Rosa Quirantes-Piné

The present study focuses on recovering phenolic compounds and terpenes from olive leaves, which are generated as by-products during olive oil processing. To this end, conventional extraction/maceration (CE) and advanced extraction techniques such as subcritical water extraction (SWE), pressurized fluid extraction (PLE) and ultrasound-assisted extraction (UAE) were employed to compare and determine the most effective procedure. The phenolic and terpenoid composition of the extracts revealed a total of 33 compounds in HPLC-QTOF-MS analysis. According to these findings, the optimal extraction techniques for the maximum recovery of secoiridoids from olive leaves were PLE and UAE, with no significant difference between them (21.9891 ± 2.5521 mg/g DW and 21.0888 ± 1.3494 mg/g DW, respectively). Regarding to flavonoids, UAE was the most effective extraction technique, yielding 4.9837 ± 0.6739 mg/g DW. However, SWE recovered the highest amount of phenolic alcohols (7.4201 ± 0.9848 mg/g DW), which could be due to degradation of the secoiridoids during extraction. Conversely, UAE was more successful than the other techniques for the extraction of the terpene family (0.7373 ± 0.0601 mg/g DW). The present study therefore focuses on comparing different extraction techniques for revalorizing olive leaves as a source of bioactive compounds, specifically polyphenols and terpenes, due to their beneficial health properties.

The olive oil industry generates by-products like olive leaves and pomace, which are rich in bioactive compounds, especially polyphenols. This study applied a circular economy approach to valorize these residues using green ultrasound-assisted extraction (UAE) with GRAS solvents. Key parameters (solvent composition, ultrasound amplitude, and specific energy) were optimized via Response Surface Methodology (RSM) to enhance polyphenol recovery and yield. Ethanol concentration proved to be the most influential factor. Optimal conditions for olive pomace were 100% ethanol, 46 μm amplitude, and 25 J∙mL⁻¹ specific energy, while olive leaves required 72% ethanol with similar ultrasound settings. Under these conditions, extracts were prepared and analyzed using HPLC-ESI-QTOF-MS and DPPH assays. The optimized UAE process achieved yields of 15–20% in less than 5 min and under mild conditions. Optimal extracts showed high oleuropein content (6 mg/g in leaves, 5 mg/g in pomace), lower hydroxytyrosol levels, and minimal oxidized derivatives, suggesting reduced degradation compared to conventional methods. These findings demonstrate UAE’s effectiveness in recovering valuable phenolics from olive by-products, supporting sustainable and efficient resource use.

Broccoli agro-industries generate a significant amount of waste, which leads to both environmental and economic problems. These by-products are typically discarded, despite being a valuable source of bioactive compounds, including glucosinolates (GSLs), which can modulate oxidant and inflammatory mediators, exerting anti-inflammatory properties. A crucial challenge in the exploitation of broccoli agro-industrial by-products is the development of sustainable and green extraction technologies. In this work, pressurized liquid extraction (PLE) based on response surface methodology (RSM) has been developed and optimized for the GSLs’ extraction, with the aim to evaluate the potential protective mechanisms triggered by GSLs-enriched extracts from broccoli by-products in CCD-18Co myofibroblasts exposed to lipopolysaccharide (LPS). The results obtained showed that the PLE is an efficient and environmentally sustainable alternative procedure for extracting GSLs from broccoli by-products. Furthermore, the GSLs-enriched extract obtained through PLE exhibited antioxidant and anti-inflammatory properties in LPS-stimulated cells, being able to attenuate the expression of some proinflammatory markers (IL-1β, IL-6, IL-8, and TNF-α). Therefore, these compounds could serve as potential nutraceutical agents for the prevention and mitigation of oxidative and inflammatory processes related to intestinal bowel diseases, while also promoting the valorization of these by-products.

Vegetable oils are highly valued for their nutritional and functional properties, driving scientific interest in developing innovative technologies to enhance production processes. These advancements aim to improve yield, nutritional profiles and organoleptic and functional characteristics. Additionally, vegetable oils have been recognised for their ability to incorporate phenolics as bioactive compounds through stabilisation methods, further enhancing their health benefits. This study conducts a systematic review addressing two main objectives: (i) advanced technologies intended to enhance extraction efficiency while improving the overall quality of vegetable oils and (ii) stabilisation strategies developed to enrich and fortify edible vegetable oils with special focus on phenolic compounds. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was applied to evaluate their applications in developing bioactive vegetable oil ingredients and foods. Extraction techniques were assessed based on efficiency in yield and their impact on nutritional, organoleptic and functional properties. Pulsed electric field technology emerged as the most promising approach, offering an optimal balance between oil yield and quality. Combining stirring or high-performance dispersion with ultrasound proved effective in forming stable emulsions for phenolic stabilisation. These strategies provide valuable insights for the agro-industrial sector to enhance production processes and develop healthier, bioactive vegetable oils.

Background/Objectives: Olive oil is valued for its health benefits, largely due to its bioactive compounds, including hydroxytyrosol (HTyr) and oleuropein (OLE), which have antioxidant, anti-inflammatory, and cardioprotective properties. However, many of these compounds are lost during the production process. This study developed a functional olive oil-derived product using water-in-oil emulsions (W/O) to incorporate commercial extracts rich in HTyr and OLE. Methods: HTyr and OLE were encapsulated in a W/O emulsion to preserve their bioactivity. The encapsulation efficiency (EE) was evaluated, and the performance of the emulsion was tested using an in vitro gastrointestinal digestion model. Bioaccessibility was measured by calculating the recovery percentage of HTyr and OLE during the digestion stages. Results: The results showed that OLE exhibited higher EE (88%) than HTyr (65%). During digestion, HTyr exhibited a gradual and controlled release, with bioaccessibility exceeding 80% in the gastric phase and a maintained stability throughout the intestinal phase. In contrast, OLE displayed high bioaccessibility in the gastric phase but experienced a notable decrease during the intestinal phase. Overall, the W/O emulsion provided superior protection and stability for both compounds, particularly for the secoiridoids, compared to the non-emulsified oil. Conclusions: The W/O emulsion improved the encapsulation and bioaccessibility of HTyr and OLE, constituting a promising method for enriching olive oil with bioactive phenolic compounds. Therefore, this method could enhance olive oil’s health benefits by increasing the availability of these bioactive compounds during digestion, offering the potential for the development of fortified foods.

Honeydew honey is produced by bees (Apis mellifera) foraging and collecting secretions produced by certain types of aphids on various parts of plants. In addition to exhibiting organoleptic characteristics that distinguish them from nectar honey, these honeys are known for their functional properties, such as strong antioxidant and anti-inflammatory activities. Despite their importance, they remain poorly characterized in comparison with flower honeys, as most studies on this subject are not only carried out on too few samples but also still focused on traditional chemical–physical parameters, such as specific rotation, major sugars, or melissopalynological information. Since mass spectrometry has consistently been a primary tool for the characterization and authentication of honeys, this review will focus on the application of these methods to the characterization of the minor fraction of honeydew honey. More specifically, this review will attempt to highlight what progress has been made so far in identifying markers of the authenticity of the botanical and/or geographical origin of honeydew honeys by mass spectrometry-based approaches. Furthermore, strategies devoted to the determination of contaminants and toxins in honeydew honeys will be addressed. Such analyses represent a valuable tool for establishing the level of food safety associated with these products. A critical analysis of the presented studies will identify their limitations and critical issues, thereby describing the current state of research on the topic.

Olive oil is a food of great importance in the Mediterranean diet and culture. However, during its production, the olive oil industry generates a large amount of waste by-products that can be an important source of bioactive compounds, such as phenolic compounds and terpenes, revalorizing them in the context of the circular economy. Therefore, it is of great interest to study the distribution and abundance of these bioactive compounds in the different by-products. This research is a screening focused on phytochemical analysis, with particular emphasis on the identification and quantification of the phenolic and terpenic fractions. Both the main products of the olive industry (olives, olive paste and produced oil) and the by-products generated throughout the oil production process (leaf, “alpeorujo”, liquid and solid residues generated during decanting commonly named “borras” and washing water) were analyzed. For this purpose, different optimized extraction procedures were performed for each matrix, followed by high-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry (HPLC-ESI-TOF/MS) analysis. Although no phenolic alcohols were quantified in the leaf and the presence of secoiridoids was low, this by-product was notable for its flavonoid (720 ± 20 µg/g) and terpene (5000 ± 300 µg/g) contents. “Alpeorujo” presented a complete profile of compounds of interest, being abundant in phenolic alcohols (900 ± 100 µg/g), secoiridoids (4500 ± 500 µg/g) and terpenes (1200 ± 100 µg/g), among others. On the other hand, while the solid residue of the borras was the most abundant in phenolic alcohols (3700 ± 200 µg/g) and secoiridoids (680 ± 20 µg/g), the liquid fraction of this waste was notable for its content of elenolic acid derivatives (1700 ± 100 µg/mL) and phenolic alcohols (3000 ± 300 µg/mL). Furthermore, to our knowledge, this is the first time that the terpene content of this by-product has been monitored, demonstrating that it is an important source of these compounds, especially maslinic acid (120 ± 20 µg/g). Finally, the phytochemical content in wash water was lower than expected, and only elenolic acid derivatives were detected (6 ± 1 µg/mL). The results highlighted the potential of the olive by-products as possible alternative sources of a wide variety of olive bioactive compounds for their revalorization into value-added products.