Amino acids process flavor from

Uses Defoamer in food processing, fennentation and extraction induding starch extraction from com flour, protein extraction from vegs., defoamer in biochemical media in the prod, of citric and amino acids, nat. flavors Features Mixes easily with water silicone-free does not affect the dissolved oxygen rale stable to conventional sterilization conditions Properties CL, colorless liq. (5% in deionized water) dens. 1.015-1.025 vise. 415 cSI (40 C) f.p. < -20 C acid no. < 3 Use Level 5040 ppm in fermentation process Environmental No toxicity towards a wide range of micro-organisms Biospumex FDA 165 K [Cognis]... 

Potential consumer benefits from biotechnology (56) are cost and quaUty. The use of biotech means to increase the level of various sulfur-containing amino acids in coffee proteins, and to enhance sucrose and oil levels, could have an impact on the flavor and aroma of the finished ground coffee product. Also, caffeine level modification/elimination through genetic manipulations of the coffee plant could yield low caffeine coffee without additional processing by the manufacturer. 

A common thread that can link the ammonium and peptone catalyst poisoning results just described could be the Maillard reactions of amino acids with sugars (5). Recent studies have shown that the ammonium ion is highly reactive, more so than substituted versions (6). Its use as ammonium bicarbonate in developing flavoring compounds by Maillard reactions in extrusion cookers has been reported (7). It is likely that such reactions could occur at our processing conditions. We can speculate that such products could have acted as catalyst surface poisons, which might have been subsequently washed from the catalyst, before it was reused in its active form. 

The flavor industry has introduced, over the years, methods of developing meat flavors by processing appropriate precursors under carefully controlled reaction conditions. As a result, meat flavors having a remarkably genuine meat character in the beef, chicken and pork tonalities are available for the food industry. It has repeatedly been stated that the Maillard reaction is particularly important for the formation of meat flavors. However, of the 600 volatile compounds isolated from natural beef aroma, only 12% of them find their origin in sugar/amino acid interactions and of these 70% are pyrazine derivatives. 

The purpose of this paper is to review the numerous papers published on flavors, tastes and odors resulting from the browning reaction. Investigations of model systems which have been observed under laboratory conditions are considered and their possible significance in basic and industrial processes will be discussed. Speculation on the possible correlation between model system results and specific processed food items will be presented. Results of recent work in our laboratory on flavor notes developed upon heating ribose with various amino acids will be discussed. 

Glucose was the only major sugar and IMP and GMP were the only major nucleotides found. A sensory evaluation of the different processed products Indicated a preference for the drum dried product over the freeze or spray dried product. This preference could not be explained from sugar or nucleotide values and the amino acid data was Inconclusive. Since the authors have amassed such a large data pool for both volatile and nonvolatile compounds 1t Is unfortunate that some form of data analysis such as multlvarlent statistical analysis was not applied so as to determine which compounds were primarily responsible for the perceived flavor preference. 

Lipid radical transfer has been demonstrated for trp, arg, his, and lys (99, 383, 384), all of which have reactive N groups on their side chains, and radical decomposition products from these amino acids have been identified (381, 382, 390). Tyrosine and methionine degradation by oxidizing lipids has also been demonstrated (390), but the intermediate radicals in the reaction may be too unstable for detection. Lipid radical adducts to amino acids are important flavor precursors (340) and also may play critical roles in pathological processes in vivo (186, 388). 

Traditional fermentation using microbial activity is commonly used for the production of nonvolatile flavor compounds such as acidulants, amino acids, and nucleotides. The formation of volatile flavor compounds via microbial fermentation on an industrial scale is still in its infancy. Although more than 100 aroma compounds may be generated microbially, only a few of them are produced on an industrial scale. The reason is probably due to the transformation efficiency, cost of the processes used, and our ignorance to their biosynthetic pathways. Nevertheless, the exploitation of microbial production of food flavors has proved to be successful in some cases. For example, the production of y-decalactone by microbial biosynthetic pathways lead to a price decrease from 20,000/kg to l,200/kg U.S. Generally, the production of lactone could be performed from a precursor of hydroxy fatty acids, followed by p-oxidation from yeast bioconversion (Benedetti et al., 2001). Most of the hydroxy fatty acids are found in very small amounts in natural sources, and the only inexpensive natural precursor is ricinoleic acid, the major fatty acid of castor oil. Due to the few natural sources of these fatty acid precursors, the most common processes have been developed from fatty acids by microbial biotransformation (Hou, 1995). Another way to obtain hydroxy fatty acid is from the action of LOX. However, there has been only limited research on using LOX to produce lactone (Gill and Valivety, 1997). 

Cysteine is an important precursor of meat flavor and is therefore often being used in precursor systems for the industrial production of meat process flavorings (1-4). Meat flavor development in these systems is usually based on the Maillard reaction of cysteine (and other amino acids) with sugars. Unfortunately, there are a few complications that prevent that high yields of volatile flavor compounds are obtained from these reactions. The first... 

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