Enhancement Effect of Chitosan Coating on Inhibition of Deoxynivalenol Accumulation by Litsea cubeba Essential Oil Emulsion during Malting

Chemical Compositions and Antibacterial Activities of Litsea cubeba Essential Oil and Its Distillates Prepared by Vacuum Fractional Distillation and Molecular Distillation

Litsea cubeba essential oil (LCEO) has various bioactivities and wide applications. However, most reported LCEOs are directly extracted from plants, and studies on further processing of LCEO to enrich bioactive components using modern separation techniques are scarce. In this study, LCEO was extracted by hydrodistillation and further processed via vacuum fractional distillation (VFD) and molecular distillation (MD). The chemical compositions of LCEO and seven distillates were analyzed, and the activities of the EOs and eight individual constituents against seven bacteria were tested. Distillates VFD3 and MDH2 showed the best activity against Escherichia coli, Staphylococcus aureus, and Agrobacterium rhizogenes. VFD3 exerted antibacterial action against A. rhizogenes by inhibiting biofilms, damaging the cell membrane and cell wall, and perturbing metabolic pathways. VFD and MD are effective processing methods for changing the chemical composition and enhancing the bioactivity of LCEO, which might be used to improve the quality and extend the applications of LCEO and other EOs.

Nanoencapsulated Essential Oils for Post-Harvest Preservation of Stored Cereals: A Review

Cereal grains are frequently attacked by microorganisms and insects during storage and processing, which negatively affects their quality, safety, and market value. Therefore, protecting stored grains from microbial contamination is crucial for food industries, farmers, public health associations, and environmental agencies. Due to the negative impact of synthetic gray chemicals, antimicrobial plant-based essential oils (EOs) can serve as alternative, safer, environmentally friendly preservatives that can prolong the shelf life of cereals. However, high volatility, low solubility, hydrophobicity, and quick oxidation limit their practical applicability. Using nanotechnology for the nanoencapsulation of EOs into polymeric matrices allows sustained release and ensures targeted delivery without significantly altering the organoleptic attributes of cereals, making EOs a new-generation green preservative. This ultimately overcomes the challenges of practical applications. The application of nanoencapsulated EOs in grain storage provides an effective and novel defense against microbes, insects, and other contaminants. Hence, the current review thoroughly examines the preservative potential of nanoencapsulated EOs in terms of antimicrobial and insecticidal efficacy for protecting stored cereal grains. It also highlights the challenges encountered during application and the safety concerns of using nanoencapsulated EOs in protecting cereal grains during post-harvest storage.

Litsea cubeba essential oil: Extraction, chemical composition, antioxidant and antimicrobial properties, and applications in the food industry

Litsea cubeba (Lour.) Pers. (Lauraceae) is a valuable industrial crop that produces essential oil. The essential oil extracted from L. cubeba (LCEO) has broad-spectrum antimicrobial activity and high antioxidant properties, with great potential for increased usage in the food industry. This literature review summarizes the extraction techniques, content and chemical composition, and antioxidant and antimicrobial activities of LCEO, with a focus on its usage in the food industry, which is an area of substantial recent research. The chemical composition of LCEO, which is affected by various factors, plays a key role in determining its bioactivity and usage in food. The potent antimicrobial activity of LCEO against various foodborne pathogens gives it potential for use in food packaging and preservation to extend shelf life. Future research challenges include the elucidation of the role and mechanism of individual chemical components of LCEO in inhibiting specific foodborne microorganisms; cultivar development to produce germplasm that yields essential oils of the desired chemical composition; and the development of commercial products that can be used in the food industry.

The antifungal substance from Bacillus velezensis B-3 improved the malt quality against premature yeast flocculation induced by Fusarium graminearum infection

Malt produced from barley contaminated with Fusarium graminearum can cause premature yeast flocculation (PYF) in beer fermentation, which ultimately affects the production efficiency and flavor quality of beer. In this study, a strain of Bacillus velezensis B-3 that was isolated from soil displayed strong antifungal activity against F. graminearum. The antifungal substances were extracted and separated by ammonium sulfate fractional precipitation and semipreparative high-performance liquid chromatography to obtain fraction VI with the strongest antifungal activity. Ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry was used to identify that the fraction contained lipopeptides such as iturin A, surfactant B, and surfactant C. The minimum inhibitory concentration of the fraction was 0.2 mg/mL, and confocal laser scanning microscopy showed that the morphology of F. graminearum hyphae was obviously abnormal, with most of them were dead. Antifungal fraction VI could inhibit the growth of F. graminearum and avoid the production of PYF factor during malting but did not affect other qualities of malt. Therefore, the development of antimicrobial agents against Fusarium provides an effective potential strategy to control the production of PYF factors for malt-manufacturing enterprises. PRACTICAL APPLICATION: Antifungal fraction VI could inhibit the growth of F. graminearum and the formation of DON during malting but did not affect other qualities of malt. The levels of soluble nitrogen, free amino nitrogen, and color experienced a substantial reduction compared to the malt infected by F. graminearum. The PYF phenomenon was significantly improved, the number of suspended yeast cells and the degree of fermentation were increased, and the level of residual extract in the wort was low, close to that of control malt.

Global distribution, toxicity to humans and animals, biodegradation, and nutritional mitigation of deoxynivalenol: A review

Deoxynivalenol (DON) is one of the main types of B trichothecenes, and it causes health-related issues in humans and animals and imposes considerable challenges to food and feed safety globally each year. This review investigates the global hazards of DON, describes the occurrence of DON in food and feed in different countries, and systematically uncovers the mechanisms of the various toxic effects of DON. For DON pollution, many treatments have been reported on the degradation of DON, and each of the treatments has different degradation efficacies and degrades DON by a distinct mechanism. These treatments include physical, chemical, and biological methods and mitigation strategies. Biodegradation methods include microorganisms, enzymes, and biological antifungal agents, which are of great research significance in food processing because of their high efficiency, low environmental hazards, and drug resistance. And we also reviewed the mechanisms of biodegradation methods of DON, the adsorption and antagonism effects of microorganisms, and the different chemical transformation mechanisms of enzymes. Moreover, nutritional mitigation including common nutrients (amino acids, fatty acids, vitamins, and microelements) and plant extracts was discussed in this review, and the mitigation mechanism of DON toxicity was elaborated from the biochemical point of view. These findings help explore various approaches to achieve the best efficiency and applicability, overcome DON pollution worldwide, ensure the sustainability and safety of food processing, and explore potential therapeutic options with the ability to reduce the deleterious effects of DON in humans and animals.

Inhibition of Chitosan with Different Molecular Weights on Barley-Borne Fusarium graminearum during Barley Malting Process for Improving Malt Quality

There are many Fusarium graminearum contaminations in barley that are often associated with malt and beer quality issues. Thus, it is important to find a biological antifungal agent to prevent the growth of F. graminearum during malting. Minimum inhibition concentration (MIC) of chitosan for mycelial growth and spore germination of F. graminearum was 2.6 g/L and 1.6 g/L, respectively, indicating that the F. graminearum strain was highly sensitive toward chitosan. Chitosan with a molecular weight of 102.7 kDa was added at 0.5 g/kg during the first steeping stage, resulting in the maximum inhibition rate of F. graminearm in barley. The biomass of F. graminearm and deoxynivalenol content in the infected barley at the end of germination with 0.5 g/kg chitosan treatment were decreased by 50.7% and 70.5%, respectively, when compared with the infected barley without chitosan. Chitosan could remove the negative effects of F. graminearm infection on barley germination and malt quality, which makes the application of chitosan during the steeping process as a potential antifungal agent in the malting process to protect from F. graminearum infection.