Baby corn is a young finger like unfertilized cobs of maize used as nutritious vegetable for human consumption. It is delicious, decorative and rich in vitamins and minerals besides a good source of easily digestible fibrous protein. It is used in developing a numbers of value added products. It is a potential crop to generate income and employment for the rural youth and women, India can be a potential export country due to low cost of production.
Baby corn being a short duration crop of 60-70 days besides it requires less water and other inputs compared to paddy, cultivation of baby corn has proved profitable for farmers under paddy-wheat cycle. The post harvest management and quality standards play a greater role in successful marketing of baby corn. This crop was first introduced at the Aterna village in Sonepat district, Haryana one and a half decades back. Besides, Aterna, other surrounding villages; Manoli, Khurampur, Bhaira, Jaati and Sersaha have also been turned into green baby corn fields. Today, baby corn farming generates employment among the villagers, and some farmers have become good entrepreneurs.
Post harvest management
Post harvest management determines quality, safety, competitiveness of the produce in the market and the profits earned by producers. Post harvest technology includes various operations such as harvesting, de-husking, grading, packaging, transportation, processing, storage, quality standards and labeling. It is an organic food being protected in the green husk sheaths and free from pesticides chemical residues.
Harvesting: After harvest, baby corn should be kept in shady places having good ventilation. Also, it should not be piled up and left for long hours in day time. It should be de-husked immediately after harvesting.
De-husking: De-husking should be done with thin knives with pointed end to lightly slit baby corn lengthwise. Next, use knives to cleave around the bigger end of baby corn, and de-husk it along slits on ears but care should be taken not to damage inner spikes. All silk should be removed properly and then put cleaned baby corn in containers such as carton boxes, net plastic baskets to facilitate ventilation. The boxes should be kept in shady areas, and water should not be sprinkled over it, otherwise it will turn blackish and rotten eventually. Clean cloth properly absorbing water can be used to cover baby corn, preventing ears on top from being too dry. Precautions should be taken to avoid knife wound on baby corn so as to save them from appearance of blackish scars which will lower the price.
Grading: Grading is the process of sorting of produce according to the grades or classes. Different classes are normally based on the length and diameter of the corn. Baby corn can be sorted and graded by machine or manually. The grades of baby corn are as under:
(i) Large size: 11-13 cm long and 1.4-1.5 cm diameter,
(ii) Medium size: 7-11 cm long with 1.2-1.4-cm diameter and
(iii) Small size: 4-7 cm long with 1.0-1.2-cm diameter.
Quality Standards: As per standards, the cobs of baby corn are classified in three classes, viz. extra class, class I and class II. The minimum quality required for the cobs of baby corn are, it must be whole, fresh in appearance, free of rotting or deterioration such as to make them unfit for consumption, clean, practically free of any visible foreign matter; free of abnormal external moisture, after packing, excluding condensation following removal from cold storage, free of any foreign smell or taste, free of pests or damage caused by pests affecting the general appearance of the produce.
The baby corn must be correctly harvested, post harvest handled, storage and transported in order to obtain quality produce in satisfactory condition at the place of destination. Silk attached to and broken from the cob must be minimal without affecting the appearance of the baby corn supplied to the consumers.The total defect area must not exceed 5 percent and 10 percent per cob for class I and class II standards respectively.
Packaging: Good packaging is necessary for easy handling, transportation and storage. Packing is normally carried out after cooling. The material used for packaging must be clean, new including reusable material of food grade quality and of a quality such as to avoid causing any external or internal damage to the produce. The contents of each package must contain only the cobs of baby corn of the same origin, and be uniform in quality and size. The containers must meet the quality, hygiene, ventilation and resistance characteristics to ensure suitable handling, shipping and storage of the baby corn. The containers must be free of all external matter and smell.
De-husked baby corn is packed in perforated poly bags, thermocol trays covered with cellophane, tin or glass bottles. For longer time of preservation, glass packing is the best having 52 percent baby corn and 48 percent brine solution. De-husked baby corn is packed in tin, glasses and poly bags. For longer time of preservation, tin or glass packing is the best. Glass packing has 52 percent baby corn and 48 percent brine solution. Farmers are generally using poly bags for packing. The packaging must possess the following quality:
(i) It should be strong enough to sustain weight while handling and transportation.
(ii)It must be convenient to handle.
(iii) It should be attractive, clean and free from any infestation etc.
(iv) It should be marked with description of the content viz. commodity name and address of packer, quantity, quality (grade), variety and date of packing etc.
Transportation: Baby corn products are usually exported by air because they are highly perishable. Packages should be transported from the packing facility to the airport in cool trucks. In all cases, trucks should be covered to prevent contact with wind, rain and sun. Mode of transport should be selected as per the requirement according to quantity and distance. It should be easily available at the time of transport, particularly during peak period after harvest and it should be comparatively cheaper among available alternatives.
Processing: Baby corn can be processed to improve its shelf-life. Main processing methods which can be used to improve the shelf -life are canning, dehydration and freezing. These are explained as follows.
(i) Canning: Canning is commonly used method for processing of baby corn. Baby corn can be canned in brine solution and can be stored for months together and can be transported to far off places. The baby corn ears are usually canned at processing factories. Flow diagram is presented as under:
Peeled baby corn → Cleaning → Boiling → Soaking → Grading → Containing →
Brine solution → Exhaust → Lid Covering → Cooling → Quality inspection
(ii) Dehydration: Dehydration can be used to increase shelf-life of baby corn for longer period. Baby corn can be cut into 0.5 cm round pieces and dried in oven (air oven, vacuum oven or can be solar dried. Dried baby corn can be packed in polythene pack/ vacuum pack/tetra pack and can be stored well for longer period. Baby corn can be rehydrated by soaking in water and can be used in preparation of food products. Products developed using dried baby corn have been found to be acceptable organoleptically like those prepared from fresh baby corn.
(iii) Freezing: Baby corn can be frozen and stored for long period like other frozen vegetables. Frozen baby corn can be used effectively for preparation of food products. Preparation like soups and vegetables prepared from frozen baby corn as acceptable as preparation made from fresh baby corn. Frozen baby corn can be directly used in various preparations.
(iv) Preservation: After filling baby corn in container, brine and water are added in cans in the proportion of 2:98 (Brine 2 percent and water 98 percent), alternatively, a solution of 3 percent brine, 2 percent sugar, 0.4 percent citric acid and balance water can also be used.
Storage: Baby corn needs refrigeration immediately to retain sweetness. Low temperatures reduce the rate of the conversion of sugar to starch. De-husked baby corn can be refrigerated for up to one week without losing its quality. It should be stored at 5o – 7 o C, with a relative humidity of 90 percent. Baby corn can also be frozen.
Labeling: Each package must bear the particulars, in the documents accompanying the shipment, in the label or on package, with legibly, indelibly marked and without false or deceptive information regarding nature of the produce. If the produce is not visible from the outside, each package shall be labeled with the name of the produce i.e. ‘Baby Corn’, class, size (optional), net weight in grams or kilograms, information of distributor i.e. name and address of the producer or packer or distributor or head office of producer in the country, name and address of importer for imported baby corn, origin of produce, country of origin, except if it is produced for domestic distribution, date of packaging, language of label of produce for domestic markets must be in national or regional languages. Produce label for export can be in language of the exporting country.
The post harvest management of baby corn in India has major constraint of inefficient handling at field and transportation levels. The other major constraints are poor technologies for storage, processing, packaging, grading and infrastructure. There is an immediate need of taking action in order to upgrade systems and to reduce the levels of post harvest losses in India.
Post harvest management of baby corn determines quality, safety, competitiveness of the produce in the market and the profits earned by the producers. Post harvest technology includes various operations such as de-husking, grading, packaging, transportation, storage and processing of baby corn. Baby corn needs refrigeration immediately after harvesting to retain sweetness. Baby corn can be processed to improve its shelf life. The major constraints include inefficient handling at field and transportation levels. Further the other major constraints are poor technologies for storage, processing processed, packaging, grading and infrastructure.
(Dr. SK Chauhan is the Chief Technical Officer in Horticulture Division, Indian Council of Agricultural Research and Dr. Dharmendra Singh is a Sr. Scientist (Plant Breeding) in Division of Genetics, Indian Agricultural Research Institute, New Delhi)