FACTORS RESPONSIBLE FOR MICROBIOLOGICAL SPOILAGE

Quality is the degree of excellence of a product. Fruit quality is a combination of several characteristics which keep the fruit fresh in appearance until acceptable by the consumers. There are a number of factors which have an overall effect on the physical, chemical, and sensory changes of the fruits in which microbiological quality factor is of utmost importance. There are lot of microorganisms which spoil the fruits (like bacteria and fungi). These microbes spoil the fruits to the extent that it is unacceptable for consumption by the consumers (Victor, 2014). It has been seen from the past three to four decades that the postharvest loss of fruits showed an increase from 25 % to 40 % due to handling problems before consumption (Kitinoja, 2002; Ray and Ravi, 2005). There are several factors which are responsible for the quality deterioration of fruits and their combined effects shows an increased rate of spoilage and if prevention measures are not taken properly the loss could reach to a maximum (Siddiqui et ah, 2015; Barman et ah, 2015; Nayyer et ah, 2015). The factors which affect the fruit quality are grouped into:

  • (1) Pre-harvest factors
  • (2) Post-harvest factors.

PRE-HARVEST FACTORS

The quality deterioration could be prevented by management of the factors at pre harvest level. Factors like irrigation, control of pests, training and pruning, use of fertilizers, fungicides, and maintenance of proper hygienic conditions are important to prevent the spoilage. Quality of fruit depends upon several environmental factors like planting tune, planting space, and timely irrigation leads to good sensoiy quality characteristics of fruits. Also use of fertilizers on appropriate times reduces chances of physiological disorders of fruits. Training and pruning of trees result in the increased yield and fruit set. Use of fungicides also has a great effect on lowering the potential of fungus to attack the fruit. Harvesting time, season of harvest influence the quality like when the fruits are harvest immediately after rains there are great chances of spoilage of fruits. Method of harvesting plays important role in quality maintenance of fruits.

POST-HARVEST FACTORS

There are several post-harvest factors which leads to the great income or losses. The fruit after harvest is cured immediately to intensifier the color and strengthen the skin. Similarly, ethylene application with controlled temperature after harvest for degreening. Similarly, removal of field heat is important consideration as it slows down the rate of respiration. Washing and drying are also important to remove the microbial load or inoculum if any from the surfaces. Sorting and grading, disinfection and waxing the surfaces of fruit reduces the physiological decay of fruits. The package in which the fruits are to be packed should be cushioned with proper material in order to safeguard the fruit during transportation and storage. Lastly, the transportation and delivery becomes an important consideration to reduce the spoilage.

CONCLUSIONS

There are physical, biological, and mechanical agents that deteriorate fruits for example, by birds damage, enzyme activity, microbial load, brushing, cutting, freezing, bursting, dehydration, drying, and so on. Most of the fruits are deteriorated by fungal as well as bacterial infection. Almost 25% of harvested fruit used for human consumption in the world is lost by microbial spoilage. Contamination can occur due to different types of microorganisms which infect fruits at any stage of harvesting, handling, processing and storage. Contamination can also be caused by direct contact between spoiled and non-spoiled fruits. Microbial growth is favored by unhygienic environmental conditions horn harvesting to marketing. Even after death of the food cells hydrolytic enzymes can still continue their action of spoiling fruits. Degradation of fruits due to microbial spoilage is responsible for producing off flavors and off odors. Therefore, it is the need of the hour to reduce microbial spoilage in fruits by spraying fungicides timely as recommended to reduce the microbial growth and contamination with mycotoxins. Good practices in agriculture (GAP), hygiene (GHP), and manufacturing (GMP) should be followed in order to reduce the foodbome illness, spoilage phenomenon and yield loss. There is a pressing need to develop hygienic conditions to remove dead and decayed debris of leaves, fruits, shoots, twigs from orchards. The behavior of the microorganisms and the metabolites associated with the spoilage should be studied well in time in order to take the preventive measure to reduce the occurrence of contamination.

KEYWORDS

  • • fruits
  • • infections
  • • microbial contamination
  • • mold
  • • postharvest loss
 
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