Question

Tests for Carbohydrates F. Testing Foods for Carbohydrates Food Item Tested Benedict's test O Seliwanoff's test Iodine test Carbohydrates present toile 1o sixedobyd abooibni as aboi sdito etust.or ob volTO eTemoul Elonsd jte Tenibol

Answer 1

Benedict's Reagent: A Test for Reducing Sugars
Carbohydrates are divided into two groups based on the complexity of their structure. Simple carbohydrates can form either a single ring structure (monosaccharides) or a double ring structure (disaccharides -- formed when a pair of monosaccharides bond). Simple carbohydrates include familiar sugars such the monosaccharides glucose (the basic fuel of cells) and fructose (found in fruits). Common disaccharides include sucrose (table sugar) and lactose (the sugar in milk).
Complex carbohydrates (polysaccharides) are chains of many bonded simple carbohydrates, and are often used for energy storage. These include starch, cellulose, and glycogen.
One test for the presence of many simple carbohydrates is to use Benedict's reagent. It turns from turquoise to yellow or orange when it reacts with reducing sugars. These are simple carbohydrates with unbound aldehyde or ketone groups. In lab, we used Benedict's reagent to test for one particular reducing sugar: glucose.

Seliwanoff’s test is a chemical test which distinguishes between aldose and ketose sugars. If the sugar contains a ketone group, it is a ketose. If a sugar contains an aldehyde group, it is an aldose. This test relies on the principle that, when heated, ketoses are more rapidly dehydrated than aldoses

Iodine Test: Iodine test is an indicator for the presence of starch. Iodine solution (iodine dissolved in an aqueous solution of potassium iodide) reacts with starch producing a blue-black color