Investigating the Browning of a Fruit or Vegetable
Aim: To design, carry out and report on an experiment which
investigates the browning of red delicious, pink lady, granny smith,
braeburn and royal gala apples with regard to temperature and pH
levels.
Hypothesis: It is expected that each apple will brown at a faster rate
at warmer temperatures and at an optimal pH level. The degree and
speed at which each apple portion browns will depend upon the strength
and amount of the enzyme phenolase present in each portion.
Background Information: Apples will turn brown when cut and exposed to
air. This can be partly attributed to the action of enzymes which are
organic catalysts. They speed up chemical reactions without taking
part in the reaction. Enzymes are sensitive to temperature and pH and
have optimal levels of each variable at which they will function at
the fastest rate.
For the browning reaction of an apple to occur, three conditions are
necessary;
1. The enzyme know as phenolase must be present
2. The target/substrate of the phenolase called phenols must be
present
3. Oxygen must be present in the surrounding atmosphere.
Apple browning occurs close to the fruit's flesh surface. This is
because cells beneath the fruit's skin are damaged and exposed to
oxygen. In whole apples, the phenolase and phenols are kept separate.
However, when one cuts or bites into any type of apple, the cells are
opened and the enzyme and target are free to react with one another.
The phenolase proceeds to combine the phenols and oxygen into the
different chemical of polyphenol oxidase which is yellow/brown in
colour. This ty...
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...e to superficial harvest
bruising meaning larger harvests and increased profits.
Processor Impact: Less product shrinkage due to bruising on packing
line. If apple is fresh cut, less flavour altering additives needed to
control browning process.
Retail Sector Impact: As bruising won't show as much, product cullage
will be significantly reduced to about 4% of total produce rather than
the current rate of 10%.
Consumer Impact: Gain access to apples that don't require additives to
control browning. Better health due to the more appetizing thought of
non browning apples
References:
www.ars.usda.gov/is/kids/mailbag/mushyapple/applemushanswer.htm
www.nysaes.cornell.edu/fst/faculty/lee/browning.html
www.urbanext.uiuc.edu/apples/preserving.html
www.madsci.org/posts/archives/feb99/917668893.Ch.r.html
Whole carrots have a different reaction to the higher concentrations of hydrogen peroxide. There is a dramatic increase in the rate of reaction of catalase enzymes in the whole carrot, meaning that the saturations kinetics can be utilized at much higher rates of concentration.
Catecholase is an enzyme formed by catechol and oxygen used to interlock oxygen at relative settings, and it is present in plants and crustaceans (Sanyal et. al, 2014). For example, in most fruits and vegetables, the bruised or exposed area of the pant becomes brown due to the reaction of catechol becoming oxidized and oxygen becoming reduced by gaining hydrogen to form water, which then creates a chain that is is the structural backbone of dark melanoid pigments (Helms et al., 1998). However, not all fruits and plants darken at the same rate. This leads to question the enzymatic strength of catecholase and how nearby surroundings affect its activity. The catecholase enzyme has an optimal temperature of approximately 40°C (Helms et al., 1998). Anything above that level would denature the tertiary or primary structure of the protein and cause it to be inoperable. At low temperatures, enzymes have a slower catalyzing rate. Enzymes also function under optimal pH level or else they will also denature, so an average quantity of ions, not too high or low, present within a solution could determine the efficiency of an enzyme (Helms et al., 1998). Also, if more enzymes were added to the concentration, the solution would have a more active sites available for substrates and allow the reaction rate to increase if excess substrate is present (Helms et al., 1998). However, if more
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
With this information we were able to identify any patterns and similarities. Hypothesis: The higher the temperature of water, potato and H²O², the rate at which the Enzyme will work will be faster therefore producing more oxygen. The reaction will be the same without the catalase (potato). Therefore in both experiments the Enzyme will work more rapidly and produce more oxygen. Aim: To test the hypothesis.
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Enzyme peroxidase is essential in any cell metabolic reaction as it breaks down the harmful hydrogen peroxide to harmful products in the body. The report analyzed its effect on changes in temperatures by determining the optimum temperatures and the effects of its reversibility. Through the method of extracting the enzyme by blending it with potato tissue in phosphate buffer, the effects were analyzed on the effect of the dye guaiacol and the activity measured under different temperatures. The optimum temperature was obtained at 22.20C and above this temperature, the enzyme was denatured. Conclusively, increase in temperature increases
Human beings need natural light to survive. Sunlight is full of vitamin D, an essential vitamin that promotes healthy bones. In fact, numerous scientific studies show that exposure to light encourages the human brain to release serotonin, a valuable hormone that doubles as an anti-depressant. However, light exposure has other benefits; it helps the body to produce Vitamin B, a substance that prevents osteoporosis, more commonly known as brittle bone disease. Light exposure also eases the unbearable symptoms of psoriasis. Organic tanning products are invaluable; they help to make us look healthy during winter months, when there is little natural sunlight. The most-effective spray tans Melbourne offers are often
The Effect of Surface Area on the Rate of Reaction Between Catalase from a Potato and Hydrogen Peroxide
When we contrasting between the two cartoons, we believe that the cartoon that representing Australian National Flag invokes critical thinking. That arguing certain points and needs further investigation. Firstly, taking the notes of the sixth stars for example. We would argue the start that used to express “the six reasons the health system doesn’t work” is a little bit fallacious. On the certain point, it raises doubt to the reader on the given definition. On the other hand, we also argue that the illustration given by the artist was an expression to criticize the government. The flag used as a satire to address the issues that maybe arise in Australia. In conclusion, the points that we’ve provided considered to be relevant as critical thinking process. Because the cartoon triggered the reader to interpret the meaning, value, interest etc. behind the cartoon itself.
Did they wake up thinking about it, did they want to stop but was unable, and if a person is constantly thinking they need to go tanning, could they be addicted? Indoor tanning has multiple effects on the human body, but many of these effects are not for the goodness of the body and can later in life cause horrible health risks. These effects on the human body are signs of addiction, health risks, and the mental state of the addict towards tanning. ADD BACKGROUND
In this lab, it was determined how the rate of an enzyme-catalyzed reaction is affected by physical factors such as enzyme concentration, temperature, and substrate concentration affect. The question of what factors influence enzyme activity can be answered by the results of peroxidase activity and its relation to temperature and whether or not hydroxylamine causes a reaction change with enzyme activity. An enzyme is a protein produced by a living organism that serves as a biological catalyst. A catalyst is a substance that speeds up the rate of a chemical reaction and does so by lowering the activation energy of a reaction. With that energy reactants are brought together so that products can be formed.
Through conquest and exploration, apples were spread when Romans conquered England and when Spaniards brought them to Mexico and South America. It wasn’t until the mid 1600’s that the Pilgrims cultivated them in Massachusetts. It is believed that John Endecott, an early governor, was the first to bring an apple tree to North America, and the first orchard was planted on Beacon Hill by a clergyman named William Blaxton. It is Blaxton who is credited for growing the first named apple, the Yellow Sweeting. Once apples were established in New England, they played an active role in everyday life. As a fruit which was easily stored through the winter, as well as being very beneficial to settlers’ health, apples were a main staple in early settlers’ diets. Despite the fact that apples were not initially from North America, and have been growing disease-free for centuries in their native habitats, the early settlers found that the long, hot summers and cold winters of New England grew apples unlike anywhere else in the world. New England apples are known not only for their unique blend of tart and sweet flavors, but also for their size and freshness.
Influence of Temperature on the Activity of Potato Catalase Hypothesis That the higher the temperature the higher the reaction rate of potato catalyse to a point were denaturing occurs in the enzyme and the reaction rate of the potato catalase drops off. Prediction The rate of Catalase activity will be faster at higher temperatures until a point, because at higher temperatures there are more chances of collisions between the enzyme's (Catalase) active site and the substrate (hydrogen peroxide). However the rate depends on the active site being able to join with the substrate, and at higher temperatures the enzyme can be denatured, which changes the shape of the active site which thus prevents the reaction from happening. At first, as the temperature increases the activity of the Potato catalase also increases this is because the collision rate of the enzyme with the hydrogen peroxide is increased.
Abstract: Enzymes are catalysts therefore we can state that they work to start a reaction or speed it up. The chemical transformed due to the enzyme (catalase) is known as the substrate. In this lab the chemical used was hydrogen peroxide because it can be broken down by catalase. The substrate in this lab would be hydrogen peroxide and the enzymes used will be catalase which is found in both potatoes and liver. This substrate will fill the active sites on the enzyme and the reaction will vary based on the concentration of both and the different factors in the experiment. Students placed either liver or potatoes in test tubes with the substrate and observed them at different temperatures as well as with different concentrations of the substrate. Upon reviewing observations, it can be concluded that liver contains the greater amount of catalase as its rates of reaction were greater than that of the potato.
It changes from blue to red with acids but loses its colour in the presence of certain chemicals, one of which is vitamin C. DCPIP solution can be used to test for the presence of vitamin C in foods. Hypothesis Orange juice has the highest content of vitamin C. Citrus fruits have a higher content of vitamin C. The orange and lemon juice contain more vitamin C than the pineapple juice. Furthermore, as lemons are more acidic than oranges, I predict that the orange juice will contain more vitamin C than the lemon juice. Vitamin C affects, the ph the more vitamin C the higher the ph. Variables Independent Variables Different fruit juices (Pineapple, orange and lemon).