Food thermometers

Use fresh heavy cream, ideally at room temperature (about 60°F/15°C), for a sweet cream hutter. If you want a more subtle continental flavor, culture the cream first before churning add two tablespoons of plain yogurt, sour cream, or creme fraiche to 17 fl oz (500 ml) of fresh heavy cream. Leave the cream for 24 hours at a warm room temperature (about 75°F/24°C) and then cool it back down to 60°F (15°C) to make the butter. A digital food thermometer is a useful way of enabling you to control the temperature correctly without having to rely on guesswork. 

Povidone—iodine is a brown, water-soluble powder containing approximately 10% iodine. However, the amount of free iodine, which is responsible for the antimicrobial activity, is low in a concentrated solution, but is released as the solution is diluted (41). Concentrated solutions have actually been contaminated with bacteria (42). For use as an antiseptic, povidine—iodine is diluted with water or alcohol to a concentration of 1% iodine. Detergents are added if it is used as a surgical scmb. lodophors are important as broad-spectmm antiseptics for the skin, although they do not have the persistent action of some other antiseptics. They are also used as disinfectants for clinical thermometers that have been used by tuberculous patients, for surface disinfection of tables, etc, and for clean equipment in hospitals, food plants, and dairies, much as chlorine disinfectants are used. 

Given this situation, it is not surprising that, over the last few years, products based on platinum thin film technology have been finding their way into the home. With the growing use of electronic control systems in the new generation of domestic appliances, platinum temperature sensors have been more widely used in ovens where they have replaced electromechanical regulators such as capillary tubes, solid expansion thermometers and NTC thermistors. Typical sensor applications in the food preparation sector are shown in Fig. 5.3. 

Figure 2.1 A bomb calorimeter. The food is ignited by an electric current within the inner compartment, which is known as the bomb because the reaction within the box is generally so rapid as to be almost explosive. Insulation prevents heat loss and the thermometer measures the rise in temperature of the water that surrounds the bomb. From this increase, and the thermal capacity of the apparatus, the amount of heat released can be calculated.

Six identical soup bowls, aluminum foil, colorless plastic food wrap, colorless plastic bubble wrap, black plastic garbage bag, liquid detergent, kitchen thermometer... 

In the field, all types of freezer storage facilities are used. The investigator may have a food freezer at his home that Is used for residue samples or the freezer may be in a rented mini-storage warehouse across the city from his home. The samples may be stored in a commercial freezer facility, In a walk-in freezer at a university, or some other facility chosen by the field investigator. Each freezer is equipped with a recording thermometer. Each time the chart is changed, the calibration is checked with a mercury thermometer and the reading recorded. All freezer records are retained in the data archive. 

Heat measurements involved in thermochemistry (see 0011) are made using a thermometer in a thermally insulated device called a calorimeter. Food calories are determined by a bomb calorimeter. 

Rats weighing 150-200 g are used. Eighteen hours prior to the experiment food is withdrawn with free access to water. The appropriate size of the study groups for the control and candidate compound consists of 5-7 animals. Anesthesia is induced by pentobarbital (priming bolus 60 mg/kg i.p. plus infusion s.c. at about 20 mg/kg/h) or i.p. injection of 5 ml/kg of 25 % urethane solution. Body temperature is artificially stabilized by means of a rectal thermometer and a heating pad. The trachea is exposed and cannulated for artificial respiration. The abdomen is opened by a mid-line incision and the pylorus ligated. The proximal part of the bile duct is ligated near the hepatic... 

Thermometers suitable for Food Chemicals Codex use conform to the specifications of the American Society for Testing and Materials, ASTM Standards E 1, and are standardized in accordance with ASTM Method E 77. 

In selecting a thermometer, careful consideration should be given to the conditions under which it is to be used. The preceding table lists several ASTM thermometers, together with their usual conditions of use, which may be required in Food Chemicals Codex tests. Complete specifications for these thermometers are given in ASTM Standards on Thermometers. ... 

For the initial pyrogen tests, groups of three healthy, mature rabbits are chosen. Accurate temperature-sensing devices, such as clinical thermometers or thermistor probes, are inserted into the rectum of the rabbits to record their body temperature. If these probes remain inserted throughout the test period, the rabbits must be restrained with light-fitting neck stocks that permit them to move about. During the test, food but not water is withheld from the animals. 

Fill a 100-mL graduated cylinder exactly to the 50.0-mL mark with water that has been tinted with food coloring. Use a dropper to adjust the volume. Insert a thermometer and read the temperature of the water. Remove the thermometer. 

A special type of calorimeter, a bomb calorimeter, is useful for the measurement of the fuel value (Calories) of foods. Such a device is illustrated in Figure 8.6. Its design is similar, in principle, to that of the "coffee cup" calorimeter discussed earlier. It incorporates the insulation from the surroundings, solution pool, reaction chamber, and thermometer. Oxygen gas is added as one of the reactants, and an electrical igniter is inserted to initiate the reaction. However, it is not open to the atmosphere. In the sealed container the reaction continues until the sample is completely oxidized. All of the heat energy released during the reaction is captured in the water. 

USE In manuf of ammonia, nitric acid, nitrates, cyanides, etc. in manuf explosives in filling high-temp thermometers, incandescent bulbs to form an inert atm for preservation of materials, for use in dry boxes or glove bags. Liquid nitrogen in food-freezing processes iu the laboratory as a coolant. Pharmaceutic aid (air displacement). Caution In high concns it is a simple asphyxiant. 

The mercury thermometer is sufficiently accurate for practical work in the determination of temperature changes in the canning of food materials if it is properly calibrated and standardized. 

Even if OSHA had discovered the serious fire hazards at Imperial Food Products it still might not have forced compliance soon enough to prevent disaster. As shown by its treatment of the Pymm Thermometer Company, the second largest manufacturer of mercury thermometers in the United States, OSHA inspectors are often reluctant to close a company down or even impose dramatic fines when they find serious violations of health and safety standards. 

Beaumont showed that the introduction of a thermometer into the gastric fistula of Alexis St. Martin induced the secretion of gastric juice. Similarly, gastric juice was secreted even when food surrounded by gauze was introduced into the stomach of St. Martin, who went on with his daily tasks not knowing what had been put in his stomach. Pavlov later established that food directly introduced into the pouch of a dog stimulates gastric secretion even if the dog does not see, smell, or taste the food. 

Mercury thermometers were used widely to measure room temperature as well as the temperature of the human body. Human body temperature is usually 98.6 to 99 degrees Fahrenheit, and variations of a few degrees either way may indicate illness or hypothermia. Alcohol thermometers are used in weather sensing and in homes. The atmospheric temperature varies between roughly 200 K in the cold air above the polar regions and more than 330 K above the deserts. With regard to food preparation, temperatures vary from the 256 K of a refrigerator freezer to the 515 Kofan oven. 

A reasonable temperature must be maintained during working hours and sufficient thermometers must be provided to enable people at work to determine the temperature in any workroom. The temperature should be comfortable without the need for special clothing. Special guidance is available for areas like food processing where it could be very hot or very cold. 

If state or local requirements are based on the 2001 FDA Food Code, wash, rinse, and sanitize food contact surfaces of sinks, tables, equipment, utensils, thermometers, carts, and equipment ... 

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