Three-Dimensional Study of F. graminearum Colonisation of Stored Wheat: Post-Harvest Growth Patterns, Dry Matter Losses and Mycotoxin Contamination

Abstract

Fusarium causes significant post-harvest quality losses and mycotoxin contamination in stored wheat but the colonisation dynamics of the grain and how this may be affected by the initial inoculum position in the grain mass is poorly understood. This study examined the 3D growth kinetics and mycotoxin production (deoxynivalenol and zearalenone) by F. graminearum during hyphal colonisation from different initial inoculum positions in wheat microcosms (top-centre, bottom-centre, and bottom-side) maintained at two water activities (aw; 0.95 and 0.97). Clear jars were used to visually follow the colonisation dynamics. Fungal respiration and associated dry matter loss (DML) and ergosterol were also quantified. Colonisation dynamics was shown to be affected by the inoculation position. At the end of the colonisation process, fungal respiration and DML were driven by the inoculation position, and the latter also by the prevailing aw. Fungal biomass (ergosterol) was mainly affected by the aw. The initial inoculum position did not affect the relative mycotoxin production. There was a positive correlation between respiration and ergosterol, and between mycotoxin production and colonisation indicators. We suggest that spatially explicit predictive models can be used to better understand the colonisation patterns and mycotoxin contamination of stored cereal commodities and to aid more effective post-harvest management.

Knowledge and Attitude of Consumers about Natural Food Toxins: A Case of Tertiary Students in the Volta Region of Ghana

“…Matumba et al (2016) noted that some members of the general public in Malawi also affirmed to consume mold-colonized foodstuffs such as maize grains and fruits. It is necessary to note that fungal toxin (especially aflatoxins) could exist in deteriorating foods as well as processed foods which may result in safety concerns (Bertero et al, 2018;Kortei et al, 2019;Portell et al, 2020).…”

What Is Fusarium Head Blight (FHB) Resistance and What Are Its Food Safety Risks in Wheat? Problems and Solutions—A Review

“…The general mean values were, however, 4.44-fold, 8.01-fold, 2.16-fold and 5.21-fold higher in terms of date in badly stored maize than in the well stored lots. The case seems to be similar in wheat [ 64 ] and the a w was the most important agent to increase DON and ZEN production. An a w of 0.95 yielded in 10 days 5 mg/kg; an a w of 0.97 (water activity), in the silo top yielded a 10 mg/kg increase on the sixth day.…”

“…An a w of 0.95 yielded in 10 days 5 mg/kg; an a w of 0.97 (water activity), in the silo top yielded a 10 mg/kg increase on the sixth day. Portell et al [ 64 ] noted that, despite the importance of the topic, the literature is sparse. Magan et al [ 33 ] and Mylona et al [ 34 ] stressed the importance of suboptimal storage conditions for the significant increase in mycotoxins in stored wheat, not only for so-called storage fungi but also because field-originated fungi can produce significant amounts of different mycotoxins under a microbe friendly environment.…”

A Mixed-Method Study to Enhance Food Security by Reducing Post-Harvest Wheat Losses in Punjab, Pakistan

“…To avoid spoilage, the best alternate method is the sun drying of the grains. A proper aeration system also reduces the growth after harvesting, insect pest attacks, and respiration as well as helps in restoring the aesthetic value of the grain (Baloch, 1999;Zachetti et al, 2019;Portell et al, 2020).…”