Manufacturing Technology of Tea, Packaging and Quality Control

Quality of tea is dependent upon the filed to factory. Quality of tea mainly depends on the raw material and method of plucking . So care should be taken both in field and during transportation and within factory  before operating the withering process. Tea leaves are damaged  at various stage from plucking of leaves. Therefore care must be done as follows,
1. There is tendency that the plucker hold the greater quantity of plucked leaves in their hands. This should be avoided.

2. Plucked shoots collected in smaller or larger container such as bamboo basket, sacks and nets should never be compressed compact. It causes burising of tea leaves, generation of excessive heat and early fermentation. Read more

Introduction to Tea: cultivation, composition and classification

Tea is the most popular and important beverage in the world. In China tea is a beverage known about for 3000 years. However, current distribution pattern of tea type originated in the area somewhere near ‘Irrawaddy basin’ from where it dispersed to South- East China, Indonesia and India. Tea grows at latitude  27° South (Argentina) to 42.43° North (Georgia) and from sea level up to altitude of 2500 m. The soil in which tea grow are widely alluvial (in Assam, India), podzols ( in USSR), volcanic ash ( in Japan), andosole (in Indonesia), red yellow podzols (in Taiwan), red soil ( in China) and sedimentary ( in Darjeeling, India). Read more

Post Harvest of Tomatoes

Tomato (Lycopersicon esculentum) was originated in South America. The improved variety of the wild fruit are grown throughout the world. Its high vitamin content and multiple uses make the tomato an important vegetable. Tomatoes are highly perishable and cannot be stored at low temperature and requires special care in handling, transportation and marketing.


Read more

Fundamental Principle of ELISA

Enzyme linked immunosorbent essay (ELISA) is a biochemical technique used mainly in immunology to detect the presence of antibody or antigen in a sample. The Elisa has been used as diagnostic tool in medicine and plant pathology as well as quality control check in various industries.

Principle: Unknown amount of antigen (protein) is affixed to the surface and then specific antibody is washed over the surface, so that it can bind to specific antigen. The antibody-antigen complex is flooded with enzyme that can convert the complex to some detectable signal. For example, in case of fluorescence ELISA, when light is shown upon the sample, antigen/antibody complexes will fluoresce so that amount of antigen in the sample can be measured. Read more

Mixing Index and Power Required for Mixing Newtonian and Non-Newtonian Fluid

Newtonian and Non-Newtonian Fluid

Newtonian fluid: For such fluids, viscosity is dependent only on temperature. There is linear increase in shear stress with increasing shear rate. For such fluid, viscosity remain constant no matter how fast they are forced to flow through pipe or channel. Example; water, organic solvent, honey Read more

Mixing and Homogenization

Mixing is a unit operation in which uniform mixture is obtained from two or more compounds by dispersing one within another. When two or more materials are mixed, the goal of mixing is to obtain homogeneous final mixture. Homogeneity is the quality of being homogeneous. A perfect homogeneous sample indicates the state of complete mixing. Mixing has no preservative effect on food. It is a processing aid to alter eating quality of food and to achieve different functional and sensory quality of food. In some food adequate mixing is necessary to ensure that the proportion of each component in the sample complies with legislative standards. Read more

SPS and International Standard Setting Bodies

Sanitary and Phytosanitary (SPS) Agreement:

SPS agreement regulates the conditions under which national regulatory authorities may set and enforce health and safety standards that directly or indirectly affect international trade. In particular, it applies to any measure applied
1. to protect consumers and animals from food and feed borne risks
2. to protect consumers, animals and plants from pest or disease related risks Read more