Foods which are made from dehydrated vegetables and fruits or other food products are known as dry foods. Water which is contained in the vegetables is removed through different methods like sun drying or mechanical drying. Some of the examples of dry food are pastiche, fig, gundruk, nuggets etc. Even after the drying of these fruits and vegetables, nutrients are almost equal to fresh fruits and vegetables. The other advantages are; these can be consumed during the off seasons when fresh food are scarce in the market and the transportation cost and risks during transportation is minimized. There are different methods of drying vegetables. The key techniques are drying in the sun, drying by steaming, drying in the oven etc. In this unit, we will discuss not only the drying processes but also, other conventional methods of fruits and vegetable processing.
Introduction to processing:The types of fruits or vegetables, the scale of production, the duration of preservation and the purpose of processing is very important for the processing of dry foods. It can be done through a number of techniques and may pass through a number of steps. Some of the tips for processing are sun drying, fermenting, converting into the new products, canning etc.
Some important factors of food processing: Factors which have to be considered while processing and storing dry foods are listed below:
Timing of storage required: We should know how long the food is going to be stored. Most of the times, the dry food can be stored for few weeks up to many years. Dry foods have a time limit depending on the food and method of drying. Those dry foods can be kept for an unlimited time.
Moisture content: Different foods contain different levels of moisture and it is very important for all kind of fruits. Some fruits even consist of 90% of moisture. Adequate moisture is required for fresh foods and vegetables to maintain their turbidity.
Temperature: Heated temperature is used in grain drying process. It can evaporate the moisture on the surface. Heated temperature is needed for dry food and low temperature is needed for the fresh fruits and vegetables.
Aeration condition: Adequate movement of air through food is known as aeration process. The aeration rateis important for deciding the drying time of foods. Without sufficient airflow, the food may be damaged.
Some techniques of processing vegetables and fruits
Drying: Drying is one of the old food techniques of preservation. It will help to reduce water contents sufficient to prevent from bacteria. Some processing techniques used in fruits and vegetables products are as follows:
Sun drying:Following are the steps for sun drying:
Underground storage:Some crops like ginger, yam, potato etc. should be stored underground. They should be stored by digging a pit which should be filled with 80% of the respective crop and rest 20% with sand and soil. Other substances should not be added inside. The pit should be covered with a flat stone or a sheet. This is one of the useful methods of storage in higher elevations.
Covering with litter, straw: Some tuber and root crops like potato and ole are wrapped with straw and suspended to hook on railings, ceilings or walls. The whole bunch of banana is wrapped with its dry leaves and packed in jute sacks and transported.
Using other local technologies:
There are many local technologies of vegetables and fruits processing such as:
Foods become useless when the fungi, bacteria or other organism attack food and damage it. It should be prevented from the growth of the microorganisms as well. Some of the various methods of processing and storage of foods are as follows:
Pasteurization:This technique is invented by Louis Pasteur and named after him. This technique is usually suitable for liquid especially milk. In this method, the milk is heated up to 700C for 15 to 30 seconds to kill bacteria and cooled to 100C. After this process, the milk is stored in sterilized bottles or plastic pouches.
Refrigeration: Microorganisms cannot live in cold temperatures. Growth and reproduction can be stopped in cold temperature. Considering this, a refrigerator can be the easy and reliable device for cooling fruits and vegetables.
Freezing: This is same as refrigeration but, in this method, meat is kept at frozen state to protect them from bacteria and can be stored for a longer period of time. Nowadays, freezing technique is used both for the commercial and domestic purposes.
Vacuum packing: In this process, oxygen is restricted in the store pack. Dry foods like chips, nuts are packaged in airtight bags.
Dipping in solution:This is another method where vegetables are kept by dipping in the edible liquids like oil, alcohol, vinegar etc. which prevent vegetables and fruits from damages.
Salting:In this method, salt is kept in foods for preventing them from becoming gray and retain moisture. Foods like fish and meat products are stored by using this technique.
Use of preservatives: Special chemical compounds can also be added to the food in order to suppress the growth of foods. These kinds of compounds may be harmful if the excess quantity is used. This should be strictly used.
Picking:Many vegetables and fruits can be preserved in this manner including peppers, cucumber etc. This method prevents food damage by adding common salt, mustard oil, mustard powder as per recipe.
Jam and jelly making: Another advanced method of storage of food is by making jelly and jam using the fruits like apple, mango, etc. Fresh fruits are very important for making good jelly because it consists of sugar which makes jelly much tasty.
Canning:Canning is another method which is applied for preserving fresh fruits and green vegetables . This method is mostly used in large scale productions.
These activities are very important for the greater efficiency of production.
Packaging:Packing is done depending on the quantity of food. It is prepared by storing foods in plastic cases, bamboo baskets, clean and dry containers sealed with zippers etc. They should be protected from moisture, mold, insects and other harms. Before sending those packets to market, they are labeled with asuitable trademark. It is very important because it enhances the goodwill of the business and also helps to identify the products in the market. This also promotes products and business through advertisement.
Introduction to the Recipe:The set of instructions which helps to prepare certain food or drinks is known as a recipe. This helps to know how can we cook food with how many ingredients, the amount needed, and the process that is combined while preparing certain food, dish or drink.
Importance of a recipe:
Recipe is very important and has many advantages such as:
Method of practicing a recipe
The recipe is very useful to make different food items at home. Some of the points which should be remembered are:
Preparation of some food items
Pickle: This is one of the famous and delicious food which is taken during the lunch and dinner. It is prepared from fruits and vegetables like mango, cauliflower, lemon, cucumber etc. The method of making pickle is explained below,
Requirement and ingredients:
Following steps should be followed:
It is a traditional additive which is sour in taste. It adds more taste to the food. It is prepared from citric fruits such as lemon and other citrus fruits. It is in the concentrated form and is mostly used as areplacement of vinegar.
Required material to make chuk
Following are the steps to make chuk:
Juice: Juice is a liquid that is naturally prepared from fruits and vegetables. It is very good for health. It is rich in vitamins, minerals, and other nutrients. It can be prepared at home and also available in bottles, cans and packs in the market.
Following steps have to be followed to prepare juice:
Requirements: Fruits according to your choice, sugar, flavoring agents, mixture machine.
It is also called bean curd. It is a food made by coagulating soy milk and then pressing the resulting curds into a soft white block. It is very popular in Nepal and other south Asian countries. It is rich in proteins and also similar to paneer in outlook and color.
Tofu can be prepared by the following method:
Requirements : Soy milk or dry soybean, coagulants, heating equipment, pots and pressing equipment.
Storage of the products
Products should either be consumed or packed and sealed properly when they are ready. If it is not consumed within a few hours, put them in the refrigerator. If the juice is to be stored for a long time, it should be packed in anairtight container with some preservatives.
There are many local technologies of vegetables and fruits processing such as,
The points that should be remembered while practicing a recipe are:
A pickle is one of the famous and delicious food which is taken during the lunch and dinner. The pickle is prepared from fruits and vegetables like mango, cauliflower, lemon, cucumber etc.
Requirement and ingredients:
Following steps should be followed for making a pickle:
The required materials for making chuk are:
Dry food means _________ form of vegetables and fruits, or other food products.
High temperature is used in _______ drying process.
_________ drying is the one of the old techniques of food preservation.
___________ makes the jelly more tasty.
Chuk is a traditional additive which is ______ in taste.
Adequate movement of air through food is known as _________ process.
Some crops like ginger, yam, potato etc. should be stored underground. It should be kept by digging a pit which should be filled with _____________ of respective crop .
In underground storage, the _____should be covered with a flat stone or any sheet. This is one of the useful methods used in higher elevations.
Salting is a method where salt is kept in foods for preventing from becoming gray and retain ________ from food.