Category Archives: Saccharomyces cerevisiae

Research – Microbial Diversity and Safety in Fermented Beverages

MDPI

For thousands of years, humans have exploited the natural process of fermentation of various foods to preserve them, and to enjoy the changes in the sensory characteristics that could be produced. Recently, the world of fermented beverages has gone through a rapid transformation linked to deep changes in consumer preferences, consumption habits, climate, new regulations and entry of emerging countries, accompanied by safety concerns and an important reduction in economic resources available to people. As with all food handling and preparation, we need to be sure the fermented food produced is safe. Fermentation is a complex biological process where microbial diversity takes place and the environment created inside of the fermented food provides the conditions to reduce the risk of pathogenic bacteria growth, thus providing safe food. In addition, food manufacturers fermenting food carefully control their processing and must comply with the National Food Standards Codes. Although these products have a generally good food safety record, sometimes inadequate manufacturing practices or the presence of acidophilic pathogens could compromise food safety. In fact, fermented beverages may adversely become contaminated with pathogens or microbial toxins and thereby transform into vehicles that can transmit diseases to the consumers. Moreover, many microorganisms can deteriorate the physical-chemical and sensory properties as well as the flavor of the final products. In this editorial, we present an overview of a review and six original research papers published in the Special Issue “Fermentation Process and Microbial Safety of Beverages” of the Beverages journal.

Research – Antimicrobial effect of UVC light-emitting diodes against Saccharomyces cerevisiae and its application in orange juice decontamination

Journal of Food Protection

UVC light-emitting diodes (UVC-LEDs) is a novel eco-friendly alternative source of UV light. This study evaluated inactivation and membrane damage of spoilage yeast Saccharomyces cerevisiae by UVC-LEDs and its application in orange juice pasteurization. The results demonstrated that the antimicrobial effect of UVC-LED treatment against S. cerevisiae enhanced with the increase of radiation dose. When the dose of UVC-LED radiation was up to 1420 mJ/cm 2 , the population of S. cerevisiae in YPD broth was reduced by 4.86 log 10 CFU/mL. Through scanning electron microscope and fluorescent staining approaches, the structure and function of plasma membrane was observed severely damaged by UVC-LED treatment. The inactivation efficacy of UVC-LEDs against S. cerevisiae in orange juice also increased with increasing radiation dose. Radiation at dose of 1420 mJ/cm 2 highly reduced the number of S. cerevisiae in orange juice by 4.44 log 10 CFU/mL and did not induce remarkable changes in pH, total soluble solids, titratable acidity, and color parameters. However, total phenolic content in orange juice was found significantly decreased by UVC-LEDs. These findings contribute to a better comprehension of UVC-LED inactivation and provide theoretical support for its potential application in fruit and vegetable juices processing.