No

Meat Preserving And Curing Guide

A Cured Meat Guide for Everyone

Get Instant Access

N-Nitroso-3-nitromethylindole

Unidentified products

Figure 5. Nitrosation products of the alkaloid gramine.

tation by microorganisms (and surface bacteria) with nitrate-reductase activity can result in a large increase in nitrite content. On prolonged storage, nitrosamine formation may occur.

Fungal Contamination of Foods

The catalysis of nitrosamine synthesis from secondary amines and nitrate by several microorganisms and fungal biosynthesis of nitrosamines from primary amines and nitrite occurs under certain conditions in a limited range of foods. In certain areas in China where widespread contamination of foods by Fusaria occurs, low concentrations (<2 //g/kg) of Af-nitroso-Af-methylacetonyl-A?-2-methylpropyl-amine (NMAMPA) and Ar-nitroso-AT-methylacetonyl-iV-3-methylbutylamine (NMAMBA) have been identified in moldy millet and wheat flour contaminated by Fusaria (13). A nonenzymic reductive condensation of isoamylam-

ine, a decarboxylation product of leucine, and 3-hydroxy-2-butanone (acetoin) preset in cereal grains have been suggested as a possible route to the formation of the amine precursor to NMAMBA. The structures of NMAMBA and NMAMPA are shown in Figure 6.

Contact Materials

The contamination of amines by their corresponding N-nitroso analogues and the use of dialkylamine-derived accelerators and stabilizers in the production of rubber results in inadvertant Af-nitrosamine contamination of rubber products. As a result, direct contact of foodstuffs with nitrosamine-contaminated food-packaging materials, in particular rubber, can result in nitrosamine contamination. Rubber nettings for the packaging of cured meats results in contamination of meat products with NDEA, N-nitrosodibutylamine (NDBA), and 7V-nitrosodibenzylam-ine (NDBzA), three TV-nitroso compounds not generally encountered in foods (14), due to both active migration of the preformed nitrosamine into the food matrix and the interaction of nitrite in cured meats with amine additives (eg, zinc dialkyl or diaryldithiocarbamates) used as accelerators during rubber vulcanization. The use of rubber baby bottle nipples and pacifiers presents a more serious problem in which both nitrosatable amines and nitrosamines migrate from the rubber matrix into baby formulations. Government regulations in most countries have limited the permissible levels of VNA to 10 ¬°ug/kg and nitrosatable amines following extraction to 200 ng/kg (expressed in terms of nipple weight). Monitoring programs in most countries currently show negligible nitrosamine concentrations in rubber nipples and pacifiers produced after 1984. In most cases, nitrosamine free products are available.

Commercial wax preparations used for coating food-packaging materials, and liquid waxes used for coating apples and citrus fruit present a potential source of N-nitrosomorpholine (NMOR) contamination (15). Morpholine (which normally contains NMOR as an impurity) is used as a boiler additive for steam used in the manufacture of paper. Both morpholine and morpholineoleate are used as solvents for waxes used to treat paper for water resistance and to coat fresh fruits. NMOR contamination of milk packed in waxed cartons and dairy products in waxed paper wrappers was reported in several countries about a decade ago. However, this is not a current problem because

Figure 6. Nitrosamines produced from fungal metabolites in Fusariiim-contaminated foods. Nonvolatile nitrosamines abbreviated as NMAMPA, iV-nitroso-iV-methylacetonyl-Ar-2-methylpro-pylamine, and NMAMBA, AT-nitroso-Af-methylacetonyl-iV-3-meth-ylbutylamine.

NMAMPA NMAMBA

Figure 6. Nitrosamines produced from fungal metabolites in Fusariiim-contaminated foods. Nonvolatile nitrosamines abbreviated as NMAMPA, iV-nitroso-iV-methylacetonyl-Ar-2-methylpro-pylamine, and NMAMBA, AT-nitroso-Af-methylacetonyl-iV-3-meth-ylbutylamine.

waxed packaging has been replaced with plastic-coated surfaces.

Was this article helpful?

0 0
The Mediterranean Diet Meltdown

The Mediterranean Diet Meltdown

Looking To Lose Weight But Not Starve Yourself? Revealed! The Secret To Long Life And Good Health Is In The Foods We Eat. Download today To Discover The Reason Why The Mediterranean Diet Will Help You Have Great Health, Enjoy Life And Live Longer.

Get My Free Ebook


Post a comment