Sushi Food Poisoning - An Overview

Introduction

Sushi is a ready-to-eat type of Japanese cuisine. It combines cooked rice acidified with vinegar with other ingredients like cooked or raw seafood, boiled eggs, fresh vegetables, etc. It is considered as a potentially hazardous food.

There are different sushi varieties, including:

• Maki Rolls - Rice layers and nori sheets with different fillings are rolled with a bamboo sheet.

• Nigiri - Small rice balls with ingredients on top.

• Gunkan - An oval or round rice ball with a nori seaweed sheet wrapped around it and with toppings.

• Hand Roll - Cone rolls made with nori sheet.

What Are the Risks for Consumption?

There are specific food safety concerns for preparing, storing, and handling sushi. Raw fish is a common ingredient used in sushi preparation, it can contain pathogenic bacteria and viruses. Sushi containing raw fish is mostly cooked alongside sushi that contains only vegetarian ingredients; this can increase the risk of cross-contamination. Improper storage and preparation of sushi can result in food poisoning, complications, and even death.

The symptoms of poisoning include:

• Nausea.

• Vomiting.

• Diarrhea (stool may contain mucous or blood).

• Loss of appetite.

• Fever.

• Chills.

• Muscle aches.

• Headache.

• Joint aches.

• Abdominal pain.

It will take about six hours to a day for the symptoms to appear and about 72 hours to heal.

Medical care is needed if the symptoms persist or are severe with dehydration signs. The risk groups for developing severe illness include:

• Adults aged 65 years or older.

• Pregnant women.

• Immunocompromised individuals.

• Infants and younger children.

What Are the Storage Considerations?

Food safety begins by ensuring that only suitable, safe ingredients are purchased from suppliers, and storage should be proper.

• All ingredients should be bought from reputable suppliers.

• The food items to be used should be within the expiry date.

• During storage and receipt, ready-made sushi should be covered to prevent contamination.

• Ready-made sushi should be transported in refrigerated vehicles.

• The temperature should be checked for each batch of ready-made sushi received; it should not be more than 5 degrees Celsius.

• After ready-made sushi is received, it should be refrigerated immediately or placed on display.

• While receiving acidified rice to be used for sushi preparation, the pH of the rice should be checked. The rice should be rejected if the pH exceeds 4.6; use only properly acidified rice (pH less than 4.6).

• The acidified rice should be properly covered when not in use to prevent contamination. Acidified rice can be stored at room temperature but must be used on the same day, after which it should be discarded.

• Potentially hazardous raw ingredients like chicken, meat, seafood, dairy products, and non-acidified rice should be refrigerated.

• Avoid storing raw food items like uncooked meat, chicken, etc. above ready-to-eat food like sushi.

What Is All to Be Considered While Preparing and Storing Sushi?

Sushi preparation involves the handling of both cooked and raw food items. As sushi preparation does not involve further cooking, proper storage, and correct preparation are important. Raw food contains bacteria and other microbes so improper handling can increase bacterial growth. Improper handling of cooked food can also result in cross-contamination from raw food.

Some of the things to be considered for sushi preparation to reduce the risk of poisoning are:

• Utensils And Equipment:

• Before sushi preparation, clean and sanitize all utensils, benches, and other equipment.

• Avoid using wooden utensils. Use utensils that can be easily cleaned and sanitized.

• Sushi rolling machines should be cleaned and sanitized regularly.

• Bamboo mats should be sanitized daily.

• Personal Hygiene Measures:

• Food handlers should avoid food preparation if they are sick.

• All food handlers involved in sushi preparation should follow good personal hygiene practices like proper hand washing before and after contact with non-food articles.

• Wash hands between handling of ready-to-cook food and raw food items.

• If disposable gloves are used, they should be used for a continuous task and discarded immediately.

• Disposable gloves should be discarded before touching non-food articles like using toilets, drinking, eating, smoking, etc.

• Regularly change disposable gloves (if a food handler uses one) to avoid cross-contamination.

• Acidified Rice Preparation:

• Proper preparation of acidified rice (pH less than 4.6) is important to prevent the growth of pathogenic bacteria.

• Rice should be acidified as soon as possible following cooking; adding vinegar to warm rice results in better absorption of vinegar solution.

• The rice container should be labeled with the time of acidification.

• Acidified rice can be stored for a maximum of eight hours at room temperature.

• Sushi Preparation:

• Vegetables should be properly washed before use.

• Chicken and meat should be cooked thoroughly. The core temperature should be at or above 75 degrees Celsius.

• All potentially hazardous raw materials should be refrigerated. All prepared potentially hazardous raw materials should be refrigerated following cooking if not used immediately.

• If cooked acid is unacidified, it must be refrigerated at 5 degrees Celsius or below.

• Only prepare sushi in specific amounts, such that it can be placed in a display section or stored in the refrigerator. Sushi should never be left unrefrigerated unless not on display.

• Retail Display:

• If all other conditions are met, sushi can be displayed up to a temperature of 25 degrees Celsius (for not more than four hours).

• The sushi should not be kept in direct sunlight during the display.

• The doors of the display cabinet should be closed when not in use.

• Display cabinets should be cleaned and sanitized daily.

• Display cabinets should have doors to prevent food contamination.

• Ensure a 'first-in-first-served' system for prepared sushi to sell the earlier-made ones first.

Records that should be maintained to ensure safe sushi are:

• Temperature of sushi and stored rice.

• Acidified rice pH.

• Time at which sushi was placed on the display.

• Time control system.

• Temperature of sushi that is displayed.

• Pattern, color, etc., to track different batches.

Conclusion

Sushi is termed as a potentially hazardous food item. Proper care is to be taken in storing, handling, preparing, and displaying the food to minimize the risk of food poisoning. Improper storage and preparation can result in poisoning.