Month: June 2020
Modification of Fats and Oil: Hydrogenation
Hydrogenation of vegetable oil refers to conversion of unsaturated liquid oil into saturated or partially saturated plastic fat by catalytic addition of hydrogen. Most widely used catalyst is nickel. The main purpose of hydrogenation of vegetable oil is
- To modify oil for application in wide range of food uses such as production of margarine, deep frying oil, shortening in biscuit etc.
- To extend shelf life of fat by improving oxidative stability by reducing unsaturation. Unsaturated fats and oils are very susceptible to spoilage called rancidity.
For successful hydrogenation, crude oil impurities like phosphorous and sulfur compounds, free fatty acids, and residual soap need to be removed before proceeding for hydrogenation. These impurities have poisoning effect on catalyst and reduce its activity. Canola and rapeseed oil are particularly notorious for high level of natural sulfur which can cause problem in hydrogenation. Read more
Modification of Fats and oil: Fractionation
Different functionalities (nutritional and physical) require specific compositions that are usually not found in a single natural fat or oil. For this reason, fats and oil are often modified in order to achieve these desired compositions and thus physical and nutritional properties. For example; melting behavior, solid fat content are important factors in formulation of shortening and margarine while decreasing poly unsaturated fatty acids (PUFAS) to increase oxidative stability is important in frying oil. Following are the commonly used methods used to modify fats and oil Read more
Protein Quality, Sources and Dificiency
Protein quality: It is the digestibility and quantity of essential amino acids for providing the protein in correct ratio for human consumption. There are various methods that rank quality of different types of protein. Some of the popular methods are Protein digestibility corrected amino acid score (PDCAAS) and Digestible indispensable amino acid score (DIAAS). Read more
Protein and Amino-Acids
Protein are complex nitrogenous organic compounds which are essential for physical and mental growth and development of body. They are defined as long chain polymer of α – amino acids bounded by peptide linkage. Therefore, protein are polypeptides of high molecular weight ranging from 5000 to many millions.
Food Contamination and Food Poisoning
Food contamination: According to National Center for Biotechnology Information (NCBI) research, Food contamination is generally defined as foods that are spoiled or tainted because they either contain microorganisms, such as bacteria or parasites, or toxic substances that make them unfit for consumption. A food contaminant can be biological, chemical or physical in nature, with the former being more common. These contaminants have several routes throughout the supply chain (farm to fork) to enter and make a food product unfit for consumption.
How to protect food from contamination? Read more
Rectification on Ideal Plate
Let us consider a column consisting of ideal plates. If we are somewhere at nth plate as shown in figure below, the plate immediately above the plate is n-1 and immediately below is n+1. Subscripts are used on all quantities showing the point of origin of the quantity. Read more