Grapes Cleaning, Sorting and Grading - Postharvest Management

1. Cleaning sorting and grading of Grapes Next

2. Introduction: • Grapes are non-climacteric fruit that grow on the perennial and deciduous woody vines • Grape is third most widely cultivated fruit crop after banana & citrus. • It is a temperate crop which has got adapted to sub-tropical climate of peninsular India. • India has the distinction of achieving the highest productivity in grapes in the world, with an average yield of 30 t/ha. • Good quality table grapes must have a good shelf life & bberries should be firm, have a crisp texture when eaten, good flavour and an even colour

3. Steps for Postharvest Management of Grapes Clipping & Sorting Harvesting Pre-cooling Packaging & Labeling Grading Storage Consumer Marketing Transportation

4. Care during harvesting ? • Grapes meant for table purpose should not be harvested until ready to eat, since they do not ripen after harvest. They should be picked only after they reach the optimum stage of acceptability in appearance, flavour and texture. • Key criterion for harvesting are: • Color of berries & • Sugar content • Before harvest, it is necessary to prune long shoots or strip leaves to allow for better grape coloration and offer pickers easier access to the fruit • Harvest the berries on the coolest time of the day (early morning). • Harvesting of berries must stop once the pulp temperature reaches 28oC. • If rain wet the cluster thoroughly, it is important to suspend/delay the harvesting operation so as to avoid the fungus infection thereafter.

5. Cleaning / Clipping, Sorting of Grapes Immediately after harvesting grapes are brought into clipping & grading area where clipper removes the berries which have the following defects: sunburn, rot, decay, bird damage, insect damage, Powdery Mildew, fruit fly or wasp damage, uneven berries and any other defects that detract from the general appearance and may cause phytosanitary problems in the receiving market.

6. Common defects in Grapes that needs to be removed during clipping Sun Burn Decay Split Berries Fruit Fly Damage Insect Damage Infested by Mealy Bug Powdery Mildew Source: httpwww.rootsofpeace.orgdocumentsAfghan_Grape_Post_Harvest_Manual_Jan-2010.pdf

7. Mechanical sorting of grapes Bunches of grapes are being weighed & classified to colour & size Source: http://www.sybu.co.za/sd/sites/defau/files/story/grapes_purple.png

8. http://www.youtube.com/watch?v=aXXT6XgxX5U (grapes sorting grading) Grading of Grapes Grading means the sorting of the homogenous lots of the produce according to the fixed grade standards. Produce is graded in accordance with the various quality factors. The harvested bunches of grapes are graded as per their size of the berries and their colour. Grading is one of the most important procedures to be followed in post-harvest handling as it determines the quality, shelf life and price of the fruits. In grading the produce is sorted according to the fixed grade standard, taking into consideration various quality factors to make a homogenous lot. Click the following link to see the videos for sorting grading of grapes http://www.youtube.com/watch?v=aXXT6XgxX5U http://www.youtube.com/watch?v=o5VaeAMg7Tw&feature=related

9. Sorting & Grading: AGMARK Standards • SCHEDULE – II • GRADE DESIGNATION AND QUALITY OF TABLE GRAPES • 1.      Table Grapes shall be fruits obtained from varieties (cultivars) of VitisviniferaL. • 2.      Minimum requirements: • i. Bunches and berries of Table grapes shall be: • a.       clean, sound, free of any visible foreign matter; • b.      free of pests, affecting the general appearance of the produce; • c.       free of damage caused by pests and diseases; • d.      free of abnormal external moisture; • e.       free of any foreign smell and / or taste; • f.        free of all visible traces of moulds; • ii. Berries shall be intact, well formed and normally developed, • iii. Table grapes shall comply with the residue levels of heavy metals, pesticides and other food safety parameters as laid down by the Codex Alimentarius Commission for exports. • iv. Table grapes shall have minimum soluble solids of 16 degrees Brix. • v. Table grapes shall have minimum sugar / acid ratio of 20 : 1.

12. 2.     Other requirements: • i.                     Grapes must have been carefully picked and have reached an appropriate degree of development and ripeness in accordance with criteria proper to the variety and / or commercial type and to the area in which they are grown. The development and condition of the Grapes must be such as to enable them : • - to withstand transport and handling, and • - to arrive in satisfactory condition at the place of destination. • TABLE ‘A’ • PROVISION CONCERNING SIZING • Size is determined by the weight of bunches (in gms). The following minimum (in gms) requirements per bunch are laid down for large and small berries grapes. • Size tolerance: • Extra Class, Class I, Class II: 10% by weight of bunches not satisfying the size requirements for the grade, but meeting the size requirements for the grade immediately below

13. Let us sum up • Grape is an one of most important but perishable fruit grown globally. • They should be harvested only when ready to eat. • Clipping & grading is important step for postharvest handling of grapes • Sorting & Grading in India is generally done manually while mechanized grading based on size and weight is also practiced. • AGMARK specifies 3 weight grades of Large berries i.e. Extra Class (200g), Class I (150g), Class II (100g) and similarly for Small berries 150, 100 & 75 g respectively