Anti-microbial effectiveness of relative humidity-controlled carvacrol release from wheat gluten/montmorillonite coated papers

• Published in: Food control Vol. 22; no. 10; pp. 1582 - 1591
• Main Authors: Mascheroni, E., Guillard, V., Gastaldi, E., Gontard, N., Chalier, P.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2011; Elsevier
• Subjects: Agropolymer; Anti-microbial system; Carvacrol; Clay; Diffusivity; Food engineering; Life Sciences; Packaging; Packaging; Clay; Carvacrol; Agropolymer; Anti-microbial system; Diffusivity; diffusivity; packaging; carvacrol; anti-microbial system; agropolymer; clay
• ISSN: 0956-7135; 1873-7129
• DOI: 10.1016/j.foodcont.2011.03.014

Wheat gluten coated papers containing carvacrol (15wt%) as anti-microbial agent and montmorillonite (0-7wt%) as filler were investigated as anti-microbial controlled delivery systems. The carvacrol losses were followed during the coating process and storage time at 30∞C under controlled RH from 40 to 100% RH. Increasing MMT content limited carvacrol losses during the coating process. A mathematical model based on Fick’s second law was used to determine the apparent diffusivities of carvacrol from experimental data of kinetic release at 30∞C and controlled RH. Diffusivity values varied from 0.143 × 10−14 m2/s (0wt% MMT, 40% RH) to 6.010 × 10−14 m2/s (5wt% MMT, 100%RH) depending on both MMT% and RH. The carvacrol diffusivities increased with increasing RH, and the presence of a high amount of MMT (≥5wt%) accentuated the RH-induced effect. Specific aggregated structure was evidenced by SEM and TEM in the presence of carvacrol and 5wt% MMT creating a preferential pathway for carvacrol diffusion. The anti-microbial efficiency of the MMT-WG-coated papers toward Escherichia Coli was assessed and showed that the anti-microbial effect was related to the carvacrol diffusivity. The diffusivity coefficients were utilized to optimize the packaging characteristics required to develop an efficient anti-microbial system and were finally validated against Botrytis cinerea.