The recent database published by National Horticulture Board revealed that India produces about 204 million MT of vegetables and ranks second in the world after China. With the advent of new technologies such as drip irrigation, fertigation, polynet house cultivation etc the vegetable production in India has increased many folds in the last five decades. However due to perishable nature of these vegetables, a significant amount of the produce gets wasted during postharvest handling. This happens due to lack of awareness about the appropriate postharvest technologies and lack of postharvest infrastructure at farm or market level. It has been seen that whenever there is over production of particular crop such as tomato, potato, peas, onion etc it leads to unrest among the farmers followed by widespread protest against the low market price of their valuable produce and farmers end up with postharvest wastage and monetary loss.
Therefore, in order to reduce the postharvest losses, the knowledge of postharvest handling practices such as harvesting, sorting/grading, packaging and storage techniques is very essential.
Harvesting
Winter season vegetables like cauliflower, cabbage, tomato, capsicum, carrot and other leafy vegetables should be harvested with due care. To ensure good quality, these should be harvested at their proper harvesting maturity or when they have attained their proper size. Some typical characteristics of maturity indices of winter vegetables are given below:
The harvesting of cauliflower, tomato, capsicum, carrot etc. should be done by using knives or clippers and should be done in a safe way so that they get minimum injuries. For the harvesting of root vegetables like carrot, radish, turnip etc., the harvesters should hold the produce firmly but gently and pull upwards or dig gently by tools. Any mishandling in the diggings may lead to mechanical injury. To reduce crop injury, wearing cotton gloves, trimming fingernails and removing jewelry such as rings and bracelets can help in reducing mechanical damage during harvest. After harvesting cauliflower, tomato, capsicum etc., should not be packed in the gunny or nylon bags for avoiding bruising. Therefore to maintain the harvest quality the plastic crates having smooth surfaces should be used.
Precooling
Precooling is considered to be a critical process in the supply chain of fruits and vegetables. It is usually the first step in postharvest operations of fruits and vegetables and is done as soon as possible after harvest. Fruits that are harvested at relatively high temperatures contain large amount of field heat, which leads to moisture loss due to continuing physiological processes of the harvested fruit, resulting in loss of quality. The field heat, if not properly removed after harvest, causes water loss, wilting and shriveling leading to an undesirable damage in the appearance and quality of produce. Various precooling techniques such as hydro-cooling, forced air cooling, room cooling, evaporative cooling and vacuum cooling are now being used in the horticultural industry.
Cleaning, washing and trimming
Vegetables like cauliflower, cabbage, carrot etc., should be trimmed or topped to remove inedible plant material or excess outer leaves. This work should be done in the field instead of the market because this leafy waste can be used as green manure and adds to the organic matter of the soil. This simple practice also helps in reducing the high rate of water loss, which occurs through the leaves of root and tuber crops. To improve the external appearance and market value, tomato and capsicum should be marketed after proper washing where as cabbage and cauliflower should never be washed.
Grading
Vegetables can be graded on the basis of size, weight, colour, maturity etc., and by doing this farmers could earn more profit. The grades for same winter vegetables are suggested by Directorate of Marketing and Inspection (DMI), Govt. of India; which are as under:
Vegetable growers should market their produce in at least three grades, i.e., best quality, moderate and other. By following such practice, they can bargain on the best and moderate quality lot and could earn more profit.
Packaging
Picture 1: Packaging of vegetables in plastic crates (A), shrink packaging (B) and LDPE film packaging (C)…
Appearance plays a major role in vegetable sales success. Packaging of produce is essential to maintain quality and prevent deterioration. There is wide range of packaging materials like bamboo baskets, wooden boxes, gunny bags, fiberboard boxes, plastic trays/crates, molded pulp trays, etc. Gunny bags are generally used for potato, net bags are used for onion and garlic. Plastic crates are used for wide range of produce like tomato, cauliflower, cabbage etc in wholesale market. At retail level shrink and cling packaging is used to maintain the quality of crops like cabbage and capsicum.
Picture 2: Bruising of vegetables due to packaging in gunny bags…
Storage
During peak winter season, the prices of cabbage, cauliflower etc., crash due to glut in the market. To avoid this situation storage of vegetables is a good measure. But to get success in the storage technical know-how about the crop to be stored, required temperature and storage period is necessary. The required storage conditions and storage period for winter vegetables are given below:
After storage one should keep watch on the market prices and whenever there is a better price he should market the produce. Only those vegetables should be stored, which are of good quality and are free from any disease, insect-pest and external injury. Carrot should never be washed for storage and cauliflower, cabbage etc. should not be trimmed.
Marketing
For successful marketing the vegetable, growers should prepare consumer packs of their produce. Consumer packages of 500 g or 1 Kg capacity with cling, shrink or LDPE film wraps can fetch better prices along with quality maintenance of the produce. Likewise leafy vegetables like spinach, coriander etc., can be bundled in 100gm or 250 gm packs. The farmers themselves can solve many market related problems by forming cooperative societies and can build up postharvest related infrastructure. The present situation demands such an initiative.
Picture 3: Schematic packhouse operations for postharvest management for fresh vegetables…
Kashika Mahajan is M.Tech in Processing & Food Engineering from Punjab Agricultural University Ludhiana. Her area of research interests are precooling, storage and postharvest handling of fruits and vegetables. Currently she is working as Asstt Manager in Global AgriSystem Private Ltd Gurugram.
Dr. Swati Kapoor is working as Food Technologist at Punjab Horticultural Postharvest Technology Centre, Punjab Agricultural University, Ludhiana. She is actively involved in Research, Extension and Teaching activities – and has published about 25 Research in National and International Journals of repute. Her research thrust area is processing of fruits and vegetables and waste utilization aspects.
Dr. BVC Mahajan is specialized in postharvest horticulture and has more than 30 years of experience in research on packaging, storage and ripening of fruits and vegetables. He has developed several protocols for export and distant marketing of fruits and vegetables and published 130 research papers in peer reviewed Journals. Currently, Dr Mahajan is serving as Director in Punjab Horticultural Postharvest Technology Centre at Punjab Agricultural University Ludhiana (Punjab).
