“The global trend led fortification advocates to study the feasibility of making instant noodles with fortified wheat flour to improve nutrition among people who consume this convenience food. The conclusion from two studies conducted in Asia is that instant noodles can successfully be made with fortified wheat flour without changing consumers’ acceptance of the product or shortening the noodles’ shelf life.”
Sarah ZIMMERMAN
Food Fortification Initiative (FFI)
It is no surprise to professionals working with wheat flour products that demand for instant noodles is rising around the world. The World Instant Noodle Association estimates that the global demand for instant noodles increased 14% from 2009 to 2013, from 92.2 billion packets (bags or cups) in 2009 to 105.5 billion packets in 2013. Bangladesh, India and Egypt had the highest estimated growth with 2009 to 2013 increases of 267%, 118% and 117% respectively.
Instant noodles are popular for their convenience and low cost. They can be easily adapted for regional taste preferences by adjusting the seasoning packet. This has helped spread this product beyond Asia. For example, from 2009 to 2013, the market demand increased by 33% in Brazil, 27% in Nigeria, and 19% in the United Kingdom, according to the World Instant Noodles Association estimates.The global trend led fortification advocates to study the feasibility of making instant noodles with fortified wheat flour to improve nutrition among people who consume this convenience food. The conclusion from two studies conducted in Asia is that instant noodles can successfully be made with fortified wheat flour without changing consumers’ acceptance of the product or shortening the noodles’ shelf life.A study published in 2011 examined fortification’s impact on typical Asian foods made with wheat flour, including instant noodles. Between August and October 2009, researchers in Malaysia and the Philippines conducted tests on instant noodles made with wheat flour fortified according to World Health Organization recommendations. The fortification premixes included at least iron, folic acid and vitamin B12. The types of tests conducted and the results follow.
COLOR
Researchers measured the color of three sets of dough sheets – one made with unfortified flour, one made with sodium iron EDTA (NaFeEDTA) as the iron fortificant, and one made with ferrous fumarate as the iron fortificant. The color was measured when the dough sheet was fresh and after 24 hours stored at room temperature. The color of three dry instant noodle blocks was also measured.In Malaysia, no unacceptable color differences were observed at any time. The color of the final products from all flours was acceptable, even though the fortified noodles were slightly less bright than the control noodles. In the Philippines, grayish specks were noted on the dough sheet made from fortified flour, and slightly less bright or yellow noodles were reported. These were considered minor and acceptable differences in all cases.
TEXTURE
In Malaysia, the texture of instant noodles made from each type of flour was similar and acceptable, as evaluated by both the texture analyzer and the sensory panel. In the Philippines, no significant difference in the firmness of the noodle strands was noted.
NOODLE CRUMB AND SHEET STRUCTURE
In Malaysia, each flour sample resulted in instant noodles of a similar crumb, which the researchers described as slightly yellow, moderately bright, and crumbly. The dough sheet for all three samples was described as having a moderately tough texture and streaky appearance. In the Philippines, noodles made with flour that had been fortified with NaFeEDTA resulted in a fine and uniform crumb structure, whereas noodles made with flour that had been fortified with ferrous fumarate gave a slightly bigger crumb structure. Both fortified flours resulted in fine grayish-brown spots on the dough sheet structure.
SENSORY EVALUATION
In Malaysia, the sensory characteristics of instant noodles from all three flours were judged to be of similar quality by a 10-member trained panel. The characteristics evaluated were brightness, yellowness, overall surface appearance, firmness, elasticity, smoothness, overall texture, and overall quality. In the Philippines, both fortified noodles were a similar firmness. Noodles made with flour that had been fortified with sodium iron EDTA were slightly darker, and noodles made with flour that had been fortified by ferrous fumarate were brighter.
RANCIDITY
Malaysian researchers conducted a separate experiment on the peroxide value of instant noodles made with five types of flour, including a non-fortified control flour. The noodles were stored for one year at ambient temperature to determine the effect of fortification on shelf life as measured by peroxide value. All samples, except for the unfortified control, exceeded the standard peroxide value limit set for noodles in Japan, indicating that fortification seems to cause some rancidity after one year of storage.
To further explore the impact of storage on instant noodles, the Food Fortification Initiative (FFI) commissioned the Food Innovation and Resource Centre (FIRC) of the Singapore Polytechnic to assess the shelf life of instant noodles made with flour fortified with different iron compounds. The study was conducted in 2013 and 2014 and co-funded by the Micronutrient Initiative, Muhlenchemie and FFI.
Using an Accelerated Shelf Life Test model, the study compared instant noodles made from non-fortified flour with instant noodles made from flour fortified with electrolytic iron, ferrous fumarate, encapsulated ferrous fumarate, and sodium iron EDTA. Control samples were stored at low temperature and humidity while test samples were stored in four different settings representing normal commercial storage conditions in Asian counties with elevated temperature and humidity conditions.
Throughout the study period, which lasted for a simulated 52 weeks, samples were tested for iron content, peroxide and free fatty acid content as measures of rancidity, pH, moisture, and color. Sensory evaluation was also done to compare test samples against control samples stored at low temperature.
The study concluded that instant noodles made with fortified flour have similar sensory properties and shelf life to noodles made with non-fortified flour. Instant noodles made with non-fortified flour and flour fortified with electrolytic iron, ferrous fumarate, and encapsulated ferrous fumarate were estimated to have shelf lives of at least 12 months when stored at 30°C or less. Noodles made with flour that had been fortified with NaFeEDTA had the greatest decline in appearance and flavor over time. The amount of NaFeEDTA used in this study, however, was greater than the amount recommended by the World Health Organization.
Global flour fortification guidelines recommend levels of iron based on the population’s average per capita wheat flour availability. Recommendations where wheat flour availability is less than 150 grams per person per day, which is typical in Asia, call for 40 parts per million NaFeEDTA or 60 parts per million ferrous sulfate or ferrous fumarate. Electrolytic iron is not recommended in Asia as it is not easily absorbed and would not be expected to have a health impact where flour availability is low.
Iron is essential for the prevention of iron-deficiency anemia. This global health problem reduces productivity, impairs a child’s mental capacity, and contributes to maternal deaths. To have a health impact, fortification must include a type of iron that will not cause sensory changes so consumers accept the product. Enough easily-absorbed iron must be included to provide a health benefit, and a commonly consumed food must be made with the fortified flour.
Flour is usually fortified with folic acid to help prevent neural tube birth defects such as spina bifida. Folic acid and other B vitamins used in fortification rarely cause sensory or shelf life problems; consequently these studies focused on iron.
These two studies indicate that fortifying flour used for instant noodles is feasible. Given the expanding global market of instant noodles, this convenience foods represents a way to provide more vitamins and minerals to potentially millions of people worldwide.