Mandarin peel is a valuable but underutilized source of numerous bioactive compounds. The main focus of this work was to develop an integrated two-step process for the subsequent extraction of polyphenols and carotenoids (step 1) and pectin (step 2) from mandarin peel by microwave-assisted extraction (MAE), using only green solvents. This represents a novel, scale-up-suitable approach that might contribute to the improved revalorization of mandarin peel. Response surface methodology was used to maximize the yields of polyphenols, flavonoids, and carotenoids, as well as antioxidative activity (DPPH- and ABTS-radical scavenging capacity). The sample-to-solvent ratio and solvent type significantly influenced extractability of polyphenols and carotenoids, while extraction time and power were the key variables influencing pectin yield. Optimal extracts contained 21.76 ± 0.46 mg GAE/g of polyphenols (with 139.7 ± 2.28 mg/g and 703.62 ± 51.72 µg/g of tangeretin and nobiletin, respectively); 352.3 ± 17.4 µg/g of β-carotene and 273 ± 23 mg/g of pectin. MAE resulted in either higher yields, reduced extraction times or both, compared to conventional solvent extraction (CSE), depending on the target compound. The energy consumption of MAE was considerably lower, compared to CSE, in four out of five developed extraction procedures. Pectin obtained in the integrated two-step process had higher purity compared to pectin extracted from intact mandarin peel.

Tomato processing waste (TPW), a byproduct of the tomato processing industry, is generated in significant quantities globally, presenting a challenge for sustainable waste management. While traditionally used as animal feed or fertilizer, TPW is increasingly recognized for its potential as a valuable raw material due to its high content of bioactive compounds, such as carotenoids, polyphenols and pectin. These compounds have significant health benefits and are in growing demand in the pharmaceutical and cosmetic industries. Despite this potential, the broader industrial utilization of TPW remains limited. This review explores the influence of various processing, pretreatment and extraction methods on the concentration and stability of the bioactive compounds found in TPW. By analyzing the effects of these methodologies, we provide insights into optimizing processes for maximum recovery and sustainable utilization of TPW. Additionally, we address the major challenges in scaling up these processes for industrial application, including the assessment of their ecological footprint through life cycle analysis (LCA). This comprehensive approach aims to bridge the gap between scientific research and industrial implementation, facilitating the valorization of TPW in line with circular economy principles.

Olive pomace extract (OPE) was investigated as a potential surface modifier for the development of the green synthesis process of selenium nanoparticles (SeNPs). In order to evaluate them as potential nutraceuticals, the obtained nanosystems were characterized in terms of size distribution, shape, zeta potential, stability in different media, gastrointestinal bioaccessibility and biocompatibility. Systems with a unimodal size distribution of spherical particles were obtained, with average diameters ranging from 53.3 nm to 181.7 nm, depending on the type of coating agent used and the presence of OPE in the reaction mixture. The nanosystems were significantly affected by the gastrointestinal conditions. Bioaccessibility ranged from 33.57% to 56.93% and it was significantly increased by functionalization of with OPE. Biocompatibility was investigated in the HepG2 and Caco2 cell models, proving that they had significantly lower toxicity in comparison to sodium selenite. Significant differences were observed in cellular responses depending on the type of cells used, indicating differences in the mechanisms of toxicity induced by SeNPs. The obtained results provide new insight into the possibilities for the utilization of valuable food-waste extracts in the sustainable development of nanonutraceuticals.

Antioxidants are essential bioactive compounds widely recognized for their health benefits in preventing oxidative stress-related diseases. However, many lipophilic antioxidants suffer from poor aqueous solubility, low chemical stability, and limited bioavailability, restricting their application in food, nutraceutical, and pharmaceutical industries. Cyclodextrins (CDs), a class of cyclic oligosaccharides with a hydrophilic exterior and lipophilic interior, present an effective strategy to encapsulate and deliver these compounds by improving their solubility, stability, and therapeutic efficacy. This review critically examines the structural features and derivatives of cyclodextrins relevant for antioxidant encapsulation, mechanisms and thermodynamics of inclusion complex formation, and advanced characterization techniques. It evaluates the influence of CD encapsulation on the oral bioavailability and antioxidant activity of various lipophilic antioxidants supported by recent in vitro and in vivo studies. Moreover, sustainable preparation methods for CD complexes are discussed alongside safety and regulatory considerations. The comprehensive synthesis of current knowledge contributes to guiding the rational design and development of CD-based antioxidant nutraceuticals, addressing formulation challenges while promoting efficacy and consumer safety.

Rising industrial demands emphasize the need for exploring other non-traditional sources for obtaining pectin. As efforts to enhance circular economy practices and reduce reliance on primary resources intensify; the focus has shifted towards utilizing various types of agricultural and food industry waste; including tomato pomace waste (TPW). In this work; the microwave-assisted extraction (MAE) and TPW pretreatment methods were optimized to improve pectin yields and decrease the environmental impact of the extraction process; compared to conventional solvent extraction (CSE). The response surface methodology was used to model the optimization process. The physico-chemical properties of pectin were determined using titrimetric methods and FTIR spectroscopy. A life cycle assessment (LCA) was applied to assess the environmental impact of MAE and CSE. Optimal microwave conditions (11.66 min/600 W/pH 1) yielded two times more pectin than CSE (2 h/85 °C/pH 1.5). Pre-processing treatments (mechanical ball milling and defatting) showed marginal effects on pectin yields and properties; and; therefore; can be omitted in order to reduce the energy consumption of the process. The LCA showed that single conventional extraction treatment had two times higher values of the ecological footprint compared to MAE; for all indicators. The results suggest that MAE can be used as an efficient green method for pectin extraction from TPW

The aim of this study was to determine the retention of fatty acids, α-tocopherol, and carotenoids in sea buckthorn oil (SBO) encapsulated with gum arabic (GA), β-cyclodextrin (β-CD), and their mixture (1:1) under pre-optimized spray drying conditions in comparison to the bioactive molecule (BAM) content of the non-encapsulated oil. In addition, the color parameters in the spray-dried powders and the bioaccessibility of β-carotene, which has the highest provitamin A activity, were evaluated. The fatty acid content remained almost unchanged, while statistically significant differences in α-tocopherol and carotenoid content were found between the SBO encapsulated with different carriers and the non-encapsulated oil. The retention of tocopherols and carotenoids compared to the non-encapsulated SBO ranged from 62.13 to 87.23% and from 21.17 to 97.61%, respectively. SBO encapsulated with β-CD showed significantly higher retention of α-tocopherol (87.23%) and individual carotenoids (40.71–97.61%). In addition, the powders showed no significant differences in color parameters, and the powders encapsulated with GA and β-CD showed high bioaccessibility of β-carotene (92.50 and 90.45%, respectively). β-CD proved to be the most suitable carrier for the encapsulation of the carotenoids and α-tocopherol of SBO, resulting in powders with high bioaccessibility of β-carotene.