• Energy Research
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AbstractThe ‘sweet herb’ (El Caa‐ehe), used by the Guaraní tribes living in the forests of today's eastern Paraguay and southern Brazil, is rapidly emerging as a natural sweetener that is an alternative both to sugar and synthetic sweeteners, well beyond Japan where it has been widely used since the mid‐1970s. Stevia rebaudiana (Bertoni) Bertoni contains very sweet steviol glycosides in its leaves, which do not add calories and do not cause an increase in blood sugar levels. The glycoside that is most abundant in the leaves, stevioside, has high reactive oxygen species quenching activity and several properties that are beneficial to health. Rapid advances in green chemistry technology allow the production of stevia extracts that are devoid of any liquorice‐like after taste. Their high chemical and physical stability enables them to be used in baked and beverage food products and this supports the large‐scale use of stevia as a natural sweetener. Addressing bioeconomic aspects ranging from production to product formulation, this study identifies the last obstacles prior to general adoption of S. rebadudiana as a sweetener that is beneficial for health. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

AbstractWe investigate hydrodynamic cavitation to inactivate commonly employed Saccharomyces cerevisiae yeast strains in an aqueous solution using different reactors and hydraulic circuit selected to demonstrate the process feasibility on the industrial scale. The target to achieve an useful lethality of the yeast at lower temperature when compared with standard thermal and even with other cavitation processes was achieved, with 90% yeast strains lethality at lower temperature (6.3–9.5°C), and about 20% lower energy input. A separate model simulating the combined thermal and cavitational effects on yeast lethality allows to accommodate the data into a comprehensive framework providing a tool to design further targeted experiments and to predict results when changing the process parameters.

The basic beer-brewing industrial practices have barely changed over time. While well proven and stable, they have been refractory to substantial innovation. Technologies harnessing hydrodynamic cavitation have emerged since the 1990s' in different technical fields including the processing of liquid foods, bringing in advantages such as acceleration of extraction processes, disinfection and energy efficiency. Nevertheless, so far beer-brewing processes were not investigated. The impacts of controlled hydrodynamic cavitation, managed by means of a dedicated unit on a real microbrewery scale (230 L), on the beer-brewing processes is the subject of this paper. The physico-chemical features of the obtained products, analyzed by means of professional instruments, were compared with both literature data and data from the outcomes of a traditional equipment. Traditional processes such as dry milling of malts and wort boiling becoming entirely unnecessary, dramatic reduction of saccharification temperature, acceleration and increase of starch extraction efficiency, relevant energy saving, while retaining safety, reliability, scalability, virtually universal application to any brewing recipe, beer quality, were the most relevant experimental results. The impacts of these findings are potentially far reaching, beer being the worldwide most widely consumed alcoholic beverage, therefore highly relevant to health, environment, the economy and even to local identities. 37 pages, 8 figures

Waste orange peel represents a heavy burden for the orange juice industry, estimated in several million tons per year worldwide; nevertheless, this by-product is endowed with valuable bioactive compounds, such as pectin, polyphenols and terpenes. The potential value of the waste orange peel has stimulated the search for extraction processes, alternative or complementary to landfilling or to the integral energy conversion. This study introduces controlled hydrodynamic cavitation processes, as a new route to the integral valorization of this by-product, based on simple equipment, speed, effectiveness and efficiency, scalability, and compliance with green extraction principles. Waste orange peel, in batches of several kg, was processed in more than 100 L of water, absent any other raw materials, in a device comprising a Venturi-shaped cavitation reactor. The extractions of pectin, endowed with a very low degree of esterification, polyphenols (flavanones and hydroxycinnamic acid derivatives), and terpenes (mainly d-limonene) were effective and fast (high yield, few min of process time), as well as the biomethane generation potential of the process residues was effectively exploited. The achieved results proved the viability of the proposed route to the integral valorization of waste orange peel, though wide margins exist for further improvements.