Effects Of Heat And PH On Plant Pigments Biology Essay

Effects Of Heat And PH On Plant Pigments Biology EssayThe aim of this research lab exercise is to determine and assume the effect of hot pants and pH on plant blusher by using the examples of peas, cranberry juice and blackberry juice. Carotenoids, chlorophylls and flavonoids ar the lead major groups of plant pigment. The results of this laboratory was that the different wring and texture of peas were caused by different pH. In addition, the heat and pH will influence the structure of carotenoids, chlorophylls and flavonoids so that changes the gloss of the plant. Anthocyanins are urine dissolvable that easily lose in pissing.INTRODUCTIONPlant pigments include a variety of different kinds of molecules that absorbs and reflects demoralise. The various pigments contained in their meanders tell the colors differently because they halt got differing abilities to absorb and reflect various colors of light (Charley 1982). Most of the pigments occur in a specialised bodies lying in the protoplasm of the cell called plastids. Occasionally, the water soluble pigments are dissolved in the vacuoles however they are non generally dispersed throughout the cell. The master(prenominal) pigments of vegetables and fruits fall into two groups water soluble and fat soluble (Srilakshmi 2003).Plant pigment can be classified as carotenoids, chlorophylls, and flavonoids. Flavonoid pigments are water soluble and it can be divided in to anthocyanins and anthoxanthins ( brownness 2008). Anthocyanins are highly water soluble pigment that range in colour from blushful to purple. The anthoxanthins are colourless, bloodless or pale white-livered. However, flavonoid pigments are sensitive to heat and readily to be lost in cooking water (Charley 1982). Carotenoids and chlorophylls are fat soluble which are found in plastids. Carotenoids are the colour groups of yellow, orange and red. Carotenoids are present as alpha-carotene, beta-carotene, gamma-carotene, xanthophylls and cryptoxanthin in plants (Hanson 1954). On the other hand, in green leaves they occur in chloroplasts. Chlorophylls are the green pigments of leaves that found in chloroplasts along with some carotenes and xanthophylls. In addition, it is critical for the light reactions of photosynthesis (Srilakshmi 2003).The pigments of chlorophyll that are commonly include chlorophyll a and chlorophyll b. Chlorophyll a is dynamic blue green in colour and it is present in the florets of blue green broccoli. Chlorophyll b is purblind yellow green colour and it is present in stalks. The different heat conditions caused the changes of the structure of chlorophyll which is connected with the loss of magnesium ion from the chlorophyll molecule and replaced by hydrogen therefore affects the colour of vegetables (Stathopoulos 2010).The factors including changes in temperature and pH may influence the colour of anthocyanin in plant food during simmering (Brown 2008). Acid tap water amplifies the red colour of anthocyanins. Alkaline water changes the reddish-blue to blue and then to green. This phenomenon of colour is because the changes in structure of the same basic compound (Srilakshmi 2003).Plant food have been recognised as a good source of carbohydrates and daily fibre. Plant food are also contain minerals and vitamins A, E, C, thiamin, vitamin B6, riboflavin, niacin and folate. Phytochemicals in fruits and vegetables, such as polyphenolics, carotenoids, and glucosinolates, may also have nutritional value (Jongen 2002). However, vegetables lose nutrients when they are cooked, mainly by solution to the cooking water (Charley 1982).The objective of this experiment is to consider the effect of heat and pH on plant pigment by using the examples of peas, cranberry juice and blue berry juice.METHODS AND MATERIALSThe methods and materials infallible to determine the effect of heat and pH on plant pigment were performed according to the laboratory manual. However, the blueberry j uice was changed to blackberry juice. In addition, in the experiment of cranberry juice, group 2 did not collect the value of pH.RESULTSTable 1 The class pH result of each(prenominal) group about chlorophyll. conference 1 multitude 2Group 3Group 4Group 5Group 6 ordinarySamplepHpHpHpHpHpHpHPeas + Distilled water system6.836.026.067.26.756.966.6Peas + Vinegar + Distilled urine2.492.722.64.83.893.773.4Peas + 1N NaOH + Distilled H2O12.2012.8812.2312.212.4912.7812.463Peas + Vinegar + coolness Distilled H2O2.772.972.54.043.653.683.3Peas + 1N NaOH + Cold Distilled H2O12.4112.7812.2412.0212.7212.5812.458Canned Peas5.955.375.26.155.906.175.8According to Table 1, the example of peas with NaOH and distilled water has the highest average pH that is 12.463, followed by peas with NaOH and cold distilled water that is 12.458, which are very close. The lowest pH is peas with vinegar and distilled water that is 3.3.Table 2 The class colour results of each group about chlorophyll.Group 1Group 2Gro up 3Group 4Group 5Group 6Sample strainColourColourColourColourColourPeas + Distilled H2OBright greenBright gulliblePea greenGreen chickenhearted greenLight green2. Peas + Vinegar + Distilled H2ODull greenLight/ grisly GreenBrown- greenFaint Green army greenOlive3.Peas + 1N NaOH + Distilled H2OBright greenGreenPea greenGreenBright greenBright green4. Peas + Vinegar + Cold Distilled H2OVery dull greenPale Green/ yellow-belliedBrown greenFaint Green YellowMore green than yellowGreen5. Peas + 1N NaOH + Cold Distilled H2OBright greenBright GreenPea greenGreenGreen uniformGreen6. Canned PeasBrownPale GreenbrownBrown YellowDark army greenOliveTable 2 reflects that sample 1, 3 and 5 have similar colour range which is green, and sample 2, 4 and 6 have semblables colour which is brown. These results shows under the acid conditions, the range of peas colour is from green to brown. On the other hand, the colour of peas will stay same under alkaline conditions.Table 3 The class texture results of each group about chlorophyll.Group 1Group 2Group 3Group 4Group 5Group 6Sample textureTextureTextureTextureTextureTexturePeas + Distilled H2O solidFirmFirmFirmDryhard2. Peas + Vinegar + Distilled H2OModerately firm, dry, loss of shape more or less FirmFirmFirmVery drySoft3.Peas + 1N NaOH + Distilled H2OSoft, mushy, sticky, loss of shapeMushyMushMushyMushyVery low-keyed /mushy4. Peas + Vinegar + Cold Distilled H2OVery firmVery FirmFirmFirmMedium plumpNot so tardily5. Peas + 1N NaOH + Cold Distilled H2OVery soft, mushy, loss of shapeMushyMushMushyVery plumpHardest6. Canned PeasVery firmSlightly FirmSoftishFirmFirmVery softAccording to the result of Table 3, the texture of sample 3 and 5 are mush and soft, and others are firm. This result shows the alkaline caused the mush and soft texture of peas, and the acidity of the water will caused the higher firmness of peas.Table 4 The class pH results of each group about anthocyanins.Group 1Group 2Group 3Group 4Group 5Group 6AverageSampl epHpHpHpHpHpHpHBlackcurrant Fruit Drink + Distilled H2O2.793.023.063.123.453.123.1Blackcurrant Fruit Drink + Distilled H2O (pH 5)4.935.074.854.985.094.955Blackcurrant Fruit Drink + Distilled H2O (pH7)6.697.177.17.27.116.947.0Blackcurrant Fruit Drink + Distilled H2O (pH10)9.9710.0210.049.9510.6410.010.1Table 5 the class colour result of blackberry juice.Group 1Group 2Group 3Group 4Group 5Group 6SampleColourColourColourColourColourColourBlackcurrant Fruit Drink + Distilled H2ODark burgundyRedRedReddishRed knockBlackcurrant Fruit Drink + Distilled H2O (pH 5)Orange/ ping evidentPink/ RedGrey pinkPinkPinkLight pinkBlackcurrant Fruit Drink + Distilled H2O (pH7)Brown/orange translucentBrown/ GreenDull greenBrown greyingLight green olivePink with a hint of yellowBlackcurrant Fruit Drink + Distilled H2O (pH10)Dark black/greenDark GreenDull greenYellow greenDark green oliveYellowish green colourTable 6 The class pH results of each group about anthocyanins.Group 1Group 2Group 3Group 4Group 5G roup 6AverageSamplepHpHpHpHpHpHpHCranberry + Distilled H2O2.722.882.923.003.002.9Cranberry + Distilled H2O (pH5)4.255.54.975.025.575.1Cranberry + Distilled H2O (pH7)7.37.27.037.037.827.3Cranberry + Distilled H2O (pH10)10.6210.19.9310.0510.4110.2Table 7 the class colour result of cranberry juice.Group 1Group 2Group 3Group 4Group 5Group 6SampleColourColourColourColourColourColourCranberry + Distilled H2OLight pinkPale PinkPale pinkFaint PinkLight pinkPinkCranberry + Distilled H2O (pH5)Lighter pinkSlight Clear/ Ting of PinkClear with a pink tingeClear PinkLighter pinkDark pink colourCranberry + Distilled H2O (pH7)Light yellowYellow/ Olive GreenYellow greenFaint yellowApple juice greenBrownishCranberry + Distilled H2O (pH10)YellowOlive GreenYellow green (slightly greener than 7 pH)Green yellowApple juice greenOlive greenAccording to the Table 4 to 7, although the average number of the pH is close to the laboratory manuals data, the results of each group are slightly different. Because t he anthocyanins is very sensitive to pH that even a small different in pH will cause the colour changed (see page 12 to 15).DISCUSSIONThe green colour becomes brighter when a green vegetable is first put to cook in stewing water. Greater translucency of plant tissue due to expulsion of intercellular air has been suggested as a possible cause (Charley 1982). As boiling continues, compartmentalization within the cell is disrupted. Constituents, there are organic acid, diffuse from the vacuoles throughout the cell and into the boiling water (Sterling 1944). As the acids contact the chlorophylls the latter are converted to their respective pheophytins. No longer masked by the intense green chlorophyll, the yellow and orange pigments present in green plant tissue now show along with green. This combination together with the pheophytins gives the vegetable a muddy olive green hue (Srilakshmi 2003). Green vegetables that are lower in acid retain a higher percentage of chlorophyll and of t heir green colour when they are cooked than do more acid vegetables. Vegetables like peas, beans, greens are sometimes canned. During canning chlorophyll gets converted to pheophytin due to high temperatures used. Sometimes to retain the colour and to neutralise the acid, alkali is added (Charley 1982).Furthermore, the pop music changed texture, any soda not required to neutralize the acid in the cooking water will react with the chlorophyll. The sodium salt of chlorophyll gives to cooked green vegetables an intense and artificial appearing greenness. Vegetables cooked with soda tend to have a mushy texture, due to breakdown of hemicelluloses in the cell walls (Charley 1982)..Anthocyanins have a authoritative charge on the molecule, and it enables to absorb light and thus have colour. Anthocyanidins are anthocyanins without sugar in their structure . They are pelargonidin, cyaniding and delphindin (Brown 2008). As pH changes, the colour of anthocyanin also changes. In the acid con ditions, the molecules have positive charge on the oxygen atom due to the acidity of the cell in which these compounds are formed. This common form at a pH of 3.0 or less, maintains or shifts the hue towards red (Charley 1982). However, as the pH is increased toward a weak acid or even neutral solution, the oxonium (the positively charged oxygen form) is changed to the quinine form. The quinine form has a violet colour. In an alkaline medium still another change takes place as a salt of the violet compound, called a colour base. The alkaline salt of the colour base has a distinctly blue colour (Srilakshmi 2003).Figure 1 The structure of anthocyanin.Red cabbage presents outstandingly wild swings in colour with a alter in pH, it is because of the presence of more than four hydroxyl groups on the anthocyanin molecule. To ensure that the pH is sufficiently acidic, red cabbage is frequently cooked with addition of some slices of a tart apple in order to avoid the development of a blue, highly unpalatable pigment colour (Srilakshmi 2003).The pigment of bluish green shade was given by the addition of alkali . This shade is probably caused by the presence of anthoxanthins with anthocyanins. On the addition of alkali, the anthoxanthins turn yellow during the anthocyanins turn blue, and then the mixture of the two colours appear green. The addition of alkali alters the structure of anthocyanin molecule and produces a salt (Srilakshmi 2003). closingIn conclusion, the bright colors of vegetables contribute to the esthetic pleasure of eating. The three major groups of plant pigment are carotenoids, chlorophylls and flavonoids which are effect by the pH and heat. The colour alters differently under variable conditions. Therefore, we need to understand the changes that take place in the colour of vegetables and how to keptthe pigment of the plant.