Katarina Fatrcova-Sramkova

Olive leaves (OL; Olea europaea L.) are an abundant by-product of olive production with functional and nutraceutical potential. This study evaluated the effects of post-harvest treatments using fresh, air-dried, and lyophilized OL of cv. ‘Frantoio’, which were infused in water at 85 °C for 10 min. The antioxidant capacity (AC; DPPH method), total phenolic content (TPC; Folin–Ciocalteu assay), and α-amylase inhibition activity of the herbal infusions were assessed. Macro- and trace elements were determined directly in air-dried and lyophilized OL by inductively coupled plasma optical emission spectrometry (ICP-OES). Potential non-carcinogenic health risks were assessed using estimated daily intake (EDI), target hazard quotient (THQ), and total THQ (TTHQ). Lyophilized OL herbal infusions exhibited the highest AC (15.32 ± 0.85%), TPC (65.61 ± 1.15 mg GAE/g DW), and α-amylase inhibition activity (23.34%). The mineral analysis identified Ca and K as the predominant macroelements, whereas Cd and Pb were below the analytical limit of detection. All individual THQ and cumulative TTHQ values remained below 1, indicating no appreciable non-carcinogenic health risk under the modeled exposure conditions. These results identify lyophilization as a favorable processing option for preserving the functional potential of OL and support their potential use as raw material for functional infusions and other food applications.

Tiger nut (Cyperus esculentus L.) is a relatively neglected tuber crop with notable nutritional, functional, and ecological value. The primary objective of this study was to evaluate the biological properties and selected nutritional parameters of tiger nut tubers and oil, including antioxidant activity, total phenolic content (TPC), fatty acid (FA) profile, health-related lipid indices, and mineral composition. Methods: Natural and peeled tiger nut tubers, as well as commercially available tiger nut oil (yellow variety, Valencia, Spain), were analyzed. Antioxidant activity was measured spectrophotometrically using the DPPH method. The content of TPC was determined using the Folin–Ciocalteu assay. Fatty acid composition was analyzed by gas chromatography coupled with flame ionization detection, and these data were used to calculate the PUFA/SFA (P/S) ratio, atherogenicity (AI), thrombogenicity (TI) index, and hypocholesterolemic/hypercholesterolemic (h/H) ratio. Macro- and microelement contents were quantified using inductively coupled plasma optical emission spectrometry. Estimated daily intake (EDI), target hazard quotient (THQ), and total THQ (TTHQ) were calculated to assess potential health risks. Results: Natural tiger nut tubers exhibited substantially higher antioxidant activity and TPC compared to peeled tubers, suggesting that the peel is the primary reservoir of phenolic compounds. Strong antioxidant activity was observed in tiger nut oil (64.82 ± 2.59 mg TEAC/L). Oleic acid (C18:1cis n-9) was identified as the predominant FA across all samples, thus contributing positively to favorable health lipid indices (P/S > 0.50, low AI and TI, high h/H ratio). Potassium was the most abundant macroelement in natural and peeled tiger nut tubers. The overall trend of microelement levels in these samples was as follows: Al > Fe > Zn > Cu > Sr > Mn > Li > Ba > Se > As > Cr. All THQ and TTHQ values were below 1, indicating no appreciable health risk associated with consumption. Conclusions: These findings support the use of tiger nuts as a functionally valuable ingredient in health-oriented food products.

A significant increase in interest in new, naturally occurring sources of antioxidants is evident not only in the food industry but also in the pharmaceutical and cosmetic industries. Plant sources such as fruits, both traditional and less common, are often investigated. Goji berries (Lycium barbarum, Lycium chinense, and Lycium ruthenicum) represent fruits rich in polyphenols, especially phenolic acids (38.91 to 455.57 mg/kg FW) and flavonoids, with black goji berries (L. ruthenicum) containing a predominance of anthocyanins (119.60 to 1112.25 mg/kg FW). In this review, a comparison of polyphenol occurrence and content in the orange-red and black berries of L. barbarum, L. chinense, and L. ruthenicum is described. Goji berries represent a valuable source of nutrients and bioactive compounds that manifest a wide range of health-promoting effects. These benefits represent antioxidant, neuroprotective, and cytoprotective impacts, with effects on the metabolic control of glucose and lipids. This review is focused on an overview of the polyphenolic compounds occurring in these fruits, as well as their antioxidant activity and health benefits.

This study assessed the potential of dried Cayenne pepper (CP; Capsicum annuum L.) as a natural additive to rice bran oil (RBO), grape seed oil (GSO), and virgin olive oil (OO). Key analyses included peroxide and acid values, oxidative stability (Rancimat method), the composition of fatty acids (FAs) (GC-FID method), antioxidant activity (AA; DPPH method), and antimicrobial properties (disc diffusion method). Capsaicin and the dihydrocapsaicin contents in CP were quantified (HPLC-DAD method) as 1499.37 ± 3.64 and 1449.04 ± 5.14 mg/kg DW, respectively. Oleic acid (C18:1cis n9) dominated in OO (69.70%), OO-CP (69.73%), and RBO-CP (38.97%), while linoleic acid (C18:2cis n6) prevailed in RBO (41.34%), GSO (57.93%), and GSO-CP (58.03%). The addition of CP influenced the FA profile, particularly linoleic acid in OO and RBO, and all FAs in GSO. Peroxide and acid values increased significantly in RBO and GSO upon CP addition, but induction times remained unaffected. The strongest AA (77.00 ± 0.13%) was observed in OO-CP. Cayenne pepper significantly enhanced the antioxidant profiles of all oils compared to the counterparts. However, the antimicrobial activity was weak (≤5.0 mm inhibition zones) against tested microorganisms. These findings support CP as a functional additive for enhancing the nutritional and functional properties of gourmet oils, while highlighting the need for further optimization to improve stability and bioactivity.

Although cornelian cherry is an underutilized fruit species, its fruits have a high biological value due to valuable biologically active substances, especially polyphenols. The total content of polyphenols accounts for 37% of all the bioactive substances examined. Flavonols, anthocyanins, flavan-3-ols, and phenolic acids represent the main groups of phenolic compounds present and thanks to these compounds, cornelian cherry fruits possess mainly antioxidant, anti-inflammatory, antimicrobial, metabolic, antidiabetic, cardioprotective, and anticancer effects. This review summarizes new research aimed at popularizing this lesser-known species not only for direct consumption but also for further processing.

The purpose of this work was to investigate whether two-months supplementation with 100% sea buckthorn juice (SBJ) would modify blood lipids, LDL subfractions and other markers of cardiovascular risk in hypercholesterolemic women. A group of 28 hypercholesterolemic non-medicated adult women with a mean age of 50.58 ± 5.76 years consumed 50 mL of 100% SBJ daily for two-months. We observed a significant reduction of body weight (BW; p < 0.05), body mass index (BMI; p < 0.05), body fat mass (BFM; p < 0.001) and visceral fat area (VFA; p < 0.001), on the contrary, a significant increase of skeletal muscle mass (SMM; p < 0.05) and fat-free mass (FFM; p < 0.05). Supplementation with 100% SBJ significantly increased the level of high-density lipoprotein (HDL; p < 0.05), reduced the level of low-density lipoprotein (LDL; p < 0.05), atherogenic LDL subfractions (LDL3–7; p < 0.05) and improved LDL/HDL ratio (p < 0.001). After the SBJ consumption, significant reduction of C-reactive protein (CRP; p < 0.001), orosomucoid (ORM; p < 0.001) and interleukin 6 (IL-6; p < 0.05) were found. In conclusion, consumption of SBJ showed an indication of beneficial effects on cardiovascular risk factors in hypercholesterolemic women.

Pollen contains nutritional elements – carbohydrates, proteins, lipids, vitamins, minerals, trace elements. The pollen contains also important amount of polyphenolic compounds, primarily antioxidants. Because the pollen is rich in nutrients, honeybee-collected pollen is recommended as a dietary supplement. The product can be used as dietary supplements to enrich food with valuable nutrients performing important functions in the human body. Pollen is a bee product affected by contaminants of various origins. In addition to important nutrients, it may also contain heavy metals that are harmful to human health. May be contaminated from air and soil by heavy metals and pesticides.