Snack water activity

More impi manl than moisture content, per se. is the objective of creating a preserved food substance lhai is stable and can he eaten directly. An idealized IMF system will have ilia microbial stability at reduced water activity. 17) storage siabiliiy without special conditions. l3i reduction of weight and more compactness of product, and (41 can be consumed from the package without rehvtlrulion Some authorities believe that IMF systems represent excellent potential in the development of the snack market... 

Figure 1-25 Modified State Diagram Showing Relationship Between Glass Transition Temperature (Tg), Water Activity (GAB isotherm), and Water Content for an Extruded Snack Food Model. Crispness is lost as water plasticization depresses Tg to below 24X2. Plasticization is indicated with critical values for water activity and water content. Source Reprinted with permission from Y.H. Roos, Glass Transition-Related Physico-Chemical Changes in Foods, Food Technology, Vol. 49, No. 10, p. 99, 1995, Institute of Food Technologists.

Figure 8-46 Relationship Between Water Activity and Crispness of Popcorn. Source. Reprinted with permission from E.E. Katz and T.P. Labuza, Effect of Water Activity on the Sensory Crispness and Mechanical Deformation of Snack Food Properties, J. Food Sci., Vol. 46, p. 403, 1981, Institute of Food Technologists.

Katz, E.E., and T.P. Labuza. 1981. Effect of water activity on the sensory crispness and mechanical deformation of snack food properties. J. Food Sci. 46 403-409. 

Another important quality defect of fried snacks is the reduction of crispness during storage due to absorption of moisture. In addition, moisture gain accelerates rancidity. Data concerning the effect of water activity (a ) on oxidation rate are presented by Labusa [39]. As a increases above the monolayer, the reaction is slowed up to the value where intermediate moisture foods begin (i.e., approximately 0.4). A further moisture increase tends to increase the rate of oxidation. Data on water activity that results in loss of crispness to an extent where the chips are perceived as not acceptable are not available, but Labusa comments that it probably occurs at an of 0.4-0.5. 

The determination of the A is critically important for low-moisture snack foods. These products are manufactured to reach a certain or given level. Water activity affects microbial growth, enzyme activity, and product texture. 

ALL-INCLUSIVE THE RIU WAY FEATURES Unlimited meals, 24-hour snacks and beverages, unlimited domestic and selected imported alcoholic beverages, tropical juice cocktails and soft drinks, unlimited use of in-room minibar and liquor dispenser, various water and land sports, daily activities for adults and children, live nightly entertainment and outstanding service. 

I encourage most Fire types to choose the cool of the day for more vigorous activities like sports or exercise. Larry pointed out that summer was a busy time on his farm, and he didn t have the option of waiting until the weather cooled to tend to his fields and livestock. I suggested that he make sure to refresh himself with plenty of filtered water or tonic water and lemon or lime, and that he find cool places for eating lunch and snacks throughout the day. 

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