Physical and sensory quality of hommos preserved with combined gamma radiation and refrigeration

A Study of Physical, Chemical, and Sensory Characteristics of Novel Legume Dips

There is a consensus among experts and consumers that pulses are a good source of nutrients and fiber. In a traditional hummus recipe, chickpeas are the major ingredient. The present study is aimed at developing new legume dips by exchanging chickpeas (Chd) with dry green (Gld) and red lentils (Rld), dry white beans (Wbd), and dry green peas (Gpd). Presoaking, boiling, proximate composition, pH, energy, color measurement, and sensory evaluation were conducted on the dips using chickpea dip (hummus) as a control. One-way ANOVA was used to determine the differences between the dips. The results revealed significant differences in the proximate composition of legume dips. The protein content of the five samples ranged between 7.46% and 9.19%, while the values varied from 8.59% to 10.93% in fat, 3.88% to 6.54% in crude fiber, 14.48% to 15.51% in carbohydrates, 171.95 to 195.13 in energy, 1.55% to 1.76% in ash, and 63.35% to 66.90% in moisture. These variations could be attributed to the type and composition of each legume, the soaking and boiling process, and the tahini added during the preparation. pH ranged between 4.5 and 4.7. The color measurement indicated that the five legume dips could be considered bright products (high L∗>67), with a positive color valuebluered-green and yellow-. Significant differences (p ≤ 0.05) were observed in the legume dips sensory evaluation, and the red lentil dip was the most acceptable with results comparable to the chickpea dip; it was followed by the green lentil, white bean, and green pea dips. These results highlight the feasibility of commercial production of legume dip that promotes human health and gives consumers more choices.

Inactivation of stressed Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes in hummus using low dose gamma irradiation

Hummus is a popular dip in the Middle East region prepared by mixing the boiled chickpeas with tahini and other ingredients, and because its consumption has increased world-wide some notoriety has developed following an increase in the incidence of hummus-related illness outbreaks and recalls. The objectives of the current research were (i) to study the efficiency of low dose gamma irradiation to inhibit Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in hummus, and (ii) to assess the effect of environmental stresses namely cold, heat, and desiccation on the resistance of these pathogens to gamma irradiation. The samples of hummus were prepared and then individually inoculated with approximately 7.0 log CFU/g of unstressed or cold-, heat-, or desiccated-stressed cocktail cultures of each of E. coli O157:H7, S. enterica, and L. monocytogenes. The inoculated samples were then exposed to gamma irradiation at doses of 0.1 to 0.6 kGy. The numbers of unstressed E. coli O157:H7, S. enterica, and L. monocytogenes were decreased by 0.6-3.9, 0.7-2.9, and 1.0-3.0 log CFU/g, respectively, by irradiation treatment. The resistance of E. coli O157:H7 to gamma irradiation was not affected by desiccation, heat, and cold stresses. However, the pre-exposure of S. enterica and L. monocytogenes cells to these stresses reduced their resistance toward gamma irradiation. PRACTICAL APPLICATION: Gamma irradiation is a non-thermal treatment that can be used in food processing to ensure food safety and quality. The current study proved that low levels (≤0.6 kGy) of gamma irradiation can effectively decrease the risk of unstressed and cold-, heat-, or desiccation-stressed Salmonella enterica, Listeria monocytogenes, or Escherichia coli O157:H7 in hummus.