Available dietary carbohydrates

Friday 2 June, 2017

Much of AEGIC’s work is focused on increasing value for Australian grains in overseas markets, however AEGIC also conducts research for the benefit of the domestic industry. The following is a short summary of a project on dietary carbohydrates conducted by AEGIC in conjunction with the Grains & Legumes Nutrition Council (of which AEGIC is a foundation contributor) and Curtin University.

Hayfa Salman (AEGIC), Peter Kolodziej (AEGIC), Michelle Broom (GLNC) and Vicky Solah (Curtin University)

Many of us have a keen interest in reducing the amount of carbohydrates we eat, but it is important to remember the benefits. A recent shift has shown a greater understanding of the nutritional value of carbohydrates and their role in the prevention and management of diet-related disease.

It is important for the Australian food industry to respond to consumer interest in different forms of carbohydrates by providing consistent, accurate information on packaging, particularly for “available carbohydrate” content.

New research from AEGIC, in conjunction with the Grains & Legumes Nutrition Council and Curtin University, could help the Australian food industry provide more accurate and consistent information to consumers on the amount of available carbohydrates in some common foods, including rice, pasta, noodles, quinoa and potatoes.

The importance of carbohydrates

The health impact of eating carbohydrates is a common  source of debate in discussions regarding nutrition and health. A common theme is to reduce serving size, calories and “available carbohydrates”, and increase fibre, demonstrating a more complex message that some carbs are good (fibre, resistant starch), while others are to be limited (available carbohydrates).

While consumer media may be warning to limit available carbohydrates, it is important to remember the benefits. Humans require a reliable source of available carbohydrates to support normal brain, kidney, red blood cell and reproductive function.

What are “available carbohydrates”?

“Available carbohydrates” include starch and sugars which are absorbed in the small intestine to provide energy. Slowly-digested starch is reported to be linked to health benefits.

“Resistant carbohydrates” are non-starch based, and include whole or pieces of plant material such as fruit, vegetables and cereal.

Non-starch polysaccharides are resistant to digestion and can be assigned the label “fibre”.

Measuring carbohydrate content

There is a need for a consistent approach to the measurement of carbohydrate content so that it reflects the health effect of the food “as eaten” (i.e. when cooked). In particular, available carbohydrates are significantly affected by the total water content of the food.

AEGIC undertook an analysis of pasta, rice, noodles, quinoa and potato samples, cooked and uncooked, to demonstrate the change in the available carbohydrate content per 100g of food.

The following table demonstrates the results compared with previously published data. Correct analysis and reporting of available carbohydrates will help the food industry provide consumers with consistent information so they can make more informed dietary choices. The industry should test their products and be careful not to rely on published data to ensure an accurate measure of available carbohydrates.

 

Table:  Available carbohydrate g per 100g of cooked product

Low GI White Rice
(SunRice Doongara)
Medium Grain Rice
(Aust Calrose)
White Quinoa
Lotus Royal
White Quinoa
Sandhurst
Spaghetti
(San Remo)
Ramen Noodles
(Hakubaku Organic)
Udon Noodles
(Hakubaku Organic)
Carisma potato Nadine Potato
Available Carb (from cooked) g/100g  from AEGIC analysis 20.4 24.4 24.4 19.2 29.9 24.3 24.8 9.4 11.1
Available carb (from uncooked) g/100g from AEGIC analysis 16.0 24.8 23.9 19.8 30.5 25.2 25.0 12.0 12.0
Low GI White Rice Medium Grain Rice White Quinoa Spaghetti Ramen Noodles Udon noodles Carisma potato Nadine Potato
Available carb from published articles g/100g* 26-28.6 28.7 17.3 24.4-28.6 25.2 19.5-26.7 10.5 14.4-17.3

*From papers by Atkinson et al 2008, Ek et al 2012 and Yasui 2015