Lucia Cuesta Ramos

Edible Insects (EIs) are an alternative source of bioactive compounds such as proteins or fatty acids and micronutrients as vitamins or minerals, thus showing potential to replace traditional foodstuffs in an economical and environmentally friendly way. Nonetheless, EIs can accumulate hazardous chemicals such as mycotoxins and heavy metals. The aim of the present study is to determine mycotoxins and heavy metal content in raw insect samples and those resulting products obtained after supercritical fluid extraction (SFE). Insect samples included Acheta domesticus (cricket) meal, Tenebrio molitor (mealworm) meal, Alphitobius diaperinus (buffalo worm), and Locusta migratoria (locust). For this purpose, a QuEChERS method followed by LC-MS/MS analysis was optimized with good results for the analysis of mycotoxins, principally Aflatoxins (AFs), Ochratoxin A (OTA), and Enniatins (ENNs). In contrast, heavy metals (As, Cd, Hg, Pb) were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results obtained revealed that Locust was positive for AFG2 at a level of 115.5 μg/kg, and mealworm was only contaminated with OTA at 58.1 μg/kg. Emerging mycotoxins (ENNA, ENNA1, ENNB, and ENNB1) were detected at lower levels < 2.2 µg/Kg. Concerning heavy metals, limits exceeding regulation were detected for Cd in the insect species studied, with levels up to 219 μg/kg, and for Pb in crickets (100.3 μg/kg). Finally, the analysis of the post-extraction solids after SFE processing revealed that heavy metals remained in the resulting SFE cakes, while mycotoxins were detected at negligible levels (up to 1.3 µg/Kg).

Azara dentata Ruiz & Pav. is a small Chilean native plant from Patagonia, a producer of small white reddish berries. For the first time, the proximal analysis of the fruits, phenolic fingerprinting, the antioxidant activity, and the enzymatic inhibition and relaxation effects in rat aorta induced by the ethanolic extract of these fruits were investigated. The proximal composition and the mineral (Ca: 2434 ± 40 mg/kg; Mg: 702 ± 13 mg/kg; Fe: 117.1 ± 1.6 mg/kg; Zn: 16.1 ± 0.4 mg/kg) and heavy metal (As: 121 ± 11 µg/kg; Cd: 152 ± 5 µg/kg; Hg: 7.7 ± 1.3 µg/kg; Pb 294 ± 4 µg/kg) contents were analyzed. Anthocyanins, flavonoids, phenolic acids, and coumarins were identified using UHPLC-PDA-QTOF-MS. The ethanolic extracts showed a total phenolic content of 23.50 ± 0.93 mg GAE/g extract. In addition, the antioxidant activity was assessed using both DPPH and TEAC (28.64 ± 1.87 and 34.72 ± 2.33 mg Trolox/g of dry fruit, respectively), FRAP (25.32 ± 0.23 mg Trolox equivalent/g dry fruit), and ORAC (64.95 ± 1.23 mg Trolox equivalents/g dry fruit). The inhibition of enzymatic activities (acetylcholinesterase IC₅₀: 2.87 + 0.23 µg extract/mL, butyrylcholinesterase IC₅₀: 6.73 + 0.07 µg extract/mL, amylase IC₅₀: 5.6 ± 0.0 µg extract/mL, lipase IC₅₀: 30.8 ± 0.0 µg extract/mL, and tyrosinase IC₅₀: 9.25 ± 0.15 µg extract/mL) was also assessed. The extract showed 50–60% relaxation in rat aorta (intact), mediated thorough the release of endothelial nitric oxide. Our results suggest that A. dentata is a good source of compounds with the capacity to inhibit important enzymes, can be hypotensive, and can thus have good potentiality as supplements in the amelioration of neurodegenerative diseases and could also have potential to be used to develop new functional foods. The study highlights the benefits of these neglected small fruits and could boost their consumption.

There is a great demand for the recovery of bioactive compounds from by-products and side streams in the food and cosmetic industries. More sustainable extraction methodologies are being chosen, such as pulsed electric field (PEF) assisted extraction, supercritical fluid extraction (SFE), pressurized liquid extraction (PLE), and ultrasound-assisted extraction. Endemic fruits represent a great and little-explored source of biomolecules that can become potential candidates for the study of new drugs and support the use of native species in functional foods or nutraceuticals. Some phenolics from Chilean fruits proved to have potential in the prevention of non-communicable or chronic diseases. The study aimed to produce polyphenolic-rich extracts from corcolen (Azara dentata Ruiz & Pav) by non-thermal methodologies. Two extracts were obtained by means of SFE, using CO₂ and ethanol as co-solvents, and PLE using water as a solvent. The total antioxidant capacity, total phenolic content, carbohydrates, and proteins of both extracts were analyzed. The resulting phenolic content of the extracts obtained by SFE and PLE was 5.37 ± 0.38 and 21.17 ± 0.57 mg GAE/g sample, respectively. The total antioxidant capacity was 3.22 ± 0.47 and 18.05 ± 1.25 mg Trolox/g sample for the SFE and PLE extracts, respectively. Moreover, corcolen composition was characterized by LC-TTOF chromatography, being chrysoeriol 7-O-glucoside, isorhamnetin 7-O-rhamnoside, isorhoifolin, rhoifolin, kaempferol 3-O-feruloyl-sophoroside 7-O-glucoside, kaempferol 3-O-feruloyl-sophorotrioside, spinacetin 3-O-(2-p-coumaroylglucosyl) (1->6)-apiosyl (1->2)-glucoside, cyanidin 3-O-(-xylosyl-(6-caffeoyl-glucosyl)-galactoside), the eight more predominant flavonoids. The different extraction methodologies allowed the obtaining of extracts with an interesting antioxidant capacity, rich in polyphenols, that could potentially find several applications as dietary supplements, ingredients for cosmetic formulations, or additives in food.

Currently, the consumption of natural extracts from medicinal plants and fruits present in nature, and the discovery of the many benefits and positive impacts on the human body connected to their intake have favored and promoted research in the field of extraction. For this purpose, in recent years, the extracts of plant parts (leaves, branches, seeds, stem, roots, fruits, etc.) of the genus of Asteriscus, Atriplex, Haloxylon, Ruta, Ficus, Olea, and Zizyphus have been investigated for their several biological properties and therapeutic activities including those as an antioxidant, antitumoral, antiproliferative, hepatoprotective, and antimicrobial. The shortcoming of using conventional methods, such as maceration, Soxhlet solvent extraction, and pressurized hot water, has promoted the development of novel, efficient, economical, and safe extraction techniques to recover the bioactive compounds without losing their quality and properties. Innovative methodologies, such as supercritical fluid technology and pulsed electric field-assisted extraction, have been proposed as sustainable methodologies to isolate nutraceuticals and pharmaceuticals from natural matrices, such as herbs, spices, and aromatic and medicinal plants. This study aimed to obtain extracts from fruits, leaves, and roots of Ziziphus lotus by Supercritical Fluid Extraction (SFE, P = 25 MPa, T = 40 °C, Time = 60 min, Flow = 10 mL/min, Solvent = 90 CO₂:10 Ethanol) and Pulsed Electric Field (PEF, E = 3 kV/cm, Ws = 100 kJ/kg, Solvent = water, followed by 60 min of agitation) assisted extraction and characterize the extracts in terms of total antioxidant capacity (Oxygen Radical Absorbance Capacity (ORAC) and Total Equivalent Antioxidant Capacity (TEAC)), total phenolics, chlorophyll, and carotenoids content. PEF extracts presented an interesting content of total phenolic compounds (TPC): Fruits: 14.8 ± 0.1; Leaves: 31.1 ± 1.8; Roots: 28.8 ± 1.7 mg GAE/g DW. On the other hand, the concentration of TPC in SFE extracts was: Fruits: 5.91 ± 0.2; Leaves: 1.184 ± 0.2; Roots: 5.72 ± 0.8 mg GAE/g DW. Total chlorophyll content (TCC) was: Fruits: 366 ± 1; Leaves: 471 ± 12; Roots: 192 ± 16 mg/g DW in the case of PEF extracts and 5.0 ± 0.3; 97 ± 1; 8.5 ± 0.1 mg/g DW, respectively, in the case of SFE. Finally, the content of carotenoids was 128.0 ± 0.5; 62 ± 1; 169 ± 1 mg/g DW for PEF-extracted fruits, leaves, and roots, respectively, and 5.92 ± 0.04; 19.76 ± 0.02; 4.97 ± 0.04 mg/g DW for SFE extracted fruits, leaves, and roots, respectively. PEF-assisted extraction allowed the recovery of more phenolics, chlorophyll, and carotenoid compounds than SFE. The TEAC was higher for PEF extracts but ORAC was higher for SFE extracts. This could be related to the different polarities of the solvent used for extraction in each technique. Green extraction methodologies represent an efficient and safe extraction technique to recover bioactive compounds without losing their quality and properties.