Since most common ways of killing bacteria is by heat treatment, which can reduce product quality, by eliminating thermal processing, HPP has a minimal effect on the freshness of foods, resulting in better taste, nutrition content, and appearance, thus technology is extremely beneﬁcial for heat sensitive products. High pressure processing can also destroy bacteria that can cause spoilage without a loss of nutrients or quality. In a HPP process, the product is enclosed in a ﬂexible container (usually a small bag or plastic bottle) and loaded into a high pressure vessel ﬁlled with a hydraulic ﬂuid (normally water) the pressure is then passed on to the food itself. After the system has reached the desired pressure, products are for a speciﬁc time, normally 3 to 5 minutes then the vessel is depressurized, the processed product is then removed
Preservation is based predominantly on delaying or preventing the growth of microorganism, and less commonly, with the exception of thermal processing, an outright killing that is more typical of disinfection (Russell et al, 1999). There are several forms of food preservation methods such as smoking, freezing, dehydration, pasteurisation and as referred to in this essay, irradiation. Foods are processed and preserved to provide the consumer with a higher standard of product over a longer period of time, thus ensuring the product is of a quality nutritional standard for the shelf life period, during transportation and storage. The radiation used in food irradiation is called ionising radiation, this is due to the knocking of electrons from
In some cases the chrmophore itself is getting destroyed into a colorless product and lead to pale or white patchy dyeing. Hence the removal residual alkali and peroxide are very much essential before starting a good dyeing operation. So any chemical that kills the residual peroxide in the fiber is called a peroxide killer. All reducing agents are in fact peroxide killers. Again we should note that excess presence of reducing agent in the fiber also lead to destruction of dyestuff molecule.
The independent variable is varying the range of concentrations by diluting the 1M solution of sodium chloride. The dependant variable is measuring the mass of the potato. The variables that were kept constant were to use the same potato, cutting identical weight and length of potato sections and use the same electronic scales. Prediction It was predicted that when increasing the concentration of sodium chloride, the mass of the potato should decrease. This is because the potato has a higher water potential than the solution.
Selective Media Lab Report Introduction Biological media acts as food for the bacteria and allows the growth of bacteria. There are two types growth media, selective media and differential media. Selective media used is when trying to promote the growth of only one bacteria, while differential media is used when trying to distinguish one media from another growing on the same plate. This experiment uses one type of differential media, Blood agar, which is differential for detecting hemolytic activity. Three types of selective media are used: Phenyl Ethyl Alcohol (PEA) are both selective for gram positive agar and Deoxycholate Citrate Agar (DCA) is selective for enteric pathogens.
There are four natural forms of botulism: food borne, infant, wound, and adult intestinal colonization (1). Food borne botulism (typically type A, B, or E toxins) is caused by ingesting food that has been in contact with contaminated soil and contains the spores. Improper canned goods and garlic/pepper infused oils with low acidity, high water activity, low concentration of salt, and no preservatives offer the organism a favorable anaerobic and nutritional environment to grow and produce the toxin (4). The spores are heat resistant and can survive improper prepared foods (5). Although, boiling canned goods for more than ten minutes will destroy the toxin (2, 5).
Food Irradiation and Its Effects on Consumer Health Food irradiation is a process that the food industry uses to reduce harmful, disease causing bacteria and increase the shelf life of foods by destroying decay causing microbes. While this process has been proven to be safe by the Center for Disease Control and the Food and Drug Administration, public misconception of the process has created doubts as to its safety and effectiveness. Through public awareness and education of this process, many concerns and misbeliefs can be dispelled. Food irradiation is performed using three different technologies, using three different kind of rays: gamma rays, x-rays, and electron beams. The different uses will depend on the food being irradiated as each technology has strengths and weaknesses.
The Effect of Alkaline pH on Reaction Rate of the Enzyme Catecholase Introduction Enzymes are essential to the metabolism of biological organisms. Several factors can influence the reaction rate of enzymes: temperature, pH, enzyme concentration and substrate concentration (Ainsley, 2010). Catecholase, an enzyme in the tyrosinase/polyphenol oxidase family, is responsible for the browning seen in potatoes, apples and mushrooms after they are cut (Capworth, 1998). These fruits and vegetables contain small amounts of catechol, along with the enzyme catecholase, that reacts with oxygen in the atmosphere and forms the brown compound benzoquinone (Hemelstine, 2004). This reaction can be delayed or prevented in fruits and vegetables by the addition of acids, such as lemon juice, and by cooking (Hemelstine, 2004).
The nutritional Value in Pasteurized milk is somewhat shocking. During the process of Centrifugation, the processors view natural fats to be fatty and high in cholesterol. So they remove the natural fats and now a body for the milk isn’t present. The processors then decide to add powdered milk, which is inevitably much more damaging for our health since it is oxidized. The body may also recognize the altered proteins to also be foreign and reactions such as allergic reactions may occur.
(www.food-facts.suite101.com/article.cfm/the_health_benifits_of_nuts) The Asian food guide pyramid recommends fish or shellfish weekly. Fish is a healthy brain food filled with Omega 3 acids, which are usually lacking in our diet. They contribute to brain and tissue development, especially in infants. (www.feap.info/pieces/hottopics/advant5_en.asp) Fish recommended to be eaten weekly is sort of a double bonus because you are getting your protein from other sources and your body acquires Omega 3 acids which cannot be found in many other foods. Since your body does not make Omega 3 on its own, you have to get it through foods.