. Allergopedia

Dictionary of Allergies .. a-amylase

A-amylase is a starch-cleaving enzyme which is used as a flour additive in the baking industry. It is product of Aspergillus oryzae. Flour for bread making must also contain an optimum level of a-amylases. a-amylases are enzymes responsible for the conversion of starch to maltose which is further broken down to form glucose - the sugar required for effective fermentaion of the yeast. If the concentration of a-amylases is too low, too little maltose will be formed and the bread will not rise sufficiently. Too much a-amylase and bread can end up as ‘sticky’ as a result of substances called dextrins forming [1].

Inhalation of dust from different enzymes can be the cause of occupational asthma in exposed workers. Enzymes from different sources are being increasingly used in food. Few cases of food allergy to alpha-amylase induced by eating bread have been reported. Those cases were reported in bakery-related patients and in a pharmaceutical-industry worker [2].

Several studies have shown that 20-32% of bakers suffering from workplace-related rhinitis and/or asthma are sensitised to fungal a-amylase in baking products can cause allergic reactions in consumers Porcine pancreatic extracts (PPE) are composed of alpha-amylase and lipase, which are common components of digestive enzymes. They have been known to cause occupational asthma in exposed workers in pharmaceutical and baking industries, as well as in a laboratory technician [3]. These findings suggest that inhalation of PPE powder can induce IgE-mediated bronchoconstriction in exposed nurses.


1. Baur X, Sander I, Jansen A, Czuppon AB. Are amylases in bakery products and flour potential food allergens? Schweiz Med Wochenschr. 1994 May 21;124(20):846-51

2. Moreno-Ancillo A, Domínguez-Noche C, Gil-Adrados AC, Cosmes PM. Bread eating induced oral angioedema due to alpha-amylase allergy. J Investig Allergol Clin Immunol. 2004;14(4):346-7.

3. Park HS, Kim HY, Suh YJ, Lee SJ, Lee SK, Kim SS, Nahm DH. Alpha amylase is a major allergenic component in occupational asthma patients caused by porcine pancreatic extract. J Asthma. 2002 Sep;39(6):511-6.

Γκέλης Ν.Δ. - Λεξικό Αλλεργίας - Εκδόσεις ΒΕΛΛΕΡOΦΟΝΤΗΣ - Κόρινθος 2013

Gelis Ν.D. - Dictionary of Allergies - VELLEROFONTIS Publications - Corinth 2013