89A-16

N. L. LEYDON¹, S. P. Suman², P. C. Ellis³, C. Palmer⁴, L. C. Faustman², and L. F. Pivarnik⁴. (1) Nutrition and Food Sciences, Univ. of Rhode Island, 530 Liberty Lane, West Kingston, RI 02892, (2) Dept. of Animal Science, Univ. of Connecticut, 3636 Horse Barn Hill Rd. Ext., Storrs, CT 06269, (3) Food Chemistry Laboratory, Rhode Island Dept. of Health, Providence, RI 02904, (4) Nutrition and Food Sciences, West Kingston, RI 02892

The filtered smoking (FS) process has been used to preserve color in fish that are frozen for distribution purposes. The impact of FS on microbial proliferation, color stabilization, quality and safety indicators and sensory assessment has not been thoroughly addressed. The objective of this study was to compare changes in the quality profiles of FS treated and untreated (UT) tilapia fillets (Oreochromis spp.). UT tilapia was evaluated as fresh fillets, while FS product was frozen only and thawed prior to storage. UT and thawed FS tilapia fillets were stored at room temperature (22º C), refrigerated temperature (4-5º C) and in ice. Samples (n=3) were analyzed at different time intervals. Sensory evaluation was conducted by NMFS sensory experts. Analysis of TVB-N (distillation), TMA-N (spectrophotometric), apparent ammonia (ISE), color (L*, a*, b*), psychrotrophic bacteria number, and lipid oxidation (TBARS, peroxide value (POV)) were determined. Differences (P<0.05) were observed in sensory assessment, where FS samples held at refrigerated temperature and on ice were rejected sooner. While microbiological assessment generally showed no differences for FS and UT product samples, biochemical markers at time zero showed FS samples significantly higher in apparent ammonia and TVB-N. Ammonia and TVB-N continued to be significantly higher over 6-9 days of storage for iced samples. At time zero, TBARS and POV values were lower for FS samples and continued to have lower trends throughout storage for all temperatures (P<0.05). Color changes over time were noted for a* for FS (all storage temperatures) and UT (room and refrigerated temperature) samples (P<0.05). In addition to filtered smoke, fillets appeared to have been treated with ozone and UV which would decrease the microbiological load. However, treatments would not mask markers used for quality assessment. Although lipid oxidation was retarded, chemical and sensory measurements indicated that the treated fillets were of lower quality.

Session 89A, Aquatic Food Products: General
2:00 PM - 5:30 PM, Tuesday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana