Causes of PSE and DFD Meats and Treatments

Causes of PSE and DFD Meats and Treatments What is PSE DFD meat? The terms pale, soft and exudative PSE and dark, firm and dry DFD describe two undesired quality characteristics that can be exhibited in the meat from most species of meat producing animals. However the PSE condition is predominantly found in pigs whilst the DFD condition occurs across all species. Within this essay the incidence rates of both PSE /DFD, the causative factors, consequences and commercial factors as well as prevention shall be considered. Pictures of the two conditions can be seen in fig 1. These undesirable conditions are very important when considering both functional and specified meat quality. They are significant factors that contribute to the economic, social and environmental wellbeing of the entire sector and encompass wide ranging issues affecting meat production, profits, yields, animal welfare considerations, processing, customer perception, consumption, food safety, spoilage, waste and levels of carbon dioxide production. Both conditions affect the colour of meat, as it can be considered abnormally pale or dark relative to what is considered normal. Colour is one of the major discriminatory factors in a buyers selection, excessively pale or dark meat is unlikely to be purchased. The texture of the meat with PSE and DFD is also affected detrimentally leading to unacceptable levels of softness or firmness. Undesired changes in water holding capacity of the meat occur, leading to problems in processing and the commercial yields of products, as well as detrimental effects on the sensory attributes of meat such as juiciness or succulence. There is thought to be a link between DFD and a lack of flavour in a cooked product. The development of both PSE and DFD meat can be associated with earlier development of rigormortis  [1]  . Products may subjectively exhibit one or more of the descriptive characteristics e.g. too pale or too dark, too soft or too firm, too exudative or too dry relative to the characteristics of normal meat. Normal acidification of muscles after an animal is slaughtered occurs through glycolysis. Glycogen and creatine phosphate are depleted. Glycogen conversion to lactic acid is described here. C6H10O5 +H2Oà ¯Ã†â€™Ã‚  2C3H6O3 There is no oxygen for aerobic metabolic processes to occur. The circulatory system can no longer remove lactic acid and it accumulates within the muscle. The abnormal conditions of PSE and DFD are linked to abnormally high or low acidity, thus the pH value of the meat can be used to more objectively describe the conditions at different times after slaughter (table 1). However these values can be different in different muscles within a carcass and different packaging methods may affect pH values. Accurate pH recordings are also particularly difficult with various methods having various problems such as lack of homogeneity of sample, fat smearing, dilution of sample etc. Using objective indices of PSE and DFD tends to produce higher estimates of the prevalence of the conditions in a population than using subjective assessment.  [2]  Subjective methods of gauging DFD / PSE using people may be less sensitive. People may only be able to judge the extremes of the conditions. There appears to be an increase in the levels of incidence of PSE and DFD. Within the United Kingdom one quarter of pigs may show evidence of PSE and one tenth DFD. The cost of PSE to the American pork industry was estimated at 30 million dollars in 1992, that of DFD pork 0.2 million dollars  [3]  estimated at 16% and 10% of total United States production respectively. This gives an indication of the economic significance of the problems. The levels of glycogen available in the muscle prior to slaughter will determine the ultimate pH. These levels can be changed through stress, theses stresses prior to slaughter are the main factors involved in causing the PSE and DFD conditions. Although there are genetic, muscle composition and processing factors that can be instrumental, these shall be discussed later and these ultimately link to abnormalities in post mortem acidification of the muscles anyway, the effects of long term and short term stress shall be considered now. It is well known that the handling of meat animals prior to slaughter is not only important from a welfare point of view but also affects the quality of the resulting meat  [4]  . It has also been known for many years that hunted animals keep less well than those kept in relative calm conditions. With PSE the cause appears to be acute (or short term) stress to the animal prior to slaughter. This acute stress leads to rapid acidification as glycogen breaks down quickly after slaughter to give lactic acid, resulting in a low ultimate pH. If carcass temperatures are high e.g. within deep muscle regions of the carcass, or rates of cooling are not rapid enough, conditions can develop that allow denaturing of the proteins within these muscles. The muscles are characterised by having lower water holding capacity due to the myofibrillar components of the muscles shrinking. This expels fluids into the space between the muscle fibres. When cut the meat will exude or lose this fluid, this is called drip. Excessive drip represents a loss in total yield but is also unsightly in shelf ready packaging and less likely to be purchased by a potential consumer. The paler appearance of PSE meat is likely due to the different refractive index of the myofibrils and the sarcoplasm. The reduction in the size of the myofilament lattice increases the light reflected from the meat, less light is absorbed by the meat, more is reflected and crucially blood pigments like myoglobin absorb less green light making the meat look more yellow as opposed to red. Also the low ultimate pH promotes oxidation of myoglobin and oxyglobin to metmyoglobin which makes the meat appear browner rather than red or purple. Again this discoloration makes the product less likely to be purchased at point of sale DFD is caused by chronic (or long term) stress to the animal. Glycogen levels are depleted prior to death, meaning that less glycogen is converted to lactic acid after slaughter and the ultimate pH of the meat remains high. Being closer to pH neutral there are significant issues with potential spoilage organisms and food borne pathogens as well as the quality issues discussed here. With a high ultimate pH there is less denaturing of the proteins leading to increased binding of the fluids and less exudates or drip giving a firm dry appearance. The lattice of myofilaments which shrank in the case of PSE does not in the case of DFD. This means that the affects of the refractive index differences of the myofibrils and sarcoplasm are reduced. More light is absorbed with less reflected leading to a darker colour. The tightly packed structure with less extracellular space between the fibres means that less oxidation of the myoglobin can occur, surface oxidation only may occur as oxygen cannot permeate the structure, this leads to a thin translucent / red outside layer with the reduced purple myoglobin pigment predominantly showing through from underneath this thin layer. The stress factors to consider are many fold but are worth at this stage categorising as acute and chronic in terms fear, pain and physical stress and their potential affect on the PSE DFD conditions. These might include noise, temperature variations, fasting or starvation, overcrowding or being put with animals of different social groups. Practical causes of short term stress might include reaction to goading, striking, restraining systems or conveyors, long term stressors associated with DFD might include long transport journeys and being exposed to other social groups of animals for periods of time. Young Bulls and veal calves have been linked to higher incident rates of DFD perhaps due to storage conditions and their fractious nature when exposed to other social groups, respectively. Different species are known to show different sensitivities to different stress factors, for example sheep are known to be less sensitive to noise than pigs. With pigs in particular there appears to be a genetic link to them being susceptible to stress, this is sometimes known as porcine stress syndrome. It exists as a double recessive gene that when apparent as an abnormal homozygote can be exposed and witnessed as a reaction to Halothane. Typically pigs with this double recessive gene react by becoming rigid and tense as opposed to the usual symptoms of anaesthesia through halothane In pigs with this mutation, Ca2+ is released from the sarcoplasmic reticulum at a rate that is equivalent to twice that of normal  [5]  Glycogen conversion to lactic acid happens much more readily and there are higher incidence of PSE amongst this genetic grouping. Measures to breed this characteristic out of pigs have been tried, it is thought that selective breeding for confirmation and fat level may have brought about this genetic mutation. The Halothane test does not work on the heterozygote parent and DNA tests are required to identify parents with the mutation to try and breed this sensitivity out. Another gene has been identified in certain strains of the Hampshire breed of pigs, known as the RN- gene. It is thought that this mutation increases the glycogen content of the white muscles that contain a higher number of glycolytic fibres, again resulting in post mortem rapid acidification leading to a lower pHu upon death leading to the PSE condition. There are other breed effects which can be demonstrated by a comparative study undertaken (Table 2) where traditional breeds were compared against modern commercially important breeds and an extreme of muscularity, this also seems to demonstrate a correlation between lighter more exudative muscles in those bred for confirmation or muscularity. In the search for modern breeds of the desired confirmation, stress susceptibility may have also been bred in. Even within the defined subjective and objective norms there are variations of colour, texture, pH and water holding capacity within different muscles of the carcasses of all species. The muscles affected by a particular stressor may be specific to a region of the anatomy rather than throughout the entire carcass. A particularly undesirable effect can be seen in the two tone appearance of meat, where the PSE, DFD and normal conditions can be exhibited in the extreme within a single carcass. An animal that is susceptible to PSE may exhibit DFD characteristics in those muscles that have been subject to long term stressors and thus have glycogen depletion prior to death. However some of the other muscles e.g. m. longissimus dorsi, within the same pig that are less likely to have glycogen depletion may exhibit the PSE condition. Processing methods can also have an effect, carcass cooling regimes that dont achieve deep muscle temperatures that are cold enough or at the wrong cooling rates can contribute to the conditions required to denature the proteins and exhibit the PSE condition. Howard and Lawrie (1956) found that the rate of pH fall post mortem was inversely proportional to the tenderness of the meat on subsequent cooking  [6]  Animal handling systems, shearing washing, crushing etc will have a direct effect on the levels of glycogen within the muscle systems and so ultimately the levels of PSE DFD occurring. Being able to measure stress indicators and indices of PSE DFD is critical if there is to be an understanding of the prevention of stress and therefore a reduction in the incidence of PSE and DFD in meat. Measurements of the level blood lactic acid, levels of creatine kinase and the electrical characteristics of pork through electrical impedance can give good objective indicators. Levels of cortisol, creatine kinase, pH and colour characteristics measured through online light reflectance spectrophotometrey can give objective PSE DFD measurements. Signs of stress in the animals can give ante mortem indications. These might be obvious in the case of fallen or injured stock but may also include levels of vocalisation, mounting, biting etc as less obvious indicators. Identifying an reducing these conditions is the key in improving functional and specified meat quality, most of the work undertaken to reduce the levels of PSE and DFD is involved in improving welfare conditions of animals in the short and longer term leading up to slaughter. It is a difficult process to reduce stressors, even with very careful handling the animals are subject to a degree of stress. Keeping handling to a minimum is the ideal situation, carefully controlling transport, design of transport to prevent loading and unloading stress, training and certification schemes to improve the skills and knowledge of animal handlers. With pigs it would be better to avoid breeding the susceptible genotypes although as seen there appears to be a direct correlation between improved confirmation and musculature and the stress susceptibility mutation. Keeping animals, especially young bulls in their own social groups would seem to be a logical preventative measure but can be very difficul t to achieve. Physical measures like cooling pigs with water sprays and covering the pens of young bulls may help stop such stress behaviour as fighting and mounting, adding supplements to feed and watering systems prior to slaughter in order to try and replenish glycogen levels may be one way in order to reduce the number of incidence of PSE , DFD as may using tranquilisers and muscle relaxants, however there are issues of potential residues in meat as well as negatively effecting the quality expectations of the consumer by treating an animal in this way. In conclusion to reduce the levels of PSE DFD in meat of all species a combined approach of improving welfare conditions, reducing fear, physical stress and pain, training and education staff, as well as online monitoring and feedback to key stakeholders is required. Carcass cooling rates should be closely controlled. There is a need to develop new methods of objective measurement, both as soon as possible after slaughter and at point of sale, emerging technologies such as near infra red spectrophotometrey, nuclear magnetic resonance, developments in immunoassay techniques and genetic markers may help us identify and prevent the causes of PSE and DFD. Linking the relationship of animal welfare and profit is very important, Traditionally it has been thought that increasing welfare means increasing costs, for example in stocking densities of transport. In seeing that increasing welfare conditions could actually be a profitable activity, aiding reduced quality complaints, increased yiel ds, better sales and less waste there is an opportunity to have large positive impact on the well being of the whole meat sector. there are few, if any, figures comparing the overall economics of these alternatives. However it seems the net effect of greater care could often be greater profitability  [7]  .

Academic Objectives Essay

By the time I attend the graduation ceremony of University of Phoenix, there are three academic objectives I would like to accomplish. First and foremost, I would like to get a bachelor’s degree in psychology. Secondly, I would like to become a better writer. Last, I would like to become a better communicator so that I can network with people who are in the same career and field of work as me. With lots of dedication, hard work and completion of my classes, these are three goals I intend to complete. Receiving a bachelor’s degree in psychology from the University of Phoenix is my first academic objective. I get one step closer to my goal by attending all my classes, completing my assignments with a passing grade, and doing the best at passing all my exams. Today, having a bachelor’s degree is like having a high school diploma. Most jobs require or prefer some type of degree from a person when hiring. Like Achieve said, â€Å"Much has been said about the importance of increasing the labor supply for ‘middle skills jobs,’ or those jobs that now (compared to decades past) require more than a high school education but less than a bachelor’s degree (e. g., associate degree, postsecondary certificate, apprenticeship, etc. )† (Achieve, 2012) I recently applied for a job as a personal therapist to children with disabilities. When it came down to the interviewing and hiring portion, I was not able to get the job because I still have not received my bachelor’s degree. It was tough hearing the news but it really motivated and pushed me to go back to school and finish my degree. A bachelor’s degree has now become a necessity rather than a choice for me. Becoming a better writer would not only help in school but also in the world after graduation. Beginning with the Gen 200 class, one main focus there is writing. Whether it is writing a paper or doing a project, it is important to know where a person is making mistakes and where he or she is doing a good job. I find myself having to refresh my memory with all the writing rules and regulations. I have to go back to what I learned in high school and in the college courses to remember what I need to know when it comes to writing. Having the proper knowledge of what a perfect paper looks like will be as important in school as it will be in the real world. If a person is required to submit a report for work, he or she wants to be fully prepared so he or she does not look like a fool to the boss and coworkers. Good writers do not just happen. Good writers work hard at becoming who they are and are not afraid to ask questions. Never being afraid to ask questions or ask for help will make me a better writer and a better student. Constantly finding myself writing papers and doing assignments that involve writing will help me achieve my second academic goal of becoming a better writer. Communication and networking are really important in a career life. The better of a communicator and net worker a person is, the better chances the person will have to escalate. In school one gets graded partly on how well he or she communicate in class, whether he or she talks, participate or just stay quiet and not say anything. But in the real world, one does not get graded on how good he or she communicates. One gets ascended or promoted if he or she is a good communicator and are not shy to speak up when needed. According to the journal The Importance of Communication, â€Å"There is a sheer necessity for personal effectiveness that stems from effective communication. Time and again researchers have reinforced the importance of communication and its impact at the workplace. † (Radhaswamy & Zia, 2011) If one is always being open and communicative, then networking should not be a problem. I want to not only be a good communicator and net worker, I also want to be a good listener to be able to get places and become someone. In order to fulfill my academic objectives, I need a plan to incorporate effective strategies for success as a student. How am I going to accomplish my goals and get them done? By me attending my classes and passing them, I get one step closer to receiving my bachelor’s degree. I need to push myself to do my best in all the assignments and test so I can pass all my courses. Each class requires students to complete papers and assignments that need to be written. With that in mind, I will be able to perfect my writing skills. I have to remember to proofread all my papers and really strive for the best. To become a better communicator and net worker, I need to put myself out there so other can get to know me. I need to find a mentor that is in the same career field as I am, so that that person can not only guide me but also help me when I need it. Nothing will get done I am willing to fully commit in achieving my academic objectives. The three academic objectives I would like to accomplish by graduation are not just to be a good student but also to set myself for greater things in life. Getting my bachelor’s degree, becoming a better writer and a better communicator/net worker are very important to me. With those three academic objectives, I will become a better employee, person and student. They are three essential things that any person can use in their lives to get further in their careers. I know with the motivation, want to succeed, and push from those around me, I can accomplish my three academic goals from here to graduation day. References Achieve, I. C. (2012). The Future of the U. S Workforce: Middle Skills Jobs and the Growing Importance of Postsecondary Education. Achieve, Inc. Radhaswamy, P. , & Zia, A. (2011). The Importance of Communication. IUP Journal Of Soft Skills, 5(4), 52-56.

Advantages and Disadvantages of the Internet Essay

Many people fear the Internet because of its disadvantages. They claim to not use the Internet because they are afraid of the possible consequences or are simply not interested. People who have yet connected to the Internet claim they are not missing anything. Today’s technological society must realize that it is up to them to protect themselves on the Internet. Children using the Internet have become a big concern. Most parents do not realize the dangers involved when their children connect to the Internet. When children are online, they can easily be lured into something dangerous. For example, children may receive pornography online by mistake; therefore, causing concern among parents everywhere. Whether surfing the Web, reading newsgroups, or using email, children can be exposed to extremely inappropriate material. To keep children safe, parents and teachers must be aware of the dangers. They must actively guide and guard their children online. There are a number of tools available today that may help keep the Internet environment safer for children. Musicians are also concerned with disadvantages to the Net such as, accessibility and freedom. They are upset because the Internet provides their music online at no charge to consumers. File-sharing services, such as Napster, provide copyrighted songs to all Internet users. The main concern is the music is free! Musicians feel they are not getting paid for their work. Because of Napster, it is almost impossible to close down all file-sharing services because there are too many of them to count. Another major disadvantage of the Internet is privacy. Electronic messages sent over the Internet can be easily tracked, revealing who is talking to whom and what they are talking about. As people surf the Internet, they are constantly giving information to web sites. People should become aware that the collection, selling, or sharing of the information they provide online increases the chances that their information will fall into the wrong hands. When giving personal information on the Internet, people should make sure the Web site is protected with a recognizable security symbol. On the other hand, this does not mean they are fully protected because anyone may obtain a user’s information. In other words, the most common Internet crimes are frauds. Today, not only humans getting viruses, but computers are also. Computers are mainly getting these viruses from the Internet, yet viruses may also be transferred through floppy disks. However, people should mainly be concerned about receiving viruses from the Internet. Some of these dangerous viruses destroy the computer’s entire hard drive, meaning that the user can no longer access the computer. Virus protection is highly recommended. Despite all of the terrible disadvantages of the Internet, there are numerous advantages. In fact, the advantages weigh out the disadvantages. The most common thing the Internet is used for is research. Children and students are among the top people who use the Internet for research. Nowadays, it is almost required that students use the Internet for research. The Internet has become one of the biggest sources for research. Almost everyday, research on medical issues becomes easier to locate. Web sites have become available for people to research diseases and talk to doctors online at sites such as, America’s Doctor. Entertainment is another popular reason why many people surf the Internet. Downloading games, going into chat rooms or just surfing the Web are some of the uses people have discovered. There are numerous games that may be downloaded from the Internet at no charge. Chat rooms are popular because users can meet new and interesting people. In fact, the Internet has been used by people to find life long partners. When people surf the Web, there are numerous things that can be found. Music, hobbies, news and more can be found on the Internet. Another popular thing to do on the Internet is to check out the news. Almost all local news can be obtained through the Internet. Up to date sports scores are probably the most popular looked at news. Sports scores are updated on the Internet as soon as the game ends. Weather is also a popular source to look up on the Internet. Using the Internet to get the weather allows people to view weather all over the world. Live radar all over the country and local forecasts are just to name a few of the things that may be obtained for weather information on the Internet. Shopping online has also become a huge success and is considered a great advantage of the Internet. No matter what people are shopping for, it can be found on the Internet. People do not even have to leave their homes. A few companies have collected millions of dollars using the Internet for selling. Clothing is probably one of the most bought items online. Almost every major clothing store has its on Web site. In fact, In US, people can even go grocery shopping online using such sites as Priceline.com. Just one click of the mouse on the items they want to purchase and the items are delivered to their front door. Unfortunately, this kind of service is not yet available in Malaysia for the time being. Groceries and clothing are only a few of the items that may be bought on the Internet. In conclusion, today’s society is in the middle of a technological boom. People can either choose to take advantage of this era, or simply let it pass them by. The Internet is a very powerful tool. It has many advantages; however, people need to be extremely aware of the disadvantages as well.

Course Work about Professional and Academic Development

How far ahead do people book for the holidays in each of your regions? Is this changing over the seven years? In North Africa and Middle East In North Africa and Middle East booking for the holiday’s ranges four to five   months prior to the due day. These bookings have been inconsistent in the last seven years. The major countries of destination in North Africa are Egypt and Morocco which enjoy adventure tours from majority of it visitors ranging from 25-34 years of age. In North and central Asia In North and Central Asia, booking for the holiday’s an average of three months to the day of departure. This record is faster than that recorded on North Africa and Central Asia. The Middle East bookings have been consistent in the last seven years. The major countries of destination in North Africa are Egypt and Morocco which enjoy adventure tours from majority of it visitors ranging from 35-44 years of age. The departure to North and central Asia include unique itinerates and routes and the major site being the Great Wall of China. Europe and Turkey Europe, booking for the holiday’s two months to the day of departure it has the list span of time. Like China Turkey booking time ranges three months. What are the growth areas in each region? Is there something you can exploit by adding an additional holiday? In North Africa and Middle East Their major destinations are the colorful Marrakech Morocco and the tranquil walking of the Atlas while in Egypt are the Nile Cruise Desert Oases in the Middle East is a place that is crossed there is the attraction of ancient civilizations that left their mark in Greek, roman and Egyptian site too these are the major factors has seen a consistent visit in these destination. There is much to learn from this destination there are a lot of unexploited resources and one has an opportunity to enjoy the serene of unpolluted environments in the Nile cruise. In North and central Asia For some one who has been in as In North and central Asia the scenes visited are repeatedly the same. Though you can not exhaustively give analysis about North and central Asia in a single tour, another holiday is somehow recommended. Europe and Turkey The major activities that one gets involved in Europe and Turkey are hiking leisure walking and maybe discoveries. There are numerous amazing site and historic sites. Europe and Turkey one can learn about the history of the Ottoman Empire and such. It is a destination worth a revisit. Work cited â€Å"Map of Europe and Turkey.† (2010). Explore. Retrieved Dec 03, 2010, from: http://www.explore.co.uk/destinations/