Food Processing and Technology Interview Questions and Answers
Question - 21 : - What Is Oily Fish?
Answer - 21 : -
These are the fish that are high in their fat content. E.g. eel, mackerel, salmon trout.
Question - 22 : - What Is White Fish?
Answer - 22 : -
These are the fish that are low in fat content e.g. cod, hake, haddock, whiting, halibut, lemon sole, turbot.
Question - 23 : - Give Example For Round Fish?
Answer - 23 : -
Cod, hake, haddock, whiting, eel, mackerel, salmon, trout.
Question - 24 : - While Frozen Fish If Purchased Should Be Checked ?
Answer - 24 : -
- No evidence of freezer burn
- Undamaged packing
- Minimum fluid loss during thawing
- Flesh still feeling firm after thawing
Question - 25 : - What Is The Basic Different Between Saturated Fatty Acids & Unsaturated Fatty Acids?
Answer - 25 : -
Saturated fatty acids in which the hydrocarbon chain is saturated with hydrogen.
Unsaturated fatty acids in which the hydrocarbon chain is not saturated with hydrogen and therefore has one or more double bonds.
Question - 26 : - Effect Of Heat :as Fats Are Heated There Are Three Temperatures At Which Noticeable Changes Take Place. Describe It ?
Answer - 26 : -
(A) MELTING-POINT:
Fats melt when heated. Since fats are mixtures of triglycerides they do not have a distinct melting-point but melt over a range of temperature. The temperature at which melting starts is called the slip point. Most fats melt at a temperature between 30°C and 40°C. The melting-point for oils is below normal air temperature. The more double bonds the lower the melting point.
(B) SMOKE-POINT:
When a fat or oil is heated to a certain temperature it starts to decompose, producing a blue haze or smoke and a characteristic acrid smell. Most fats and oils start to smoke at a temperature around 200°C. In general, vegetable oils have a higher smoke-point than animal fats. Decomposition of the triglycerides produces small quantities of glycerol and fatty acids. The glycerol decomposes further producing a compound called acrolein. This decomposition is irreversible and, when using a fat or oil for deep frying, the frying temperature should be kept below the smoke-point. Smoke-point is a useful measure when assessing the suitability of a fat or oil for frying purposes. Repeated heating of a fat or oil or the presence of burnt food particles will reduce the smoke-point. Repeated beating will also produce oxidative and hydrolytic changes in the fat and result in the accumulation of substances giving undesirable flavours to the foods cooked in the fat.
( C ) FLASH-POINT :
When a fat is heated to a high enough temperature, the vapours given off will spontaneously ignite. This temperature is known as the flash-point. For corn oil the flash-point is 360°C. A fat fire should never be put out with water; this will only spread the fire. The heat should be turned off and the oxygen supply cut off by covering the container of burning fat with a lid or blanket.
Question - 27 : - What Is Meant By Lard ?
Answer - 27 : -
Lard is fat extracted from pigs. The extraction is carried out by heating or “rendering”. Lard is almost 100% pure fat.
Question - 28 : - How Butter Is Made ?
Answer - 28 : -
Butter is made by churning pasteurized cream. During churning the cream becomes more viscous and finally a mass of solid butter is produced. The liquid by-product, known as buttermilk, is removed and the butter is mixed to give the desired consistency. Salt and colouring matter may be added at this stage, although some butter is sold unsalted.
The churning or agitation process reverses the emulsion. Cream is an emulsion of fat globules dispersed in a water phase. During churning the fat globules aggregate and form a solid phase which is interspersed by small water droplets. Butter is therefore a water-in-fat emulsion.
Question - 29 : - What Are The Basics Types Of Cheeses ?
Answer - 29 : -
- Fresh Cheeses
- Soft Cheeses
- Semi-hard Cheeses
- Hard Cheeses
- Blue Cheeses
Question - 30 : - What Is Cheese?
Answer - 30 : -
Cheese is the curd of or the fresh or matured product obtained by enzyme activity and subsequent separation of whey by drainage, after coagulation of milk, cream, partly skimmed milk, butter milk or a combination of these bases.