Potatoes cooking French fries

Waste or scrap potato chips, french fries or crisps which have been cooked in oil for human consumption are very palatable and high in energy due to the fat taken up in deep frying. They consist of about 500g/kg starch, 350g/kg fat, 50g/kg CP and 30g/kg minerals, mainly potassium and sodium salts. Generally they have a high salt content, and a plentiful supply of fresh water should be made available if they are used in poultry diets. They can be included in diets for poultry at low levels. 

Peas, canned Corn, boiled Onion rings, cooked French fries, cooked Mashed potatoes Sweet potatoes, candied Cream of potato soup Catsup... 

In addition to generation of toxic compounds in the frying oil, toxic molecules may be generated in foodstuff. In April 2002, Swedish scientists sounded an alarm when they discovered that certain cooked food, particularly potato chips and French fries, contained high levels of acrylamide, a chemical compound that is listed by the World Health Organization (WHO) as a probable human carcinogen (Mitka,... 

French fries are made from potatoes that have been cut into thin strips (around 1 cm square in cross-section), washed briefly in cold water, partly dried to remove surface moisture and deep fired in vegetable oil at around 180°C to a light golden color. The final product comprises around 10% fat, most of which is retained on the surface. Frozen fry manufacturers ship their products raw, par-fried, or partially cooked and drizzled with oil for baking, to suit the end user. The product is frozen at —40°C and stored at —20°C. Moisture content needs to be less than 70% in par-fried fries to prevent limpness and separation of the interior and the cmst. Heterogeneity in moisture content between strips can result in variability in texture. Fr5dng is finished by immersing the frozen product in deep fat at about 200°C until the desired color and texture are achieved. 

In April 2002, Swedish researchers shocked the food safety world when they presented preliminary findings of acrylamide in some Ified and baked foods, most notably potato chips and French fries, at levels of 30-2300 p,m/kg. Reports of the presence of acrylamide in a range of fried and oven-cooked foods have caused worldwide concern because this compound has been classified as probably carcinogenic in humans with significant toxicological effects, namely neurotoxic and mutagenic (Rosen and Hellenas, 2002 Tareke et al., 2002). French fries and potato crisps exhibit relatively high values of acrylamide 424 p-g/kg and 1739 p-g/kg, respectively. 

A sample of french fried potatoes weighing 100.0 g was extracted with the volatile organic solvent hexane. After separation and evaporation of the hexane, 6.25 g of cooking oil was recovered. What was the percent oil in the potatoes Show your calculations. 

The oxidation products of lipids include volatile aldehydes and acids. Therefore, lipids are one of the major sources of flavors in foods. For example, much of the desirable flavors of vegetables such as tomatoes, cucumbers, mushrooms, and peas (Ho and Chen, 1994) fresh fish (Hsieh and Kinsella, 1989), fish oil (Hu and Pan, 2000) and cooked shrimp (Kuo and Pan, 1991 Kuo et al., 1994), as well as many deep-fat fried foods such as French-fried potatoes (Salinas et al., 1994) and fried chicken (Shi and Ho, 1994), are contributed by lipid oxidation. LOX-catalyzed lipid oxidation produces secondary derivatives, e.g., tetradecatrienone, which is a key compound of shrimp (Kuo and Pan, 1991). The major difference between the flavors of chicken broth and beef broth is the abundance of 2,4-decadienal and y-dodeca-lactone in chicken broth (Shi and Ho, 1994). Both compounds are well-known lipid oxidation products. A total of 193 compounds has been reported in the flavor of chicken. Forty-one of them are lipid-derived aldehydes. 

French frying reduces the water content of potatoes to the extent that the cooked product contains over twice the solids. 3 to 4 times the calories, and double the protein content of baked or boiled potatoes. Furthermore, each ounce (28 g) of french fries contains almost 1 tsp (5 ml) of fat. 

Potato flavor is greatly influenced by methods of cooking or preparation. Raw potato contains the characteristic earthy aroma component, 2-ixo-propyl-3-methoxypyrazine. A character impact compound common to boiled and baked potatoes is methional (3-[methylthio]propanal). Baked potatoes contain Maillard products such as 2-ethyl-3-methylpyrazine (earthy, nutty) and 2-ethyl-6-vinylpyr-azine (buttery, baked potato) (34). In potato chips and French-fried potatoes, the potato flavor character of methional is modified by volatile aromatics from frying oils, such as ( , )-2,4-decadienal, and thermally generated alkyl oxazoles possessing lactone-like flavors (34,39). The pyrazines 2-ethyl-3,5-dimethyl and 2,3-diethyl-5-methylpyrazine are described as potato chip like (40). 

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