Preservation of agricultural products after harvest is the golden key that lets a business maximise profit and establish its position in the food market. Applying the right technical standards not only extends shelf life but keeps the flavour, colour and nutritional value intact. With many years in industrial refrigeration, Tan Long will take you through the process of agricultural preservationin depth, from the basic concepts to compliant cold storage for agricultural products design that cuts losses to the lowest possible level.
What is produce preservation, and why does this stage decide the value of a harvest?
Preservation of agricultural products is the whole process of controlling the storage environment — temperature, humidity and air composition — to maintain the quality and nutritional value of produce once it leaves the field. It is not simply a matter of "putting goods in a warehouse" but the stage that determines most of the economic value the business and the farmer actually realise. To get the best out of it, investing in a compliant cold storage for agricultural products system is the pressing need today.
The reality in Vietnam: according to the 2024–2025 report from the Ministry of Agriculture and Rural Development, post-harvest produce losses run from 20% to 40% depending on the crop. Fresh fruit and vegetables alone can lose 35% to 45% of the harvest through bruising, spoilage or incorrect agricultural preservation during transport and storage. The lack of purpose-made equipment such as large-capacity industrial refrigeration puts total losses at an estimated 3.5 to 4.1 billion USD a year, equivalent to 12% to 14% of the country’s agricultural GDP.
That figure is more than a material loss. It is the work of millions of farmers wasted for want of properly engineered agricultural preservation infrastructure.
Why produce spoils after harvest
Once separated from the plant, produce keeps changing through natural biochemical reactions. Respiration continues strongly, consuming the internal sugars and starches so quality falls away quickly. At the same time, active enzymes break down the cells while micro-organisms such as bacteria and moulds enter easily through mechanical wounds or the stomata. agricultural preservation does not control humidity well, humidity that is too high encourages mould, while humidity that is too low causes moisture loss and wilting.
Three environmental factors directly affect the effectiveness of agricultural preservation include:
- Temperature is the primary control: Bacteria and moulds grow strongly between 5°C and 60°C. Once the temperature is brought below 5°C by a correctly sized refrigeration compressor system, microbial metabolism all but stops, extending storage life.
- Relative humidity: This directly affects the rate of moisture loss and the risk of a mould outbreak. Most fruit and vegetables need 85% to 95% humidity to stay fresh without giving micro-organisms the conditions to grow.
- Atmosphere composition: O2 and CO2 concentrations in particular regulate the respiration rate of the produce. Modern technology with integrated PLC control cabinet monitors and adjusts atmospheric concentrations precisely, suppressing respiration and significantly extending the life of agricultural preservation .
Five common produce preservation methods
1. Dry storage (drying)
This method reduces moisture content to a safe level — typically 11% to 13% for rice — to suppress micro-organisms and enzymes. Sun drying is the simplest approach but depends entirely on the weather. An industrial dryer costs more up front but gives better quality control and cuts drying time. agricultural preservation drying is done correctly, grain can be stored for 4 to 5 years with its quality intact.
2. Sealed storage (controlled atmosphere)
Sealed storage minimises contact with oxygen, slowing oxidation and the produce’s respiration rate. On a small scale, people use zip bags or vacuum packing. Commercially, technologies such as MAP (modified atmosphere packaging) or CA (controlled atmosphere) control the proportions of O2, CO2 and N2 inside the pack or room precisely. However, this agricultural preservation method does not suit seed stock or products that have to be stored for years.
3. Refrigerated storage (chilling and freezing)
This is the most complete and effective method for fresh fruit and vegetables, seafood and export fruit. Low temperature suppresses micro-organisms, slows respiration and keeps the cell structure sound.
- Cool storage: Holds 0°C to 10°C, suiting fruit and vegetables stored short term.
- Deep-freeze storage: Uses −18°C to −40°C for seafood and long-term frozen food.
To achieve this, installing a compliant cold storage for agricultural products together with a high-efficiency industrial refrigeration is the key to keeping running costs down.
4. Chemical preservation
Certain chemicals permitted in agriculture suppress sprouting in potatoes or onions, kill surface moulds or add a protective coating. However, this agricultural preservation method requires strict compliance with the approved chemical list and safe dosages set by the Ministry of Agriculture and Rural Development, to protect consumer health.
5. Forced ventilation
Forced ventilation uses high-capacity fans to move air evenly through the stacked goods, controlling temperature and humidity inside the store. It is economical and low-cost, and is often built into intelligent control cabinet systems to automate operation when outside conditions are stable.
Detailed temperature and humidity table for storing produce
Every type of produce has its own biology and respiration rate, so the agricultural preservation process has to be set up with very precise parameters. The table below summarises the ideal conditions in a standard cold storage for agricultural products system, so a business can optimise both storage time and product quality.
| Type of produce | Storage temperature | Relative humidity (%) | Storage time |
| Leafy greens | 0°C to 2°C (32°F to 36°F) | 95% to 100% | 1 to 3 weeks |
| Ripe tomatoes | 10°C to 13°C (50°F to 55°F) | 85% to 90% | 1 to 2 weeks |
| Potato | 4°C to 10°C (39°F to 50°F) | 90% to 95% | 2 to 4 months |
| Khoai lang | 13°C to 15°C (55°F to 59°F) | 85% to 90% | 4 to 6 months |
| Onions | 0°C to 3°C (32°F to 37°F) | 65% to 70% | 6 to 8 months |
| Apples, pears | 0°C to 4°C (32°F to 39°F) | 90% to 95% | 2 to 6 months |
| Mango, dragon fruit | 10°C to 13°C (50°F to 55°F) | 85% to 90% | 2 to 4 weeks |
| Rice (dry) | 15°C to 20°C (59°F to 68°F) | Below 70% | 12 to 60 months |
| Fresh seafood | 0°C to 2°C (32°F to 36°F) | 95% to 100% | 3 to 5 days |
| Frozen seafood | −18°C to −25°C | Not required | 6 to 12 months |
For cold storage for vegetables, potatoes in particular should never be held below 4°C (39°F). At that temperature the starch in the potato converts to sugar, causing discolouration and poorer quality in further processing. A refrigeration compressor with intelligent controls lets you hold these sensitive temperature bands precisely.
The correct technical procedure for storing produce
Whichever method a business uses, a professional, industry-standard agricultural preservation process has to follow these core steps:
- Step 1: Sorting and initial preparation This is the key step for removing damaged, bruised or diseased produce right at the point of harvest. Separating faulty produce promptly stops disease spreading to sound produce once it enters the closed agricultural preservation chain.
- Step 2: Cleaning and surface treatment Depending on the characteristics of the produce, it is washed, dried or given a protective wax coating. Note that excess surface moisture is the leading cause of mould, so a industrial refrigeration system with good humidity control is essential.
- Step 3: Setting the right storage conditions Set the temperature and humidity precisely to suit each type of product. In Tân Long’s cold storage for agricultural products systems, the air distribution fans provide forced convection so the temperature stays even at every point in the store.
- Step 4: Routine inspection and monitoring A business needs to follow the environmental parameters and the actual condition of the produce closely, at least once a day. Today, a PLC control cabinet with integrated remote monitoring lets technicians spot a temperature problem early and deal with it before widespread spoilage occurs.
- Step 5: Controlling goods in and out Apply FIFO (first in, first out) strictly so that goods move in the right chronological order. That optimises shelf life and avoids older produce sitting in store, improving the economics of the whole agricultural preservation.
Cold storage — the most effective large-scale solution for produce
For smallholders, manual methods can meet basic needs. But for large farms, processing businesses, supermarket chains or professional exporters, installing cold storage for agricultural products is an industrial solution with no substitute.
System cold storage design A compliant facility controls temperature, humidity and air circulation simultaneously across a large space, from a few dozen cubic metres to thousands of tonnes of goods. By holding ideal conditions, a business can hold stock out of season and sell when prices are 2 to 3 times higher than at peak harvest.
A practical example: Đà Lạt potatoes given proper agricultural preservation in cold storage for 6 months can sell in the rainy season at 15,000 VND/kg, against only 8,000 VND/kg in season.
The financial benefit is clear. More than that, a business’s competitive position is strengthened considerably, particularly for exports that have to meet demanding international standards such as GlobalG.A.P., HACCP or the FDA. A high-quality industrial refrigeration system from Tân Long is the foundation on which Vietnamese produce reaches world markets.
Tân Long produce cold storage — more than 20 years of hands-on experience
Tân Long is proud to be a leading name in consulting, designing and building agricultural preservation systems, with more than 20 years in the market. Our experienced engineers calculate the heat load accurately for each particular group of goods, from leafy greens held short term to export fruit or deep-frozen seafood, to select the optimum refrigeration compressor and industrial refrigeration capacity for the investor.
System cold storage for agricultural products Tân Long systems hold a flexible temperature range from +15°C to −40°C and integrate modern intelligent monitoring. That lets a business track and manage product quality to strict ISO procedures. With new-generation PLC control cabinet applied, temperature error is kept to a minimum, so every degree of variation is no longer a risk but a competitive advantage in keeping goods fresh.
Tân Long currently serves all three scales end to end:
- Kho mini: Capacity from 1 to 20 tonnes, for restaurants and F&B chains.
- Commercial stores: Capacity from 5 tonnes to several hundred tonnes, suiting large distributors.
- Industrial stores: From thousands to hundreds of thousands of tonnes, serving processing plants and international export ports.
If you are looking for a complete agricultural preservation solution — from cold storage design tailored to your type of goods, through a transparent construction quotation, to post-installation support — Tân Long’s engineers are ready to advise in detail.
With more than 20 years of hands-on experience, Tân Long has worked alongside hundreds of food and seafood businesses across the country to build agricultural preservation systems to international standards, saving as much electricity as possible while preserving the full value of the goods.
Contact Tân Long today for in-depth technical advice and a free quotation.
The economics of holding stock across seasons: when holding produce over to the next season makes cold storage pay.
Frequently asked questions about produce preservation
What is the best temperature for storing produce?
There is no single figure. Each type of produce needs its own temperature range. Leafy greens need 0°C–2°C (32°F–36°F), while mango or dragon fruit need 10°C–13°C (50°F–55°F). Getting the temperature wrong — even by a few degrees — can cause wilting, chilling injury or unusually fast ripening.
What is the current rate of produce loss in Vietnam?
According to the Ministry of Agriculture & Rural Development, overall losses run at 20–40%. Fresh fruit and vegetables can lose up to 35–45%. That is a worrying figure against the 5–10% average in countries with developed cold chain infrastructure.
Is cold storage suitable for a smallholder farmer?
A mini cold store of 1–5 tonnes is entirely suitable and pays back quickly if the out-of-season selling opportunity is taken. Tân Long designs to each specific need, from a household to a large business.
Which technical standards does a produce cold store need to meet?
Beyond temperature, a produce cold store needs to control relative humidity, air circulation speed, PU/EPS insulated panels of sufficient thickness, and an automatic temperature alarm system. Some thin-leaved greens are also sensitive to air speed — too strong a draught scorches the leaves.
Frequently asked questions about produce preservation
Why does produce need refrigerated storage?
Because after harvest produce keeps respiring and losing moisture, which reduces weight and quality. Lowering the temperature slows this, keeping it fresh and extending the selling window.
Does each type of produce need a different temperature?
Yes. Leafy greens, root vegetables, tropical fruit and temperate fruit all have their own temperature and humidity ranges. Many tropical fruits also suffer chilling injury if held below their threshold.
Besides temperature, what else needs controlling?
Relative humidity, to limit moisture loss; even air circulation through the room; and, for some products, control of the ethylene given off by ripening fruit, because it makes other produce ripen faster.
How does a produce cold store differ from a seafood cold store?
A produce store runs mainly in the chilled range, needing high humidity and gentle air movement to avoid drying out. A seafood store usually runs deep-frozen and prioritises the speed of cooling.
Does Tân Long build produce cold stores?
Yes. Tân Long designs and builds produce cold storage to the temperature and humidity requirements of each type of goods, suiting both cooperatives and large packing plants.
Related pages
- What is a CFS warehouse? Operating process and role in logistics
- What is the FDA? FDA standards in food and pharmaceutical storage
- What is a bonded warehouse? Latest regulations and procedures for 2026
- What is ISO 22000? The latest food safety standard
- industrial refrigeration systems designed and built by Tan Long
- Produce cold storage solutions: temperature, humidity and room separation
Doanh Nghiệp Đang Cần Khảo Sát, Nâng Cấp Hoặc Thiết Kế Mới Hệ Thống Lạnh Công Nghiệp?
Đội ngũ kỹ sư Cơ Điện Lạnh Tân Long với hơn 18 năm kinh nghiệm thực chiến chỉ đạo hơn 29 đại dự án quốc gia, cam kết tư vấn tính toán phụ tải nhiệt chuẩn xác, tối ưu hóa hệ số hiệu suất COP, chuyển dịch môi chất tự nhiên NH3/CO2 và tiết kiệm 20–30% chi phí điện năng vận hành.
Kỹ sư Nguyễn Toàn Thịnh (Giám đốc Kỹ thuật)
Hơn 18 năm kinh nghiệm thực chiến chỉ đạo tư vấn thiết kế và thi công hệ thống lạnh công nghiệp nặng, kho tự động ASRS và cấp đông IQF qua hơn 29 đại dự án quốc gia.
