Electrophysiological and Behavioral Activity of (E)-2-Hexenal in the Granary Weevil and Its Application in Food Packaging

Abstract

The purpose of this work was to develop a biodegradable carrier material to control insect pests in cereal products. To this aim, (E)-2-hexenal was used, being a natural compound with antimicrobial activity that is also commonly adopted as a flavoring agent. Three coating layers of polycaprolactone (PCL) were spread onto the internal side of a paperboard carton, the first being the active coating containing (E)-2-hexenal. The antennal sensitivity of Sitophilus granarius to a broad range of doses of (E)-2-hexenal was first demonstrated. Next, the ability of different concentrations of this compound to disrupt the orientation of adult S. granarius beetles to odors of intact wheat kernels was established in a two-choice pitfall bioassay. In addition, invasion tests were carried out over an 8-week period to highlight the effects of the biobased repellent packaging and their potential persistence. The results demonstrated that during the entire monitoring period, the percentage of S. granarius adults found in cartons coated with (E)-2-hexenal-loaded multilayer PCL was about 10 % of the total number of insects used in the bioassay, very low compared with the respective control samples, thus assessing both the effectiveness and persistence of the repellent system developed. Although the infestation level of treated packages was reduced relative to the infestation levels in the controls, any infestation of food packages is unacceptable to consumers, so further tests are required to determine whether infestation can be completely prevented using (E)-2-hexenal.

Repellency of Hydroethanolic Extracts ofRicinus communis(Euphorbiaceae) toScyphophorus acupunctatus(Coleoptera: Curculionidae) in the Laboratory

“…Weevils detect and discriminate toxic and food factors before choosing a host, and their response can be positive (attraction) or negative (repellency) for food, shelter, or oviposition (Reeves & Lorch 2009;Blake et al 2011;Germinara et al 2012).…”

Effect of Wheat Flour Packaging Materials on Infestation by Lasioderma serricorne (F.)

“…For example, rapid turnover of the stock can hinder insect pest attack and population establishment during the storage period. In addition, some insect-resistant packaging materi als can be improved by combining them with insect repellents f6 , 11,14,17,28). Implementing rigorous quality checks on packaging materials and the stored product as well as keeping strict hygienic conditions in the storage environment can effectively restrain insect infestation.…”

Repellents effectively disrupt the olfactory orientation of Sitophilus granarius to wheat kernels

“…Thirdly, the compounds were recognized as toxic and therefore avoided. Short-chain saturated and unsaturated aliphatic aldehydes are produced by plant tissues in response to mechanical and herbivory damage through the hydroperoxide lyase pathway of oxylipin metabolism (Matsui 2006) and they have been shown to possess fumigant and contact toxicity against various stored-product insect pests (Ferguson and Pirie 1948;Hammond et al 2000;Hubert et al 2008;Germinara et al 2012a;Anfora et al 2014).…”

“…Allelochemicals able to repel insects (allomones) have the potential to provide direct control through deterring pests from food and oviposition sites (Agelopoulos et al 1999;Cook et al 2007). Possible applications of repellents to avoid infestation by stored-product insect pests are to treat empty stores in order to flush out hidden infestation before fresh grain is introduced, to create chemical barriers able to mask odors of grain bulks to insects, and to incorporate them into packaging materials to prevent insects from entering packaged foods (Cox 2004;Hou et al 2004;Germinara et al 2010Germinara et al , 2012a.…”