Flavor desirable, production

Because of the lower temperatures and nearly neutral conditions employed in tire enzyme-catalyzed hydrolysis of starch, there are generally fewer side-reactions than in the acid-catalysis systems this can result in greater yields of the desired products and less formation of color and deleterious flavor. This is important, because the cost of refining processes needed to lower color and deleterious flavor to acceptable levels in the sweeteners becomes prohibitive if these levels are too high prior to refining. 

A typical restaurant fryer operates at 335-375°F (168-190.6°C). A measured amount of food is placed in the basket. The basket is lowered into the oil, which is already heated to the desired temperature. The oil temperature in the fryer drops immediately, and then it gradually recovers. The recovery time for the oil temperature within a specific time is critical for French fries, coated vegetables, and so on to achieve the desired product texture, flavor, and appearance. However, the recovery time for the fryer oil temperature is especially critical for chicken, fish, and other meat products, where the interior of the product must reach a specific temperature to prevent food-bome diseases associated with the meat and poultry products. 

There are several reasons why the actual yield is usually less than the theoretical yield in chemical reactions. Many reactions do not completely use up the limiting reactant. Instead, some of the products turn back into reactants so that the final result is a mixture of reactants and products. In many cases the main product must go through additional steps to purify or separate it from other chemicals. For example, banana flavoring must be distilled, or isolated based on its boiling point. Solid compounds, such as sugar, must be recrystallized. Some of the product may be lost in the process. There also may be other reactions, called side reactions, that can use up reactants without making the desired product. 

To outline the process, the aqueous substrate for beer production is made by brewing cereals with hops, which provide the characteristic bitter flavor component. Barley is the chief cereal ingredient, which is first malted to give enzymes required to breakdown starches to simple sugars, and also to contribute an important flavor component. Barley is a fairly expensive source of starch, so it is usually supplemented by the addition of less expensive starch adjuncts such as corn (maize), oats, millet, wheat, or rice. The adjunct contributes to carbohydrates, but makes little contribution to the flavor. Various strains of yeasts selected for their efficient conversion of glucose to ethanol are refined by individual brewers to achieve desired product qualities. 

Spices have long been important for food products. It was found that small amounts of various plants could be used to enhance the flavor of a food and also served to help preserve that food. In some cases spices were even used to mask spoilage or off-flavors in products. This use continued for centuries without any real understanding of how the spices were being effective. People simply understood that spices helped create a more desirable taste in the foods that were being prepared. Dinerent cuisines are noted for using specific types of spices to create their characteristic flavors. 

Spoilage of food is caused by growth of microorganisms, enzyme action, oxidation (chemical reactions), extremes in physical surroundings, anckor pests. Insofar as possible, the aim of preservation is to reduce, eliminate, and/or control the causes of spoilage. With the modern methods of preservation, seasonal harvests can be enjoyed year round, and food specifically grown in one area can be shipped across the country or even worldwide. Still, scientists continue to search for better methods of preservation that yield a nutritious, flavorful, and desirable product, with minimal long-term requirements. 

LAB produce a range of flavor products such as diacetyl, which has a buttery aroma and is a highly desirable product in many foods (Cogan and Accolas 1996). Strategies involving metabolic engineering, whereby metabolic pathways are manipulated to overproduce specific products, have been used to develop cultures that elaborate elevated levels of diacetyl. 

In addition, because of their milky appearance, emulsions are not suitable if clarity is a desired product attribute. The o/w microemulsions or micelles can greatly increase the soluhiUty of flavor compounds, vitamins, and other additives that are insoluble or marginally soluble in water by solubilizing them in the hydrophobic core. 

Lactic Acid B cteri. The lactic acid bacteria are ubiquitous in nature from plant surfaces to gastrointestinal tracts of many animals. These gram-positive facultative anaerobes convert carbohydrates (qv) to lactic acid and are used extensively in the food industry, for example, for the production of yogurt, cheese, sour dough bread, etc. The sour aromatic flavor imparted upon fermentation appears to be a desirable food trait. In addition, certain species produce a variety of antibiotics. 

Experimental procedures have been described in which the desired reactions have been carried out either by whole microbial cells or by enzymes (1—3). These involve carbohydrates (qv) (4,5) steroids (qv), sterols, and bile acids (6—11) nonsteroid cycHc compounds (12) ahcycHc and alkane hydroxylations (13—16) alkaloids (7,17,18) various pharmaceuticals (qv) (19—21), including antibiotics (19—24) and miscellaneous natural products (25—27). Reviews of the microbial oxidation of aUphatic and aromatic hydrocarbons (qv) (28), monoterpenes (29,30), pesticides (qv) (31,32), lignin (qv) (33,34), flavors and fragrances (35), and other organic molecules (8,12,36,37) have been pubflshed (see Enzyp applications, industrial Enzyt s in organic synthesis Elavors AND spices). 

Nearly half of the U.S. domestic food consumption of peanuts in 1993 was as peanut butter salted peanuts, at 27.3%, and peanut candy, at 23.9% made up the other half (137). Although the per capita domestic peanut consumption in the United States has increased steadily, the consumption in recent years has not kept pace with production. Domestic food use of peanuts has been confined almost entirely to roasted peanuts. A number of investigations and developmental efforts are being made to extend the use of nonroasted peanut products such as flour and meal flakes. As of the mid-1990s, market outlets for these latter products are neither sizable nor firmly established. The food-use patterns emphasize the uniqueness and demand for products having a distinct roasted-peanut flavor. The development of the desired flavor as well as the storage stability of such flavor in peanut-food products are therefore important. 

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