Pumpkin flowers, in their composition, contain many bioactive ingredients that have a beneficial effect on the human body. The aim of the research was to evaluate the antioxidant activity and chemical composition of flowers of various species and varieties of pumpkins: Amazonka, Ambar, Atlantic Giant, Bambino (Cucurbita maxima L.), Butternut, Muscade de Provence, Rouge vif d’Etampes (Cucurbita moschata Duch.), and Miranda (Cucurbia pepo L.). The flowers came from flowering pumpkin shoots, grown in Poland (Krakow). The total polyphenols, carotenoids, total sugar contents, antioxidant activity, and fatty acid composition were determined. The content of dry matter, protein, ash, fat, and selected minerals were also determined. Pumpkin flowers of the Atlantic Giant variety were characterized by the highest content of total polyphenols and sugars and antioxidant activity. They also showed the highest percentage of n-myristic acid (C14:0) and docosanoic acid (C22:0). The energy value of fresh pumpkin flowers, of all varieties, was low and averaged 22 kcal/100 g. Fresh pumpkin flowers are a significant source of iron, covering 60–80% of the EAR standard for adults (Atlantic Giant and Bambino varieties).

In this study, the content of total polyphenols (TP) and the antioxidant activity (AA) of fresh herbs (13 in total) and those subjected to the freeze-drying process (stems and leaves separately) were compared. Moreover, the content of TP and AA of retail, commercial food spices (19 in total) of the two leading companies on the Polish market were compared. The novelty of our studies is the comparison between fresh and dried forms of herbs and spices and additionally between dried in a freeze-drying process and commercially available (in dried forms). It was found that fresh herbs and spices showed a large accumulation of polyphenolic compounds (from 466.55 to 17.23 CAE/100 g, respectively, for lemon balm and ginger). For freeze-dried herbs and spices, the highest TP content was found for marjoram (3052.34 CAE/100 g—leaves). Among commercial herbs and spices, sage (971.28 CAE/100 g) deserves attention. Fresh herbal spices, in particular oregano, (236.21 µM TE/g) had the highest AA. AA of freeze-dried herbs and spices was much lower (5.27–1.20 µM TE/g). The average value obtained for commercially available herbs and spices purchased was 1.44 µM TE/g. In the case of AA measured by the DPPH radical, thyme was characterized by the highest activity among fresh marjoram for freeze-dried herbs and spices. For dried commercial spices, the highest levels of AA were found for cumin.

Stevia rebaudiana, as a plant with favorable technological features, and, above all, with potential health-promoting properties, seems to be an ideal sugar substitute. The aim of this study was to compare the effect of adding pure steviol glycosides or Stevia leaves to a hypercholesterolemic diet on selected growth and biochemical parameters of experimental (non-diabetes) rats. The research material consisted of dried leaves of Stevia (Stevia rebaudiana Bertoni, Polish, Brazilian and Paraguayan origin) and steviol glycosides (GS). In the animal experiment, young male Wistar rats were used. The animals were divided into six experimental groups, six rats per group, and placed in individual metabolic cages, provided with drinking bowls and feeders. The animals from particular groups received a semi-synthetic AIN-93G diet for growing rats or its modification (group I—AIN-93G diet; group II—hypercholesterolemic diet; group III—hypercholesterolemic diet with 0.28 g of GS/kg of diet; group IV; V; VI—hypercholesterolemic diet with dried Stevia leaves addition from Polish (PL), Brazilian (BR) and Paraguayan (PR) cultivation) in amounts providing GS as in group III, i.e., 10, 17 and 18%, respectively. The addition of GS to the hypercholesterolemic diet resulted only in a tendency to lower the weight of the kidneys, heart and liver compared to animals fed with the hypercholesterolemic diet. The lowest glucose concentration was found in animals receiving the 17%BR diet. In general, all lipid profile parameters were similar or increased in rats fed the hypercholesterolemic diet with the addition of steviol glycosides and Stevia leaves, respectively. The highest antioxidant activity was recorded in the blood serum of rats fed the hypercholesterolemic diet with 10%PL dried Stevia leaves addition.