keerti

General Characters and their importance of  1.Prokaryotes,  2.Eubacteria, 3.Archaebacteria, 4.Eukaryotic Microorganisms-(Fungi, Algae, protozoa) ,  5.Viruses, viroid and prions.  1. General Characters and their importance of   Prokaryotes: The prokaryotic (Gr., pro-primitive, karyon-nucleus) cells are the most primitive cells from morphological point of view. They occur in bacteria and blue green algae. Prokaryotes are small, single cell organisms, usually less than a micrometer (abbreviated µm; 1000 µm=1 millimeter, abbreviated mm) are generally not longer than Зµm. Prokaryotic cells have different characteristic features. The characteristics of the prokaryotic cells are mentioned below. They lack a nuclear membrane. Mitochondria, Golgi bodies, chloroplast, and lysosomes are absent. The genetic material is present on a single chromosome. The histone proteins, the important constituents of eukaryotic chromosomes, are lacking in them. The cell wall is made up of carbohydrates and amino

Preservation of Milk by Pasteurization & its storage a.  Methods of Pasteurization – LTH, HTST, UHT  b.  Storage specifications after pasteurization  c.  Phosphatase test and its significance  Methods of Pasteurization – LTH, HTST, UHT History:       The term    pasteurization has been coined after the name of Louis Paster of France, who in 1860-18 demonstrated that heating wine at a temperature between 122 to 140 ⁰  F ( 50 to 60 ⁰ C) killed the spoilage organisms and helped in its preservation .  The application of this process gave rise to the new term ‘Pasteurization’ which soon become current in technical language .  Although Louis Paster pioneered studies on heat-treatment for preservation, pasteurization of milk was first attributed to Dr Soxhlet of Germany in 1886. B.        Defination: The    term pasteurization , as applied to market milk today, refers to the process of heating every particles of  milk to at least 63 ⁰ C (145⁰F) for 30 minutes or 72⁰C(161⁰F) for 15 seconds