Microwave flavors

Microwave flavor generation 1s an area which has not yet received much attention. It is estimated that microwave oven penetration in US households 1s now approximately 75X. A few years ago, food processors simply added microwave instructions to their regular line of products. More recently, microwave specific products have arrived and include popcorn, pizza, cake and brownie mixes, stuffing mixes, and main meals. Major food processors will continue to design... 

Two areas where we can expect to see advances made are 1n extruded flavors and microwave flavors. These two technologies do not lend themselves to browning reactions due to the t1me/tempera-ture/moisture relationships. Thus these areas remain an area of active research. 

Flavors added to microwave food systems have a greatly expanded role compared to flavors added to products prepared by conventional heating. The flavors must provide not only the characterizing flavor (i.e., lemon, butter, vanilla, etc.), but also the typical roasted, toasted, and baked flavors which do not develop in microwave heated products. New flavors designed for use in microwave products must mask the raw uncooked flavor characteristics and other undesirable flavor notes frequently found in many microwave bases. Microwave flavors must also deliver pleasant aromas into the room during the microwave process. Development of these flavors for microwave application is dependent upon a fundamental understanding of microwave heating on flavor performance in food systems. 

A good compilation of the functions of fats in various food products is available (26). Some functions are quite subtle, eg, fats lend sheen, color, color development, and crystallinity. One of the principal roles is that of texture modification which includes viscosity, tenderness (shortening), control of ice crystals, elasticity, and flakiness, as in puff pastry. Fats also contribute to moisture retention, flavor in cultured dairy products, and heat transfer in deep fried foods. For the new technology of microwave cooking, fats assist in the distribution of the heating patterns of microwave cooking. 

The diazines pyridazine, pyrimidine, pyrazine, and their benzo derivatives cinnoline, phthalazine, quinazoline, quinoxaline, and phenazine once again played a central role in many investigations. Progress was made on the syntheses and reactions of these heterocycles, and their use as intermediates toward broader goals. Some studies relied on solid-phase, microwave irradiation, or metal-assisted synthetic approaches, while others focused attention more on the X-ray, computational, spectroscopic, and natural product and other biological aspects of these heterocycles. Reports with a common flavor have been grouped together whenever possible. 

Feng, H., Tang, J., Mattinson, D.S., and Fellman, J.K. 1999. Microwave and spouted bed drying of frozen blueberries The effect of drying and pre-treatment methods on physical properties and retention of flavor volatiles. J. Food Process. Preserv. 23, 463-479. 

In 2002, 14 cases of flavoring-related BO among microwave popcorn workers and flavor-manufacturing workers were reported (CDC, 2002 Kreiss et ah, 2002a Lockey et ah, 2002 Parmet and von Essen, 2002). The NIOSH Alert on flavoring-related lung disease was disseminated in 2004 to flavor and food manufacturers and regional OSHA offices (CDC, 2004). 

Kanwal, R., Kullman, G., Piacitelli, C., Boylstein, R., Sahakian, N., Martin, S., Fedan, K., and Kreiss, K. (2006). Evaluation of flavorings-related lung disease risk at six microwave popcorn plants. /. Occup. Environ. Med. 48, 149-157. 

Mauron J (1981) In Eriksson C (ed) Maillard Reactions in Food. Pergamon, Oxford, p 3 Mottram DS (1994) In Parliment TH, Morello M), McGorrin R) (eds) Thermally Generated Flavors Maillard, Microwave, and Extrusion Processes. ACS Symposium Series 543. American Chemical Society Washington, p 104 Nursten HE (1980) Food Chem. 6 263... 

The research indicated that comparatively few common flavorings absorb beat Ithus. temperature rise/unit offline) as fast as water. Among the more Volatile under microwave radiation are fenugreek and onion oleoresin, whereas, in decreasing order of volatility, arc sage oleoresiu. ginger oleoresin, carrot seed oil. anise nil. hasil sweet oil. oleoresin celery, and oleoresin black pepper. 

In summary, headspace concentration method is the usual way of analyzing the odor quality of packaging materials and has been shown to give reliable data which can be correlated with sensory evaluation data. Oven-heated microwavable packaging materials may pose a special flavor problem in the food consumed. 

Samples were reheated at full power for 1 minute in a microwave oven prior to proceeding with flavor volatile analysis (60 C internal temperature). A reproducibility study was carried out on 5 identical, 100 g samples that had been stored for 3 days after cooking, except that they were not reheated in the microwave prior to analysis. An ad hoc panel convened for these experiments consisted of two trained meat flavor panelists who scored the samples for characterization of MFD according to descriptive sensory methods described by Johnsen and Civille (12) and Love (13). The panelists were also active members of a twelve member descriptive sensory panel at the Center. Two duplicate repetitions were carried out for each experiment (4 samples studied). 

Over 500 raw materials used to create flavors were analyzed through a series of experiments designed to characterize their heat absorption in the microwave oven. From the data gathered, we have proposed the Delta T (AT ) theory to describe the behavior of flavors in the microwave environment. The AT values calculated for these raw materials, which comprise a range of functional groups, allow for the extrapolation of our data to the thousands of rav materials currently used in creating food flavors. This ultimately will enable the design of flavors which are customized for microwave food applications. 

SHAATH AND AZZO Design of Flavors for the Microwave Oven... 

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