High temperature-high humidity processing for production of smoked chub

Abstract

Four partial smokehouse load and four full smokehouse load experiments were conducted to determine the effect of high temperature-high humidity (HT/HH) processing on production and quality of smoked whitefish chub. Chub were brined in 6.6% NaCl for 16 hours and leached in 2.0% NaCl for 24 hours prior to smoke processing. A smokehouse process using a 60 min. drying stage at 120°F (ambient R.H.), a 60 min. smoking stage at 160°F (60% R.H.), two 10 min. stages at 180 and 190°F (87% R.H.), respectively, and a final stage at 200°F (86% R.H.) was found to produce smoked chub which compared favorably with chub processed by a process (control) typical of processes used commercially to produce smoked chub. Chub were held in the final stage (12 min.) of this HT/HH process until F₁₈₀¹³ - and F₁₈₀¹⁰ -values exceeded 30 min. (49. 5 min.) for the coldest monitored chub. These HT/HH process chub were rated not significantly different (P>.01) than control chub for any taste attribute, and significantly more acceptable than control chub for a general appearance rating. In all experiments, with 2 exceptions, mean water phase salt values for chub dorsal or ventral sections exceeded 3.0%, and most exceeded 3.5%. Moisture and water phase salt variation between dorsal and ventral sections and between chub of different weights was small. Processing weight loss was generally slightly less for HT/HH process chub but differences were generally not significant. Process improvements are necessary to improve the dull dark brown color to a light golden color, to reduce skin wrinkling, and to decrease loss during smokehouse processing.