Novel Affordable, Reliable and Efficient Technologies to Help Addressing the Water-Energy-Food Nexus

Abstract

Improving the food system sustainability and security is becoming an urgent global challenge. In this regard, one of the most effective routes is the shift of the human diet toward healthier and more sustainable consumption, involving in particular the prevalence of plant-based raw food materials. Controlled hydrodynamic cavitation (HC) technologies could help considerably in this transition. HC techniques are gaining increased scientific interest, and are quickly spreading across a wide range of technical fields, recently showing surprising performances with biological raw materials related to the food, agricultural and forestry sectors and resources. HC processes enjoy recognized advantages in the acceleration of the processing steps of plant-based food, the extraction of valuable bioactive compounds, the reduction and the valorization of waste streams, as well as the superior efficiency in resource use, energy consumption, process yield, and exergy balance than competing processes. Thus, HC is very promising candidate to help addressing the water-energy-food nexus, and, ultimately, sustainability. Findings obtained from direct experimental trials and recent literature concerning the applications of HC to food processing, provide a strong basis for novel investigation aimed at standardization, starting from the identification of the most suitable devices and the optimal processing parameters, eventually oriented to further spreading of HC applications.

Exceptional Antioxidant, Non-Cytotoxic Activity of Integral Lemon Pectin from Hydrodynamic Cavitation

“…These results open the route to the development of a number of new, integral pectin-based nutraceutical formulations based on the simple, low cost, scalable and efficient hydrodynamic cavitation extraction process applied to waste lemon peel suspended in water, while meeting all the principles of natural product green extraction [8,9].…”

“…Amid them, perhaps the most promising method from the industrial viewpoint is the extraction based on controlled hydrodynamic cavitation (HC) [8]. Originally demonstrated in the citrus fruit field with waste orange peel on semi-industrial scale (42 kg of raw material in 142 L water) [9], the process quickly affords extraction and separation of water soluble and insoluble bioproducts with practically no degradation neither of pectin nor of the valued phytochemicals contained in the orange peel.…”

Hydrodynamic Cavitation-based Rapid Expansion of Hesperidin-rich Products from Waste Citrus Peel as a Potential Tool Against COVID-19

“…Figure 2 shows the main technological components of the proposed process based on the experience gained by authors, although variants are easy to set up, such as replacing the centrifugal pump and the Venturi-shaped reactor with a rotor-stator arrangement, according to specific and local expertise or whatever preference. Moreover, the Venturi-shaped reactor could be realized in accordance with long established rules for circular-section ones [60], or in the form of generally more performing slit Venturi [43], as well as optimized by numerical simulations [62]. Other emerging setups could be used too, such as based on vortex diode [63].…”

“…The implosion events release extraordinary intense energy pulses and, eventually, pressure shockwaves, hydraulic jets, extreme transient heating, and chemical dissociation reactions. Past studies and comprehensive reviews are available, which explain the above-mentioned mechanisms in great detail [43][44][45].…”

“…In terms of process yield, HC methods were found to outperform alternative long established and emerging methods, including acoustic cavitation, for most of applications including wastewater remediation, water disinfection, and especially extraction of natural products [43,46], showed compliance with the principles of green extraction [47], and demonstrated straightforward scalability [48]. In particular, fixed-reactor arrangements, such as based on orifice plates or Venturi tubes, are easy to construct and operate, reliable and can be easily optimized towards the desired effect [43]. Venturi-shaped reactors are particularly suitable for applications such as extraction of natural products, due to more diffuse bubble implosion events and avoidance of clogging, in comparison to orifice plates.…”