The issue of spoilage and deterioration in the processing of fruits and vegetables can be quite headache-inducing. Preservation technology is the solution. A preservation cold storage not only ensures the quality of packaged fresh vegetables but also brings significant economic benefits.

Why Do Fruits and Vegetables Spoil and Rot?

Processed fruits and vegetables undergo cell tissue disruption on their surface, leading to an increased area of microbial contamination, enhanced respiration in wounds, and accelerated nutrient consumption. Respiration intensity and microbial status are the primary factors determining the quality of the shelf life for fresh vegetables, while temperature is the main external factor affecting respiration intensity and the rate of microbial reproduction. The higher the temperature, the stronger the respiration intensity, the more intense the metabolic respiration of fruits and vegetables, and the faster the consumption of various nutrients. This results in accelerated cell decomposition, severely reducing the storability and disease resistance of fruits and vegetables. How to prevent the rot and spoilage of vegetable products?

Low temperatures are an effective and safe method to inhibit the growth of microorganisms. Below 5°C, the reproduction of various microorganisms is significantly suppressed, thereby effectively ensuring the quality and freshness of fresh vegetables. However, not all fresh vegetables are suitable for low temperatures; many vegetables are sensitive to cold and prone to chilling injury. For example, cucumbers, zucchinis, and bitter melons are easily damaged by cold below 7°C, with symptoms such as a boiled appearance on the surface, softening of the tissue, bitterness in the edible parts, or a rapid decline in flavor, rendering them inedible. Therefore, for vegetables prone to chilling injury, measures such as batch purchasing, delaying the delivery time, packaging and loading simultaneously, or individual storage with insulation can be taken to prevent chilling injury. Although many vegetables are sensitive to low temperatures, due to the short shelf life and perishability of fresh vegetables, and when production is low and sales are timely, the issue of product chilling injury can be overlooked in practice.

Key Technical Points in the Operation of Cold Storage Facilities

1 Temperature

Utilizing cold storage preservation technology, maintaining the right temperature in the cold storage is crucial. For short-term stored fresh vegetable products, the temperature inside the cold storage should generally be controlled between 2~4°C. For vegetables prone to cold damage (such as cucumbers, zucchinis, bitter melons, etc.), they can be stored in a cold storage at 5~7°C, or protective measures like covering with cotton blankets can be taken to prevent freezing. Vegetables that are prone to aging, like scallions and broccoli, should be stored around 0°C. To ensure the quality of finished vegetables, and to avoid drastic temperature changes and enhanced respiration metabolism, vegetable trimming and covering with film should also be conducted under temperatures of 2~5°C.

2 Humidity

To ensure freshness and minimize wilting due to water loss, the humidity during storage and processing is typically maintained between 80% and 95%. Additionally, during storage, attention is paid to ventilation and air exchange as needed, based on the quantity of goods and the temperature conditions between storage rooms.

Properly air-dry mushrooms, onions, ginger, and other varieties with high surface moisture content before storage. This must be done to reduce the moisture adhering to the surface of the vegetables, thereby extending their storage life.

4. Prevent Piling

Vegetables upon arrival should be neatly arranged on shelves or stacked in piles within the warehouse to prevent overstacking, which can cause mechanical damage to the vegetables or heat buildup within the piles, leading to a decline in their quality.