Introduction

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.

Drying and Processing Vegetables and Fruits

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:

• Clean and peel the products and cut them into pieces and thinly slice fruits or vegetables that will dry quickly.
• Prevent fresh food from getting rusted due to sun or air. To prevent, the fruit can be soaked in salty water.
• If we have a solar drier, place the food in a tray ensuring that the pieces do not touch each other. If a solar dryer is not available, use tray which should be covered with thin white cloth so that it would not be damaged by birds or insects.
• Let the food dry for 3-4 days and we should take care of food from all the harms.
• Food should be kept in airtight containers and things which are required.

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:

• Steaming and sun drying.
• Slicing and sun drying for radish slices, cauliflower etc.
• Fermentation and sun drying for gundruk and kimchi and some other vegetables.
• Nugget making and sun drying of soybean, black gram, green gram etc.
• Making jam, jelly, wine with ruined fruits.

Advanced methods of processing and storage of foods

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.

Introduction and the Importance of Recipe

Packaging and storage

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:

• Recipe helps to enable purchasing, preparing, and pre-measuring all the ingredients necessary for a dish before you start cooking.
• It also helps to check all the ingredients and equipment required.
• It is beneficial when you prepare a new dish that you have not tried before.
• Your dishes will be better prepared and you will actually enjoy cooking more than ever.

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:

• We have to find the source for making the recipe. We can buy books, access the internet or just check the operational manuals of our cooking apparatus.
• We should make choice of recipe name which tells us what we should make.
• We should study the preparation instructions carefully because most well-written recipes will spell out detailed information including cooking temperature, amount of ingredients needed and so on.

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:

• cucumber or any vegetable/fruit as per need,
• 1 ½ cup of vinegar,
• 1 ½ cup of water,
• 2 teaspoon of salt or as per need,
• 8 garlic cloves,
• 4 teaspoon of dill seed,
• 1 teaspoon of red chili flakes and other spices needed as per taste,
• a jar for putting pickle

Following steps should be followed:

• Collect all required ingredients and materials, wash jar with warm water and leave it dry.
• Wash and dry vegetable or fruit for the pickle. Cut into pieces, chips or spears depending on your preference.
• Expose the stuff to sunlight for few hours.
• Put the stuff in a pot and mix all the ingredients namely the flakes of garlic cloves etc. and other things needed.
• Mix and stir vinegar, boiled water and salt in a sauce pan.
• Fill the prepared cucumber stuff into the jar as tightly as you can without crushing them and we have to leave space at the top and pour the salt and vinegar water into the jar.
• Close the lid tightly and leave a jar for one week.

Chuk:

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

• Citrus fruits ex lemon, lime etc.
• pot
• jar
• heating material

Following are the steps to make chuk:

• We should first take citrus fruit, wash them, peel and cut them.
• Squeeze the fruit and collect the juice in a clean vessel.
• Boil and steer the juice in a steel pot till it becomes thick.
• Let the liquid cool down. After the temperature of liquid lowers down to the room temperature, pour the liquid to the air tight jar.

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.

Preparation method

• Wash the fruits according to your choice.
• Remove parts that might be damaged.
• Make your mixture ready and make sure it's clean and dry.
• Peel and cut fruits in small size.
• You can also mix varieties of fruits. Process the prepared fruits until you have the quantity you desire.
• Add sugar and flavoring according to your choice.
• You can enjoy your juices. If you’re using a blender or food processor, you can replace waterwith ice.

Tofu:

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.

Preparation methods

• Soya milk is purchased from the market or prepared by making own soy, by boiling, soaking, grinding, filtering, and straining soybeans.
• Coagulation of the proteins and oil emulsion suspended in the boiled soy milk is the most important step in the production of tofu.
• The solid materials after coagulation are poured in a compressor or in a sack of muslin cloth and pressed with a heavy object.
• After a few hours, take the tofu block out of the compressor or the sack, cut into rectangular pieces of required size and dip the pieces in water.

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.