Lipoxygenase Inhibition by Plant Extracts.

Lipoxygenases are widespread enzymes that catalyze oxidation of polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acid) to produce hydroperoxides. Lipoxygenase reactions can be desirable, but also lipoxygenases can react in undesirable ways. Most of the products of lipoxygenase reactions are aromatic compounds that can affect food properties, especially during long-term storage. Lipoxygenase action on unsaturated fatty acids could result in off-flavor/off-odor development, causing food spoilage. In addition, lipoxygenases are present in the human body and play an important role in stimulation of inflammatory reactions. Inflammation is linked to many diseases, such as cancer, stroke, and cardiovascular and neurodegenerative diseases. This review summarized recent research on plant families and species that can inhibit lipoxygenase activity.

Green Extraction Methods for Extraction of Polyphenolic Compounds from Blueberry Pomace.

In this study, green extraction methods-high voltage electrical discharges (HVED), pulsed electric field (PEF), and ultrasound-assisted extraction (UAE)-were compared in terms of extraction yield of total and individual polyphenolic compounds, as well as the antioxidant capacity of blueberry pomace extracts. All extractions were performed with methanol- and ethanol-based solvents. The highest total polyphenols content (TPC) (10.52 mg of gallic acid equivalent (GAE) per g of dry weight (dw)) and antioxidant activity (AA) (0.83 mmol TE/g dw) were obtained by PEF-assisted extraction in the ethanol-based solvent after 100 pulses and 20 kV/cm, which corresponds to an energy input of 41.03 kJ/kg. A total of eighteen individual polyphenols were identified in all investigated blueberry pomace extracts by high-performance liquid chromatography with the diode-array detector (HPLC-DAD) and liquid chromatography electrospray ionization tandem mass spectrometric (LC-(HESI)-MS/MS). The highest anthocyanin (1757.32 µg/g of dw) and flavanol (297.86 µg/g of dw) yields were obtained in the methanol-based solvent, while the highest phenolic acid (625.47 µg/g of dw) and flavonol (157.54 µg/g of dw) yields were obtained in the ethanol-based solvent by PEF-assisted extraction at the energy input of 41.03 kJ/kg. These results indicated that PEF is a promising green extraction method which can improve the blueberry pomace's polyphenol extraction yield.

Podravka and Slavonka Varieties of Pepper Seeds (Capsicum annuum L.) as a New Source of Highly Nutritional Edible Oil.

The aim of this study was to evaluate Croatian pepper seed varieties (Podravka and Slavonka) as a new source of added value ingredients. Pepper seed is mostly considered a by-product. For the first time, the pepper (Capsicum annuum L.) seeds of the Slavonka and Podravka varieties were examined as the source material for oil production by the two methods of extraction: cold pressing (CP) and supercritical CO2 extraction (SC-CO2). Further, fatty acid profile, tocopherols, and sensory analysis of the oils were examined, as well as the chemical characteristics and antioxidant potential of seed flour. The antioxidant potential of pepper seed flour was different between varieties (Podravka 107 antioxidant unit (AU); Slavonka 70 antioxidant unit (AU)). The Podravka variety pepper seed oil has shown higher γ-tocopherol content (CP 80.1 mg/100 g; SC-CO2 extraction 65.3 mg/100 g) than the Slavonka variety (CP 65.3 mg/100 g; SC-CO2 extraction 16.0 mg/100 g). According to the obtained results, cold pressing (CP) would be a more favourable method for pepper seed oil extraction, taking into account sensory evaluation and nutritional quality. The pepper seed oil has potential for culinary application with a nutritional quality comparable to vegetable oils of a higher price class.

Alternative to Conventional Edible Oil Sources: Cold Pressing and Supercritical CO2 Extraction of Plum (Prunus domestica L.) Kernel Seed.

Plum (Prunus domestica L.) is a fruit widely cultivated across Europe and its processing generates a considerable amount of waste in form of discharged plum kernels. This creates a new opportunity to exploit plum kernels in order to provide an alternative to conventional edible oils. The main aim of this study was to obtain high-quality oil from plum kernel seeds by applying traditional cold pressing (CP) and supercritical carbon dioxide (ScCO2) extraction as a modern tech-nology. The obtained oils were characterized based on the chemical composition of fatty acids and tocopherols. In ob-tained oils, twelve fatty acids were identified. The oleic acid was the most dominant in both oils (68.66% in oil obtained by ScCO2, 65.86% in oil obtained by CP), followed by linoleic acid (22.24-25.44%). While total tocopherols content in oil obtained by ScCO2 was 4 to 5.8-fold higher than CP. The results proved that the utilization of plum kernel seeds possess high potential as an alternative oil source due a high amount of oleic acid and tocopherols and a low amount of saturated fatty acids and amygdalin.

Valorization of Olive Pomace-Based Nutraceuticals as Antioxidants in Chemical, Food, and Biological Models.

Waste remaining after the production of olive oil (olive pomace) is known to contain significant amounts of phenolic compounds that exert different types of biological activities, primarily acting as antioxidants. In this work, a sustainable approach that combines ultrasound-assisted extraction with food-grade solvents and encapsulation with different types of cyclodextrins was used to prepare olive pomace-based polyphenol rich extracts that were tested as antioxidants in various chemical, food, and biological model systems. Encapsulation with cyclodextrins had a significant positive impact on the chemical composition of obtained extracts and it positively affected their antioxidant activity. Observed effects can be explained by an increased content of polyphenols in the formulations, specific physical properties of encapsulated compounds improving their antioxidant activity in complex food/physiological environment, and enhanced interaction with natural substrates. Depending on the applied model, the tested samples showed significant antioxidant protection in the concentration range 0.1⁻3%. Among the investigated cyclodextrins, hydroxypropyl-ß-cyclodextrin and randomly methylated-ß-cyclodextrin encapsulated extracts showed particularly good antioxidant activity and were especially potent in oil-in-water emulsion systems (1242 mg/g and 1422 mg/g of Trolox equivalents, respectively), showing significantly higher antioxidant activity than Trolox (reference antioxidant). In other models, they provided antioxidant protection comparable to commonly used synthetic antioxidants at concentration levels of 2⁻3%.