Postharvest Treatments with Three Yeast Strains and Their Combinations to Control Botrytis cinerea of Snap Beans

Biocontrol mechanisms of antagonistic yeasts on postharvest fruits and vegetables and the approaches to enhance the biocontrol potential of antagonistic yeasts

During storage and transportation, fruits and vegetables are susceptible to various pathogens, leading to quality degradation and significant economic losses. Currently, chemical pesticides are primarily used for control; however, their overuse poses serious threats to human health and causes environmental pollution. Biocontrol, known for its environmentally friendly characteristics, has been extensively studied. Among biocontrol agents, yeasts are widely distributed and possesses strong antagonistic abilities, making them crucial agents against numerous pathogenic fungi. Despite their considerable promise, the full potential of antagonistic yeasts for broader application remains untapped. Therefore, this paper reviews the mechanisms of antagonistic yeasts as biocontrol agents for postharvest diseases, including space and nutrients competition, competition for scarce iron resources, parasitism, production of soluble and volatile antifungal compounds, and induction of host systemic resistance. The paper also introduces research on the combined application of antagonistic yeasts with physical, chemical, and other microbial methods. Ultimately, this review provides a potential pathway to enhance the biocontrol effectiveness of antagonistic yeasts and expand their application prospects.

Current insights into yeast application for reduction of patulin contamination in foods: A comprehensive review

Patulin, a fungal secondary metabolite with multiple toxicities, is widely existed in a variety of fruits and their products. This not only causes significant economic losses to the agricultural and food industries but also poses a serious threat to human health. Conventional techniques mainly involved physical and chemical methods present several challenges include incomplete patulin degradation, high technical cost, and fruit quality decline. In comparison, removal of mycotoxin through biodegradation is regarded as a greener and safer strategy which has become popular research. Among them, yeast has a unique advantage in detoxification effect and application, which has attracted our attention. Therefore, this review provides a comprehensive account of the yeast species that can degrade patulin, degradation mechanism, current application status, and future challenges. Yeasts can efficiently convert patulin into nontoxic or low-toxic substances through biodegradation. Alternatively, it can use physical adsorption, which has the advantages of safety, high efficiency, and environmental friendliness. Nevertheless, due to the inherent complexity of the production environment, the sole utilization of yeast as a control agent remains inherently unstable and challenging to implement on a large scale in a practical manner. Integration control, enhancement of yeast resilience, improvement of yeast cell wall adsorption capacity, and research on additional patulin-degrading enzymes will facilitate the practical application of this approach. Furthermore, we analyzed the feasibility of the yeast commercial application in patulin reduction and provided suggestions on how to enhance its commercial value, which is of great significance for the control of mycotoxins in food products.

Antimicrobial function of yeast against pathogenic and spoilage microorganisms via either antagonism or encapsulation: A review

Contaminations of pathogenic and spoilage microbes on foods are threatening food safety and quality, highlighting the importance of developing antimicrobial agents. According to different working mechanisms, the antimicrobial activities of yeast-based agents were summarized from two aspects: antagonism and encapsulation. Antagonistic yeasts are usually applied as biocontrol agents for the preservation of fruits and vegetables via inactivating spoilage microbes, usually phytopathogens. This review systematically summarized various species of antagonistic yeasts, potential combinations to improve the antimicrobial efficiency, and the antagonistic mechanisms. The wide applications of the antagonistic yeasts are significantly limited by undesirable antimicrobial efficiency, poor environmental resistance, and a narrow antimicrobial spectrum. Another strategy for achieving effective antimicrobial activity is to encapsulate various chemical antimicrobial agents into a yeast-based carrier that has been previously inactivated. This is accomplished by immersing the dead yeast cells with porous structure in an antimicrobial suspension and applying high vacuum pressure to allow the agents to diffuse inside the yeast cells. Typical antimicrobial agents encapsulated in the yeast carriers have been reviewed, including chlorine-based biocides, antimicrobial essential oils, and photosensitizers. Benefiting from the existence of the inactive yeast carrier, the antimicrobial efficiencies and functional durability of the encapsulated antimicrobial agents, such as chlorine-based agents, essential oils, and photosensitizers, are significantly improved compared with the unencapsulated ones.

The Metabolite Profiling and Microbial Community Dynamics during Pineapple By-Product Fermentation Using Co-Inoculation of Lactic Acid Bacteria and Yeast

Value-added utilization of pineapple waste is very import for the food industry and environmental protection. In this study, whey protein (2.6%, w/w) was added to pineapple waste in order to make up for the protein deficiency of the raw material and give the final products better flavor characteristics. Autochthonous Lactococcus lactis LA5 and Hanseniaspora opuntiae SA2 were used for the co-inoculation of pineapple by-products; during fermentation, the metabolite profiling and microbial community dynamics were investigated. Results showed that the contents of organic acids, total FAAs, total phenolic compounds and flavonoids significantly increased with fermentation, and 152 kinds of peptides were identified in the final products. Relevant analyses demonstrated that dominant strains including Lactococcus lactis, Hanseniaspora and Saccharomyces not only significantly promoted the accumulation of organic acids, total phenols and other active substances, but also inhibited the growth of pathogenic bacteria and further influenced the fermentation process of pineapple waste.