Effects of ultrasound treatments on wine microorganisms

Pulsed electric field treatment of seeds altered the endophytic bacterial community and promotes early growth of roots in buckwheat

BACKGROUND

Endophytic bacteria provide nutrients and stimulate systemic resistance during seed germination and plant growth and development, and their functional properties in combating various stresses make them a powerful tool in green agricultural production. In this paper we explored the function of the endophyte community in buckwheat seeds in order to provide a theoretical basis for the application and scientific research of endophytes in buckwheat cultivation. We used pulsed electric field (PEF) technology to treat buckwheat seeds, monitored the effect of high-voltage pulse treatment on buckwheat seed germination, and analyzed the diversity of endophytic bacteria in buckwheat seeds using the amplicon sequencing method.

RESULTS

PEF treatment promoted root development during buckwheat seed germination. A total of 350 Operational taxonomic units (OTUs) that were assigned into 103 genera were obtained from control and treatment groups using 16SrRNA amplicon sequencing technology. Additionally, PEF treatment also caused a significant decrease in the abundance of Actinobacteria, Proteobacteria, and Bacteroidetes. The abundance of 28 genera changed significantly as well: 11 genera were more abundant, and 17 were less abundant. The number of associated network edges was reduced from 980 to 117, the number of positive correlations decreased by 89.1%, and the number of negative correlations decreased by 86.6%.

CONCLUSION

PEF treatment promoted early root development in buckwheat and was able to alter the seed endophytic bacterial community. This study thus makes a significant contribution to the field of endophyte research and to the application of PEF technology in plant cultivation.

Graphene-encapsulated yeast cells in harsh conditions

Yeast, as a versatile microorganism, holds significant importance in various industries and research fields due to its remarkable characteristics. In the pursuit of biotechnological applications, cell-surface engineering including encapsulation has been proposed as a new strategy to interface with individual living yeast cells. While previous researches of yeast encapsulation with materials have shown promise, it often involves complex processes and lacks confirmation of condition-dependent yeast viability under harsh conditions. To address these issues, we present a rational and facile design for graphene-encapsulated yeast cells. Through a straightforward blending technique, yeast cells are encapsulated with graphene layers, demonstrating the unique properties of yeast cells in structural and functional aspects with graphene. We show graphene layer-dependent functions of yeast cells under various conditions, including pH and temperature-dependent conditions. The layer of graphene can induce the delayed lag time without the transfer of graphene-layered membrane. Our findings highlight the high potential of graphene-encapsulated yeast cells for various industrial applications, offering new avenues for exploration in biotechnology.

Trends in Food Pathogens Risk Attenuation

Foodborne pathogens represent one of the most dangerous threats to public health along the food chain all over the world. Over time, many methods were studied for pathogen inhibition in food, such as the development of novel packaging materials with enhanced properties for microorganisms' growth inhibition (coatings, films) and the use of emerging technologies, like ultrasound, radio frequency or microwave. The aim of this study was to evaluate the current trends in the food industry for pathogenic microorganisms' inhibition and food preservation in two directions, namely technology used for food processing and novel packaging materials development. Five technologies were discussed in this study, namely high-voltage atmospheric cold plasma (HVACP), High-Pressure Processing (HPP), microwaves, radio frequency (RF) heating and ultrasound. These technologies proved to be efficient in the reduction of pathogenic microbial loads in different food products. Further, a series of studies were performed, related to novel packaging material development, by using a series of antimicrobial agents such as natural extracts, bacteriocins or antimicrobial nanoparticles. These materials proved to be efficient in the inhibition of a wide range of microorganisms, including Gram-negative and Gram-positive bacteria, fungi and yeasts.

Ultrasound-assisted production of alcoholic beverages: From fermentation and sterilization to extraction and aging

Ultrasound is sound waves above 20 kHz that can be used as a nonthermal ''green'' technology for agri-food processing. It has a cavitation effect, causing bubbles to form and collapse rapidly as they travel through the medium during ultrasonication. Therefore, it inactivates microorganisms and enzymes through cell membrane disruption with physicochemical and sterilization effects on foods or beverages. This emerging technology has been explored in wineries to improve wine color, taste, aroma, and phenolic profile. This paper aims to comprehensively review the research on ultrasound applications in the winery and alcoholic beverages industry, discuss the impacts of this process on the physicochemical properties of liquors, the benefits involved, and the research needed in this area. Studies have shown that ultrasonic technology enhances wine maturation, improves wine fermentation, accelerates wine aging, and deactivates microbes while enhancing quality, as observed with better critical aging markers such as phenolic compounds and color intensity. Besides, ultrasound enhances phytochemical, physicochemical, biological, and organoleptic properties of alcoholic beverages. For example, this technology increased anthocyanin in red wine by 50%. It also enhanced the production rate by decreasing the aging time by more than 90%. Ultrasound can be considered an economically viable technology that may contribute to wineries' waste valorization, resource efficiency improvement, and industry profit enhancement. Despite numerous publications and successful industrial applications discussed in this paper, ultrasound up-scaling and applications for other types of liquors need further efforts.

Application of High-Intensity Ultrasound to Improve Food Processing Efficiency: A Review

The use of non-thermal processing technologies has grown in response to an ever-increasing demand for high-quality, convenient meals with natural taste and flavour that are free of chemical additions and preservatives. Food processing plays a crucial role in addressing food security issues by reducing loss and controlling spoilage. Among the several non-thermal processing methods, ultrasound technology has shown to be very beneficial. Ultrasound processing, whether used alone or in combination with other methods, improves food quality significantly and is thus considered beneficial. Cutting, freezing, drying, homogenization, foaming and defoaming, filtration, emulsification, and extraction are just a few of the applications for ultrasound in the food business. Ultrasounds can be used to destroy germs and inactivate enzymes without affecting the quality of the food. As a result, ultrasonography is being hailed as a game-changing processing technique for reducing organoleptic and nutritional waste. This review intends to investigate the underlying principles of ultrasonic generation and to improve understanding of their applications in food processing to make ultrasonic generation a safe, viable, and innovative food processing technology, as well as investigate the technology's benefits and downsides. The breadth of ultrasound's application in the industry has also been examined. This will also help researchers and the food sector develop more efficient strategies for frequency-controlled power ultrasound in food processing applications.