Starches+Group+4

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 * Amylose:** is a soluble component of starch that can bind molecular iodine and stiffen the gel structure. This then makes iodine fit to form a complex that contains deep color blue depending on the temperature. Amylose forms a helix as a result to the bonds 200 to 20,000 glucose units. Amylose is known for its gelling ability in a thicker. The long water soluble chains increase the viscosity, which the viscosity does not change the temperature. The chains then will curl up into helices as known as spirals that contain hydrophobic parts inside allowing them to trap oils and fats inside the helix. Starches do so well at absorbing water and bulking up that they are used for fat substitutes.
 * [[image:http://www.scientificpsychic.com/fitness/starch.gif width="543" height="104" align="center" caption="starch"]] ||



Together amylose and amylopectin are the primary storage polysaccharides of plants composing starch.
 * Amylopectin (Waxy Starch):** is found in plants and constructed of highly branched polymer of glucose. It is formed by a 1→6 branching of amylose and a 1→4 glucose structure. The branching is determined by enzymes that leaves the chain with 30 glucose residues. Amylopectin has a reputation of interfering with amylose chains and its solution, which causes the loss in viscosity and slimy consistency. It is a kind of starch, a complex carbohydrate that comprises 60% of the carbohydrates that humans consume. It is a polysaccharide, a long chain of sugars, in this case composed of glucose (3). It looks like branches of molecules attached to an amylose lenear molecule.

Link to a video of Amylopectin:
 * []**

**Amylose/Amylopectin and gelling ability**: Amylose is a D-glucose homopolymer that contains linear bundles associated in a tight solution responsible for gel formation. Since Amylopectin is a branched glucose polymer, it is unable to gel due to the immobilization of water.

This is a great example of gelling ability made from mango-orange jelly and it is also a great snack!

**__Mango and Orange Jelly __** //Top Layer// 180gm cubed mango flesh from about 1 large ripe mango 2 cups (500ml) orange juice, unsweetened 1/2 cup caster sugar, or to taste 1-1/2 tablespoons agar-agar powder 1/2 teaspoon orange essence

//Bottom Layer// 1 cup (250ml) fresh cream 2 cups (375ml) water 1-1/2 tablespoons agar-agar powder 1/2 cup caster sugar, or to taste <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 13.5pt;">1/2 teaspooon pandan essence <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 13.5pt;">a pinch of salt
 * 1) <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 10pt; tabstops: list .5in;">To make top layer : Place mango and half of orange juice in a blender and puree till mixture is smooth. Pour into a deep saucepan and mix in the remaining of the orange juice. Stir to evenly combined.
 * 2) <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 10pt; tabstops: list .5in;">Scatter the agar-agar powder over the mango and orange juice mixture and stir well. Bring to a boil over medium heat, stirring constantly for about 5 minutes. Add sugar to taste, depending on the sweetness from the mango and orange juice, adjust the amount of sugar to your liking and continue to stir until completely dissolves. Add the orange essence.
 * 3) <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 10pt; tabstops: list .5in;">Remove from heat and pour into a 9" cake pan. Leave to set. Small jelly moulds or any moulds may be used, filling only about half full.
 * 4) <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 10pt; tabstops: list .5in;">To make bottom layer : Combine fresh cream and water in a deep saucepan. Scatter the agar-agar powder on top and stir to combine. Add in sugar, pandan essence and salt. Bring to boil over medium heat for about 4-5 minutes.
 * 5) <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 10pt; tabstops: list .5in;">Remove from heat and pour mxiture over the top layer gently. Set aside to cool and store in refrigerator, covered, until fully set.
 * 6) <span style="color: #666666; font-family: 'Arial','sans-serif'; font-size: 10pt; line-height: normal; margin: 0in 0in 10pt; tabstops: list .5in;">To serve, turn Mango Agar-Agar onto serving plate. Sliced to desired size or use a jelly or a deep cookie cutter to form shapes. Serve it well chilled. Enjoy!

The ratio of Amylose and Amylopectin found in the starch varies depending on the plant source it is created from. The majority of starches contain 75% amylopectin and 25% amylose. The percentage of amylose in a starch is what determines the consistency of the starch and how it gels in foods. Starches that have a higher percentage of amylose will gel more easily than those that contain higher levels of amylopectin. Starches that has a low percentage of amylose and a higher percentage of amylopectin are considered non-gelling but will still form a gummy consistency. Starches comprised of 100% amylopectin are called waxy starches. (5)
 * How the Amylose/Amylopectin Ratio Affects Starches:**


 * Retrogradation:** As a gel cools, bonds continue to form between amylose molecules.The process is accelerated by freezing the gel. The best way to prevent retrogradation is to use the gelled food as soon as possible (4). This is also known as syneresis or weeping.




 * Dextrinization:** "Is the breakdown of starch molecules to smaller, sweeter tasting dextrin molecules in the presence of dry heat (5)." How does this relate to starches? When a starch undergoes dextrinization many of its properties change. The first is that the taste becomes sweeter; an example of this would be toasting bread. The dry heat causes the starch molecules in the bread to breakdown into dextin thus creating a sweeter taste than a regular slice of bread. Another change is that their thickening ability decreases. The reason why this happens is due to the molecules being broken down into smaller units thus you will need more of the starch to thicken at the same level than if the starch had not gone under dextrinization. (5)


 * Gelatination:** When starches granules are heated in a liquid they absorb the liquid, swell, and increase in viscosity. What affects gelatinization is the amount of water put in a pot to heat the starch in, the temperature that the starch is being heated, how logn you heat it for, its pH, and what coats the starch that prevents the obsoption like protien.
 * Viscosity Chart of Starches**

See Retrogradation explanation for further detail of process. || wheat flour. || There are three different kinds of rice flour (short, medium, and long) all with different gelling capabilities. The short has less amylose (creating a sticky gel) while the long has a higher concentration of amylose making it gel thicker and behave closer to wheat flour (8). In our lab we believe we used rice flour made from long grained rice because it created a thick, pasty gel and exhibited retrogradation quicker than the other flours. Rice flour use has increased recently due to the rise in gluten free diets. Below is a recipe for shortbread that uses rice flour instead of wheat flour to make it gluten free.
 * = **Starch** ||= **Viscosity Hot** ||= **Viscosity Cold** ||= **Concentrations of Amylose/Amylopectin** ||= **Line Spread Test**
 * (note this test was only performed hot)** ||= **Comments about Results** ||
 * = Cornstarch ||= Thin ||= Solid ||= 28% / 72% (11) ||= Line spread test hot= 9.5 ||= Its appearance came out to be cloudy. ||
 * = Cornstarch with Acid ||=  ||=   ||=   ||=   ||=   ||
 * = Cornstarch with Sugar ||=  ||=   ||=   ||=   ||=   ||
 * = Potato Starch ||= Thick and Gooy ||= Hard and sticky ||= 21% / 79% (11) ||= Line spread test hot= 6.75 ||= Its appearance came out to be glossy and cloudy. ||
 * = Tapioca Starch ||= Thin ||= Liquity ||= 17% / 83% (11) ||= Line spread test hot= 9.75 ||= Its apearance came out to be clear. ||
 * = Arrowroot ||= Very thick ||= Even thicker ||= ? ||= Line spread test hot= 6.75 ||= Performed as expected. Its appearance came out to be glosy and solid. ||
 * = Rice Flour ||= Pasty, thick ||= Solid Paste- Began to Weep (Retrogradation) ||= 23-26%/ 77-74% (8) ||= Line spread test hot= 7.5 ||= Performed as expected.
 * = Wheat Flour ||= Liquid but thick ||= Formed a solid top layer ||= 28%/72% (5) ||= Line spread test hot=10.25 ||= Performed as expected. ||
 * = Browned Wheat Flour ||= Liquid but stable ||= Solid on top layer ||= 28%/72% (5) ||= Line spread test hot=10 ||= Had similar viscosity to regular
 * Cornstarch:**
 * Potato Starch:**
 * Tapioca Starch:**
 * Arrowroot:**
 * Rice Flour:**
 * Wheat Flour:**
 * Extra Information:**
 * Gelatinization: Stach granules heated in liquid initially swell, increasing viscosity. Heating beyond the maximum obtainable volume ruptures the starch granules, resulting in less viscosity.
 * Some of these starches had unique qualities and formed differently. For one, the rice flour seperated at the top after letting it sit for about 10 minutes. For others, some were very sticky, some looked liquity, and some felt like gelatin.
 * Starch contributes to the texture, taste, and appearance of many foods. They are also used in many food products as thickening agents, edible films, and sweeteners.
 * Acid will weaken the ability of starches to thicken.
 * Sugar competes with starch for available water, delays the onset of gelatinization, and increases the required temperature. This makes the gel thicker.
 * Discussion about Rice Flour:** [[image:41JCXSK74WL__SL500_AA300_PIbundle-4,TopRight,0,0_AA300_SH20_.jpg width="110" height="81"]]

//Rice Flour Shortbread// 7oz rice flour 4oz caster sugar few drops vanilla essence (extract is better if you've got it) 2oz cornflour 7oz soft butter

Cream the sugar and butter together, then add the vanilla essence and the flour and cornflour. Mix well until you can form a dough. Then wrap and chill for a few minutes before pressing into a greased 7 x 10" baking/swiss roll tin. Prick all over the surface with a fork and bake in a pre-heated over (160C, 325F) for 30 mins or until pale golden. Cut the shortbread into fingers, allow to cool in the tin for a while, then remove and put on a wire rack to cool completely. (9)

Wheat flour is the most commonly used flour and largely used as a thickening component when making a roux. In our lab we tested wheat flour and also browned the wheat flour to see dextrinization change the thickening capability. For the results both the regular wheat flour and the browned wheat flour did gel and performed similarly on the line spread test. During the experiment the browned flour definitely seemed thinner; we might not have browned it enough to see dextrinization take its full effect. Browned wheat flour is often used as the base for gumbo, in this dish the dextrinization of the starch helps develop the deep flavors that make a gumbo distinct. Here is a link on how to make the perfect roux for gumbo: [|Gumbo Roux]
 * Discussion on Wheat Flour and Browned Wheat Flour:** [[image:ry0304_gumbo1_sm.jpg]]

Just for Fun...How Dextrinization can get you extra cash!!! We have all seen stories on the news of Mother Teresa's face magically appearing on a piece of toast and then selling for thousands on ebay. Now you can create your own at home. Follow the steps in the following video, create your own toast art, and dextrinization could help you earn some extra cash! (10)

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References: 1. [] 2. [] 3. [] 4. [] 5. [] 6. Understanding Foods: Principles of Preperation. Starches and Sauces Pg. 396 (*My book is different) 7. [] 8. Brown A. //Understanding Food: Principles & Preparation//, Fourth Edition. Belmont, CA: Thomson Wadsworth; 2011, 393-396. 9. Vaclavik V. //Essentials of Food Science//, Thrid Edition. New York, NY: Springer Science & Business Media; 2008, 92-93. 10. [] 11. "YouTube- "[]" YouTube-rowstacy78 Web 22 June 2007. 12. Understanding Foods: Princeples of Preperation. Starches and Sauces Pg. 393 (*My book is different) 13. [] 14. [] 15. <span style="font-family: 'Arial','sans-serif'; font-size: 12pt; line-height: 115%;">[]