Ion Chromatography Analysis: Nitrites in Swallow Birds Nest

Last summer, when this story broke, China’s Zhejiang Provincial Administration for Industry and Commerce found nitrite levels in the rare red Swallow Birds Nest imported from Malaysia averaged 4,400 mg/kg, far above the allowed maximum of 70 mg/kg. The administration said that the contamination was the result of adulteration—dying white Swallow Birds Nests and selling them as the rare and more expensive blood-red Swallow Birds Nests.

This contamination is of concern because nitrite can react with secondary amines in food products or in the digestive system to form nitrosoamines (link to a Wikipedia page), a class of carcinogenic compounds. Nitrate, although more stable than nitrite, can act as a reservoir for nitrite. Also, nitrate can readily be converted into nitrite by microbial reduction. Thus, both nitrate and nitrite must be monitored to ensure the quality and safety of meat products.

A few months later, it was reported on China.org.cn that the Chinese government was mulling over chemical standards for Swallow Birds Nest. Then, as recently as December of 2011, the CHINADAILY.com.cn reported that again nitrite had been found in bird nests originating from Malaysia.

With vast experience with nitrite and nitrate analyses, we offer the following three methods as solid starting points for the analysis of nitrites and nitrates in Swallow Birds Nests and other food products.

• Application Note 154, Inorganic Anions in Environmental Waters Using a Hydroxide-Selective Column (downloadable PDF)
• Application Note 131, Nitrite and Nitrate in Drinking Water Using Chemically Suppressed Ion Chromatography (downloadable PDF)
• Application 132, Nitrite and Nitrate in Drinking Water Using Ion Chromatography with Direct UV Detection (downloadable PDF)
Let us know of your food testing challenges in the comments field below.

Ion Chromatography Analysis: Nitrites in Swallow Birds Nest

Swallow Birds Nest is hot sell among Vietnam’s emerging middle class

In Vietnam, where the average income is $151 a month, Mai Vu and husband David Nguyen routinely spend $250 on edible Swallow Birds Nest.

“You want to impress people.”

The couple accounts for the soaring appetite among Vietnam’s young and upwardly mobile population for one of the world’s most expensive foods, congealed saliva of Asian swiftlets. The country’s expanding middle class hungers for healthy food. Swallow Birds Nest is believed to ward off diseases and feeds a growing demand for luxury products. “It’s one of the most valuable products one can give to those who have everything,” said Vu, 28, who works at an international bank in Hanoi and was shopping for Swallow Birds Nest for her toddler daughter at a new, upscale mall. “You want to impress people.”

The demand for Swallow Birds Nest, once reserved for emperors and their courts, has created a global market with annual revenue as high as $5 billion that caters to Asia’s growing wealthy consumers, said Tok Teng Sai, president of the Federation of Malaysian Swallow Birds Nest Merchants Association. Vietnam is racing to catch up with Malaysia and Indonesia, the region’s top producers of the delicacy, and cash in on the demand.

“People have a lot of money now, especially people in China,” Tok said.

Known as the “caviar of the East,” edible nests sell for $1,000-$1,500 per kilogram wholesale and about $2,500 per kilogram retail, according to Le Danh Hoang, founder of Ho Chi Minh City-based NutriNest.

 “A lot of people are making a ton of money,”

“A lot of people are making a ton of money,” said Loke Yeu Loong, group managing director of Malaysia’s Swiftlet Eco Park, which produces an array of Swallow Birds Nest-based products, from coffee to skincare, and is targeting the Middle East as a new market.

Indonesia produces about 70 percent of the world’s Swallow Birds Nest, followed by Malaysia with 20 percent, Tok said.

The edible nests are as much as 70 percent protein, one reason aristocracy has consumed the delicacy for thousands of years, according to Massimo Marcone, an associate professor of food science at the University of Guelph in Ontario.

Some Vietnamese say Swallow Birds Nest has other powers, including keeping bodies youthful for decades.

Concrete, four-story structures replicating the natural coastal cave habitat of the birds have been erected across Vietnam among paddy fields and neighborhoods to capitalize on the boom. After an initial investment of $70,000 to $500,000 to build a bird structure, and monthly costs of about $50, a successful house can earn its owners as much as $1 million annually, said Hoang, who founded a Ho Chi Minh City-based Swallow Birds Nest business as a college student in 2005 and now advises provincial governments on the industry.