What is Swiftlet’s Spit Soup?

Q : What is Swiftlet’s Spit Soup?

A : Swiftlet’s Spit Soup is the nest of certain kinds of swiftlets. Swiftlet’s Spit Soup is a Chinese delicacy that has been claimed by Chinese for Centuries to be an effective health-giving tonic. The nest in itself is made from a nourishment-rich gel secretion which modern research has revealed to contain a number of health promoting qualities.

Q : How good is the Swiftlet’s Spit Soup to human body?

A : Swiftlet’s Spit Soup contains plenty of nourishment and possesses what the Chinese call “rejuvenating effects”. Modern science has help ascertain the age-old belief that Swiftlet’s Spit Soup contains a host of different proteins (water-soluble glycol-protein that promotes cell division within the immune system), vitamins, and various other minerals.
For more information, go to Beneficial Page.

What is Swiftlet’s Spit Soup?

Q : What are ingredients the crook added to fake Swiftlet’s Spit Soups?

A : The ingredients used to fake the nests include resin, seaweed, and white fungus called “the white Tremella”. White Tremella mushroom is added in between the nest-pieces. So, one of the keys to distinguish it when you are purchasing Swiftlet’s Spit Soup is to quickly check the base of the nest pieces. Fake Swiftlet’s Spit Soup externally looks very similar to the real ones but if you were to check the base, it is very obvious you can deteck chunks of Tremella mushrooms. Swiftlet’s Spit Soup is never this chunky.

Q : What are the difference of Swiftlet’s Spit Soup in white, black, and red color?

A : The white and black nests are differentiated by type of the swiftlet who build the nest, the white nest is made from the white nest swiftlet call “Aerodramus Fuciphaga” and the black nest is made from the black nest swiftlet call” Aerodramus maxima”. The price of black nest is less expensive than other color nests. The white nest is the best Swiftlet’s Spit Soup with its quality. The red nest is the rarest one that would be made by both kinds of swiftlets. The red nest have been believed contain the bird’s blood but the color actually comes from a chemical reaction between the bird’s saliva and the limestone cave.

Q : Is there any test to differentiate the contaminants from Swiftlet’s Spit Soup?

A : The difference between chemically treated processed nests from those of untreated materials can be detecked by the shine of the cement strands. Nest cement that is too shiny may also be the result of chemical additive. Because the color within the nest is permanent, cleaned nests that are too red in color could be the result of dye treatment which will dissolve when cooked. A simple test that can be carried out to determine if the nests are genuine is the iodine test for starch. Adulterated nests will turn mouldy if left in a moist chamber for a couple days. Other more complicated tests such as gas or gel chromatography can be used to separate the contents in the laboratory.

Q : What is the difference between Cave Swiftlet’s Spit Soup and House Swiftlet’s Spit Soup?

A : Since cave nest are made by natural cave living swallows and difficult to collect, some believe them to be more valuable than house nests, and they often fetch a higher price. However, cave nest generally contains more dirt and feather than house nest. House nest are also made by naturally-living swallows but are built in the human construction such as abandoned houses, building, tunnels. Generally, the texture of house nest are smoother compared to those of cave nest, and with less feathers and other contaminants. Some consider house nests are more superior in comparison of shape, size, color, cleanliness and consistency.

Q : Tips for choosing Swiftlet’s Spit Soup

A : 1. You should feel the Swiftlet’s Spit Soup with your hands. It should be dry, light and hard. Swiftlet’s Spit Soup that are sticky, soft and weighs heavier will become mouldy easily.
2. Swiftlet’s Spit Soup should be clean and with little dirt. Swiftlet’s Spit Soup with feather and dirt is not only time-consuming to clean. It also weighs heavier.
3 .If the Swiftlet’s Spit Soup in cupped shape is dry, there should be 6-7 pieces in every 38 grams. On the other hand, there are usually 9-11 pieces of Swiftlet’s Spit Soup cake in every 38 grams. However, this depends on the size of the Swiftlet’s Spit Soup cake.
4. After soaking, 38 grams of good-quality (processed) Swiftlet’s Spit Soup will weigh around 263 to 300 grams.
5. The quality of processed Swiftlet’s Spit Soup depends on how many the long strands. The more the long strands are, the better quality is.

Nitrite in Swiftlet’s Spit Soup

Some scientific studies have shown that nitrite may naturally form in Swiftlet’s Spit Soups due to fermentation under certain temperature and humidity. Some studies also suggested that high level of nitrite in Swiftlet’s Spit Soup may due to environmental contamination e.g. from bird droppings which contain high level of nitrate. However, the exact mechanism for the presence of nitrite in Swiftlet’s Spit Soup is not entirely clear at this stage.

Introduction

In 2011, surveillance conducted by Mainland authority and local studies found that nitrite was present in various Swiftlet’s Spit Soups, in particular blood-red Swiftlet’s Spit Soup, available at the market.
Nitrite occurs in the environment, in food and water, and is produced inside living organisms. It can be used as a food additive, mainly as a preservative and colour fixative in foods such as cheese and cheese products as well as cured and fermented meats.

Some scientific studies have shown that nitrite may naturally form in Swiftlet’s Spit Soups due to fermentation under certain temperature and humidity. Some studies also suggested that high level of nitrite in Swiftlet’s Spit Soup may due to environmental contamination e.g. from bird droppings which contain high level of nitrate. However, the exact mechanism for the presence of nitrite in Swiftlet’s Spit Soup is not entirely clear at this stage.

Safety and Public Health Significance

The safety of nitrite in food has raised concern because of its possible implication for the adverse health effects such as methaemoglobinaemia and cancers.
In the body, nitrite can oxidise haemoglobin in blood and make it unable to carry oxygen to the body tissues. Having insufficient oxygen, the person may develop blue or purple colouration in the lip and skin and the condition is called methaemoglobinaemia. Population subgroups such as young infants and people with glucose-6-phosphate dehydrogenase (G6PD) deficiency are more susceptible to the above condition. According to the Centre for Health Protection record, since 2003 there were two cases of nitrite related food poisoning and both were related to consumption of vegetables with high levels of nitrate in infants and young children.
The International Agency for Research on Cancer (IARC) of the World Health Organization has evaluated the carcinogenicity of ingested nitrite and concluded that ingested nitrite under conditions that result in endogenous nitrosation (i.e. conversion into nitroso compounds such as nitrosamines) is probably carcinogenic to humans (i.e. Group 2A). However, JECFA * considered that there was no evidence for an association between nitrite exposure in humans and the risk of cancer.
JECFA has evaluated the safety of nitrite and allocated an acceptable daily intake (ADI) of 0-0.07 mg per kg body weight (bw), expressed as nitrite ion and the ADI does not apply to infants below the age of 3 months. According to the results from recent local studies, any adverse health effect due to the consumption of thoroughly washed, soaked and stewed Swiftlet’s Spit Soup is not likely.

Regulatory Control

Like other countries, nitrites (potassium nitrite and sodium nitrite) are permitted preservatives in a number of food categories e.g. cured meats, fermented meats, cheeses and cheese products, but do not include Swiftlet’s Spit Soups in Hong Kong . However, Section 3(10) of the Preservatives in Food Regulation stated that it does not apply to an article of food containing any food additive that is naturally present in that food.
For Swiftlet’s Spit Soups containing naturally formed nitrite, there is no international consensus on their reference and regulatory levels.

Recommended Preparation Method for Swiftlet’s Spit Soup

In practice, dried Swiftlet’s Spit Soup should be thoroughly washed and soaked before stewing. Both local and Mainland studies have showed that thoroughly washing and soaking for a few hours can in general remove substantial quantity (up to more than 90%) of nitrite in Swiftlet’s Spit Soup. However, since nitrites are dissolved into the soaking water, they should be discarded after soaking. Water used for soaking Swiftlet’s Spit Soups should also be replaced once or twice during the soaking process. The public can also refer to the suppliers' recommendation when preparing Swiftlet’s Spit Soup.

Advice to the Public

Buy Swiftlet’s Spit Soups from reliable premises.
Since nitrite is water-soluble, washing and soaking Swiftlet’s Spit Soups thoroughly can in general remove up to more than 90% of nitrite.
Water used for soaking Swiftlet’s Spit Soups should be replaced once or twice and should be discarded after use.
Young infants are not recommended to take Swiftlet’s Spit Soup.

Advice to the Trade

Source Swiftlet’s Spit Soups from reliable suppliers.
According to the Preservatives in Food Regulation, nitrites should not be added in Swiftlet’s Spit Soup.
Provide clear instruction to consumers on proper way of preparation of Swiftlet’s Spit Soup.