1. The document provides a detailed overview of sushi, including its origins in 7th century China, different types of sushi like nigiri and maki rolls, recipes, nutritional benefits, and cultural significance. 2. It discusses how sushi has evolved from a fast food in 19th century Japan to a global cuisine, with the California roll playing a key role in popularizing sushi in the US from the 1960s onwards. 3. Sushi is considered an art form in Japanese culture, with sushi chefs undergoing long training, while debates surround the health impacts of raw fish and mercury levels.

1. Case study: SUSHI Presenter: Lê Đỗ Đăng Trình

2. 1. Origin of sushi 1.1. History The traditional form of sushi is fermented fish and rice , preserved with salt in a process that has been traced to 7th century China (Tang Dynasty). Literally, "sushi" means " sour-tasting ", a reflection of its historic fermented roots.

3. The vinegar produced from fermenting rice breaks down the fish proteins into amino acids. This results in one of the five basic tastes, called umami in Japanese. The contemporary version was created by Hanaya Yohei ( 1799–1858) at the end of the Edo period in Edo. The sushi invented by Hanaya was an early form of fast food that was not fermented and could be eaten with one's hands at a roadside or in a theatre.

4. 1.2. Types of sushi Nigiri Small rice balls with fish, shellfish, etc. on top. There are countless varieties of nigirizushi , some of the most common ones being tuna, shrimp, eel, squid, octopus and fried egg .

5. Gunkan Small cups made of sushi rice and dried seaweed filled with seafood, etc. There are countless varieties of gunkanzushi , some of the most common ones being sea urchin and various kinds of fish eggs .

6. Norimaki Sushi rice and seafood , etc. rolled in dried seaweed sheets . There are countless varieties of sushi rolls differing in ingredients and thickness. Sushi rolls prepared " inside out " are very popular outside of Japan, but rarely found in Japan.

7. Temaki Temakizushi (literally: hand rolls) are cones made of nori seaweed and filled with sushi rice, seafood and vegetables.

8. Oshizushi Oshizushi is pressed sushi, in which the fish is pressed onto the sushi rice in a wooden box. The picture shows trout oshizushi in form of a popular ekiben (train station lunch box).

9. Inari Inarizushi is a simple and inexpensive type of sushi, in which sushi rice is filled into aburaage (deep fried tofu) bags.

10. Chirashi Chirashizushi is a dish in which seafood , mushroom and vegetables are spread over sushi rice .

11. 1.3. Recipe Ingredients • 1 cup short-grain rice • 1 tbs caster sugar • 5 tbs rice vinegar • 100g fresh fish fillet • 1 small Lebanese cucumber, peeled • 1/2 avocado • 4 nori sheets • Wasabi, to taste • Pickled ginger, to serve • Japanese soy, to serve

12. Method 1. Rinse rice under cold water and drain well. Place rice and 500ml (2 cups) of water in a saucepan and bring to boil. Decrease heat to low and simmer uncovered for 12-15 minutes, stirring occasionally, until the water is absorbed. Remove from heat and let stand with lid on for a further 10 minutes. 2. Place rice in a large bowl. In a separate bowl, combine the sugar, 2 tablespoons vinegar and 1 teaspoon salt, and pour over rice. Stir to combine. Cover a flat tray with aluminium foil and spread rice on it to cool.The rice should be completely cool before using. 3. Choose from a variety of fillings. We used fresh salmon and tuna, cucumber and avocado. Prepare the fish and vegetables by slicing into batons about 5cm long. Set aside. Meanwhile, combine remaining vinegar and 300ml cold water in a bowl. 4. Place 1 nori sheet, shiny-side down, on a bamboo mat (or non-stick baking paper). Make sure longest edge of nori is at top of mat. Dip hands in water mixture (to prevent rice from sticking) and spread a quarter of rice over bottom two-thirds of nori, leaving a small border around edge. 5. Spread a thin line of wasabi along the middle of the rice and arrange a little of the fish and vegetables alongside the wasabi. Gently lift the end of the mat closest to you, and roll it over the ingredients to enclose. 6. Continue rolling the mat forward to make a complete roll. With one hand on top, gently roll mat back and forth a few times to make a nice round shape. Use a sharp knife to slice the rolls at 2cm intervals. Serve with pickled ginger, soy sauce and extra wasabi.

13. 2. Functions of sushi 2.1. Nutrition – The Food Fuction The main ingredients of sushi, raw fish and rice, are naturally low in fat , high in protein , carbohydrates , vitamins , and minerals . Seafood also contain high levels of Omega-3.

14. Health risks Some large fish, such as tuna (especially bluefin), can harbor high levels of mercury . This is due to the tuna's position at the top of the food chain. Parasite infection by raw fish is rare in the modern world, and can be avoided by boiling, burning, preserving in salt or vinegar, or freezing overnight. Some forms of sushi, notably those containing pufferfish fugu and some kinds of shellfish, can cause severe poisoning if not prepared properly. The Emperor of Japan is forbidden to eat fugu,

15. 2.2. Relationship with natural environment Overfishing and intensive farming represent a threat towards the ecological balance of some coastal areas. A much appreciated delicacy of sushi eaters, the tuna is a victim of its own success. It is estimated that 80% of stocks of blue fin tuna have disappeared in the last 20 years (from 1990 to 2010). The farming of these fish also has grave ecological consequences. 15kg of wild fish are necessary to feed 1kg of blue fin tuna.

16. In Tokyo’s main fish market each day they exchange around 2000 tons of fish, of which 50 are tuna from the Mediterranean, condemned to extinction by the absence of quick and effective solutions. “ When the last tree has been cut down, the last fish caught, and the last river has disappeared, then man will discover that money can’t be eaten.”

17. 2.3. Sushi and Communication Contrary to popular belief, Japanese don’t eat sushi very often at all. It’s expensive , for one thing, but also usually reserved for special occasions .

18. If you want to eat like a true Tokyo-ite or edokko “ child of Edo“), follow these steps: • To get a good sample of the chef’s skill, start with the fried egg sushi first (and end with it too). Move on to light fishes, before moving on to other dishes. • Use hands, not chopsticks! That’s how it’s been traditionally eaten since the old days when it was a light snack for fishermen. • Don’t use any soy sauce, or very, very little. It masks the flavor of the sushi. • Eat it in one bite. Don’t nibble.

19. 2.4. Fish and religions Several religions use the fish to symbolize life , spiritual change and motion : Fish were considered sacred to the Greeks and Romans. The first Christians represented trinity by three fishes. Fish is also one of the eight sacred symbols of the Buddha, etc. The fish moves freely through water - a symbol of life which is honored in many cultures. Water is constantly flowing and the fish totem is an excellent teacher of transitions through life.

20. 2.5. The sushi economy What the world now knows as sushi began as a street snack in 19th-century Edo-era Tokyo — fast food well before that term was ever applied to hamburgers, fries and shakes. In the place of its birth, sushi has changed since then. Tastes for sushi traveled with migrant Japanese farmer and railroad workers in the 19th century and with the country’s corporate executives in the 20th. Individual chefs, through their own desultory career paths, mixed flavors across continents.

21. Today, it is a ubiquitously coveted delicacy outside Japan found in nearly every city in the United States , where it’s usually sold out of the deli case at supermarket counters. In Sydney , an “Internet Café & Sushi Bar” sells rolls of poached chicken with peas and corn to scraggly backpackers and pimply online gamers. The London -based chain YO! Sushi applied impersonal fast-food economics to the sushi bar and raised it to a status design element.

22. 3. Properties of sushi 3.1. Cultural icon Sushi is considered an art form. It is elegantly arranged to enhance its simplicity and natural beauty . Sushi is very attractive because it is prepared quickly before the customer's eyes by the sushi chef. Often nature is captured by using a plate resembling a fish in motion, a quiet river nook, or a deep pool.

23. To be a sushi chef ( shokunin ) is considered an honor. It may take ten years of training to be considered a master and become the head chef. A sushi chef usually wears spotless ghi 's and a knotted headband, evidence that he is serious about his work. A sushi chef's knives are as important to him as a sword is to a samurai. His knives are made from carbon-steel that can be sharpened to literally cut a hair. A sushi chef has his own set of knives which can cost several hundred dollars apiece.

24. 3.2. Sushi – Healthy or Harmful? The Pros Many of the sushi ingredients are very beneficial to your health. If you want the greatest amount of protein try yellowtail and tuna fish . Another great benefit in the oily fish like salmon are the omega-3 fatty acids . These can improve many aspects of your health such as blood circulation and the heart .

25. The roasted seaweed is another great source of protein and calcium , as well as many different vitamins including Vitamin A, C, and ten types of Vitamin B. It is also a great digestive aid . The Wasabi is more powerful than ultraviolet radiation in killing bacteria . It is also rich in Vitamin C . Sushi can help you if you're exhausted, achy, or moody, as a result of hypothyroidism. A healthy thyroid needs iodine , selenium , and magnesium . As iodine is present in sushi, seafood, and kelp, eating these foods will aid in maintaining healthy thyroid hormone levels.

26. The Cons One of the most talked-about problems with eating any fish or seafood is the level of mercury present. It is suggested that people should limit the amount of fish they consume to no more than 12 ounces per week and pregnant women are encouraged not to eat fish at all as the mercury can cause birth defects. The serving size of a sushi roll may not be enough compared to the average meal, but beware, the calories in those little rolls can really add up. This is mainly thanks to the rice which is full of complex carbohydrates ; a quarter cup of white rice has 160 calories.

27. There is one more notable drawback to sushi: as most sushi is composed of raw fish there is a lot of opportunity for parasites to populate the raw meat. This occurs more when the fish are cleaned and gutted out at sea as there is more opportunity for infestation.

28. 3.3. Acculturation: From Sushi to California roll The California roll is a maki-sushi, a kind of sushi roll, usually made inside-out , containing cucumber , imitation crab stick , and avocado . In some countries it is made with mango instead of avocado. Sometimes crab salad is substituted for the crab stick, and often the outer layer of rice is sprinkled with toasted sesame seeds or tobiko .

29. In the 1960s , Los Angeles became the entry point for sushi chefs from Japan seeking to make their fortune in the United States. Ichiro Mashita , a sushi chef at the Kaitlyn, began substituting avocado for fatty tuna (toro), due to their oily texture , and after further experimentation, the California roll was born. Traditionally sushi rolls are wrapped with nori on the outside , but Mashita also eventually made the roll " inside-out ", i.e. uramaki , because Americans did not like seeing and chewing the nori on the outside.

30. After becoming a favorite in southern California it eventually became popular all across the United States by the 1980s . The roll contributed to sushi's growing popularity in the United States by easing diners into more exotic sushi options. Sushi chefs have since devised many kinds of rolls, beyond simple variations of the California roll.