4 research outputs found
Natural Cellulosic Material Characteristics: A Possibility to Develop Antimicrobial Active Fiber-based Packaging
No full textCoconut husk, rubberwood sawdust, and palm leaf base are cellulosic agricultural wastes that have potential to be processed to fiber as absorbing material. This study investigated characteristics (morphological, physiological properties, chemical composition, absorption capacity, and water absorption isotherms) of coconut, rubberwood, and palm fiber. Also, the study aimed to develop an antimicrobial sachet packaging to resist against foodborne pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli) by adding lime oil (LO) emulsion or Litsea cubeba (LC) oil at 50 to 700 μL into the material (1 g) before, and then dried and placed in the 1-L seal box. Results showed that among the three, coconut performed the best in terms of releasing the essential oil (EO) emulsion against bacteria. Coconut could adsorb and release volatile LO or LC at the lowest concentrations (LO, 500 μL/L; LC, 300 μL/L) to inhibit bacteria compared with the other fibers (700 μL/L) at 35 °C. Results indicated that coconut has a low water absorption rate, which influenced the faster adsorption of EO emulsion in the beginning of the process; therefore, using low concentrations of EO in coconut for bacterial inhibition is possible. Coconut contains 34.5% lignin, 68.7% holocellulose, 37.6% cellulose, and 31.2% hemicellulose. Coconut is suitable as an alternative to the biocomposite material in developing a new antimicrobial packaging design
The aromatic plant essential oils and their hormetic effect on Rhyzopertha dominica (Coleoptera: Bostrichidae)
No full textEssential oils (EOs) are increasingly recognized as eco-friendly alternatives to synthetic pesticides due to their biodegradability and reduced risks to non-target species. This study investigates the bioactivity of 30 EOs on Rhyzopertha dominica, a major pest of stored grains, with a focus on their repellency and attractiveness across varying concentrations. The area preference method (APM) was used to evaluate EO bioactivity at concentrations ranging from 0.00064 to 0.064 μL cm−2. The results revealed strong repellent or attractive activity for certain EOs, while others exhibited concentration-dependent dual effects, acting as attractants at lower concentrations and repellents at higher ones. In addition, the bioactivity shown in the APM by nine selected EOs was compared to that obtained by testing the same EOs through a two-choice behavioral bioassay (TCB) at corresponding concentrations. At a 2 % EO concentration, the TCB results indicated significant repellent activity (p < 0.05) for lemon verbena, palo santo, matico, pumin, cinnamon, and anise, which exhibited the strongest effects. In contrast, nutmeg demonstrated significant attractive properties (p < 0.05). Black pepper and mandarin EOs displayed trends toward repellency and attractiveness, respectively. Both methods confirmed the bioactivity of the EOs against R. dominica. These results underscore the concentration-dependent hormetic effects of EOs on R. dominica and highlight the importance of precise optimization in pest management strategies for their application
From Attraction to Repellency: The Hormesis of Essential Oils on Rhyzopertha dominica
No full textGli oli essenziali (OE) stanno attirando l’attenzione come alternative sostenibili ai pesticidi sintetici, grazie alle loro caratteristiche tra cui la loro biodegradabilità e i minori rischi per le specie non target. Questo studio esplora la bioattività di 30 OEs contro Rhyzopertha dominica, un parassita primario dei cereali immagazzinati, considerando la loro ormesi come fattore dipendente dalla loro concentrazione. Utilizzando il metodo dell’”Area Preference” in Petri, abbiamo valutato l'attività degli OE a concentrazioni comprese tra 0,00064 e 0,064 μL cm−2, individuando OE repellenti, attrattivi e oli con spiccata ormesi che agiscono cioè come attrattivi a basse concentrazioni e come repellenti a concentrazioni più elevate. I test in olfattometro piano a due vie, condotto con OE alla concentrazione del 2%, hanno confermato una repellenza significativa (P < 0,05) per quelli di Aloysia citrodora, Bursera graveolens, Buddleja globosa, Clinopodium tomentosum, Cinnamomum verum e Pimpinella anisum, mentre Myristica fragrans ha mostrato una forte attrattività. Questi risultati, che forniscono criteri per la classificazione degli OE, sottolineano anche l'importanza della loro concentrazione di utilizzo per la gestione dei parassiti. Inoltre, comprendere l’ormesi di tali sostanze consentirebbe di ottimizzare le loro formulazioni per strategie di controllo dei parassiti più efficaci ed ecocompatibili nei sistemi di conservazione dei cereali
Behavioral Selectivity: Species-Specific Effects of Nutmeg, Cinnamon, and Clove Essential Oils on Sitophilus oryzae and Its Parasitoid Lariophagus distinguendus
No full text: The integration of essential oils (EOs) with biological control agents offers a promising alternative to synthetic pesticides, though compatibility remains unclear. This study evaluated nutmeg (Myristica fragrans, NM), cinnamon (Cinnamomum verum, CIN), and clove (Syzygium aromaticum, CL) specifically on S. oryzae and L. distinguendus. Olfactory and behavioral responses to whole EOs and major constituents (myristicin, cinnamaldehyde, eugenol) were analyzed using the area preference method (APM) and two-choice behavioral bioassay (TCB), with confirmation by gas chromatography-mass spectrometry (GC-MS). In S. oryzae, APM showed attraction to all three EOs (PI = 0.14 to 0.56). A paradox emerged, however, as single constituents were mostly repellent (eugenol: PI = -0.58 to -0.70; cinnamaldehyde: PI shifted from 0.16 to -0.20), underscoring the complexity of EO mixtures where multiple compounds act jointly rather than individually. In contrast, L. distinguendus strongly avoided CL and CIN in TCB, with fewer than 30% of parasitoids choosing the EO-treated side (χ2 test, p < 0.05). CIN therefore demonstrated selective potential, simultaneously attracting S. oryzae while repelling L. distinguendus. These findings highlight the dual role of EOs as botanical pest control tools, while stressing the need to consider non-target effects before practical application
