N ATURE ’ S C HEMISTRY Chemistry of Cooking. F LAVOURS IN F OOD Many of the flavours in foods are due to the presence of volatile molecules. Many flavour.

Slides:



Advertisements
Similar presentations
Aldehydes and Ketones Higher Chemistry.
Advertisements

Nature’s Chemistry Oxidation of Food.
Oxidation of alcohols, aldehydes and ketones
Oxidation of alcohols.
Aldehydes and ketones. Aldehydes and ketones can be structural isomers of each other. Aldehydes are produced by the oxidation of a primary alcohol and.
Organic Compounds Lab 3. Carbohydrates Contain C, H, O atoms (1:2:1 ratio) # Carbon atoms = # Oxygen atoms Fx: 1. ENERGY STORAGE…WHY?? The C-H bonds store.
Unit 2 The World of Carbon. Fuels -substances which burn releasing energy. Petrol – from fractional distillation of crude oil and reforming of naphtha.
Chapter 14 Aldehydes and Ketones Spencer L. Seager Michael R. Slabaugh Jennifer P. Harris.
HIGHER CHEMISTRY REVISION. Unit 2:- Reactions of Carbon Compounds 1. Although aldehydes and ketones have different structures, they both contain the carbonyl.
1 Chapter 14: Aldehydes and Ketones. 2 ALDEHYDES AND KETONES The carbonyl group: Aldehydes have at least one hydrogen attached to the carbonyl group.
Carbonyl Compounds A2 Chemistry Unit 4.
Homologous Series A group of Hydrocarbons with the same General Formula and similar chemical properties. Examples – Alkanes, Alkenes and Cycloalkanes.
Homologous Series (family) There is a gradual change in physical properties from one member to the next. The most common example of this is the increasing.
Qualitative organic analysis
Capsaicin. Aldehydes and ketones Carbonyl Compounds Contain the carbonyl group C=O Aldehydes: R may be hydrogen, usually a carbon containing group Ketones:
Oxidation of alcohols and aldehydes L.O.:  Recognise and name aldehydes and ketones.  Describe the oxidation of alcohols (primary, secondary)
16.1 Intro to Alcohols Learning Objectives: 1.Know the general formula for alcohols. 2.Be able to name alcohols. 3.Describe the shape of alcohols. 4.Classify.
Alcohols IB Chemistry Topic Alcohols Asmt. Stmts Describe, using equations, the complete combustion of alcohols Describe, using.
Aldehydes and Ketones Chapter 23
Aldehyde and ketones Lec.10. Introduction Aldehydes and ketones are characterized by the presence of the carbonyl group, perhaps the most important functional.
4.1 Systematic Nomenclature 1. Definitions Molecular formula Number of atoms in a molecule (element or compound) e.g. C 2 H 4 O 2 Empirical formula Simplest.
Advanced Higher Chemistry Unit 3 Carboxylic acids.
HIGHER CHEMISTRY REVISION.
CHAPTER 23 ORGANIC CHEMISTRY. The Nature of Organic Molecules Carbon is tetravalent. It has four outer-shell electrons (1s 2 2s 2 2p 2 ) and forms four.
Week 3 © Pearson Education Ltd 2009 This document may have been altered from the original Recognise and name aldehydes and ketones.
Carbonyl compounds Carbonyl compounds have the functional group C=O and form an homologous series with a general formula CnH2nO There are two types; 1)
Alcohols Oh yeah!. Alcohol Compound where a hydroxyl group (-OH) replaces one of the hydrogens on a carbon General Formula: – R- OH Example: – CH 3 CH.
Chapter 16 Aldehydes and Ketones.
By: Kendra & Ashley. General Structure Carbon double bonded to oxygen with two hydrocarbon groups (alkyl groups) Ketones never have a hydrogen atom attached.
By: Kendra & Ashley. General Structure Carbon double bonded to oxygen with two hydrocarbon groups (alkyl groups) Ketones never have a hydrogen atom attached.
Chapter 14 Aldehydes and Ketones Spencer L. Seager Michael R. Slabaugh Jennifer P. Harris.
What is combustion? Write a definition Write an equation of combustion for the following alcohols: Ethanol Methanol Propanol.
Let us look at the basic reaction of an alcohol with a strong oxidising agent.
Aldehydes and Ketones. Introduction Aldehydes and Ketones are among the most widely occurring organic compounds, both in nature and in the chemical industry.
Aldehydes By: Nicole Murphy & Michaela Miller. General Structure What makes an aldehyde an aldehyde? A carbon double bonded to an oxygen molecule. This.
Structures of Aldehydes and Ketones Both aldehydes and ketones contain a carbonyl group Aldehydes have at least one H attached, while ketones have two.
SCH4U Spring Aldehydes (suffix: -al)  Contain a formyl group (-CHO)  Contains a carbonyl group (-C=O)  Always found at the end of a hydrocarbon.
Oxidation of Alcohols By Iona and Catherine. Oxidising Agents Primary and secondary alcohols can be oxidised using an oxidising agent, notated by [o].
(D) The Chemistry of Cooking and the Oxidation of Food
Reactions with Alcohols Section Combustion of Alcohols Strongly exothermic Amount of energy released increases as you go up the homologous series.
Alcohols IB Chemistry Topic 10.4.
LO: I understand which alkanols can be oxidised.
General, Organic and Biochemistry 7 th Edition ORGANIC CHEMISTRY Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Carbonyl Compounds We just keep going, and going, and going.
Chemistry of Cooking and Oxidation Higher Supported Study Week 3 – Part 2.
After completing this lesson you should be able to : Many flavour and aroma molecules are aldehydes. Straight-chain and branched-chain aldehydes and ketones,
Organic Functional Groups: Aldehydes, Ketones, Acids, Esters, Amines, and Amides.
Higher Chemistry Kitchen Chemistry - Food
Lecture 11 Monday 2/8/17.
ORGANIC CHEMISTRY 13 Aldehydes and Ketones
Alcohols.
Aldehydes and Ketones.
13.7 Aldehydes and Ketones.
Access to Science - Chemistry
Alcohols… Alcohols are a homologous series where:
(D) The Chemistry of Cooking and the Oxidation of Food
Biochemistry lab 4 (Proteins)
Alcohols IB Chemistry Topic 10.
Carboxylic acid.
Chapter 17 Aldehydes and Ketones
6.6 Aldehydes and Ketones Aldehyde Structures
Testing for carbonyl compounds
Aldehydes and Ketones AH Chemistry, Unit 3(b).
Complete the diagram.
Aldehydes and Ketones.
Flavour 03/01/2019.
Proteins Describe what a protein is and give examples of what they are used for. Describe the structure and shape of the different types of proteins. Explain,
REACTIONS OF ALDEHYDES, KETONES AND CARBOXYLIC ACIDS
Presentation transcript:

N ATURE ’ S C HEMISTRY Chemistry of Cooking

F LAVOURS IN F OOD Many of the flavours in foods are due to the presence of volatile molecules. Many flavour and aroma molecules belong to the family called aldehydes Overcooking food using either method will cause more flavour to be lost. The toxicity of aldehydes, however, can result in unfortunate symptoms such as severe headaches.

A LDEHYDES AND K ETONES Aldehydes and ketones both contain the carbonyl functional group, >C=O. Aldehydes based on the alkane hydrocarbons are called alkanals and the -al ending identifies the substance as an aldehyde. They have the functional group -CHO. Ketones which are based on the alkane hydrocarbons are called alkanones and the -one ending identifies the substance as a ketone. Ketones all have the >C=O group.

Aldehydes You will be expected to name straight- chain and branched-chain aldehydes, with no more than eight carbon atoms in their longest chain from structural formulae. You will also be expected to draw structural formulae and write molecular formulae given the names of straight-chain or branched-chain aldehydes. Ketones You will be expected to name straight-chain and branched-chain ketones, with no more than eight carbon atoms in their longest chain from structural formulae. You will also be expected to draw structural formulae and write molecular formulae given the names of straight-chain or branched-chain ketones.

O XIDATION OF A LDEHYDES AND K ETONES Oxidising agents such as copper (II) oxide, Fehling's (or Benedict's) solution, acidified potassium dichromate or Tollen's reagents will convert aldehydes to carboxylic acids The reaction is classed as an oxidation because of an increase in the oxidation: hydrogen ratio. Ketones do not undergo oxidation and this fact can be used to distinguish aldehydes from ketones.

O XIDISING A GENTS ReagentAldehydeKetone Copper(II) oxideBlack to Red-BrownNo change Acidified Potassium Dichromate Orange to Green/Blue No change Fehling's (or Benedict's) solution Blue to Red-BrownNo change Tollen's reagentColourless to SilverNo change

P ROTEINS Proteins are complex molecules made from long, amino acid chains which are also branched. The chains are held together by intermolecular bonding between the side chains of the constituent amino acids. Hydrogen bonds occur between the amide links and between other groups present in the molecule. Proteins form three-dimensional structures which are sheets, spirals or coils.

C OOKING P ROTEINS When proteins are heated, during cooking, these intermolecular bonds are broken allowing the proteins to change shape (denature). These changes alter the texture of foods. For example, egg whites contain many molecules of a globular protein called albumen. When an egg is boiled or fried, the protein structure is irreversibly changed and a solid is made.