Contaminants and microorganisms in Dutch organic food products: a comparison with conventional products.

Organic products were analysed for the presence of contaminants, microorganisms and antibiotic resistance and compared with those from conventional products. No differences were observed in the Fusarium toxins deoxynivalenol and zearalenone in organic and conventional wheat, during both a dry period and a very wet period which promoted the production of these toxins. Nitrate levels in head lettuce produced organically in the open field were much lower than those in conventional products.

Detection, growth, and amine-producing capacity of lactobacilli in cheese.

A differential plating medium was developed to detect decarboxylating lactobacilli in cheese. With this medium, 15 cheeses made from raw milk were investigated for the presence of these bacteria. Five histidine-decarboxylating strains and one tyrosine-decarboxylating strain were isolated.

Prevention of Mold Growth and Toxin Production through Control of Environmental Conditions.

Environmental conditions influence mold growth and mycotoxin production. Such things as water activity (a), temperature, pH and atmosphere can strongly affect and profoundly alter patterns of growth and mycotoxin production. Generally, maintenance of low temperatures will prevent aflatoxin production in stored products, whereas other toxins such as penicillic acid, patulin, zearolenone and T-2 toxin may be produced at low temperatures.

The Salt Crystal Liquefaction Test - A Simple Method for Testing the Water Activity of Foods.

A simple method for testing the water activity (a) of foods has been developed. The test can be used to check the a of products which must comply with required a standards. The test is based on the property of salt crystals to attract water vapor and to liquefy when they are placed in a jar containing a product with an a above the specific a of the salt.

Fungal growth and the presence of sterigmatocystin in hard cheese.

Molds isolated from visibly molded cheeses in shops, households, and warehouses have been identified. Mold flora of cheeses in shops and households consisted mainly of Penicillium verrucosum var. cyclopium.

Penicillic Acid Production by Some Fungal Species in Relation to Water Activity and Temperature.

The combined effects of water activity (a) and temperature on growth of and penicillic acid (PA) production by strains of Penicillium cyclopium , Penicillium martensii , and Aspergillus ochraceus were determined. On malt agar media in which the a had been adjusted by addition of sucrose or glycerol, the minimum a for PA production by P. cyclopium and A.

Ochratoxin A Production by Some Fungal Species in Relation to Water Activity and Temperature.

The effects of water activity (a) and temperature on growth of and ochratoxin A (OA) production by strains of Aspergillus ochraceus , Penicillium cyclopium , and Penicillium viridicatum were investigated. On agar media in which the a had been adjusted by addition of sucrose or glycerol, the minimum a values for OA production by A. ochraceus , P.

Patulin Production by Some Fungal Species in Relation to Water Activity and Temperature.

The combined effects of water activity (a) and temperature on growth and patulin production by strains of Penicillium expansum , Penicillium patulum , and Aspergillus clavatus were determined. Malt agar media were used, in which the a was adjusted by addition of sucrose or glycerine. The minimum a values for patulin production by P.

Differences Between Aspergillus flavus Strains in Growth and Aflatoxin B Production in Relation to Water Activity and Temperature.

The optimum and limiting conditions of water activity (a) and temperature for growth of and aflatoxin B production by various Aspergillus flavus strains were determined. Agar media were used in which the a was adjusted by addition of sucrose or glycerine. Optimum temperatures for aflatoxin B production at high a varied with the strain tested being 13-16, 16-24, or 31 C.

Studies on the estimation of the hygienic condition of frozen broiler chickens.

Various sampling techniques to determine the aerobic, E. coli and Enterobacteriaceae counts and to detect the presence of salmonellas were compared. As a simple method for the detection of salmonellas a modified Surkeiwicz procedure using both drip and rinse water is advocated.