Bulgur: The new old wheat

by Emily Wilson
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People have specialized in processing wheat, an important food source, since the Stone Age.

Bulgur, which is pre-cooked, small-sized wheat, is one of the earliest forms of processed wheat. Although it has remained popular in the Middle East, due to its high nutritional benefits and easy storage and preparation, bulgur seems to be growing in popularity around the world. Bulgur is a versatile, nutty tasting food that can be used in breads, salads, casseroles, stew, desserts or served as a side dish.

Making wheat into bulgur is an ancient process originating in the Mediterranean. Bulgur has been an integral part of Middle Eastern cuisine for thousands of years.

In Turkey, bulgur is widely produced and consumed in villages and homes. There are about 500 bulgur plants producing nearly 1 million tonnes annually, with per capita consumption around 12 kg per person. A large amount of new factories have been constructed and some pasta and flour plants have converted their design to process bulgur.

Turkey produces the majority of bulgur for the Middle East, and it is the leading exporter of bulgur to Western Europe, where bulgur is dubbed a "health food." Germany is one of the top importers.

Bulgur is rapidly coming into commercial prominence in the United States, as large amounts are being shipped overseas under government assistance programs, and its availability in domestic food channels is growing. Because it is a wholegrain food, bulgur is popular in the health foods sector, and its hearty flavor lends itself to be included frequently in vegetarian meals.

Bulgur has been produced commercially in the United States for many years. As a result of publicity from scientific research on bulgur’s nutritional benefits, Fisher Mills set out to develop modern processing methods. Early in 1955, a plant capable of producing 100,000 pounds daily was designed and put into operation. Although no longer in the milling business, Fisher Mills is still respected for its scientific and technological developments in bulgur production.

Facilities now producing bulgur in the U.S. are operated by only a few companies, including Sunnyland Mills, ADM Milling and Bunge North America. Slowly but steadily, the U.S. domestic sale of bulgur has increased and more companies are considering production. Overseas promotional efforts, aided by government export policies, also are beginning to be successful. Large tonnages have been shipped to Korea, African and Arabic countries.

BULGUR PROCESSING

Although making bulgur has developed into a modern, mechanized manufacturing process, the same basic ancient steps of preparation are still followed today.

Durum wheat is the main wheat used to produce bulgur because of its good milling properties; light yellow color; nitrogen and starch compounds that form a hard texture; uniform water absorption; and good texture and chewing characteristics. In addition, at the final stage, there is no disruption or adhesiveness due to durum’s hard structure and high protein content (gluten). However, hard red wheat or white wheat is sometimes used. Bulgur is ground into different sizes to create the different textures and cooking properties for various foods. The bulgur types include coarse, medium, fine, double fine and ultra fine grinds.

Bulgur processing needs significant attention to create the semi- and ready-to-eat-food. The ancient preparation process is still used in small villages in the Eastern Mediterranean. Wheat is boiled in huge pots until thoroughly cooked, then spread out flat on rooftops to dry in the sun. Then the kernels are cracked into coarse pieces and sieved into different sizes for various uses.

Recently, several companies, notably Gunmak Milling Machinery Co. in Turkey, have made advances for bulgur production machinery and systems. Sun drying methods have been abandoned in many Turkish facilities, and new rotary and tower dryers have been constructed. There are several production flow diagrams for bulgur. The basic system can be classified into three stages.

In the first stage is a pre-cleaning unit, where dust and foreign materials are removed by sieves, washers, triors and separators. Here, broken wheat kernels and foreign cereals are separated out and used as animal feed.

The second stage consists of cooking and drying. The cooking process varies from using atmospheric cooking (100°C) in smaller operations to pressurized cookers in larger facilities. While cooking, vitamins and other solubilized nutrients are re-absorbed by the wheat kernel. The amount of water added is very important. If a large amount of water is added, loss of nutritional compounds will occur. If too little water is added, complete gelatinization will not be achieved.

The drying, traditionally done by the sun, is now often performed with tower, rotary, tunnel or fluidized bed dryers. Dryers are growing in popularity because they offer increased capacity, sanitation benefits, and they eliminate reliance on suitable drying climatic conditions. The best results are obtained with a rotary and tower dryer combination. Additionally, airflow rate, temperature and drying time are very important to obtain good product.

In Syria, a modern plant that uses a combination of rotary and tower driers was constructed in 1998 with a capacity of 36 to 48 tonnes per day. In that country, other available companies have only 4- to 5-tonnes-per-day capacity using the sun-drying method.

Finally, the finishing stage includes peeling, grinding, polishing, classification, and destoning. During the grinding period, byproducts such as flour and bran are obtained and usually used in animal feed.

In Turkey, grinding is performed with stone, disc, cutter and roller-type milling equipment. Use of roller milling equipment is becoming more widespread, but color and shape problems sometimes occur. The most important characteristics for bulgur are the size and shape. Shape should be oval and smooth; size should be standardized and within traditional scales.

The polisher system is a new step that enhances good yellow color and improves the appearance of bulgur surface. But during this system, bulgur is nutritionally damaged. That’s why, especially in Turkey, polishing is not always performed.

Turkish factories typically produce the Antep or Mut types of bulgur. For the Antep type, after dry cleaning, cooking and drying, wheat is peeled and ground. In Mut type production, wheat is dry- and wet-cleaned, cooked, dried, tempered, stone peeled and ground, then re-dried, cleaned and sized. The Antep system is often preferred because of easy processing, good control, shelf-life extension and easy control of moisture content.

NUTRITIONAL VALUE

The nutritional value of bulgur is a dominant factor in its growing popularity. In addition to its high dietary fiber, it contains easily absorbed minerals and vitamins, such as iron and calcium. Also, bulgur is easier to digest than other grains because it is pre-cooked.

The amount of protein in bulgur averages 12% to 15%. Rich in B-vitamins, iron, phosphorous and manganese, it complements the protein profile of legumes such as pinto beans and its B-vitamins complement the folate in vegetables, such as spinach, asparagus, broccoli or brussel sprouts. Additionally, bulgur is a good source of folic acid.

The Washington D.C.-based Center for Science in the Public Interest in 1992 scored nutritional characteristics of several grains, and bulgur ranked at the top.

Long listed as a suggested daily food item on the Mediterranean Diet Pyramid by Oldways Preservation &Trust, an organization promoting healthy eating, other regions of the world are beginning to recognize bulgur’s nutritional benefits and are encouraging bulgur into diets.

 

Functional Characteristics of Bulgur

• Resists mold contamination.

• Resists insect attacks.

• All enzymes are inactivated due to cooking.

• All microorganisms are inactivated (pasteurized).

• Numerous nutritional benefits. Original wheat kernel nutrients are encapsulated during processing.

• Low fat, high protein, wholegrain food.

• Easy preparation and semi/ready to eat food.

• Inexpensive and economical.

• Does not absorb radiation.

• Long shelf-life. Because all starch is gelatinized and the kernel is almost cooked during processing, bulgur is more stable than wheat in hot and humid environments.

• Appealing taste.

Table 1. Basic flow chart of bulgur processing

A) PRE-CLEANING UNIT

1. Pre-cleaning sieve

5. Light Grain Sep.

2. Air duct

6. Aspiration

3. Aspirator

7. Cyclone

4. Trior

8. Air Locker

B) COOKING AND DRYING UNIT

1. Pre-washer

6. Main Drying

2. Vertical Dryer

7. Conveyors

3. Tempering

8. Aspiration

4. Cooker

9. Dryed product silos

5. Pre-dryer

C) MILLING UNITS

1. Volume measurer

10. Polisher sieves

2. Pre-cleaning sieves

11. Polisher conveyor

3. Air duct

12. Polisher

4. Vertical Washer/peeler

13. Stone seperator

5. Conveyors

14. Classification sieves

6. Aspirator

15. Aspirator

7. Stone Seperator

16. Flour conveyor

8. Screw conveyor

17. Cyclone

9. Milling

18. Conveyors

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