Impact Mineralization of Chokeberry and Cranberry Fruit Juices Using a New Functional Additive on the Protection of Bioactive Compounds and Antioxidative Properties.

Chicken eggshells can be used as an attractive dietary source of mineral compounds, including calcium (Ca). However, the effects of chicken eggshell powder (CESP) on berry fruit juices have not been studied to date. Therefore, the objective of this study was to evaluate the effect of its addition to juices from chokeberry and cranberry on their phytochemical properties. The juices were determined for contents of polyphenols (determined by ultra-efficient liquid chromatography coupled with a mass detector (UPLC-PDA-ESI-MS/MS)), macro- and microelements (by inductively coupled plasma - optical emission spectrometry (ICP-OES)), and organic acids (by high-performance liquid chromatography (HPLC-PDA)) as well as for their antioxidative activity by radical scavenging capacity (ABTS) and ferric reducing antioxidative power (FRAP) assay, color profile (CIE L* a* b* system), and sensory attributes. The study results demonstrate that CESP addition to chokeberry and cranberry juices enriched them with minerals and increased their Ca content 25.7 times and 66.3 times, respectively, compared to the control samples. Juices supplementation with CESP significantly decreased their acidity and total organic acids content as well as increased their pH value. Chokeberry and cranberry juices supplementation with 1% CESP caused no significant changes in the amount of precipitate and their color, but it significantly improved their taste. For this reason, CESP addition in the amount of up to 1% can be suggested as the optimal supplementation of berry fruit juices. The study also demonstrated that CESP addition in the amount of up to 1% caused no significant differences in the content of polyphenolic compounds and in the antioxidative activity of juices, which can be deemed important from the viewpoint of their putative health benefits. In addition, the heat treatment of juices contributed to only a 4% loss of polyphenolic compounds from the CESP-supplemented juices compared to the 6% loss from the non-supplemented juices.

Comparison of the Effectiveness of Water-Based Extraction of Substances from Dry Tea Leaves with the Use of Magnetic Field Assisted Extraction Techniques.

This article presents the findings of a study investigating the feasibility of using a magnetic field assisted technique for the water-based extraction of mineral components, polyphenols, and caffeine from dry black and green tea leaves. The authors present a concept of applying constant and variable magnetic fields in the process of producing water-based infusions from selected types of tea. Analyses investigating the effectiveness of the proposed technique in comparison with conventional infusion methods assessed the contents of selected mineral components-i.e., Al, Ca, Cu, K, Mg, P, S, and Zn-which were examined with the use of ICP-OES. The contents of caffeine and polyphenolic compounds were assessed using the HPLC. A changing magnetic field permitted an increased effectiveness of extraction of the mineral components, caffeine, and polyphenols. The findings support the conclusion that a changing magnetic field assisted extraction method is useful for obtaining biologically valuable components from tea infusions.

Study of nutritional value of dried tea leaves and infusions of black, green and white teas from Chinese plantations

Background: The processing of tea leaves determines the contents of bioactive ingredients, hence it should be expected that each variety of tea, black, red or green, will represent a different package of compounds of physiological importance. Taste and aroma, as well as price and brand are the main factors impacting consumers' preferences with regard to tea of their choice; on the other hand consumers less frequently pay attention to the chemical composition and nutritional value of tea. Objective: The purpose of the study was assessment of the nutritional value of black, green and white high-quality tea leaf from Chinese plantations based on the chemical composition of the dried leaves as well as minerals and caffeine content in tea infusions. Material and methods: The research material included 18 high-quality loose-leaf teas produced at Chinese plantations, imported to Poland, and purchased in an online store. The analyses included examination of the dried tea leaves for their chemical composition (contents of water, protein, volatile substances and ash) and assessment of selected minerals and caffeine contents in the tea infusions. Results: High-quality Chinese green teas were found with the most valuable composition of minerals, i.e. the highest contents of Zn, Mn, Mg, K, Ca and Al and the highest contents of protein in comparison to the other products. Chinese black teas had the highest contents of total ash and caffeine and white teas were characterized with high content of volatile substances, similar to the black teas, and the highest content of water and the lowest content of total ash. Conclusions: The three types of tea brews examined in the present study, in particular green tea beverages, significantly enhance the organism's mineral balance by providing valuable elements