الفهرس 
3.1. TRADITIONAL MAYONNAISEOnly 14 pages are availabe for public view
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Abstract
Low-fat (LF) mayonnaise was produced by replacing different levels of oil with different types (xanthan gum, XG; guar gum, GG; and a combination of XG and GG, 1:1) and levels (0.00, 0.25, 0.50, 0.75 and 1.00%) of hydrocolloid gums. Various types of oil (sunflower, soybean, corn, sesame and olive oil) were preliminary used in mayonnaise formulation. The most sensorially acceptable types of oil were selected to be incorporated in the production of LF mayonnaise. Sensorial, physical, chemical, physicochemical and microbiological characteristics of the best LF formulations (based on sensory analysis) were evaluated during a course of 9 months with interval period of 30 days. The full fat (FF) mayonnaise (75% oil) without hydrocolloid gum was used as a control. Results revealed that sunflower and soybean oils were the most sensorially acceptable oil types. Moreover, the best LF mayonnaise product was formulated with either sunflower or soybean oil at 60% and 45% oil level and addition of a combination of XG and GG (1:1) at 0.75% concentration. No significant (P>0.05) differences were observed in protein, carbohydrate and ash content among all FF and LF formulations during the entire period of storage. The LF mayonnaise products showed lower (P≤0.05) caloric values and higher (P≤0.05) water activity (aw) and pH values compared to the FF formulation at the end of storage period. The colour measurements of the freshly prepared LF mayonnaise revealed higher lightness (L*), similar participation of green colour (-a*) and lower yellowness (b*) than FF mayonnaise. In terms of texture, LF mayonnaise 45% oil showed higher (P≤0.05) firmness, adhesiveness, adhesive force, cohesiveness and gumminess compared to FF mayonnaise. As for oxidation the acid and peroxide values increased significantly by increasing the storage period more so in the LF samples. Salmonella was not detected in any of the samples throughout the entire period of storage. The results of the current study show good potential for the combination of XG and GG (1:1) at 0.75% as a fat substitute in mayonnaise using 45% oil level of either sunflower or soybean oil.