Hazard Analysis of vegetable-based food products
Vegetables contain significant amount of bacteria and fungi during and after harvest. These microorganisms are mostly soil inhabitants and are initially present on the skin of vegetables. Their growth and the germination of their spores can be inhibited if the harvested vegetables are handled, processed and stored properly. The improper handling results in damaging the skin of the plants that allows the survived organisms to invade the inner tissues and develop decomposition and degradation of the tissues. This is mainly attributed to the activity of the secreted enzymes that exert adverse effects on the structure and flavour of the vegetables.
Various species of moulds including Penicillium Rhizopus and Mucor can grow in vegetables and produce undesirable rotting/softening in vegetables. The most prevalent bacterial species which are responsible for the spoilage of the vegetables include Pseudomonas spp, Xanthomonas campestris, Erwinia carotovora and lactic acid bacteria. Deterioration also relies on the metabolism of the freshly harvested vegetables. They continue to ripen as they respire to take in oxygen and give off carbon dioxide. The respiration can be hindered by controlling the temperature of the harvested crops. As a result, the shelf-life can be favourably extended.
Good manufacturing and adequate hygiene practices are essential during manufacturing to control and minimise contamination. The incoming crops often contain foreign materials such as stones, grits, stalks and insects which necessitate proper cleaning and auditing at the receiving stage.
The storage condition of the crops is a key determinant in the extension of the shelf-life. The storage rooms should be cool, dry, well-ventilated and protected from contaminants (harmful foreign objects, insects, pests, birds and toxic chemicals). The stored vegetables should be separated from other kind of raw materials such meats, poultry, fish and eggs. . The refrigeration temperature is between 1°C and 4°C to protect the vegetables from the growth of spoilage organisms for a short period of time. Refrigeration is not always preferable as the cold temperature itself can develop unfavourable effects on the stored foods.
Regular inspections of the equipment and storage environment are vital to be carried out to ensure sufficient cleanliness. They must be free from visible residues, metal fragments, and equipment corrosion. Hand washing must be carried out regularly to prevent contamination of foods by pathogens. Protective clothing must be worn properly. The skin cuts of handlers must be completely covered by a suitable waterproof dressing. The sickness of diarrhoea, colds, eye and ear infections must be reported. Smoking and eating must be prohibited in the food handling areas.
Microbiological samplings such as total plate count for bacterial spoilage as well as determination of Coliform and Ecoli should be implemented on a routine basis. The results of the samplings should be verified with reference to the respective food regulations imposed by the law. The cleaning procedures which involve the enumeration of bacteria on the surfaces of the equipment (used for the product such as chopping board, blender, exhaust box, steam jacket pan) are also required to be verified in accordance to the standard guidelines.