I didn't know... The "incorrect storage method" for "potatoes" increases the risk of food poisoning - Ministry of Agriculture, Forestry and Fisheries' Safety Guide 2025

Table of Contents

1. Introduction: Why Learn "Potato Storage" Now

2. Natural Toxins in Potatoes: Solanine & Chaconine

3. Impact of Storage Environment on Toxin Production

4. Recommended by the Ministry of Agriculture! Five Correct Storage Rules

5. Refrigeration, Freezing, and Vegetable Compartments: Risk Analysis by Temperature

6. Additional Measures Through Cooking

7. Accident Prevention Manual for School and Home Gardens

8. Global Potato Culture and Storage Techniques

9. Frequently Asked Q&A

10. Conclusion: Balancing Safety and Taste with "Potato Life Hacks"

11. List of Reference Articles

1. Introduction: Why Learn "Potato Storage" Now

1-1 The Spring-Summer "New Potato Boom" and Its Risks

New potatoes are popular for their thin skin and juiciness, but their high moisture content makes them prone to spoilage. Cases of sprouting and greening due to exposure to light near kitchen windows or being left in non-breathable plastic bags continue to occur. In 2024, the number of consultations to the National Consumer Affairs Center increased by 15% compared to the previous year. There were even reports of school closures due to croquettes used in children's lunchboxes.

1-2 Background of the 2025 "Re-Warning"

On May 20, the Ministry of Agriculture announced that potatoes ranked in the "Top 10 Cause Foods" in a 10-year analysis of household food poisoning statistics. To correct misinformation spread on social media that "long-term storage in the refrigerator is safe," a new leaflet and video were released.

2. Natural Toxins in Potatoes: Solanine & Chaconine

2-1 Mechanism of Toxin Production

Solanine and chaconine are classified as steroidal glycoalkaloids, synthesized as a self-defense response when potatoes are exposed to external threats or light stimuli. They concentrate in the sprouts and skin, with toxin concentration at the sprout tip reaching 10 to 30 times that of the edible part.

2-2 Effects on the Body and Lethal Dose

Symptoms of poisoning in humans occur at 2 mg per kg, and infants are more susceptible to severe effects even with small amounts. The toxins are heat-resistant, with a boiling point above 280°C. They cannot be completely broken down at the temperatures used for frying, making "preventive removal" the basic strategy.

3. Impact of Storage Environment on Toxin Production

3-1 Temperature

The optimal storage temperature is around 10°C. Below 6°C, reducing sugars increase, producing large amounts of acrylamide during heating above 180°C. Above 30°C, evaporation progresses, and quality rapidly declines.

3-2 Light

Visible light, especially wavelengths in the blue and red regions, synthesizes chlorophyll, which is accompanied by an increase in alkaloid concentration. Experiments have shown greening can be confirmed within days under incandescent light.

3-3 Humidity and Ventilation

At humidity levels above 80%, both moisture and mold occur, promoting the growth of rot bacteria. Conversely, excessive dryness leads to wrinkles and weight loss. A double structure of paper bags and cardboard balances light blocking and moisture absorption.

4. Recommended by the Ministry of Agriculture! Five Correct Storage Rules

1. Cool and Dark Place—Ensure a room temperature of around 10°C, such as underfloor storage or the lower section of a shoe box by the entrance.

2. Paper Bag + Cardboard—Reduce contact between individual potatoes with paper bags and ensure light blocking and ventilation with cardboard.

3. No Refrigeration—Low-temperature saccharification increases the carcinogen acrylamide in French fries by an average of 2.4 times.

4. Consume New Potatoes Early—Plan menus with a storage guideline of within two weeks.

5. Thick Peeling for Sprouts and Green Skin—Remove sprouts at least 5 mm from the base and green skin at least 1 mm as per Ministry of Health standards.

5. Refrigeration, Freezing, and Vegetable Compartments: Risk Analysis by Temperature

*Dark room temperature offers the longest quality retention, but be cautious of rising room temperatures in summer.

6. Additional Measures Through Cooking

1. Shorten Frying Time—Opt for single frying at low to high temperature instead of double frying.

2. Boil Before Roasting—Pre-boiling reduces toxins by 15%.

3. Combining Potatoes with Fats—Said to suppress toxin absorption, but be cautious of excessive intake.

4. To Peel or Not to Peel—A trade-off between nutritional value and toxin risk. Discard if there is greening, bitterness, or astringency.

7. Accident Prevention Manual for School and Home Gardens

• Maintain a Dry State with Light-Blocking Sheets

• Remove Soil Immediately After Harvest and Store in a Cool, Dark Place

• Teachers Should Check Sprouts and Skin and Instruct on Thick Peeling When Children Cook

• Prohibit or Outsource French Fry Sales at School Festivals

8. Global Potato Culture and Storage Techniques

8-1 The Nordic "Root Cellar"

A 1.5 m deep earth cellar maintains an average annual temperature of 8°C and 85% humidity. Buffered with rice husks and straw, it preserves freshness until the following spring.

8-2 Asia—Innovations in Hot and Humid Regions

In Thailand, clay pots with ventilation holes are filled with sand to block heat, and potatoes are buried inside.

8-3 North America—Home Curved Potato Racks

A style gaining popularity involves placing wooden racks in garages and covering them with light-blocking fabric.

9. Frequently Asked Q&A

Q1: Is it safe to eat potatoes that haven't sprouted but have slightly green skin?
A: The greening of the skin is chlorophyll, but toxins increase simultaneously. Peel the green parts thickly, and if the remaining part is white, it is edible.

Q2: Are potatoes stored in the refrigerator that taste sweet safe to eat?
A: The sweetness is due to reducing sugars. Since acrylamide increases when baking or frying, it's safer to use them in stews or steamed dishes.

Q3: Is it safe after removing the sprouts?
A: The toxin concentration at the sprout base is more than 10 times that of the surrounding area. It needs to be deeply gouged out along with the base. Discard if bitterness or astringency remains.

10. Conclusion: Balancing Safety and Taste with "Potato Life Hacks"

Potatoes should be "not too cold, avoid light, and allow airflow." By adhering to these three principles, toxin production and acrylamide issues can be minimized. Aim to stock up for a month, and regularly check the temperature in dark areas of the kitchen with a thermometer. Keeping a sprout removal knife or a dedicated peeler on hand will enhance cooking safety. With the right knowledge and a little effort, enjoy a potato life that combines safety, health, and deliciousness.

🔗 List of Reference Articles (External Links, Chronological Order)

• 📅 October 10, 2024
  　🔗 Ministry of Agriculture, Forestry and Fisheries "Efforts to Reduce Acrylamide in Food"

• 📅 May 20, 2025
  　🔗 Ministry of Agriculture, Forestry and Fisheries "To Prevent Food Poisoning from Potatoes"

• 📅 June 3, 2025
  　🔗 Otonanswer "Increased Risk of Food Poisoning Due to 'Incorrect Storage Methods'"

• 📅 June 4, 2025
  　🔗 Tohoku Newspaper "Natural Toxins Increase, Risk of Food Poisoning"

• 📅 June 10, 2025 (English)
  　🔗 Tokyo Food Safety Information Center "Knowledge about Potatoes"