Search results

(1 - 1 of 1)

Title

CHEMICAL INACTIVATION OF RICIN ON FOOD CONTACT SURFACES

Creator

Aluri, Bharat

Date

2011-08, 2011-07

Description

Ricin is a glycoprotein which can be easily extracted from the seeds of the castor bean plant. Ricin has potential for being used as a...
Show moreRicin is a glycoprotein which can be easily extracted from the seeds of the castor bean plant. Ricin has potential for being used as a biological weapon since it is highly toxic, relatively easy to isolate and purify and can be disseminated as a food contaminant. Thus in the case deliberate contamination event with ricin in a food processing facility, remediation of the food-contact surfaces must be done safely and effectively. The objectives of this project were to 1) identify cleaning/sanitizing treatments that result in inactivation of ricin on food contact surfaces in the absence and presence of different classes of food matrices (high fat and high starch), and 2) evaluate glucose oxidase as a surrogate for ricin in chemical inactivation studies. Ricin dissolved in PBS or mixed with a slurry of peanut butter or pancake mix was treated with different classes of detergents (phosphoric acid-based, chlorinated alkaline-based) and a sanitizer (peroxy acid-based) used to clean and sanitize food-contact surfaces. A commercially available ELISA kit was used to detect ricin after chemical treatments. Of the cleaning solutions evaluated, the phosphoric acid-based detergent was the least effective at reducing ricin detection after exposure to the cleaning chemical. In contrast, chlorinated alkaline detergent was the most effective cleaning solution for chemically inactivating ricin. The half-lives for inactivation of ricin on coupons (without food matrices) exposed to 0.5, 2 and 5% chlorinated alkaline detergent were 2.38 ± 0.25, 0.48 ± 0.05 and <0.1 min, respectively, and half-live values for inactivation of ricin in solution were 3.05 ± 0.33, 0.36 ± 0.04 and <0.1 min, respectively. The half-lives for inactivation of ricin on coupons (without food matrices) treated with 0.1, 0.5 and 1% peroxyacid-based sanitizer were 4.28 ± 0.44, 0.45 ix ± 0.05 and 0.13 ± 0.01 min, respectively, and half-live values for inactivation of ricin in solution were 6.09 ± 0.70, 0.34 ± 0.03 and 0.12 ± 0.01 min, respectively. Although no significant difference was found for ricin stability in solution vs. on coupons, in the presence of food matrices, ricin on coupons was significantly more stable than ricin in the absence of food residue. Overall, the results from this study indicated that significantly (p<0.05) higher cleaning solution concentrations were needed to inactivate the toxin in the presence of food matrices. Initial studies aimed at the evaluation of glucose oxidase as a surrogate for ricin in chemical inactivation studies indicated that the enzyme demonstrates similar susceptibility to inactivation in the presence of chemical sanitizers (sodium hypochlorite, peroxy acetic acid) as ricin. More work is needed to validate the results found in this lab-scale study with experiments conducted in a pilot-scale operation and to determine if loss of ricin activity after chemical inactivation studies also corresponds to loss in biological activity of toxin.
M.S. in Food Safety and Technology, July 2011
Show less