Sorting and Grading of Fruits for better returns from farms

 

4.2. Sorting and Grading of Fruits for better returns from farms:

by. Dr. V. J. Savaliya

                 M.Sc.(Agri), Ph.D.

......  .......................

        The sorting and grading of fruits is very beneficial to producers to get the proper price of produce as per qualities and the consumers have the choice to have desired or high-quality fruits. Simultaneously, the sorting and grading improve the shelf life of fruits and create employment generation. Thus, win-win-win situations for producers, consumers, and concerned people.

        The sorting and grading of fruits is the process of making different groups of fruits. It is the separating of fruits based on maturity, size, color, weight, and appearance. Thus, keeping in view these physical characteristics the fruits are separated into different grades, and damaged fruits are eliminated. This helps to make packing of similar and desired quality fruits which is very useful to sell with comparative higher prices as per quality parameters because it improves the shelf life of fruits and adds value in fruits.

        There are main two methods of sorting and grading fruits. It can be done manually for small quantities of fruits and when less quality specifications are required.

        Mechanical methods are used when large quantities of fruits are required to sort and grade with more quality specifications. The fruits are washed and cleaned by different machinery after harvesting according to the types and stages of fruits and the needs of final products.  These fruits are in bulk with different colors, sizes maturity stages, and quality. Therefore, sorting and grading of washed and cleaned fruits are necessary for further processing or packing with similar stages and quality. The sorting and grading are followed in different ways according to types and other factors for processing and value addition. The fruits are sorted and graded using the following some machines in various ways or methods.

4.2.1 Machines for Sorting and Grading of Fruits:

(a) Optical sorting machines:

    The optical sorting machines are very speedy and give very precise results of sorting and grading. The cameras and feelers of such machines can sort fruits as per desired gradating values i.e. maturity, size, color, and quality and appearance of fruits. The cameras and feelers of machines are standardized and calibrated to identify imperfections or defects such as blemishes, marks, spots, bruises, hurts, bumps, ripeness, and over or lower maturity.

(b) Weight graders: 

    The weight graders are chipper and mostly used for sorting and grading of fruits according to their weight. These machines are also used with other machines for sorting fruit with two parameters i.e. weight and shape of fruits

(c) Shape graders:

    The shape graders are for sorting the fruits according to various and desired shapes.

(d) Colour graders: 

    The fruits are graded according to the colours of fruits to add value through similarity in appearance and quality.

(e) Maturity graders:

    The harvested fruits are in bulk with different stages of maturity or ripening stages. These fruits are graded based on the maturity or ripening stage of fruits using maturity graders.

4.2.2 The different fruits are sorted and graded in different categories as per the            

         following.

(a) Apples: 

    The sorting and grading of apples are mostly based on size, color, and maturity. The apples are sorted and graded as small, medium, large, and extra-large according to size. The fruits are graded as per the colors that are yellow, green, and red. The starch content and firmness aspects are considered for maturity and accordingly, fruits are sorted and graded. Machines such as optical sorting machines, shape graders, and weight graders are used for grading apples.

 (b) Citrus fruits:

    The citrus fruits like lemons, grapefruit, and oranges are graded according to colour, appearance, size, and maturity of fruits.  The citrus fruits are classified and graded into small, medium, large, and extra-large sizes measured in millimetres. The fruits are categorised as green, yellow, and orange according preferred colour of a particular fruit. The firmness and sugar stage and its content factors of maturity are mostly considered for sorting and grading of citrus fruits into desired qualities and adding values.

(c) Bananas:

    The sorting and grading of bananas are mostly based on the colour and size of the fruits. The bananas are graded as small, medium, and large size measured in centimetres. According to colour, bananas are categorised as brown, green, and yellow.

(d) Stone fruits: 

    The plums, peaches, and nectarines graded as small, medium, and large measured in millimetres. The stone fruits are categorised according to colour as red, yellow, and green fruits. The firmness and sugar content factors are considered for grading according to maturity and sorted as per defects in the form of bruises and cuts in fruits.

 (e) Berries:

     The size (millimetres), colour (red, blue, and purple), and damage (defects, bruises) in strawberries, blueberries and raspberries are considered for sorting and grading in desired qualities.

 4.2.3 Machines and Instruments Used for Sorting and Grading of Fruits

Sr. No.	Machines/Instruments	Fruits
1	Optical sorting machines	Apples, lemons, grapes, kiwifruit, berries, oranges
2	Shape sorting machines
3	Density sorting machines
4	Size grading machines
5	Weight grading machines
6	Firmness sorting machines
7	Color sorting machines
8	Acid sorting machines	Grapes
9	Brix sorting machines
10	Sugar sorting machines
11	Pit sorting machines	Plums, Peaches, nectarines
12	Flesh sorting machines
13	Skin sorting machines
14	Maturity sorting machines	Bananas, avocados
15	Oil content sorting machines	Bananas
16	Ethylene sorting machines	Avocados
17	Flavor sorting machines	Apples, berries, kiwifruit, lemons, grapes, oranges
18	Texture sorting machines
19	Water content sorting machines

 

 4.2.4   Small Tools and Implements used for Sorting and Grading of various fruits (apples,                    oranges, grapes, lemons, kiwifruit, berries) are:

·         Sorting bin	·         Sorting apron	·         Sorting goggles
·         Sorting glove	·         Packing crate	·         Sorting cap
·         Sorting earplugs	·         Sorting mask	·         Bruise sorting table
·         Sorting ladder  ..........................	·         Sorting boots .......................................

                                                 More details will be next article...........