Uses and commercialization of food grade and effectiveness of coated ham nets to combat Tyrophagus putrescentiae: a review

Since the 1930s, the dry-cured ham industry has used methyl bromide fumigation to control Tyrophagus putrescentiae (ham mite) infestations. However, due to methyl bromide being a class I ozone depleting substance and no longer being manufactured, alternatives to methyl bromide have been studied extensively. Direct contact food-grade coatings and coated ham nets of various materials have shown efficacy in controlling ham mite growth and reproduction. These coated nets, often including propylene glycol, can be dried to ease application and reduce shipping cost, but chemical and thermal treatments on fabrics may cause the fabrics to become more brittle, which negatively impacts stretchability and bursting strength, and ultimately the effectiveness of the net. Scanning electron microscopy can provide precise visual inspection of fabric surface morphology, allowing for a detection of potential damage to the fibers. This purpose of this review is to summarize the application of food-grade coatings on nets used in the dry-cured ham industry to control mite infestations. More importantly, the review provides comprehensive information on coated nets, covering various aspects such as the selection of netting materials, evaluation of fabric properties, techniques for coating nets, net drying method, all in relation to their efficacy for mite control. This review contributes to the broad area of this applied technology by highlighting efficacious treatments to control mites, ineffective treatments, a discussion of processes to evaluate their properties, and future prospectives regarding this area of study.