Chitosan and Essential Oils Combined for Beef Meat Protection against the Oviposition of Calliphora vomitoria, Water Loss, Lipid Peroxidation, and Colour Changes

Ecotoxicological assessment of basil essential oil on soil nematode communities

Intensive agriculture has over-exploited natural resources and altered the functioning of soil systems, mainly because of the abuse of synthetic products to increase yields. To improve sustainability, the European Commission has adopted the New Green Deal program, which aims to reduce the use of synthetic products by 50% and restore biodiversity by limiting human impact. Essential oils (EOs) can be sustainable alternatives to synthetic pesticides for crops and agricultural products protection against pests and diseases and, therefore, are attracting increasing interest from the scientific community. However, while most studies have focused on in vitro effects on target organisms (i.e., soil borne-phytopathogens, insects, phytoparasitic nematodes), the impact of EOs on natural soil communities remains unexplored. This study employed a field experiment using the Before-After-Control-Impact (BACI) approach to investigate the potential effects of basil EO on nematode communities. Chickpea seeds were coated with a high concentration (25% v/v) of Ocimum basilicum EO in different formulations, with the basil EO and chitosan combination standing out for its potential applicability as a seed-coating treatment for future crop use. The results demonstrated that the basil EO and chitosan seed coating had no significant negative impact on nematode taxonomic diversity or functional indices. Furthermore, the taxonomic community structure-recognized as the most sensitive detection metric-revealed that the observed effects were primarily influenced by temporal changes, likely reflecting the natural progression of the crop system rather than the EO treatment itself. These findings are particularly promising, as they suggest that EO-based coatings can be compatible with maintaining soil health.

Benefits of Essential Oil-Enriched Chitosan on Beef: From Appearance and Odour Improvement to Protection Against Blowfly Oviposition

The food industry is increasingly turning to healthy and eco-friendly alternatives for meat preservation, with recent attention focused on chitosan (CH) and essential oils (EOs). Here, we propose two liquid formulations of CH enriched with Laurus nobilis or Piper nigrum EOs to preserve beef patties stored for 4 days at 4 °C from colour changes, secondary lipid oxidation, and alteration in volatile organic compound emissions while also preventing oviposition by Calliphora vomitoria on beef loaves hung for the same time at around 13 °C in a netted polytunnel. Overall, the L. nobilis EO-enriched CH solution increased the meat colour lightness compared to the control (+7.58%), kept redness and yellowness comparable to the control, maintained the level of thiobarbituric acid-reacting substances below the threshold for rancidity perception for at least 96 h, reduced the release of ethanol, enhanced the perception of fatty and woody notes in the meat along with the fresh, green, and citrusy aromas specific to the EO, and also provided significant protection (88.83%) against blowfly oviposition compared to the control. Therefore, the development of a spray CH formulation containing the L. nobilis EO appears to be a promising tool for stable and prolonged meat protection.

Reduced Doses of Diatomaceous Earth and Basil Essential Oil on Stored Grain Against the Wheat-Damaging Sitophilus oryzae: Influence on Bread Quality and Sensory Profile

Stored grain pests like Sitophilus oryzae pose significant challenges to food security and quality, necessitating eco-friendly pest management strategies. This study investigates the combined efficacy of reduced doses of diatomaceous earth (DE) and basil (Ocimum basilicum L.) essential oil (EO) as an alternative to conventional pesticides. Laboratory trials evaluated the effectiveness of the treatments-DE, EO, and a mixture of both (at halved doses)-against S. oryzae in wheat, alongside their impact on bread quality and sensory attributes. Results showed that DE and the DE + EO at halved doses combination achieved over 82% pest mortality, comparable to standard DE doses but with reduced mechanical and environmental drawbacks. EO alone demonstrated limited insecticidal activity. Bread made from treated wheat retained high sensory acceptability, with DE enhancing elasticity and crumb aroma. EO-enriched bread exhibited a complex aromatic profile due to methyl chavicol, though with reduced crumb elasticity and a slightly bitter aftertaste. Shelf-life assessments indicated that DE and DE + EO at halved doses extended mold-free storage by one day compared to untreated bread. These findings highlight the potential of combining DE and EO at reduced doses to manage stored grain pests sustainably, aligning with integrated pest management (IPM) and organic farming principles, while preserving the technological and sensory qualities of derived food products.

Effect of Nutmeg (Myristica fragrans) and Tea Tree (Melaleuca alternifolia) Essential Oils on the Oxidative and Microbial Stability of Chicken Fillets During Refrigerated Storage

The current study investigated the impact of nutmeg essential oil (NEO) and tea tree essential oil (TTEO) on the preservation of raw chicken fillets during nine days of refrigerated storage study. The primary aim was to explore the antioxidant and antimicrobial properties of these essential oils (EOs) and assess their ability to extend the shelf life of poultry meat. Gas chromatography-mass spectrometry (GC-MS) was utilized to identify the chemical compositions of NEO and TTEO, revealing the presence of compounds like myristicin and terpenoids, known for their antimicrobial and antioxidant activities. Antioxidant properties were evaluated using DPPH and ABTS radical scavenging assays, where both oils exhibited potent free radical scavenging abilities, with NEO showing higher efficacy than TTEO. The EOs showed their antimicrobial potential, exhibiting significant antibacterial activities against tested Gram-positive and Gram-negative pathogens, such as Staphylococcus aureus and Escherichia coli, respectively. Raw chicken fillets treated with either NEO or TTEO at 1% were analyzed for physico-chemical, microbiological, and sensory attributes. Results demonstrated that both NEO- and TTEO-treated samples maintained better microbiological qualities, with lower total viable counts and enhanced sensory attributes, such as color and odor, compared to the control samples. Furthermore, NEO and TTEO effectively delayed spoilage, extending the shelf life of chicken fillets by up to seven days. This study concludes that both the test's essential oils can be considered natural preservatives for enhancing the safety and quality of meat.

From Food Waste to Functional Biopolymers: Characterization of Chitin and Chitosan Produced from Prepupae of Black Soldier Fly Reared with Different Food Waste-Based Diets

The use of food waste as a rearing substrate to grow insects is an ecofriendly and sustainable alternative to food waste disposal. In the present research, Hermetia illucens prepupae were reared with a standard diet, different food waste-based diets based on vegetables, fruits, and meat, and a mixed one, where the previous three components were present equally. The demineralization and deproteination of the prepupae allowed for the obtainment of chitin that was then deacetylated to produce chitosan. Also, the bleaching of chitosan was attempted for further purification. The yield of the different reactions was investigated, and the infrared spectra of the obtained materials were analyzed to obtain information on the quantity and acetylation degree trend of the chitin and chitosan as a function of the diet. The possibility to slightly modulate the yield and acetylation degree of both biopolymers thanks to the specific diet was enlightened. Interestingly, the standard diet resulted in the highest fraction of chitin having the highest acetylation degree, and in the highest fraction of chitosan having the lowest acetylation degree.

Chitosan as a Control Tool for Insect Pest Management: A Review

Chitosan, a polysaccharide derived from the deacetylation of chitin, is a versatile and eco-friendly biopolymer with several applications. Chitosan is recognized for its biodegradability, biocompatibility, and non-toxicity, beyond its antimicrobial, antioxidant, and antitumoral activities. Thanks to its properties, chitosan is used in many fields including medicine, pharmacy, cosmetics, textile, nutrition, and agriculture. This review focuses on chitosan's role as a tool in insect pest control, particularly for agriculture, foodstuff, and public health pests. Different formulations, including plain chitosan, chitosan coating, chitosan with nematodes, chitosan's modifications, and chitosan nanoparticles, are explored. Biological assays using these formulations highlighted the use of chitosan-essential oil nanoparticles as an effective tool for pest control, due to their enhanced mobility and essential oils' prolonged release over time. Chitosan's derivatives with alkyl, benzyl, and acyl groups showed good activity against insect pests due to improved solubility and enhanced activity compared to plain chitosan. Thus, the purpose of this review is to provide the reader with updated information concerning the use and potential applications of chitosan formulations as pest control tools.

Chemical Composition and Antimicrobial Activity against the Listeria monocytogenes of Essential Oils from Seven Salvia Species

In recent years, essential oils (EOs) have received interest due to their antibacterial properties. Accordingly, the present study aimed to investigate the effectiveness of the EOs obtained from seven species of Salvia on three strains of Listeria monocytogenes (two serotyped wild strains and one ATCC strain), a bacterium able to contaminate food products and cause foodborne disease in humans. The Salvia species analysed in the present study were cultivated at the Botanic Garden and Museum of the University of Pisa, and their air-dried aerial parts were subjected to hydrodistillation using a Clevenger apparatus. The obtained EOs were analysed via gas chromatography coupled with mass spectrometry for the evaluation of their chemical composition, and they were tested for their inhibitory and bactericidal activities by means of MIC and MBC. The tested Eos showed promising results, and the best outcomes were reached by S. chamaedryoides EO, showing an MIC of 1:256 and an MBC of 1:64. The predominant compounds of this EO were the sesquiterpenes caryophyllene oxide and β-caryophyllene, together with the monoterpenes bornyl acetate and borneol. These results suggest that these EOs may possibly be used in the food industry as preservatives of natural origins.