Phenolic Acid Content and Antioxidant Properties of Edible Potato (Solanum tuberosum L.) with Various Tuber Flesh Colours.

The aim of the paper was to evaluate the phenolic acid content and antioxidant properties in potato cultivars with coloured flesh and bright flesh. The study material included eight cultivars of edible potato grown in a temperate climate in Poland. Five cultivars were potato tubers with coloured flesh: "Rote Emma", "Blue Salad", "Vitelotte", "Red Emmalie", and "Blue Congo"; and three were potato tubers with bright flesh: "Bella Rosa", "Lord", and "Tajfun". In all potato samples under study, four phenolic acids were identified: chlorogenic acid, gallic acid, p-coumaric acid, and caffeic acid. The predominant acid was chlorogenic acid, the levels of which ranged from 62.95 mg·100 g-1 FM to 126.77 mg·100 g-1 FM. The total concentration of the identified phenolic acids was diverse and depended on the genotype of the cultivar and the tuber flesh colour, with coloured-fleshed potatoes having higher phenolic acid contents in comparison to bright-fleshed potato cultivars. The average concentration of phenolic acids in the samples was 89.19 mg∙100 g-1 FM, and the average concentrations of the individual phenolic acids identified were as follows: chlorogenic acid (86.19 mg∙100 g-1 FM), gallic acid (1.18 mg∙100 g-1 FM), p-coumaric acid (0.64 mg∙100 g-1 FM), and caffeic acid (1.18 mg∙100 g-1 FM). In addition, three groups of anthocyanins were identified: pelargonidin-3,5-di-O-glucoside, peonidin-3,5-di-O-glucoside, and petunidin-3,5-di-O-glucoside. Anthocyanins were not found in the "Lord" or "Tajfun" varieties characterised by white tuber flesh. The predominant pigment was petunidin-3,5-di-O-glucoside, with an average content of 23.15 mg∙100 g-1 FM, and the highest value was observed in the "Vitelotte" variety (51.27 mg∙100 g-1 FM). The antioxidant activity of the flesh of the potatoes under study was diverse depending on flesh colour. The FRAP (Ferric Reducing Antioxidant Power) assay indicated higher antioxidant activity of coloured-fleshed potato cultivars. The highest concentration was identified in the "Vitelotte" cultivar flesh and was 114% higher than in the "Lord" cultivar. Similar dependencies were found in the case of the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay; however, in this case, the "Vitelotte" cultivar flesh demonstrated nearly 6.4 times higher antioxidant activity than the "Lord" cultivar. Summarizing our own research, we can conclude that potato varieties with coloured flesh are characterised by a higher content of biologically active substances, including phenolic acids, and antioxidant properties compared to potato tubers with bright flesh.

Polyphenols, Antioxidant Activity and Volatile Compounds in Fermented Leaves of Medicinal Plant Rosebay Willowherb (Chamerion angustifolium (L.) Holub).

At present, the consumption of medical plants and functional foods is growing in the whole world. Rosebay willowherb (Chamerionangustifolium (L.) Holub) is an important medicinal plant that has various pharmacological effects (antioxidant, anti-inflammatory, anticancer, and others), can improve the state of health and well-being, and reduce the risk of various diseases. The aim of this work was to investigate volatile compounds, polyphenols, and antioxidant activity in rosebay willowherb leaves fermented for 24 and 48 h in solid state fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method for antioxidant activity determinations were used. To recognize and identify the leaves' fragrances, electronic nose (Alpha M.O.S) measurement technology was used. The results showed that the highest amounts of total polyphenols in dried matter were after 48 h aerobic solid state fermentation (SSF). Antioxidant activity was higher under 48 h SSF compared to the control. The most abundant flavoring compound groups were esters, terpenes, and aldehydes. In unfermented leaves, (z)-3-hexen-1-ol, acetate, hexyl acetate, and trans-hex-2-enyl acetate prevailed, characterized by fragrances of greenery, flowers, and fruits. The undesired esters group compounds, ethyl butyrate and butyl acetate, with pungent odor, were detected after 48 h anaerobic SSF.

New approach to the fungal decontamination of wheat used for wheat sprouts: effects of aminolevulinic acid.

Nowadays, there is a growing interest in natural, minimally processed, nutritional and healthy foods. Sprouted seeds can be offered as natural nutritive products. Regrettably, existing seed decontamination technologies are limited and have specific disadvantages. 5-aminolevulinic acid (5-ALA) as a novel and effective tool for wheat decontamination from microfungi is proposed in this work. Inhibition of wheat with 5-ALA revealed a drastically suppressed development of microfungi. Studies of wheat germination characteristics showed that 5-ALA stimulates the growth of wheat seedlings and roots without impairing the vigor of germination and the viability of seeds. 5-ALA also induces either marginal or significant activities of antioxidant enzymes which can be associated with enhanced cellular capacity to detoxify reactive oxygen species. The results indicate that 5-ALA application may be an effective, environmentally friendly and inexpensive technology to be used in producing sprouts for human consumption.