Grains & Cereals

Grains RS C 1

Grains or the seeds of cereal crops have been consumed by humans for thousands of years since they were first cultivated in around 10,000 BC. They are used as a staple food source across the world with cultures developing traditional foods based on those grains which grow the best in their climate and location. Grains are very versatile, can be processed into a range of ingredients and are used in a number of ways to provide an easily accessible energy source for our bodies.

Whole Grains are the whole seeds of plants packed full of nutrients, energy, vitamins and minerals, all they need to begin growing a new plant given the right growing conditions. Unprocessed whole grains are made up of several components including the outer layers called Bran, the Germ and the Endosperm. These layers may also be covered in an outer coating or husk which protects the grain from pests, water, disease etc.

The bran layer may be made up of several outer layers. Bran provides us with an important fibre source and contains antioxidants, and B vitamins. The germ is the portion of the grain that can germinate into a new plant. It contains vitamins, minerals, some protein and healthy fats. The endosperm is the energy source the new plant uses for growth. This is the largest portion of the grain containing carbohydrates, proteins, and a small amount of vitamins and minerals. 

During the processing of grains the husk, bran and germ is usually removed, leaving the endosperm. This process removes the fibre and a large proportion of the nutrients. The whole grain provide an excellent source of nutrition and fibre, but the more you move away from the full grain, the less whole nutrition they provide. An example of this is brown rice vs white rice, wholemeal flour containing the ground whole grain vs white flour.

Products made from grains such as wheat, corn or maize, rice, rye and barley, often make up the bulk of our modern diets, providing a dense carbohydrate source that’s processed into energy by the body. To compensate for the natural fibre, vitamins and minerals lost during the refining process, manufacturers may then add back vitamins and minerals to enrich the flours or foods made from these grains.

Grains can be sold in different forms –

  • Whole grain – husk removed, bran, germ and endosperm intact with all its fibre and nutrients. (such as brown rice)
  • Refined grain – husk, bran and germ removed. Endosperm remains. (e.g. white rice)
  • Cracked grains – Whole grains cracked into smaller particle sizes.
  • Flours – Whole grains (bran, germ and endosperm) or just the endosperm is ground into different particle sizes depending on the application (e.g. coarse vs fine ground rice flour). The flour miller also standardises the protein content depending on the application (e.g. hard high protein flours used in pasta vs lower protein soft flours for cakes).
  • Oils – Oils can be made from the bran layer of rice, endosperm of corn and wheat germ.
  • Flakes – Grains are cooked and cooled, then flattened between rollers and dried or toasted in ovens.
  • Kibbled Grains – Grains are cracked as per above and then moistened or steamed and then re-dried.
  • Rolled – Husk removed, steamed and rolled
  • Puffed – Husked and depending on the product, bran removed and the grain is puffed by using high pressure or temperature. Extrusion can also be used below.
  • Extruded Grains – Grains and other ingredients are mixed into a mass which is forced through an extruder plate under a combination of time, temperature, pressure and shear. This plate has a specific shape cut into it depending on the final shape required (circle, flake, rice grain etc). On exiting the extruder plate the mass is cooked and expands before its cut off with a blade to a specific shape and size. This technology is commonly used to produce breakfast cereals and cereal based snack foods in different shapes and sizes. Other cereal products produced by non-expansion extrusion includes pasta, breads, snacks such as pretzels and co-extruded products which forces a filling into an outer cereal based layer. Examples of this are filled pillow style biscuits or cereals and cereal bars with fruit fillings.
  • Starches – Please see the Starch section at the base of this page.

According to the Food Standards Code Standard 2.1.1, “Wholegrain food is any food which uses every part of the grain including the outer layers, bran and germ. “ Wholegrains can be either whole, puffed, flaked, milled or kibbled or ground into flours. “Wholemeal applies to foods in which the whole grains have been refined into finer particles”. Food manufacturers can use either terms to describe their foods.  “The information above is based on content from the Federal Register of Legislation at 5/11/2017. For the latest information on Australian Government law please go to https://www.legislation.gov.au.”  The section of our Food Standards Code governing this area is Standard 2.1.1., which can be found at http://www.foodstandards.gov.au/code/Pages/default.aspx

For more information on wholegrains in the diet please read–

https://www.sanitarium.com.au/food-nutrition/nutrition/why-choose-wholegrains

 

Grain Facts –

Wheat – A variety of wheat types are grown in Australia for manufacturing purposes.  Each of these wheats and the flours they produce have specific and unique qualities from the variety of wheat grown, their location and the growing conditions. Wheat flours from different varieties of wheat are often blended by the miller to provide specific characteristics to finished products being made. The important factors considered by processors using flours includes colour, protein content and quality, water absorption and their ability to retain gas bubbles formed during chemical and yeast leavening.  

Wheat is special as it contains a unique set of proteins called Glutenin and Gliadin which when mixed with water and physically kneaded forms a flexible elastic network. This network is called gluten and it traps the gas produced during yeast fermentation or by chemical leavening. These gas bubbles expand when exposed to heat during baking and the gluten structure sets at around 71C. Durum wheat contains the highest amount of protein and is used in semolina and pasta manufacture. Soft wheat flours that are used to make cakes and biscuits are the lowest in protein. Bread and noodle flours can contain a range of protein depending on the types of bread and noodles to be manufactured.  Please see AWB’s website for more information – http://www.awb.com.au/customers/australianwheat/

Wheat Starches – Commonly used in food products mainly for thickening purposes. Wheat starch is also used in textiles and paper manufacture as a base to produce ethanol alcohol. Please see the starch section at the bottom of this page.

 

Rice – Rice grains can either be consumed as whole, puffed or rolled grains, flours or starches. Different types of rice are grown for different purposes. Just some of the common varieties that we see here in Australia include long, medium and short grain, Aborio (Italian rice used as the base for Risotto), Sticky or glutinous rice (used in Asian cooking does not contain gluten), Sushi rice (small sticky grain), Jasmine (A fragrant rice used to complement Asian dishes), Basmati (only grown in India and Pakistan and used to accompany Indian dishes).  

Rice can be further processed into either flour, starch, rice bran oil, brown rice syrup and rice bran. Whole grains can be puffed or flaked for use in cereal products. Rice does not contain gluten which makes it perfect to use as a base flour for Gluten Free bakery products. To manufacture rice flour the raw grains are ground into different particle sizes. Available in both brown rice (contains the bran layer) and white rice variants (just endosperm), rice flour is a very important component of gluten free flours. Rice flour is also used as an ingredient to make rice crackers, rice paper wraps and noodles, rice based snacks etc. For more information on Rice Starches please see the Starch section at the bottom of this page.

For more information please see –

http://www.rga.org.au/the-rice-industry.aspx

https://www.glnc.org.au/grains-2/types-of-grains/rice/

 

Rye – Rye is a type of grass that is grown and used for food and beverage applications. It has a low level of the gluten forming proteins Glutenin and Gliadin and produces loaves and baked goods that are very dense in texture and packed full of flavour e.g. European Pumpernickel breads. For this reason it’s often blended with wheat flours to produce light or medium rye breads and crackers. Rye can be found in cereals in both puffs and rolled flakes and it’s also used as the base for alcoholic beverages including vodka, beer and whisky.

For more information please see –

https://www.glnc.org.au/grains/types-of-grains/rye/

https://en.wikipedia.org/wiki/Rye

 

Triticale – Triticale is a hybrid of wheat and rye. It’s mainly grown for animal food but rolled triticale can be found in cereals, granola and museli bars. For more information on Triticale please see –  https://en.wikipedia.org/wiki/Triticale

 

Barley  Barley has been used for centuries. It’s a food source for animals and it’s used in food and beverage manufacture. Barley is fermented to make malt, which is used as the base for beer and distilled beverages such as whiskey. Barley is sold as pearled barley which has had the husk and part of the bran removed during the polishing process. Pearled barely is used in soups and stews and is ground into flour or made into flakes for cereals. Barley flour has no gluten forming proteins so must be blended with wheat flour to be used in bakery products. For more information on Barley please see – https://en.wikipedia.org/wiki/Barley

 

Corn or Maize – Corn or Maize is a staple grain across the world. It’s a high starch grain used in products for both human and animal consumption as well as base for ethanol production. Maize can be eaten in a number of forms including whole cobs and kernels, cornmeal, oil, flour, popped grains, flakes, and starch. Corn starch is used as the base material for high fructose corn syrup. It’s also used in the base or mash for alcoholic beverages such as whiskey and beer. For more information on corn starch please see the Starch section at the bottom of this page. For more information on HFCS please see the Sugars page and for more information on Corn or Maize please see – https://en.wikipedia.org/wiki/Maize

 

Oats – Oats are most commonly found in breakfast food products as rolled oats or quick oats (rolled oats broken into a smaller particle size allowing quicker cooking).  Oats are one of the most common cereal grains used for breakfast cereals, muesli, granola, and porridge and can also be found in breads, biscuits, muesli bars, baked slices, baby foods, yoghurts and non-dairy milks. Other products manufactured from oats can include oat meal and oat bran as a fibre source. 

https://www.glnc.org.au/grains-2/types-of-grains/oats/

 

Ancient Grains and Pseudocereal –

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Starches

Starches are complex carbohydrates that exist in our everyday diet. Complex carbohydrates are essentially long chains of sugar molecules. Once digested, starch is broken down by enzymes in the body into the simplest form of sugar glucose, to be used as a source of energy for the body to utilise.

Starches are extracted from many sources (including cereal grains, vegetables, beans and legumes) to be used as ingredients in processed foods. Each starch type has unique properties and there uses vary accordingly. Common forms of starch used as an ingredient include cornflour or corn starch, tapioca starch, rice starch, wheat starch, and potato starch. Be aware that “corn starch” sold in Australia may actually be wheat starch so check the label.

Processed food and beverage products are usually put through processing steps that require either high shear, extremes in pH, and changes in temperature (e.g. heating, cooling and freezing).  Starches are chosen for their unique qualities, price point and their ability to withstand the process they are to go through. As a food ingredient they are added to thicken (e.g. instant soup or custard), stabilise (refrigerated soups), to bind water for increased yield (used in processed meats), stabilise emulsions and to be used as fillers (such as maltodextrin in spray or drum dried products).

Starches can either be Native starches or Modified starches. Native starches are extracted from the source using a physical method. These are considered to be clean label and don’t require an additive or e number in the ingredient listing. Modified starches have been chemically, physically or enzymatically modified to enhance their abilities and tolerance to allow them to withstand the harsh conditions of processing better than their native counterparts. These starches require an E-Number to help identify them and are not considered natural. Chemical processes to modify starch are done by either cross-linking, esterification or hydrolysis. More information on how these processes are achieved are below in the Starch Facts section.

As a result of consumer demand starch producers are investing a lot of money into research and development to find new ways to produce new clean label starches for use in processed food products.

 

Function of Starch in Food

Starches can be used as an ingredient in a food or can be the base material to manufacture foods. A range of Asian food ingredients are produced from starch. These include a wide range of noodles and vermicelli products produced using mung bean, rice, pea and sweet potato starches.  

Starches perform a range of functions in foods including stabilising, emulsifying thickening. Starches are commonly used in bakery fillings, custards, soups, sauces and salad dressing for this purpose, providing body and mouthfeel to a product. When starches are added to liquid and heated you will see thickening occur. This is due to the starch granules going through a process called gelatinization, where they begin to swell, absorbing as much moisture as they can. As the temperature rises they will lose some of their opacity but will continue swelling until all the free moisture has been absorbed by the granules. Once cooled and depending on the starch used, fillings such as bakery fillings or custards containing starch will remain set and stable throughout chilling, freezing, thawing and reheating. 

It’s really important to ensure that when using starches for thickening that they’re fully cooked and hydrated before the cooking process is complete. If they are overcooked the starch cells will become damaged and release the moisture they have absorbed. This causes syeresis or free water in the product. If they are undercooked they won’t provide the best water holding capacity possible.

Pre-gelatinised starches are also available for instant meals, fillings, instant soups and sauce products where hot water is added and they are stirred before consuming. These starches have been fully cooked or gelatinised, then dried. They are more expensive than others due to the additional processing steps but provide immediate thickening, body and mouthfeel to instant products. 

 

Sugars from Starch

Just like in our bodies, manufactures can use enzymes or acids to separate the starch molecules made up of many sugar molecules, into simpler molecules. The resulting products are called Dextrin’s. These “Starch Sugars” are found in a few different forms. They are still sugars so be aware when you are looking on your food labels.

  • Maltodextrin – Used in processed food products as a filler, thickener and is a common base used to Spray Dry other ingredients onto, such as Flavours, Fruit and Vegetables Powders, Oils etc.
  • Glucose Syrup or Corn Syrup. This is commonly used commonly in confectionary, beverages and bakery items.
  • Dextrose Syrup or Powder – The commercial form of glucose
  • High Fructose Corn Syrup. This is not commonly used in Australia but is commonly found in imported products.
  • Sugar Alcohols. These ingredients also fall into this list as they are produced from Starch as a raw material.

For more information please see the following pages –  

http://www.livestrong.com/article/483010-what-is-the-function-of-starch/

http://pubs.acs.org/doi/abs/10.1021/jf60172a030

https://en.wikipedia.org/wiki/Modified_starch

 
 

Copyright 2017 Food Facts for Healthy Eating

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