This study aimed to evaluate the antifungal effect of allyl isothiocyanate (AITC) against Penicillium nordicum in vitro and in chilled pizzas. First, P. nordicum was inoculated in potato dextrose agar plates, which were placed in glass jars containing different doses of gaseous AITC and mycelia growth was monitored at 25 °C for 7 days. Stickers containing AITC were used against the growth of P. nordicum in pizza at 4 °C for 30 days. Devices were calculated to generate a maximum of 5, 10, 15, 20, or 25 µL AITC/L of packaging volume. The lowest dose of AITC used in vitro (0.125 μL/L) could reduce 66% of the mycelial growth, while higher doses were able to suppress the visual growth for 7 days. In pizza, all levels tested significantly delay the visual fungal growth in a dose‐dependent manner. Stickers containing AITC can potentially be used to increase the shelf life of chilled pizza. Practical applications Pizza is a very popular food consumed worldwide, and visual mold growth is the main cause of the losses in chilled pizzas. This study demonstrated the efficacy of a sticker containing allyl isothiocyanate (AITC) against Penicillium nordicum, a mycotoxigenic mold, applied in chilled pizzas. The low shelf life of these products generates losses mainly at small companies with deficient distribution system. AITC could significantly inhibit the visual growth of P. nordicum in refrigerated pizza, which contains ingredients such as cheese and dry‐cured meats, where this type of mold is commonly found. Stickers extended the shelf life from ∼12 days (control) to 28 days (25 µL AITC/L). The device may be used on storage or transport of refrigerated pizza, since the active compound is volatile and easily diffuse into the environment. Moreover, it showed potential antifungal effect with fast, simple, and affordable application, and could be used as natural additive to extend the shelf life of chilled pizzas.

Filter paper and stickers containing allyl isothiocyanate (AIT), as well as pouches containing mustard meal and water for intrinsic production of AIT, were tested against aflatoxigenic strains of Penicillium digitatum CECT 2954 and Aspergillus parasiticus CECT 2681 in sliced mozzarella. Slices were inoculated with either fungus, packaged in plastic bags or plastic trays with one antimicrobial device (2–16 µL/L of AIT). Control groups presented visual growth of P. digitatum after 19.0 ± 1.5 d in bags and 26.1 ± 2.1 d in trays. A. parasiticus was visually detectable after 41.4 ± 1.7 d and 28.4 ± 1.5 d in trays and bags, respectively. AIT‐treated samples did not present visual fungal growth for 60 d. In trays, aflatoxin B1 was present only in the control; and in plastic bags it was found in the control (6.03 ± 1.23 mg/kg) and in groups treated with 2‐µL/L AIT: filter 0.03 ± 0.05, sticker 0.56 ± 0.13 and pouches 2.02 ± 0.05 mg/kg. Results show that all devices could increase the shelf life and safety of mozzarella. Practical applications AIT is a component of brown/black mustard essential oil with antimicrobial activity. This natural substance was used in a newly designed bioactive packaging system to inhibit fungal growth. The device was an effective alternative to inhibit the growth of P. digitatum and A. parasiticus in sliced mozzarella cheese packaged in plastic bags or plastic trays. The antimicrobial sticker could be easily applied in products that are sliced in supermarkets and specialized shops, as well as in the industry avoiding the use of synthetic preservatives, such as sorbates and propionates.