Flavor compounds, retention

The process parameters which have been stated as influencing the retention of volatile flavor compounds during spray drying are (36) ... 

Spray drying is the most widely used, least expensive and favored route among the methods available for encapsulation (2) Various theories of volatile retention in spray drying have been proposed and reviewed (3). In addition to the nature of flavor compounds, flavor retention is governed by type of carriers, infeed composition, solids concentration (4), dryer inlet/exit air temperature, air velocity and humidity, feeding rate and atomization characteristics. In addition to flavor retention,the stability of the encapsulated product, as mentioned earlier, is also of importance and is governed by nearly the same parameters. However,the effect and mechanics of each individual factor are much less understood. 

Published studies on extrusion formation/retention of flavor are rather limited (2J3). None have reported the effects of protein sources and concentrations on flavor compound formation in extrudates, the major objective of this study. 

Understanding the mechanism by which flavor compounds are formed can lead to better methods of food processing for better formation and retention of flavor. Fundamental flavor chemistry information is also essential in genetic engineering of plants and animals to improve flavor in the starting materials of food products. 

Sadafian, A. and Crouzet, J., Aroma compounds retention during extrusion cooking, in Frontiers of Flavor, Charalambous, G., Ed., Elsevier Science Publishing, Amsterdam, 1987, p. 623. 

In food-related applications, flavor compounds are being encapsulated into CDs for better retention and protection from various possible means of deterioration as well as for controlled delivery (Szente and Szejtli, 1986,2004 Hedges et al., 1995 Hedges and McBride, 1999). 

Volatile compound retention by edible films is complex, and many factors could affect it and interact. Figure 38.6 is a simplified summary view of the main parameters influencing the flavor release from edible films. 

Some of the stated advantages of direct osmosis in comparison with other drying processes include minimized heat damage to color and flavor, less discoloration of fruit by enzymatic oxidative browning, better retention of flavor compounds, and less energy consumption since water can be removed without change of phase. However, products cannot be dried to completion solely by this method and some means of stabilizing them is required to extend their shelf lives. 

Encapsulation involves the incorporation of active ingredients such as flavors, enzymes, cells or other materials in small capsules. The choice of excipients for encapsulation is very important for the encapsulation efficiency and protein stability within the matrix. Applications of this technique have increased in the food and pharmaceutical industries since the encapsulated materials can be protected from moisture, heat or other extreme conditions. Thus their stability is improved and their viability maintained. Powder formation can lower the water activity of the material, the reactivity and the diffusivity of encapsulated compounds, and the diffusivity of residual water. In the food industry microencapsulation is often associated with the already discussed retention of flavor compounds during drying and storage. In pharmaceutical applications, the purpose of microencapsulation is to control the release and improve the bioavailability of active ingredients. 

Bolton, T.A., The Retention and Stability of Volatile Flavor Compounds Absorbed in Amorphous Silicon Dioxide, M.S. thesis, Department of Food Science and Nutrition, University of Minnesota, St. Paul, p. 182, 1993. 

There is better retention of cellular constituents like su is, oi nic acids, cellular proteins and flavor compounds. The desirable effect of MA on plant tissues has also been attributed to lower pH, due to dissolution of CO in tissues. MA can use comparatively higher temperatures than refrigerated storage, and hence reduces physiological disorders like chilling injury. MAP reduces moisture loss from the cormnodity and keeps it fresh like for longer period. Usually the need for adding chemical preservatives is also reduced. 

Example 1.3-7 Flavor retention When food products are spray-dried, they lose a lot of flavor. However, they lose less than would be expected on the basis of the relative vapor pressures of water and the flavor compounds. The reason apparently is that the drying food often forms a tight gellike skin across which diffusion of the flavor compounds is inhibited. What diffusion model should you use to study this effect ... 

Implementation GC-MS in an ion-profiling mode was used to compare the two samples. At the retention time where sniff-port detection noted the off-flavor, differences were observed (Fig. 21.10). A compound with a mass-to-charge ratio (m/z) of 104 (the off-flavor suspect ) is co-eluting with another compound. 

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