Use of Allyl Isothiocyanate-containing Sachets to Reduce Aspergillus flavus Sporulation in Peanuts

Abstract

Peanuts are oilseed crops that are frequently infected by fungi (including Aspergillus flavus) that may produce aflatoxin, a highly carcinogenic mycotoxin. Conventional food packaging techniques can only prevent aflatoxin production to a certain extent. Therefore, the development of novel active packaging strategies to control post-harvest sporulation by A. flavus is important. Essential oils from plants have antimicrobial potential, and one of the most powerful components is allyl isothiocyanate (AITC), the major component of mustard essential oil. Here, we aimed to evaluate the antifungal effect of AITC against A. flavus, develop an AITC-containing sachet to control A. flavus sporulation in peanuts and quantify residual AITC in grains and package headspaces during a 90 day period. Diffusion and volatile susceptibility tests showed the in vitro effectiveness of AITC at 0.215 ppb against A. flavus. Because in vitro and real food assays may provide distinct antimicrobial efficiencies due to different compositions, sachets incorporated with AITC were stored with peanuts for 90 days at 25°C. A 10-fold reduction in A. flavus survival was observed in 1 week, and after 60 days, survival was reduced by 4.81 log cycles. No residual AITC was detected in grains throughout the storage period, whereas volatile AITC within the package headspaces decreased with time: 92.4% of volatile AITC was reduced within the first 15 days, and AITC was no longer detected after 30 days. We proved that AITC retards A. flavus sporulation and that sachets are a promising delivery system for AITC to act as an antimicrobial agent for peanuts. Copyright © 2014 John Wiley & Sons, Ltd.