Purpose: To evaluate the impact of different almond coatings (Honey, Xanthan, Starch) on the effectiveness of oil roasting at 260°F for various holding times to kill Salmonella on almonds.
Methods: Whole kernel almonds were artificially-inoculated with Salmonella, coated with a Honey, Xanthan, or Starch-based coating, and then oil-roasted at 260°F for 0.0, 1.0, 1.5, 2.0 minutes. Inoculated uncoated almonds were also included in the study for comparison. Log reductions following heat treatment for each treatment time between each almond product were compared using ANOVA.
Results: Log reductions of Salmonella following heat treatment at 260°F for 1 or 1.5 minutes were inconsistent, and ranged between 3.08±0.93 and 4.89±1.73 logs (n=9), or 4.87±0.38 and 6.28±0.90 logs (n=9), respectively, with standard deviations ranging from 0.35-1.73 log CFU/g for each of the different almond products. A greater than 5-log reduction of Salmonella was achieved after oil roasting at 260°F for 2.0 min, with the least amount of reduction observed on the uncoated almonds. No significant differences (P>0.05) were observed between the log reduction of Salmonella achieved for each type of sugar-coated almond after exposure to hot oil for 1.5 or 2.0 minutes.
Significance: The commercial oil roasting process at a higher temperature of 260°F for longer than 2.0 minutes should be sufficient to achieve a greater than 5-log reduction of Salmonella on Uncoated, Honey Coated, Xanthan Coated, and Starch Coated almonds.