Food Protection Trends - September/October 2016 - 351

BPW to prevent mold spores from clumping while keeping spores in suspension. The BPW/Tween 80 spore solution was filtered through sterile cheesecloth to separate mold spores from other fungal debris and transferred to a sterile 500-ml glass bottle. This process was repeated five times for each individual mold culture to ensure complete removal of spores and produce a spore solution of 500 ml. Through this technique, spore concentrations of ~6 log10 spores/ml were produced for each mold culture, based on plate counts performed using a pour plating technique. Briefly, 1 ml of BPW spore solution was added to molten 1% (wt/vol) MEA in a 15 ml Falcon test tube (VWR, Radnor, PA) and held in a 50ºC water bath (Precision, Winchester, VA). The 15-ml Falcon tubes were then vortexed, pour-plated, and incubated at 25ºC for 72 to 96 h before enumeration. To prepare the final inoculum, 500 ml of each of the four mold cultures were mixed in a sterilized metal container under a biological safety hood to produce a homogenous mold cocktail (2 liters total) for the sausage inoculation immersion bath. The 2-liter yeast cocktail was then mixed with the 2-liter mold spore cocktail to produce homogeneous yeast and mold cocktail inoculum (4 liters total) for the sausage inoculation immersion bath. This procedure was repeated in the same manner for each of the 3 replications of the challenge study. formulated as a percent of the ingredient weight of the total batch weight (wt/wt) with the following ingredients: beef trim (80% lean; 22% wt/wt), pork trim (80% lean; 44% wt/wt and 50% lean; 22% wt/wt), water (7% wt/wt), salt (2.2% wt/wt), dextrose (0.44% wt/wt), ground black pepper (0.28% wt/wt), sodium tripolyphosphate (2500 ppm), ground mustard (0.55% wt/wt), granulated garlic (0.55% wt/wt), ground ginger (0.013% wt/wt), sodium erythorbate (540 ppm) and curing salt (6.25% NaNO2; 156 ppm). Sausages were stuffed to a weight of 130.4 g into a 35-mm curved, edible collagen casing (Devro Ltd., Moodiesburn, Scotland, UK), using a vacuum stuffer with a twist linker attachment (Handtmann VF608 Plus Albert Handtmann Maschinenfabrik GmbH & Co., Biberach, DE). A large diameter (> 30 mm), collagen type casing was chosen, because it demonstrated the most resistance to brine penetration and acidification, compared with skinless and natural type casings, in preliminary experiments (data not shown). The sausages were smoked and cooked in a Kerres Smoke Air® JS 1950 (Kerres Anlagensysteme GmbH, Backnang, DE) to a core temperature of 70ºC to comply with the time-temperature requirements in Appendix A for meeting lethality performance standards (30). After cooking, the sausages were transferred to a walk-in cooler (1-2ºC) and chilled to 4ºC in accordance with Appendix B (31). Table 2 illustrates the thermal processing schedule used to smoke and cook the sausages. The average measurements of the cooked and chilled sausages were: length 144 mm ± Preparation of sausages Sausages used in this study were manufactured at The Pennsylvania State University Meat Laboratory and Table 2. Thermal processing schedule of sausages used in the spoilage challenge study Function House Temperature (ºF) % Relative Humidity Core Temperature (ºF) Time (minutes) Steam Cook Dry Cook Steam Cook Dry Cook Heissrauch Dry Cook Heissrauch Dry Cook Heissrauch Dry Cook Steam Cook Dry Cook Steam Cook Dry Cook Shower 120 135 163 135 140 140 140 140 140 140 154 140 165 140 0 90 0 90 0 0 0 0 0 0 0 90 0 90 0 0 158 - 00:15 00:15 00:10 00:15 00:15 00:20 00:15 00:20 00:10 00:10 00:10 00:10 00:00 00:10 00:15 Note: "Heissrauch" - hot smoking step September/October Food Protection Trends 351

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