Association of enzymatic and optimized ultrasound-assisted aqueous extraction of flavonoid glycosides from dried Hippophae rhamnoides L. (Sea Buckthorn) berries.

The main purpose of the present study was to determine the effect of associating an optimized ultrasound-assisted extraction (UAE) protocol with enzyme-assisted extraction (EAE) in aqueous media, using the dried berries of Hippophae rhamnoides L. (sea buckthorn) as plant material. A specialized software was used for the determination of potential optimal extraction parameters, leading to the development of four optimized extracts with different characteristics (UAE ± EAE). For these extracts, buffered or non-buffered solutions have been used, with the aim to determine the influence of adjustable pH on extractability. As enzymatic solution, a pectinase, cellulase, and hemicellulase mix (2:1:1) has been applied, acting as pre-treatment for the optimized protocol. The highest extractive yields have been identified for non-buffered extracts, and the E-UAE combination obtained extracts with the highest overall in vitro antioxidant activity. The HPLC-MSn analysis demonstrated a rich composition in different types of isorhamnetin-O-glycosides, as well as some quercetin-O-glycosides, showing a high recovery of specific flavonol-type polyphenolic species. Moreover, we have tentatively identified two flavanols (i.e., catechin and epigallocatechin) and one flavone derivative (i.e., luteolin).

In situ extraction/encapsulation of olive leaves antioxidants in zein for improved oxidative stability of edible oils.

This study presents a sustainable and cost-effective method for preserving the bioactivity of phenolic compounds in olive leaves (OLE) during their application. The extraction and nanoencapsulation of OLE were performed in a single-step process using a rotor-stator system with zein as the encapsulating agent. The nanoprecipitation step was carried out using an aqueous sodium caseinate solution, resulting in spherical particles with an average diameter of about 640 nm, as confirmed by Transmission Electron Microscopy. Thermal characterization showed that the produced nanoparticles were more thermally stable than free OLE until 250 °C, and FTIR spectra indicated effective interaction between the phenolic compounds and zein. Antioxidant activity was evaluated using TBARS, DPPH, ABTS, and FRAP assays, with results showing that encapsulated OLE had lower antioxidant activity than free OLE. The best antioxidant capacity results were determined by TBARS assay, with IC50 results equal to 43 and 103 µgOLE/mL for free and encapsulated OLE, respectively. No anti-inflammatory potential was detected for both samples using the RAW 264.7 model, and only free OLE showed cytotoxic activity against lung cancer and gastric carcinoma. Encapsulated and free OLE were used as antioxidants in soy, palm, and palm kernel oils and compared to BHT using Rancimat. The Schaal Oven Test was also performed, and the PARAFAC chemometric method analyzed the UV-Vis spectra, which revealed high stability of the oil when 300 mg or the nanoparticles were added per kg oil. Results suggested that zein-encapsulated olive leaf antioxidants can improve the oxidative stability of edible oils.

Chemical characterization of carob seeds (Ceratonia siliqua L.) and use of different extraction techniques to promote its bioactivity.

Nowadays, the use of carob (Ceratonia siliqua L.) is reduced to its seeds. In fact, the food additive E410, locust bean gum, is obtained from its endosperm. However, the available information regarding the bioactive potential of carob seeds is limited and, often, with poorly established terminologies, not allowing the reader to know if the studied samples included seedless or seeded samples. So, the present study intended to carry out a chemical characterization of carob seeds focused on their bioactive compounds and test their bioactive properties. Carob seeds proved to be a source of tocopherols and organic acids, including phenolic compounds. Its antioxidant potential was demonstrated in vitro, as well as its antimicrobial capacity. This work proves that carob seeds have other functions in addition to those associated with E410. Thus, another potential can be given to the locust bean seed, namely the function of food preservative.

Development of new bilberry (Vaccinium myrtillus L.) based snacks: Nutritional, chemical and bioactive features.

The sustainable exploitation of fruit and cereal processing is being conducted to produce novel food products with promising nutritional properties and high content in added value compounds. Herein, three bilberry fruit-based snacks supplemented with edible petals and fruits were characterized for their nutritional properties and chemical composition. The phenolic profile, antioxidant, antibacterial and hepatotoxic properties were analyzed. Protein (3-4 g/100 g dw) and carbohydrates (94.3-94.8 g/100 g dw) represented the major macronutrients. The combination of bilberry fruits with edible petals, calendula and rose, improved the nutritional and phytochemical input in organic acids and tocopherols content, respectively. Also, the supplementation with apple and goji fruits provided higher content in phenolic acids and anthocyanins (up to a 9-fold higher concentration, 199.7 µg/g of extract), also resulting in a higher antioxidant and antibacterial activities. The results obtained can contribute for the development of novel sustainable and healthier snacks for the food industry.