The Influence of the Use of Different Polysaccharide Coatings on the Stability of Phenolic Compounds and Antioxidant Capacity of Chokeberry Hydrogel Microcapsules Obtained by Indirect Extrusion

Impact of Conventional Pasteurization, High Temperature Short Time, Ultra-High Temperature, and Storage Time on Physicochemical Characteristics, Bioactive Compounds, Antioxidant Activity, and Microbiological Quality of Fruit Nectars

Berries are a valuable source of numerous bioactive compounds, and they have an interesting organoleptic profile. Unfortunately, their low storage life determines the need for their preservation. Among the various methods used in this regard, it was decided to use the High Temperature Short Time (HTST) (90 °C/15 s) and Ultra-High Temperature (UHT) (130 °C/5 s) methods to preserve the produced fruit nectar blends (strawberry-blackcurrant and strawberry-chokeberry). For comparison, the nectars were also preserved using conventional pasteurization (90 °C/10 min). Physicochemical, chromatographic, and microbiological determinations were carried out in the tested nectars before and immediately after processing, as well as after 1, 2, 3, 4, and 6 months of refrigerated storage. All methods allowed for the significant inactivation of selected microbial groups. Non-significant changes were observed as a result of HTST and UHT processing in the context of pH, TSS, and titratable acidity. Varied major changes occurred in the content of bioactive components (TPC-decrease or increase by 2-4%, TAC-decrease by 3-20%, vitamin C-decrease by 15-78%), antioxidant activity (decrease or increase by 3-9%), and nephelometric turbidity (decrease or increase by 11-65%). Both nectars showed better quality and nutritional value after the HTST and UHT processes compared to treatment with classic pasteurization. Storage affected the degradation of bioactive compounds, reduced antioxidant activity, increased turbidity, and caused the brightening of samples together with reducing redness and yellowness. Considering the results obtained, it is reasonable to recommend the use of the HTST and UHT methods in industrial conditions for the preservation of liquid fruit and vegetable products such as juices, nectars, and beverages.

Preparation and Study of the Physicochemical and Functional Properties of Nano/Micromicellar Structures Containing Chokeberry Fruit Pomace Extracts Using Egg White and Egg Yolk

There is currently a growing interest in health-promoting foods. The beneficial effects of food on human health are actively promoted by health professionals and nutritionists. This growing awareness is influencing the increasing range of functional foods and the pursuit of more innovative solutions. Recent research indicates that spherical nanoparticles have the potential to be used as functional biomaterials in the food industry, particularly for encapsulating hydrophobic natural phytochemicals. Techniques and systems based on micro- and nano-encapsulation are of great importance in the food and pharmaceutical industries. It is of paramount importance that encapsulation materials are safe for use in food. The aim of this study was to obtain micelles containing extracts from chokeberry fruit pomace using egg yolk powder (EYP) for emulsification (as a source of lecithin) and egg white powder (EWP) for stabilisation. The structural properties of the micelles in the resulting powders were characterised using Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) analysis confirmed the presence of spherical micellar structures between 500 and 1000 nm in size. The water activity and water content of the obtained powders were determined, and the thermal (DSC) and antioxidant properties were investigated. The results indicated that the powder with the micellar structures had a higher stability compared to the powder obtained by simple mixing without the use of encapsulation techniques.

Astaxanthin-loaded alginate-chitosan gel beads activate Nrf2 and pro-apoptotic signalling pathways against oxidative stress

Oxidative stress (OS) plays a crucial role in disease development. Astaxanthin (ATX), a valuable natural compound, may reduce OS and serve as a treatment for diseases like neurodegenerative disorders and cancer. Nuclear factor-erythroid 2-related factor 2 (Nrf2) regulates antioxidant enzymes and OS management. We evaluated ATX's antioxidant activity via Alg-CS/ATX gel beads in vitro. ATX-encapsulated alginate-chitosan (Alg-CS/ATX) gel beads were synthesized and structurally/morphologically characterized by SEM, FT-IR, and XRD. Their biological effects were examined in human umbilical vein endothelial cells (HUVECs) treated with H2O2 through MTT assay, Annexin V/PI, cell cycle studies, and western blotting. Alg-CS effectively carried ATX, with high capacity and reduced pore size. Alg-CS/ATX displayed an 84% encapsulation efficiency, maintaining stability for 30 days. In vitro studies showed a 1.4-fold faster release at pH 5.4 than at neutral pH, improving ATX's therapeutic potential. HUVECs treated with Alg-CS/ATX showed enhanced viability via increased Nrf2 expression. Alg-CS gel beads exhibit significant potential as a biocompatible vehicle for delivering ATX to combat OS with considerable opportunity for clinical applications.