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Kale is a biennial herbaceous plant that is traditionally grown in the coastal area of Croatia. Microgreens have higher nutrient content compared to adult plants and can be produced in a short period of time. A two-factor experiment was set up to determine the influence of harvest time and load on yield, dry matter, total glucosinolates and phenolic content, total antioxidant capacity measured by DPPH, FRAP and ORAC, as well as on the sugar profile. Significantly higher yields were found in the later harvest dates, while, at the same time, the dry matter content decreased significantly. Prolonged load treatment showed a significant reduction in yield as well as a significant reduction in total phenolic content of microgreens. The bioactive potential of microgreens changed significantly with the harvest date, where early and medium harvests showed more total glucosinolates, higher antioxidant capacity measured by the FRAP method, and a higher amount of inulin compared to the late harvest. In addition to significantly higher yields, the late harvest also showed a significantly higher total phenolic content compared to earlier harvest dates. The determined nutritional parameters in the kale microgreens represent excellent potential for their valorization as a food product.

Allium ursinum L., also known as bear’s garlic or ramson is a perennial plant species from the Allium genus of the Amaryllidaceae family, known and consumed for centuries due to its medicinal properties. It is native and widely spread across Europe and Asia and prefers habitats with nutrient-rich and damp soils, in shaded areas such as forests. The medicinal properties of A. ursinum are attributed to a plethora of bioactive substances present in both bulbs and leaves such as S-alk(en)yl-cystein-sulfoxides and phenolic compounds, as well as other compounds such as lectins, polysaccharides, fatty acids, and amino acids. The main goal of this study was to collect and evaluate the total phenolic content and antioxidant capacity, as well as the free amino acid content of A. ursinum populations at six different locations across Croatia. Antioxidant capacity measured by ORAC was higher in leaves compared to bulbs while threonine, arginine and methionine were more abundant in bulbs compared to leaves across all investigated locations. The Platak location had plants with the highest leaf antioxidant capacity measured by ORAC while Japetić and Vukomerec had higher bulb antioxidant capacity measured by FRAP compared to other investigated locations, except Platak. Total phenolic content did not differ between leaves and bulbs while leaf total phenolic content did not differ between locations. Total phenolic content in bulbs was higher in Vukomerec compared to Motovun and Rude. Positive correlations were observed between leaf antioxidant capacity measured by FRAP and DPPH and several leaf amino acids, including valine, isoleucine, leucine, lysine and cystine. Higher bulb total phenolic content was observed in bulbs with higher glutamic acid, arginine, valine, phenylalanine, and lysine content while the bulb antioxidant capacity measured by ORAC also positively correlated with aspartic acid, tyrosine, methionine, isoleucine, lysine, and cystine in addition to the aforementioned amino acids. Our study showed that all A. ursinum populations from the investigated locations had excellent bioactive properties.

Stres izazvan abiotičkim čimbenicima, kao što je suša, izaziva prekomjernu proizvodnju prolina u biljkama što u konačnici daje toleranciju na stres održavanjem osmotske ravnoteže, stabilizacijom membrana i sprječavanjem oksidativnih izboja. Kao takav, prolin se smatra markerom stresa za određivanje biljnog fiziološkog stanja i razine tolerancije na stres. Osim što utječe na fiziološko stanje biljaka, stres povezan sa sušom utječe i na biosintezu sekundarnih metabolita, kao što su fenoli, te se na taj način mijenja ukupnim antioksidacijski kapacitet biljke. Cilj ovog istraživanja bio je istražiti utjecaj abiotičkog stresa od strane suše na 36 sorte češnjaka (A.sativum L.), mjerenjem razine prolina, fenola kao i antioksidativnog kapaciteta.

Allium ursinum L. is a perennial plant from the Allium genus of the Amaryllidaceae family and is native to the European and Asian forests. Organosulfur compounds and polyphenols contribute to overall health-promoting action, which makes A. ursinum a great medicinal plant, equally or even more valuable as its domestic relative garlic (Allium sativum L.). All parts of the plant are edible, although leaves and bulbs are the one mostly used. Used in traditional medicine throughout Europe, A. ursinum has been generally recommended as digestive stimulant, antimicrobial agent and strong antioxidant. To investigate the biochemical diversity of A. ursinum plant populations across Croatia eight locations were selected and the plants were sampled in the 2021 season. The plants were investigated for their total phenolic content, total antioxidant capacity (measured by FRAP, DPPH and ORAC), volatile organosulfur compounds and free amino acid content. In all investigated locations the A. ursinum plants exhibited excellent bioactive properties. Although the plants were similar across Croatia several locations were found to be distinctive based on specifi c bioactive properties. The highest antioxidant capacity measured by the FRAP method was found in plants at the Velanov Brijeg location, the most abundant plants in organosulfur compounds were found at the location of Brana Gornja while plants most abundant in free amino acid content were found at the Prodin Dol location.

Inevitably, plants are very often exposed to various abiotic stresses such as drought. Proline rapidly accumulates under abiotic stress conditions and imparts stress tolerance by maintaining osmotic balance, stabilizing proteins in membranes, and scavenging reactive oxygen species (ROS). Moreover, drought stress can reduce plant’s growth and change the levels of numerous bioactive secondary metabolites such as phenols, and thus changing the overall plant’s antioxidant capacity. The aim of this study was to test the effect of drought on level of proline, total phenolic content, and total antioxidant capacity (FRAP, DPPH, and ORAC) of 2 garlic landraces (IPT195 and IPT266). An interaction between landrace and drought stress was observed for proline level, and in IPT195 it was increased by 39% at drought treatment compared to well-watered plants in IPT195, however, no response in proline was observed for landrace IPT266. The total phenolic content and FRAP values were not affected by landrace or drought stress. A higher antioxidant capacity expressed as DPPH was observed in landrace IPT266 compared to IPT195, but it was not changed by water shortage. On the other hand, ORAC assay results show significant increase of total antioxidant capacity in landrace IPT195 after drought treatment (218%), while no significant difference was observed in landrace IPT266. According to results of proline levels and ORAC it seems that landrace IPT195 has faster response on drought stress than landrace IPT266 which may also indicate its higher tolerance to drought stress.

Allium ursinum L. is a wild relative of onion and garlic, along with many other species of the numerous Allium genus. It is also known as wild garlic, ramsons, wood garlic, bear’s garlic, wild cowleek, and buckrams. Phytochemicals containing sulfur atoms (organosulfur compounds) are characteristic for Allium species and are directly responsible for distinct flavor and pungent odor. One such compound is S-alk(en)yl-l-cysteine sulfoxide, which is precursor for said flavor. S- alk(en)yl-l-cysteine sulfoxide is described as non-volatile sulfur metabolite, which is compartmentalized in the cytoplasm of the intact plant cells. Disruption of cellular structure caused by mechanical force and/or heat, leads to releasing of hydrolytic enzyme alliinase found in vacuole and sulfoxide from the compartmentalized sections in cytoplasm, resulting in subsequent hydrolysis which gives rise to many volatile compounds such as thiosulfinates, and (poly)sulfides, which are considered as the principal flavor compounds. The aim of this study was to investigate the difference in volatile profiles between bulbs and leaves of wild garlic samples originating from 5 different locations. In total, 29 volatile compounds were determined in bulb, of which 28 were (poly)sulfides, and 1 was aldehyde, while in leaf altogether 19 volatile compounds were determined, of which 18 were (poly)sulfides, and 1 was aldehyde. Some sulfur containing secondary metabolites have not been detected in leaf samples, such as allyl propyl sulfide, 6-methyl-4, 5-dithia-1-heptene, (E)-1- propenyl propyl disulfide, 1-(methylthio)dimethyl disulfide, 3-vinyl-1, 2-dithi-4-ene, 4H-1, 2, 3- trithiin, dimethyl tetrasulfide, allyl (Z)-prop-1- enyl trisulfide, allyl (E)-prop-1-enyl trisulfide, and methyl-1, 2, 3, 4-tetrathiane. Furthermore, statistical analysis (factorial ANOVA) showed how quantity of investigated compounds is not only depending on the plant’s organ, but on location as well. Therefore, significant interaction between plant organ and location was established.

Češnjak je vrlo pogodan za istraživanja jer se razmnožava nespolno, odnosno radi se o klonovima. Unatoč navedenom, među njima postoji razlika u sastavu i količini antioksidansa i šećera. Antioksidansi su od velike važnosti u prehrani ljudi jer reduciraju slobodne radikale i prihvaćaju nesparene elektrone te na taj način čuvaju sastavne dijelove stanica poput lipida i DNK. Kako bi se doznalo koje namirnice imaju više ili manje antioksidansa te samim time veći ili manji učinak na zdravlje potrebno odrediti udio antioksidansa te njihov kapacitet. Za analizu je prikupljeno 77 ekotipova češnjaka s područja Republike Hrvatske kao i izvan njenih granica. Šećeri imaju važnu ulogu u staničnim funkcijama kao što je pohranjivanje energije te su od interesa istraživačima, pogotovo inulin koji se nalazi u malom broju biljaka, pri čemu je češnjak jedan od njih. Detekcija i kvantifikacija šećera u uzorcima češnjaka provedena je pomoću tekućinske kromatografije visoke djelotvornosti. Garlic is suitable for research because it breeds inexofield, that is, they are clones. Despite the above, among them there is a difference in the composition and amount of antioxidants and sugars. Antioxidants are of great importance in human nutrition because they preserve the constituent parts of cells such as lipids and DNA. To find out which foods have more or less antioxidants and therefore a greater or lesser effect on health, it is necessary to determine the proportion of antioxidants and their capacity. For the analysis, 77 garlic ecotypes from the Republic of Croatia were collected as well as outside its borders. Sugars play an important role in cellular functions such as energy storage and are of interest to researchers, especially inulin found in a small number of plants, where garlic is one of them. Sugar detection and quantification in garlic samples was carried out using high-performance liquid chromatography.