Ohmic-assisted hydrodistillation: A novel method for ethanol distillation

Spontaneous sieving of water from ethanol using angstrom-sized nanopores

Ethanol is widely used as a precursor in products ranging from drugs to cosmetics. However, distillation of ethanol from aqueous solution is energy intensive and expensive. Here, we show that angstrom-sized nanopores with precisely controlled pore sizes can spontaneously remove water from ethanol-water mixtures through molecular sieving at room temperature and pressure. For small-diameter nanotubes, water-filling is observed, but ethanol is completely excluded, as evidenced by time-dependent density functional theory (TD-DFT) calculations and spectroscopy measurements. Potential of mean force calculations were performed to determine how the free energy barriers for water and ethanol-filling of the nanotubes change with increasing pore size. Water/ethanol selectivity ratio reaching as high as 6700 is observed with a (6,4) nanotube, which has a pore size of 0.204 nm. This selectivity vanishes as the pore size increases beyond 0.306 nm. These findings provide insights that may help realize energy efficient molecular sieving of ethanol and water.

Environmental and economic analysis of bioethanol production from sugarcane molasses and agave juice

In this article, sugarcane molasses and agave juice were compared as potential feedstocks for producing bioethanol in Mexico in terms of their environmental impact and economic factors. Life cycle assessment (LCA) using SimaPro was carried out to calculate environmental impacts by using a cradle-to-gate approach. A preliminary economic analysis was performed to determine the economic feasibility of the studied options. Also, capital goods costs were obtained using the Aspen Plus economy package. Moreover, a sensitivity analysis was involved to compare the environmental and economic viability of producing bioethanol from sugarcane molasses and agave juice. LCA results revealed that cultivation and fermentation were the most harmful stages when producing bioethanol from sugarcane molasses and agave juice, respectively. Furthermore, when it was derived from agave juice rather than sugarcane molasses, it had more environmental benefits. This was ascribed to the lower consumption rate of fertilizers, pesticides, and emissions given off from the former. Regarding financial aspects, the preliminary analysis showed that producing bioethanol was not economically viable when grid energy alone was used. However, if power from the grid is partially replaced with renewable energy, producing bioethanol becomes economically feasible, and sugarcane molasses is the most suitable feedstock.

Combinations of emerging technologies with fermentation: Interaction effects for detoxification of mycotoxins?

Consumption of foods containing mycotoxins, as crucial groups of naturally occurring toxic agents, could pose significant health risks. While the extensive scientific literature indicates that prevention of contamination by toxigenic fungi is one of the best ways to reduce mycotoxins, detoxifying strategies are useful for improving the safety of food products. Nowadays, the food and pharmaceutical industries are using the concept of combined technologies to enhance the product yield by implementing emerging techniques, such as ultrasound, ohmic heating, moderate electric field (MEF), pulsed electric field (PEF) and high-pressure processing, during the fermentation process. While the application of emerging technologies in improving the fermentation process is well explained in this literature, there is a lack of scientific texts discussing the possibility of mycotoxin degradation through the interaction effects of emerging technologies and fermentation. Therefore, this study was undertaken to provide deep insight into applying emerging processing technologies in fermentation, mechanisms and the prospects of innovative combinations of physical and biological techniques for mycotoxins' detoxification. Among various emerging technologies, ultrasound, ohmic heating, MEF, PEF, and cold plasma have shown significant positive effects on fermentation and mycotoxins detoxification, highlighting the possibility of interactions from such combinations to degrade mycotoxins in foods.

Ohmic heating as a promising technique for extraction of herbal essential oils: Understanding mechanisms, recent findings, and associated challenges

The applicability of ohmic heating, as a volumetric heating technique, has been explored in various sectors of the food industry. The use of ohmic heating for essential oil extraction is among its emerging applications. This chapter overviews the recent progress in this area of research, discusses the mechanisms involved in ohmic-based essential oil extraction processes, explains the effective process parameters, highlights their benefits, and explains the considerations to address the obstacles to industrial implementation. Ohmic-assisted hydrodistillation (OAHD) and ohmic-accelerated steam distillation (OASD) systems were proposed as alternatives to conventional hydrodistillation and steam distillation, respectively. These techniques have successfully extracted essential oils from several aromatic plants (e.g., thyme, peppermint, citronella, and lavender). Both OAHD and OASD possess a number of benefits, such as reducing the extraction time and energy consumption, compared to classical extraction methods. However, these techniques are in their infancy and further economic and upscaling studies are required for their industrial adaptation.

Essential oils as natural additives to prevent oxidation reactions in meat and meat products: A review

Oxidation reactions during manufacturing, distribution, and storage of meat and meat products result in undesirable physicochemical changes and aromas, which leads to detrimental effects on the product quality. This could be translated into the consumer dissatisfaction and economic loss. One of the most common practices to overcome this issue is the incorporation of synthetic antioxidants. However, the increasing health-consciousness of consumers and their preference for natural additives leads to the search of natural alternatives to synthetic antioxidants. A number of essential oils have strong antioxidant properties and are explored as potential alternatives to chemical antioxidants in the meat industry. These compounds are classified as Generally Recognized as Safe (GRAS), and their application single or combined with other essential oils, ingredients or preservation technologies have beneficial effects on meat products. Their activity depends on several parameters including their concentrations, their possible synergistic effects, and the extraction method used to obtain them. Although steam distillation is the most common industrial technique for essential oils extraction, novel technologies have been emerged to address the drawbacks of the traditional extraction method and to obtain high-quality essential oils. This paper provides an overview of the application of essential oils as potential substitutes for synthetic antioxidants in the meat industry, exploring their mechanism of action against oxidation reactions, and the effect of extraction methods on their effectiveness.