89D-31

G. F. MEHYAR, Dept. of Food Science, Univ. of Manitoba, 250 Ellis Bldg., Winnipeg, R3T 2N2, Canada, S. A. Ibrahim, Food Science & Nutrition Program, North Carolina A&T State Univ., Dept. of Human Environment & Family Sciences, 171-B Carver Hall, Greensboro, NC 27411-1064, and M. I. Yamani, Dept. of Nutrition & Food Technology, Univ. of Jordan, Faculty of Agriculture, Amman, 11947, Jordan.

Hummus is one of the most popular traditional foods in Jordan and other Middle Eastern countries. Hummus is prepared by mixing boiled chick pea with, tahineh (ground roasted sesame seeds). It has a pH value of 5, relatively high aw and availability of simple and complex carbohydrates which make hummus very susceptible for bacterial contamination and limits the shelf life to 48hr under refrigeration. Lowering the pH of hummus and the addition of food preservatives could be an effective method to extend the shelf-life of this product. The objective of this study was to determine the effect of potassium sorbate, sodium benzoate and sodium metabisulfate on the shelf life and growth of natural flora in hummas. Hummus was prepared according to the traditional method and divided into portions to receive one of the following treatments: potassium sorbate, sodium benzoate or sodium metabisulfate at four different concentrations, 0.0, 0.05, 0.1, and 0.15% (w/w). Control samples that did not have any preservatives were also included. Samples were then mixed well and divided into three portions and stored at 5, 10, and 15^o C to determine the shelf life. Samples were withdrawn everyday and analyzed for the total bacterial population. Results showed that sodium metabisulfite had the most inhibitory effect at 0.01%, hummus samples could be stored at 63 days without spoilage. Potassium sorbate was more effective than sodium benzoate; samples could be stored for 35 and 14 d at 5^o C for potassium sorbate and sodium benzoate respectively. Hummus samples would remain unspoiled for more than 90 d at 5^o C when treated with 0.01% sodium metabisulfite and potassium sorbate. Keeping the hummus at 10 and 15 C lowered its shelf-life but in all cases it remained more that 4 d. Combinations of sodium metabisulfite and potassium sorbate could be used to improve the shelf life of hummus.

Session 89D, Food Microbiology: Antimicrobial effects on foodborne microorganisms
2:00 PM - 5:30 PM, Tuesday PM Room Hall I-2

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