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Developing food-grade coatings for dry-cured hams to protect against ham mite infestation.

Dry-cured hams may become infested with ham mites, Tyrophagus putrescentiae, during the aging process. Methyl bromide is the only known available fumigant pesticide that is effective at controlling ham mite infestations in dry cured ham plants. However, methyl bromide will be phased out of all industries as early as 2015 due to its status as an ozone-depleting substance. Research was conducted to develop and evaluate the potential of using food-grade film coatings to control mite infestations, without affecting the aging process and sensory properties of the dry-cured hams. Cubes coated with xanthan gum+20% propylene glycol and carrageenan/propylene glycol alginate+10% propylene glycol were effective at controlling mite infestations under laboratory conditions. Water vapor permeability was measured to estimate the impact of coatings during the aging process. It was evident that carrageenan/propylene glycol alginate coatings were permeable to moisture, which potentially makes them usable during aging.

Efficacy of selected food-safe compounds to prevent infestation of the ham mite, Tyrophagus putrescentiae (Schrank) (Acarina: Acaridae), on southern dry-cured hams.

BACKGROUND Tyrophagus putrescentiae (Schrank) is a serious mite pest of dried meats and cheeses. Infestations of T. putrescentiae are controlled with the fumigant methyl bromide, which is an ozone-depleting substance and is currently being banned in most countries. Effective alternatives to methyl bromide are needed. The objective of this research was to use laboratory assays to investigate the effectiveness of food-safe compounds for preventing infestation of T. putrescentiae on dry-cured hams. RESULTS Ham pieces dipped in solutions of either propylene glycol (1,2-propanediol), lard, ethoxyquin or butylated hydroxytoluene prevented or significantly reduced mite population growth. Behavioral assays revealed that more mites oriented to the untreated control ham cubes, and more eggs were laid on these untreated ham cubes, compared with cubes treated with various dips. Our results also indicated that a combination of carrageenan + propylene glycol alginate + 40% propylene glycol was effective in reducing mite numbers on whole aging hams compared with untreated whole hams. CONCLUSIONS Several food-safe compounds can prevent infestation of T. putrescentiae on dry-cured hams and may represent alternatives for managing this pest.

Controlling pests in dry-cured ham: A review.

Dry-cured hams can become infested with ham mites, red-legged beetles, cheese skippers, and larder beetles during the aging process. Though other methods may be used for beetles and cheese skippers, methyl bromide is the only available fumigant that is effective at controlling ham mites in dry-cured ham plants in the United States. However, methyl bromide will be phased out of all industries by approximately 2015. This paper will review and explore potential alternatives that have been investigated to determine their feasibility for replacing methyl bromide to control pest infestations in dry-cured ham plants in the United States. Potential alternatives include: 1) fumigants such as phosphine and sulfuryl fluoride; 2) physical control approaches through cold treatment, modified atmosphere, inert dusts, etc.; 3) pesticides and bioactive compounds; 4) food-grade processing aids. The most promising potential alternatives to date include the use of propylene glycol on the ham surface, the exploration of alternative fumigants, and implementation of an integrated pest management plan.

Phosphine fumigation and residues in dry-cured ham in commercial applications

Dry-cured hams often become infested with ham mites (Tyrophagus putrescentiae) during the aging process. Methyl bromide has been used to fumigate dry cured ham plants and is the only available fumigant that is effective at controlling ham mite infestations. However, methyl bromide will eventually be phased out of all industries. This research was designed to determine the efficacy of phosphine fumigation at controlling ham mites and red-legged beetles and any impact of phosphine fumigation on the sensory quality and safety of dry cured hams. Fumigation trials were conducted in simulated ham aging houses and commercial ham aging houses. Mite postembryonic mortality was 99.8% in the simulated aging houses and >99.9% in commercial aging houses three weeks post fumigation. Sensory tests with trained panelists indicated that there were no detectable differences (P > 0.05) between phosphine fumigated and control hams. In addition, residual phosphine concentration was below the legal limit of 0.01 ppm in ham slices that were taken from phosphine fumigated hams.

Time-Mortality Relationships to Control Tyrophagus putrescentiae (Sarcoptiformes: Acaridae) Exposed to High and Low Temperatures.

Abstract Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) is a widely distributed pest species that is of significant economic importance for dry-cured country hams. Methyl bromide was used for decades in country ham plants to control this pest, but now this fumigant is recognized as an atmospheric ozone-depleting compound and will be phased out for all uses in the near future. Of various chemical and nonchemical alternatives to methyl bromide, extreme temperatures are viable and straightforward nonchemical methods to control pests. This study evaluated the efficacy of high and low temperatures on mortality of mold mite in the laboratory. Ten eggs and a mixture of 40 adults and nymphs were separately exposed to different high and low temperatures, ranging from +35 to 45 °C and from –20 to +5 °C, for several periods of time. Mortality was assessed after a recovery period for each life stage. Tyrophagus putrescentiae eggs were found to be more tolerant to both high and low temperatures than were the mobile stages. Results showed that high temperatures from 40-45 °C killed all mites within 4 to 1 d, respectively, while –10 °C or lower killed all mites in less than 1 d. Regression analyses of mortality data as a function of exposure predicted times for achieving desired levels of mite mortality. This study suggests that extreme temperature treatment can play an important role in integrated pest management programs for dry-cured ham as an alternative to methyl bromide or other chemical treatments.