Bakers Journal

Features Technical
Flax in Focus


November 14, 2007
By Kelley C. Fitzpatrick M.Sc.

Topics


Flax
has been valued for decades by the bakery sector for its appearance and
versatility and the nutty flavour it imparts to food products. More
recently, the numerous health benefits being attributed to flax have
increased its popularity.

An in-depth look at flax and why it's so good for you.

Flax
has been valued for decades by the bakery sector for its appearance and
versatility and the nutty flavour it imparts to food products. More
recently, the numerous health benefits being attributed to flax have
increased its popularity. Flax contains approximately 40 per cent fat,
28 per cent dietary fibre, 21 per cent protein, four per cent ash, and
six per cent carbohydrates such as sugars, phenolic acids, lignans, and
hemicellulose. Flax possesses a unique nutritional composition of
omega-3 fatty acid, phytoestrogens, antioxidants and fibre, and is a
nutritious plant protein, with an amino acid composition similar to
that of soybean protein.

FULL OF HEALTHFUL FATS

Flax
has a unique and healthy fatty acid profile with very low saturated fat
(approximately nine per cent) and moderate amounts of monounsaturated
fat (approximately 18 per cent). Of the nutritionally beneficial
polyunsaturated fats, about 16 per cent belong to the omega-6 family as
linoleic acid (LA) and 57 per cent is the omega-3 fatty acid,
alpha-linoleic acid (ALA).

Both LA and ALA are essential fatty
acids, considered "essential to life" as they cannot be produced by the
body and therefore must be obtained from the diet. The omega-6 and the
omega-3 fatty acid families are precursors for different series of
hormone-like substances known as eicosanoids. Omega-6 derived
eicosanoids stimulate pro-inflammatory, pro-thrombotic and hypertensive
events. Eicsoanoids synthesized from omega-3 fatty acids have opposite
effects. For optimal health, Health Canada, for example, recommends an
omega-6:omega-3 fatty acid dietary ratio of 4:1 to 10:1.

It is
speculated that Western diets may have ratios of omega-6:omega-3 fatty
acids as high as 20-30:1. Flaxseed contains an omega-6 to omega-3 ratio
of 0.3:1.

Health Canada has established a Recommended Nutrient
Intake for ALA, specifying the minimum daily intake should be 0.5 per
cent of total energy. In the U.S., the National Academy of Sciences'
Institute of Medicine (IOM) recommends 1.6 g/day of ALA for men and 1.1
g/day for women.

DIETARY FIBRE

Total
fibre accounts for about 28 per cent of the weight of full-fat flax
seeds and is found in both soluble and insoluble forms. Water-soluble
fibres, such as mucilage, which is found in flax, will delay transit
through the stomach and small intestine. Because of their hydration
characteristics, mucilage gums "trap" lipids and aid in excretion, thus
helping to lower serum cholesterol level, an effect that ultimately
benefits cardiovascular health.

Fibres that are predominantly
water insoluble promote laxation and are either slowly or not
fermented. Diets high in insoluble fibre result in good colon health,
which may have protective effects against colon cancer.

Daily
recommended intakes target amounts of 25 g for women and 38 g for men.
However, in the North American population, usual intakes average only
14 to 15 g/day. One tablespoon of whole flax or milled flax contains
600 mg to 1.2 g and 440 mg to 880 mg of insoluble fibre, and 1.8 to 2.4
g and 1.3 to 1.8 g of soluble fibre, respectively.

FLAX LIGNANS

Lignans
are phytoestrogens: estrogen-like compounds found in plants (hence,
"phyto"). Flax produces 75 to 800 times higher levels of active lignans
than other vegetables, fruit, legumes, cereals, or seeds. Lignans have
shown promise in reducing growth of cancerous tumours, especially
hormone-sensitive ones such as those of the breast, endometrium and
prostate.

Flax lignans play a very important role in reducing
the risk of diabetes. In a study of volunteers who consumed 50 g of
carbohydrates from bread containing flaxseed, significant improvements
in glucose absorption were observed. The consumption of 40 g of ground
flaxseed for a two-month period also reduced postprandial blood
glucose, insulin, and serum lipid levels.

The powerful
antioxidant properties of lignans as well as the phenolic acids and
flavanoids found in flax can reduce the activity of cell-damaging free
radicals that are generated through oxidation in the body and are
strongly associated with aging.

FLAX NUTRIENTS AND CARDIOVASCULAR DISEASE

Intervention
studies have shown beneficial effects of ALA on cardiac health. In the
Health Professionals Follow-up Study, a one per cent increase in ALA
intake (as per cent of energy) has been associated with a 40 per cent
reduction in the risk of non-fatal coronary heart disease. Another
major study, the Lyon Diet Heart Study, included participants who had
previously survived a myocardial infarction. The experimental group who
consumed a typical Mediterranean-style diet rich in ALA had a 75 per
cent reduction in non-fatal myocardial infarctions, and a 70 per cent
reduction in total death compared to the control group.

Recent
research is focusing upon the role that ALA can play in lowering
inflammatory biomarkers. A diet high in ALA dramatically decreased C
reactive protein in men and women with high cholesterol levels.

Flax
nutrients such as fibre, lignans and other antioxidants also offer
protection against cardiovascular disease. Milled flax levels of three
to six tablespoons (30-50 g) for as little as four weeks reduced blood
total and LDL-cholesterol significantly in clinical trials. Blood total
cholesterol decreased six to 13 per cent and LDL-cholesterol decreased
nine to 18 per cent in studies of healthy young adults, men and women
with moderately high levels of blood cholesterol, postmenopausal women
and men with prostate cancer.

REGULATORY STATUS

In
Canada, food manufacturers may declare the omega-3 fatty acid content
of their food products. For example, the label of a food containing
flax can state the amount of ALA (e.g., 0.5 g of ALA) per serving.
Flax-based products containing at least 300 mg of ALA per serving can
also use nutrient content claims, which allow "Source of Omega-3 fatty
acids" to appear on the label.

In the U.S., the Food and Drug
Administration (FDA) and the Institute of Medicine (IOM) define food or
supplement products as "high in" omega-3 when they contain at least 130
mg per serving of EPA/DHA or 260 g or more of ALA. Additional
guidelines are in place for products labelled a "good source" and
"more." Additionally, products containing flax qualify for
Structure/Function Claims that describe the effect that a food product
has on the normal structure or function of the body. These need not be
pre-approved by the FDA, but they must be true and not misleading to
the consumer. An increasing number of food products are using packaging
claims such as "Now with Omega-3 ALA To Help Support A Healthy Heart!"

Blending Fish Oil and Flax

A closer look at a new, omega-3-filled flaxseed ingredient.

MeadowPure Omega 3 Ultra
is a milled flaxseed and fish oil ingredient for use in bakery and
cereal applications, available from Manitoba-based Pizzey's Milling.
The fish oil is naturally encapsulated in the milled flaxseed, is shelf
stable, has no taste or smell, and is easily incorporated into dry
formulations. This product offers both the evidence-based health and
nutrition attributes of flaxseed and fish oil while taking advantage of
the natural antioxidant components present in flaxseed.

MeadowPure
is a granulated, free-flowing powder of milled flax in combination with
either 2.2 per cent or 8 per cent fish oil intended for use in bakery
and cereal applications. This unusual ingredient supplies the
beneficial nutrients found in flaxseed as well as the long chain
omega-3 polyunsaturated fatty acids (PUFAs) from fish oil, in
particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

THE SCIENCE

It
is well accepted that while foods prepared with long chain PUFAs are
healthier, they also have an increased vulnerability to rancidity,
which is caused by oxidation, the chemical reaction of lipids with
oxygen. Long chain PUFAs such as EPA and DHA are particularly
vulnerable to oxidative breakdown, leading to the development of food
deterioration that affects flavour, aroma, colour, texture, and
nutritional value.

In a previous patent, Pizzey's Milling
demonstrated that the lipid in full fat milled flaxseed is very stable
when the seed has been carefully selected to remove discoloured and
immature parts. This is due to a very active antioxidant system present
in flaxseed, which includes lignans, phenolic acids, anthocyanin
pigments, several flavonols and flavones, and phytic acid.

Pizzey's
has shown that milled flaxseed provides excellent oxidative protection
to a fish oil containing 18 per cent EPA and 12 per cent DHA in a
flax/fish oil blend. In a number of experiments, under accelerated and
real time conditions, the antioxidant system in the flaxseed provided a
highly protective environment to both the fish oil and the indigenous
flax oil. This protective environment was effective in maintaining
lipid stability of the blend for at least one year under ambient
storage conditions in standard polylined paper packaging. The result of
these experiments led to the development of MeadowPure.

This
ingredient has the added advantage of significantly improved stability
with no detectable "fishy" tastes or odours. When used at various
levels, desirable omega-3 label claims can be used on food packaging
including "Qualified Heart Health" for EPA and DHA, "Excellent Source"
for all omega-3s and a "Structure/Function" claim for ALA.

Because
it's flaxseed based, MeadowPure provides food manufacturers with an
ingredient that is tasty, easy to use and rich in dietary fibre,
lignans, antioxidants and the essential fatty acid, ALA. The addition
of 2.2 per cent or 8 per cent fish oil provides EPA and DHA in a highly
stable, convenient to use application.

Kelley C.
Fitzpatrick, M.Sc., is director of health and nutrition for Flax Canada
2015 in Winnipeg, Man. She can be reached at kelleyf@shaw.ca.


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