Final Term

• Mechanical Injury - Fresh fruits and vegetables are highly susceptible to mechanical injury owing to their tender texture and high moisture content.
• Mechanical Injury - Poor handling, unsuitable packaging and improper packaging during transportation are the cause of bruising, cutting, breaking, impact wounding, and other forms of injury in fresh fruits and vegetables.
• Types of Mechanical Injury

  1. Impact Injury
  2. Abrasion Injury
  3. Compression Injury
• Impact Injury, resulting from: - Dropping the product onto a hard surface
• Impact Injury, resulting from: - Dropping the product into the back of a car
• Impact Injury, resulting from: Excessive drops during loading and unloading
• Impact Injury, resulting from: - Suddenly stopping or accelerating a vehicle
• Abrasion Injury, results from - Vehicles with small wheels and bad shock-absorbers
• Abrasion Injury, results from - Weak crates
• Abrasion Injury, results from - Bad roads
• Abrasion Injury, results from - Transmission vibration
• Compression Injury, results from - over-packaging of crates and boxes
• Compression Injury, results from - Too high stacking of crates
• Compression Injury, results from - Weak packaging
• Microbial Diseases - The invasion of fruits and vegetables by fungi, bacteria, viruses and other organisms, is a major cause of post harvest in fruits and vegetables.
• Microbial Diseases - Microorganisms readily attack fresh produce and spread rapidly, owing to the lack of natural defense mechanisms in the tissues of fresh produce, and the abundance of nutrients and moisture which supports their growth.
• Microbial Diseases | Symptoms:

  1. Rot
  2. Mold
  3. Discoloration
• Types of Microbial Diseases

  1. Soft Rot
  2. Dry Rot
  3. Anthracnose
  4. Blue Mold
  5. Black Rot
  6. Brown Rot
• Soft Rot – Characterized by a softening of the fruit tissue, often accompanied by water-soaked lesions and foul odor. It’s caused by bacteria like Erwinia spp. and fungi like Rhizopus spp
• Dry Rot – Results in the formation of dry, sunken lesions on the fruit’s surface, often with a powdery appearance. It’s commonly caused by fungi like Botrytis cinerea and Penicillium spp.
• Anthracnose – causes dark, sunken lesions on the fruit’s surface, sometimes with pink or orange spore masses.
• Blue Mold – Characterized by growth of fuzzy blue or green colonies on the fruit’s surface, often accompanied by softening and decay
• Black Rot – Leads to the formation of black, sunken lesions on the fruit’s surface, with potential for internal decay
• Brown Rot – Results in the development of brown, mushy areas on the fruit, often with a sour or alcoholic odor.
• Physiological Deterioration - can also occur spontaneously owing to enzymatic activity, leading to over ripeness and senescence, a simple aging phenomenon.
• Physiological Disorders - occur as a result of mineral deficiency, low or high temperature injury, or undesirable environmental conditions, such as high humidity.
• Senescence – biological aging characterized by gradual deterioration or functional decline.
• Example of physiological deterioration in crops after harvest is the loss of moisture and nutrient content in fruits and vegetables, leading to wilting, decay and loss of quality. This deterioration can be accelerated by factors such as improper storage conditions, temperature fluctuations, and exposure to pathogens, ultimately reducing the shelf life and market value of the produce.
• Low Temperature – are not lethal to bacteria and other microorganisms. However at temperatures below 10 °C, their growth is slow. Therefore, both their growth and multiplication are being retarded by lowering temperature and can be almost stopped if all the water in food were frozen.
• Temperature below 0°C : Microbes can’t grow below freezing point because there is no water. They are dormant until food is thawed.
• 0°C to 5°C: Microbes grow very slowly. (chilling and chilled storage)
• 5°C to 60°C: Microbes grow rapidly.
• 60°C and up: Microbes can’t grow above 60°C
• Chilling injury - can occur during storage, transport, or even during harvesting if the produce is exposed to low temperatures for too long.
• Chilling injury – is a physiological disorder that occurs in certain fruits and vegetables when they are exposed to temperatures below their optimal range but above freezing.
• Symptoms of Chilling Injury

  1. Pitting
  2. Discoloration
  3. Softening
  4. Increased Susceptibility to Decay
  5. Loss of Flavor or Aroma
• Pitting – small depressions or indentations may form on the surface of the produce.
• Discoloration – This can manifest as darkening or browning of the skin or flesh of the produce.
• Softening – The texture of the fruit or vegetable may become mushy or soft, particularly in areas affected by chilling injury.
• Increased susceptibility to decay – chilled produce may be more prone to rot or decay, as low temperatures can weaken the natural defenses against pathogens.