Fermentation at non-conventional conditions in food- and bio-sciences by the application of advanced processing technologies
The interest in improving the yield and productivity values of relevant microbial fermentations is an increasingly important issue for the scientific community. Therefore, several strategies have been tested for the stimulation of microbial growth and manipulation of their metabolic behavior. One promising approach involves the performance of fermentative processes during non-conventional conditions, which includes high pressure (HP), electric fields (EF) and ultrasound (US). These advanced technologies are usually applied for microbial inactivation in the context of food processing. However, the approach described in this study focuses on the use of these technologies at sub-lethal levels,…
Utilization of glycerol during consecutive cycles of Lactobacillus reuteri fermentation under pressure: The impact on cell growth and fermentation profile
Abstract Exposure of bacterial cells to sub-lethal high pressure (HP) during growth and fermentation may promote development of new adaptive features, with potential biotechnological interest. The present work evaluated the effect of consecutive fermentation cycles under HP on Lactobacillus reuteri growth and glycerol/glucose co-fermentation. At all conditions tested (0.1, 10 and 25 MPa), 1,3-propanediol production from glycerol was enhanced over the cycles. The highest titers, yields and productivities were achieved at 10 MPa. In addition, the HP-cycles promoted shifts in by-product formation (ethanol, acetate and lactate), with different profiles according to the pressure. Ratios between …
Fruit juice sonication: Implications on food safety and physicochemical and nutritional properties
Abstract Over the last years, consumers are increasingly demanding for nutritious, healthy and fresh-like food products, with high organoleptic quality. Nowadays, emerging non-thermal technologies have raised great interest as a viable alternative to the conventional thermal methods, since they have minimal impact on sensorial and nutritional properties of fresh foods. Ultrasound (US) is one of these promising non-conventional processing technologies and it is especially suitable for preservation of fluid foods. US may be used alone or in combination with other preservation techniques, such as mild heat temperatures, high pressures and antimicrobials. Besides, data on inactivation of food m…