Food Preservation: Modified Atmosphere, Osmosis, and Filtration
Food Preservation Techniques
Modified atmosphere conservation involves altering the air around food to maintain its quality. This can be done by replacing the air with a specific gas or mixture, or by removing it through vacuum sealing. This helps preserve the food’s chemical, structural, and microbiological properties.
Types of Modified Atmosphere Preservation
- Vacuum Packaging: Removes air to prevent bacterial growth, lipid oxidation, and enzymatic changes. However, it can cause reversible color changes
Molecular Theory, States of Matter, and Material Properties
Molecular Theory of Gases
The scientific theory explains the performance of gases. Scientists Clusius, Maxwell, and Boltzmann developed this theory in the eighteenth century. Gases are composed of a large number of tiny particles, too small to see with a microscope. These particles occupy a very small volume compared to the gas container. When they collide, no energy is lost.
The movement of these particles is determined by two types of forces: attractive forces, which tend to keep particles together,
Read MoreChemical Bonds: Covalent, Ionic, and Metallic Explained
Unit 5: Chemical Bonding
1. Introduction
The things around us are made up of different atoms that have been joined together.
1.1. What Happens When Atoms Bond?
A chemical bond is formed when atoms are held together by attractive forces. A chemical bond is the physical process that causes atoms and molecules to be attracted to each other and held together in more stable chemical compounds. There are three types of chemical bonds: covalent, ionic, and metallic bonding.
1.2. Lewis Structures
Lewis notation
Read MoreFundamentals of Life Sciences, Atoms, and Biomolecules
Life Sciences
Genetic (biological inheritance laws and the variation), Cytology (structure and functioning of cells), Histology (tissue structure), Botanica (algal photosynthesis, plants, and some bacteria), Zoology (animals in their development and interaction with the environment), Anatomy (macroscopic structures that form the body of living organisms such as organs and organ systems), Embryology (the development of organisms from zygote to the characteristics of the adult organism), Biochemistry
Read MoreNuclear Reactions: Fission and Fusion Explained
Fission
This reaction is caused by the bombardment of certain nuclides of high atomic number with neutrons. After absorbing a neutron, the nucleus splits into two nuclides of lower atomic number and additional neutrons, releasing energy corresponding to the mass difference between initial and final particles. In the above example, this should be greater than 200 MeV. This energy appears as kinetic energy of product particles and gamma rays. The neutrons generated in the process can also interact
Read MoreFundamental Chemical Laws and Gas Properties
Laws of Chemical Combination
Weight Laws
- Law of Conservation of Mass (Lavoisier): In any chemical process, the mass of the reactants must equal the mass of the products of the reaction.
- Law of Constant Proportions (Proust): When two elements come together to form a compound, they do so in a fixed mass ratio.
- Law of Multiple Proportions (Dalton): When two elements combine to form more than one compound, the amounts of one of them that are combined with a fixed amount of the second bear a simple whole