What is post harvest psiology of yam?
Postharvest physiology of yam refers to the changes that occur in yam after it has been harvested. Yam is a perishable crop, and proper postharvest handling is crucial to maintain its quality and prolong its shelf life. Here are some key points about the postharvest physiology of yam:
1. Respiration: After harvest, yam continues to respire, converting stored sugars into energy, water, and carbon dioxide. This leads to a gradual depletion of stored carbohydrates and a loss of weight.
2. Moisture loss: Yam has a high moisture content, and it tends to lose water after harvest. This can result in weight loss and shrinkage of the tubers. Proper storage conditions with high humidity can help minimize moisture loss.
3. Wound healing: Yam tubers are often susceptible to mechanical damage during harvesting and handling. After harvest, the yam initiates wound healing processes to seal damaged areas and prevent further deterioration.
4. Sprouting: Yam tubers can start sprouting after harvest if conditions are favorable. Sprouting is triggered by environmental factors like temperature and humidity. Sprouting can lead to reduced quality and loss of market value.
5. Color changes: The color of yam flesh can change over time during storage. The white flesh may develop a yellowish or pinkish hue due to enzymatic browning reactions. This color change is often considered undesirable by consumers.
6. Degradation of stored nutrients: Over time, the nutrients stored in yam can degrade. Vitamin C content, for example, may decrease during storage, affecting the nutritional value of the yam.
Proper postharvest handling techniques such as curing, storage in cool conditions, and the use of appropriate packaging can help slow down the physiological changes and maintain the quality of yam for an extended period.