Food Biochemistry and Food Processing (2 edition)

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BLBS102-c42 BLBS102-Simpson March 21, 2012 14:27 Trim: 276mm X 219mm Printer Name: Yet to Come


808 Part 8: Food Safety and Food Allegens

of antigen in the food consumed. The proteins responsible for
this type of allergy can be the albumins, globulin, gliadins or
glutenins and will vary depending on the individual and the spe-
cific allergenic food. Offending foods include buckwheat, rice,
corn, millet, wheat, oats, rye and barley (Cantani 2008). Buck-
wheat and rice allergies are more frequently observed in Asia
than in Europe or North America (Taylor and Hefle 2001, Ku-
mar et al. 2007). The pathway for sensitisation and cereal allergy
elicitation is by ingestion (mouth) and/or inhalation (nose) (e.g.
baker’s asthma). Wheat allergy is responsible for up to 30% of
occupational asthma in the bakery industry.
Another type of cereal allergy is exercise-induced cereal al-
lergy. Symptoms in this case appear only after food allergen
consumption is followed by exercise. Wheat, as well as shellfish
and nuts, is mostly associated with this type of allergy (Romano
et al. 2001, Beaudouin et al. 2006, Porcel et al. 2006).

Foods to Avoid for Gluten-Sensitive
Enteropathy Patients and IgE-Mediated
Cereal-Allergic Patients

As with the other allergens, there are presently no cures for
CD. Major foods to avoid include barley, wheat, durum, farina,
kamut, rye, semolina, spelt and triticale. Oats was previously
included in the list of gluten-containing foods; however, sev-
eral recent studies suggest that quantities of oats of up to 50
g/day are harmless to the majority of gluten-sensitive individu-
als (Janatuinen et al. 1995, 2000, 2002, Lundin et al. 2003). A
major challenge for the industry is that commercial oats is very
frequently contaminated with high amounts of wheat, barley or
rye (Thompson 2004, 2005) as these crops are often grown in
the same regions and in close proximity. Furthermore, a small
percentage of CD patients may react to oat proteins. The mech-
anisms at play in this instance and the specific proteins in oats
to which these patients react still remain to be clarified. As
gluten-containing cereals are often used as ingredients in food
formulation, other foods to avoid include hydrolyzed vegetable
protein, flavouring, malt, maltodextrin, malted barley, malt vine-
gar and starch from gluten sources, especially if these contain
residual amounts of gluten proteins.
Many countries have adopted the gluten-free Codex Alimen-
tarius Standards (Joint FAO/WHO Food Standards Programme
and Codex Alimentarius Commission 2008), which sets a max-
imum limit of 20 ppm for gluten-free foods that are naturally
free from gluten and 100 ppm for gluten-free foods that have
been rendered gluten-free through processing.
For IgE-mediated cereal allergy, foods to avoid will depend
on the particular allergy. Major challenges for cereal-allergic in-
dividuals are cross-reactivity and cross-contamination of foods.
Food ingredients that are particularly problematic if not prop-
erly labelled are starches, spices, seasonings, sauces, flavourings,
colourings, some vinegars, hydrolysed plant protein, syrups (e.g.
brown rice syrup), beverages (e.g. beer, ale, etc.). Other poten-
tial hidden sources of cereals or cereal ingredients are cosmetics,
pillows, toy stuffings and certain medications when products de-
rived from these are used as ingredients.

SESAME AND MUSTARD ALLERGENS


Sesame Allergy

Sesame (Sesamum indicum) is a herbaceous plant of thePe d -
aliaceaefamily originating from India, which is now grown in
many countries. It is also known as Benne, Gingelly, Til or Teel,
Simsim and Ajonjoli and is now a common ingredient used ex-
tensively in everyday foods because of its high nutritional value
(Perkins 2000). Sesame proteins are rich in methionine (Dalal
et al. 2002, Wolff et al. 2003). Common sesame products in-
clude biscuits, crackers, breadsticks, rice cakes, etc., as well as
prepacked delicatessen and processed foods such as noodles,
dips, soups, sausages, samosas, processed meats, vegeburgers,
chutneys, etc., (Perkins 2000, Allergyexpert 2010).
Sesame seeds, which may be used whole or crushed, are ex-
tremely potent allergens, causing severe allergic reactions in
susceptible individuals. The first case of sesame allergy was
reported in 1950 (Gangur et al. 2005). More recently, a study
of Australian children showed that allergic reactions to sesame
ranked fourth behind reactions to egg, milk, and peanuts, and
sesame was also found to be the third most common allergy-
inducing food in Israeli children (Gangur et al. 2005). Another
recent study showed that sesame allergy in Israeli children was
more common than peanut allergy (More 2009). Sesame allergy
seems to affect people of all ages, which imply that this food
allergy is not commonly outgrown. The symptoms of sesame
allergy can include urticaria, angioedema, asthma, atopic der-
matitis, oral allergy syndrome, allergic rhinitis and anaphylaxis.
One of the major sesame seed allergens is the 9 kDa, 2S albu-
min (Pastorello et al. 2001). Beyer et al. (2002) also identified
10 IgE-binding proteins in sesame, four of which had MWs of
7, 34, 45 and 78 kDa. Wolff et al. (2003) have also reported a
14 kDa sesame allergenic protein belonging to the 2S albumin
family.
Sesame products are used in a wide variety of food products
and may represent hidden allergens in foods. Fatal anaphylactic
reactions have occurred as a result of consuming sesame (Gangur
et al. 2005). Unrefined sesame oil may be used in food products,
which may trigger allergic reactions in susceptible individuals.
The oil resists rancidity and is popular with Oriental chefs. In
the bakery industry, workers have reported allergic reactions,
which include asthma, to sesame products. In addition to its use
in the food industry, sesame and sesame products are used in
the pharmaceutical and cosmetic industries. Sesame products
used in cosmetics and ointments may cause allergic dermatitis,
an inflammatory condition of the skin, in sensitised individuals.
Contact dermatitis as a result of direct exposure to cosmetics or
pharmaceutical products containing sesame allergens has been
reported. Specific instances of sesame allergy resulting in skin
rashes and inflammation after baking with sesame seeds and
skin rashes from cosmetics that contain sesame oil have also
been reported (Stoppler and Marks 2005).
As sesame allergens are similar in biochemical structure to
peanut allergens, people with sesame allergy may be at risk of
having allergic reactions as a result of eating peanuts and vice-
versa (Gangur et al. 2005). Cross-reactivity may also exist with
rye, kiwi, poppy seed and various tree nuts (such as hazelnut,
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