• Energy Research

The aim of this work was to investigate ultrasound (US)-assisted green solvent extraction of valuable compounds from the microalgae Nannochloropsis spp. Individual green solvents (water, ethanol (EtOH), dimethyl sulfoxide (DMSO)) and binary mixture of solvents (water-DMSO and water-EtOH) were used for the extraction procedures. Maximum total phenolic compounds yield (Yp ≈ 0.33) was obtained after US pre-treatment (W=400 W, 15 min), being almost 5-folds higher compared to that found for the untreated samples and aqueous extraction (Yp ≈ 0.06). The highest yield of total chlorophylls (Yc ≈ 0.043) was obtained after US (W=400 W, 7.5 min), being more than 9-folds higher than those obtained for the untreated samples and aqueous extraction (Yc ≈ 0.004). The recovery efficiency decreased as DMSO>EtOH>H2O. The optimal conditions to recover phenolic compounds and chlorophylls from microalgae were obtained after US pre-treatment (400 W, 5 min), binary mixtures of solvents (water-DMSO and water-EtOH) at 25-30%, and microalgae concentration of 10%.

Chamomile (Matricaria chamomilla L.) dried flowers contain a group of interesting biologically active compounds such as sesquiterpenes, flavonoids, coumarins, vitamins, phenolic acids and glucosides. Therefore, the aim of the present study was to characterize the composition in bioactive compounds (specialized metabolites) present in water and ethanol extracts of chamomile flowers, together with monitoring the impact of different extraction techniques (conventional vs. ultrasound-assisted extraction (UAE)) on the parameters under investigation. UAE treatment significantly decreased the extraction time of bioactive compounds from herbal material. Polyphenolic compounds content and antioxidant capacity were significantly higher in UAE extracts. Moreover, solvent type had a significant impact on the specialized metabolites content, while the highest vitamin C and polyphenols content were recorded in 50% ethanol (v/v) extracts. Optimization of basic extraction factors: solvent type, temperature and technique is crucial for obtaining the extracts with the highest content of specialized metabolites and antioxidant capacity.

One of the developmental aspects of food science is testing and adapting advanced technologies for food production that save resources and improve food quality. More often than not, this includes technologies that operate at lower temperatures, shorter time and result with better preservation of the thermolabile compounds in the foods, as compared to conventional technologies. Nutritionally rich, but thermally sensitive raw materials as fruit, vegetables, meats and other, can particularly benefit from application of such advanced food technologies. Technologies with the most tested potential for industrial implementation include non-thermal plasma, pulsed electric field, high hydrostatic pressure, high intensity ultrasound, and others. Even though such technologies have obstacles to wide industrial implementation, they can be widely applied in unit operations such as processing, pasteurization, and extraction. Additionally, those technologies combined with exploitation of the economic and sustainable raw materials, as industrial wastes from food production, are foundation for green and ecofriendly food production and processing. This chapter gives overview of green food processing concepts, strategies and tools.

The paper presents experimental results concerning the ultrasonically-assisted extraction of bioactive compounds from Erodium glaucophyllum roots. A comparison with conventional methodology is presented, and thereby the phytochemical composition and the antioxidant and anti-inflammatory activities of extracts are evaluated. The phenolic profile of Erodium extracts was analyzed by TOF–LC–MS–MS. The identification of phenolic compounds revealed that the major component was (+)-gallocatechin in the aqueous extracts obtained for the different extraction methodologies. The highest quantity of phenolic compounds and antioxidant capacity was found in the hydroethanolic extract obtained by conventional extraction (29.22–25.50 mg GAE/g DM; 21.174 mM Trolox equivalent). The highest content of carotenoids, varying from 0.035 to 0.114 mg/g dry matter, was reached by ultrasonic-assisted extraction. Furthermore, Erodium extracts showed a potent inhibition of the inflammatory reaction by means of the inhibition of tumor necrosis factor-alpha (TNF-α). The extracts obtained when ultrasound extraction was combined with ethanol:water (50:50, v/v) presented the greatest inhibition (92%).

In recent years, the rapid increase in the global population, the challenges associated with climate change, and the emergence of new pandemics have all become major threats to food security worldwide. Consequently, innovative solutions are urgently needed to address the current challenges and enhance food sustainability. Green technologies have gained significant attention for many food applications, while the technologies of the fourth industrial revolution (Industry 4.0) are reshaping different production and consumption sectors, such as food and agriculture. In this review, a general overview of green and Industry 4.0 technologies from a food perspective will be provided. Connections between green food technologies (e.g., green preservation, processing, extraction, and analysis) and Industry 4.0 enablers (e.g., artificial intelligence, big data, smart sensors, robotics, blockchain, and the Internet of Things) and the Sustainable Development Goals (SDGs) will be identified and explained. Green and Industry 4.0 technologies are both rapidly becoming a valuable part of meeting the SDGs. These technologies demonstrate high potential to foster ecological and digital transitions of food systems, delivering societal, economic, and environmental outcomes. A range of green technologies has already provided innovative solutions for major food system transformations, while the application of digital technologies and other Industry 4.0 technological innovations is still limited in the food sector. It is therefore expected that more green and digital solutions will be adopted in the coming years, harnessing their full potential to achieve a healthier, smarter, more sustainable and more resilient food future.

Abstract Solar energy has recently attracted the attention of both industry and academia, to be used as a source of clean energy for green production of various products such as food-related commodities. This review aims to explore the applicability of this green energy source for extraction of valuable components (e.g., bioactive compounds and essential oils) from plant materials and waste biomass, dehydration of plant materials, water recovery through desalination, decontamination, cooking, and baking of agri-food products. According to the literature, concentrated solar power systems (CSP) have been successfully employed for bioactive compounds (e.g. essential oils) extraction, drying process, water desalination and decontamination, baking, and cooking. While CSP systems provide several benefits, such as low greenhouse gases emission and reduced production cost, their application is associated with several limitations which are taken into account in this review. Further considerations for improving the performance and applicability of CSP in the food industry are also discussed in the present study.