Undesired fermentation of fruit-derived beverages by fungal, yeast and bacterial spoilage organisms are among the major contributors of product losses in the food industry. As an alternative to chemical preservatives, the use of Candida pyralidae and Pichia kluyveri was assessed for antimicrobial activity against several yeasts (Dekkera bruxellensis, Dekkera anomala, Zygosaccharomyces bailii) and fungi (Botrytis cinerea, Colletotrichum acutatum and Rhizopus stolonifer) associated with spoilage of fruit and fruit-derived beverages. The antagonistic properties of C. pyralidae and P. kluyveri were evaluated on cheap solidified medium (grape pomace extract) as well as on fruits (grapes and apples). Volatile organic compounds (VOCs) from C. pyralidae and P. kluyveri deemed to have antimicrobial activity were identified by gas chromatography-mass spectrometry (GC-MS). A cell suspension of C. pyralidae and P. kluyveri showed growth inhibition activity against all spoilage microorganisms studied. Direct contact and extracellular VOCs were two of the mechanisms of inhibition. Twenty-five VOCs belonging to the categories of alcohols, organic acids and esters were identified as potential sources for the biocontrol activity observed in this study. This study reports, for the first time, the ability of C. pyralidae to inhibit fungal growth and also for P. kluyveri to show growth inhibition activity against spoilage organisms (n = 6) in a single study.

Microbial spoilage causes food losses in the food industry and as such, the use of synthetic chemical preservatives is still required. The current study proposes the use of agro-waste, i.e., grape pomace extracts (GPE), as production medium for biopreservation compounds. Production kinetics, subsequent to optimization using response surface methodology (RSM) for biopreservation compounds production was studied for three yeasts using GPE broth as a fermentation medium. The results showed that the highest volumetric zone of inhibition (VZI) was 1.24 L contaminated solidified media (CSM) per mL biopreservation compounds used (BCU) when Candida pyralidae Y1117 was inoculated in a pH 3-diluted GPE broth (150 g L⁻¹) incubated at 25 °C for 24 h. Similar conditions were applied for Pichia kluyveri Y1125 and P. kluyveri Y1164, albeit under slightly elongated fermentation periods (up to 28 h), prior to the attainment of a maximum VZI of only 0.72 and 0.76 L CSM mL⁻¹ ACU, respectively. The potential biopreservation compounds produced were identified to be isoamyl acetate, isoamyl alcohol, 2-phenyl ethylacetate and 2-phenyl ethanol.

Since food waste is a contemporary and complicated issue that is widely debated across many societal areas, the world community has designated the reduction of food waste as a crucial aspect of establishing a sustainable economy. However, waste management has numerous challenges, such as inadequate funding, poor waste treatment infrastructure, technological limitations, limited public awareness of proper sanitary practices, and inadequate legal and regulatory frameworks. A variety of microorganisms participate in the process of anaerobic digestion, which can be used to convert organic waste into biogas (e.g., methane) and nutrient-rich digestate. In this study, we propose a synergy among multiple disciplines such as nanotechnology, omics, artificial intelligence, and bioengineering that leverage anaerobic digestion processes to optimize the use of current scientific and technological knowledge in addressing global food waste challenges. The integration of these fields carries with it a vast amount of potential for improved waste management. In addition, we highlighted the relevance, importance, and applicability of numerous biogas-generating technologies accessible in each discipline, as well as assessing the impact of the COVID-19 epidemic on waste production and management systems. We identify diverse solutions that acknowledge the necessity for integration aimed at drawing expertise from broad interdisciplinary research to address food waste management challenges.

Postharvest fruit loss due to spoilage is mainly attributed to fungal infections. Synthetic chemicals can be used to preserve fruits, but they are expensive and pose risks to human health. The replacement of these chemicals by safer and cost- effective biocontrol agents is now a priority. This...

Optimum fermentor conditions are essential for desired microbial growth and activity in fermentations. In balsamic vinegar fermentation systems, the microorganisms used must endure several stressful conditions including high sugar concentration, low water activity, high osmotic pressure and high acetic acid concentration. Consequently, the present study was aimed at improving the performance of a microbial consortium of non-Saccharomyces yeast and acetic acid bacteria during balsamic-styled vinegar fermentation. Cell immobilization via adsorption on corncobs and oak wood chips in combination with aeration and agitation effects, have never been tested during balsamic-styled vinegar fermentation. Therefore, fermentations were initially conducted under static conditions without aeration with successive fermentations also being subjected to low (0.15 vvm min⁻¹) and high (0.3 vvm min⁻¹) aeration. The results showed improved acetification rates when cells were immobilized on corncobs under static conditions. Low aeration showed better acetification rates (1.45–1.56 g·L·day⁻¹), while only free-floating cells were able to complete fermentations (1.2 g·L·day⁻¹) under high aeration conditions. Overall, cells immobilized on corncobs showed higher acetification rates of 1.56 and 2.7 g·L·day⁻¹ under low aeration and static fermentations, respectively. Oak wood chips were determined to be less efficient adsorbents due to their relatively smooth surface, while the rough surface and porosity of corncobs led to improved adsorption and, therefore, enhanced acetification rates.