Stored product mites (Acari: Astigmata) infesting food in various types of packaging
From 2008 to 2014, stored product mites have been reported from prepackaged dried food on the market in the Czech Republic. The infestation was by Carpoglyphus lactis (L.) in dried fruits and Tyrophagus putrescentiae (Schrank) in dog feed. The infestation is presumably caused by poor protection of the packages. We compared various packaging methods for their resistance to mites using dried apricots and dog feed in laboratory experiments. The trial packages included nine different plastic films, monofilm, duplex and triplex, and one type of plastic cup (ten replicates per packaging type). All packaging materials are available on the Czech market for dried food products. The samples of dried food were professionally packed in a factory and packaged dried apricots were exposed to C. lactis and dog food to T. putrescentiae. After 3 months of exposure, the infestation and mite density of the prepackaged food was assessed. Mites were found to infest six types of packages. Of the packaging types with mites, 1–5 samples were infested and the maximum abundance was 1,900 mites g−1 of dried food. Mites entered the prepackaged food by faulty sealing. Inadequate sealing is suggested to be the major cause of the emerged infestation of dried food.
[Storage mites as the source of household allergens].
Storage mites of the families Acaridae and Glycyphagidae attracted attention as the source of household allergens. Storage mites occurring in house dust were studied. The fauna of storage mites in house dust was represented by two families. The dominating species, both in the relative amount and occurrence, were Tyrophagus putrescentiae and Chortoglyphus arcuatus. In addition, Caloglyphus rodionovi and Carpoglyphus lactis occur regularly. The specific activity of allergenic extracts obtained from storage mites was studied in ELISA. They were shown to have sensitizing and immunogenic properties. The study revealed that storage mites possessed specific determinants and those common with pyroglyphid, not linked with allergens of groups 1 and 2.
Evaluation of antioxidants by a rapid polarographic method
A simple, rapid, precise, and reproducible method and an adaptable apparatus for polarographic measurement of lipid peroxidation and antioxidant activity is described. This method measures antioxidant activity within a few min time as compared to the hours or days needed for several widely used methods. Peroxidation rates were measured for different lipids as a function of amount of lipid, and amount of biocatalyst. The method is applicable to the detection and measurement of the antioxidant effects exhibited by weak antioxidants and has been satisfactorily used for the measurement of the antioxidant activity of different concentrations of powerful antioxidants.