated. Three-stage sampling procedures were used for the study. Oyo State was stratified into four Agricultural Development Programme zones (Ibadan/Ibarapa, Ogbomoso, Oyo and Saki). All cold store operators (n=67) and 5.0% of registered retailers per zone (n=150) were randomly selected and assessed using 217 structured questionnaires to obtain information on compliance level on temperature management, personal hygiene, facilities‟ sanitation and handling. Sardinella species and Micromesistius poutassou were selected for sensory and non-sensory assessment based on their availability in all zones. Overall acceptability was based on 7-point hedonic scale (very much liked (7) - very much disliked (1). Chemical tests such as Hypoxanthine (Hx), Peroxide value (PV), Trimethylamine (TMA) and Free fatty acid (FFA) were carried out using standard methods. Bacteria and Fungal counts were determined using standard procedures. Data were analysed using descriptive statistics and ANOVA at 𝛼0.05.

Compliance level to quality measures by cold store operators in all the zones were 65.7%, 83.6% and 92.5% for temperature management, personal hygiene and facilities‟ sanitation, respectively. Ibadan/Ibarapa zone had the highest cold storage capacity of 7,433 tonnes and the least was Saki zone with 61 tonnes. Transportation of fish to retail points were by motorcycle (43.3%), taxi cab (31.1%) and by head load (24.0%). Fish was displayed by retailers using bowls (50.0%), wooden tables (36.7%) and wooden boards (10.0%). Only 57.3% of retailers washed their tables daily and none used chlorinated water. Overall acceptability was 5.47±0.20 (Sardinella spp.) and 5.57±0.13 (M. poutassou). The Hx (25.54±0.41 mg/100g; 26.28±1.06 mg/100g), PV (19.47±0.90 meq/kg; 20.03±0.53 meq/kg,) TMA (23.79±0.52 mg/100g; 23.45±0.89 mg/100g) and FFA (1.85±0.31%; 1.82±0.19%) were recorded for Sardinella spp. and M. poutassou, respectively. Oyo zone had the least PV (17.48±0.81; 17.90±0.60 meq/kg), TMA (20.58±0.91; 17.90±0.60 mg/100g), bacteria count (1.2 x105 ±0.49; 1.5x105 ±0.43cfu/g) and fungal load (7.9x104 ±0.35; 1.4x105 ±0.38 cfu/g) in both Sardinella spp. and M. poutassou, respectively. Ogbomoso had highest PV (18.83±0.60 meq/kg), FFA (1.84±0.13%), TMA (23.62±0.60 mg/100g), bacteria and fungal load (3.1x105 ±1.34 cfu/g; 1.8x105 ±0.81cfu/g) for Sardinella spp. and highest FFA (1.81±0.19%) and bacteria load (3.2x105 ±0.78cfu/g) in M. poutassou. Hypoxanthine and TMA were significantly different for Sardinella spp. and M. poutassou across the zones, respectively. Predominant bacteria isolates were Shewanella putrefaciens and Streptococcus faecium while fungi included Penicillium notatum and Aspergillus niger. Total viable count iii for bacteria and fungal load were 3.1x105 ±1.34 cfu/g and 1.8x105 ±0.81 cfu/g, respectively for Sardinella spp. and 3.2x105 ±0.78 cfu/g and 2.4x105 ±0.41 cfu/g for M. poutassou. Quality of frozen fish was best in Oyo zone. Most cold stores met the recommended temperature for cold storage. All sensory and non-sensory indicators of fish quality were within acceptable limits.