Strawberries are appreciated by consumers for their characteristic taste and health benefits, which enhance their demand throughout the year. Everbearing strawberries can produce fruits for a longer period and could thus meet this demand, but the fruit quality depends on environmental factors and the cultivar. This study focused on the effect of environmental conditions on the physical attributes and the composition of everbearing Capri cultivar fruit harvested from the end of June to the end of October. A positive correlation was observed between temperature and organic acid content (r = 0.87), and a positive correlation was observed between sunshine duration, anthocyanin (r = 0.87) and phenolic compound contents (r = 0.89). Additionally, the composition of sugars was affected by the environmental conditions. While strawberries harvested towards the end of October, when lower temperatures predominated, were larger in size and had a higher sugar/acid ratio, fruit harvested in the middle of August, when there were longer periods of sunshine, had higher anthocyanin and phenolic compound contents. In conclusion, strawberries with higher sugar/acid ratios are obtained when temperatures are lower, while strawberries exposed to longer periods of sunshine are richer in health-promoting compounds.

The study was conducted during the harvest season in the year 2020 to identify and quantify primary and secondary metabolites in olive fruit of the ‘Leccino’ cultivar during ripening. Sugars, individual phenolic compounds, total phenolic content and total tannin content were measured separately for the first time in the skin and pulp. Most of the studied metabolites were higher in the skin. Five sugars were identified, the most important being glucose in both tissues, although its content decreased during ripening. The highest total phenolic content was observed in the skin at the last stage of ripening, because of the accumulation of anthocyanins. Individual phenolic compounds were measured by high performance liquid chromatography with-diode array detector (HPLC-DAD) and confirmed by mass spectrometry. Thirty phenolic compounds were characterized and quantified. The main individual phenolic compound in the skin and pulp was oleuropein, which decreased during ripening. Two previously unreported anthocyanins, cyanidin-3-O-diglucoside and cyanidin-3,5-O-sophoroside, were identified for the first time in olive skin. These results will allow us to better understand the synthesis, distribution and storage of some primary and secondary metabolites in different tissues of olive fruits during ripening.

Olives ripen in the late autumn and represent a good source of nutrients that Halyomorpha halys uses to prepare for diapause. This is the first study to investigate the impact of H. halys infestation on the phenolic response and olive fruit quality in the pierced tissue of damaged fruits and in the non-pierced part of damaged fruits of ‘Istrska belica’ and ‘Pendolino’ cultivars. Both total phenolic content and antioxidant capacity contents significantly increased in the infested fruits of the cultivar ‘Istrska belica’. Total phenolic content in the pierced tissue of damaged fruits increased by 10.7%, while the content of AC in the non-pierced tissue of damaged fruits increased by 7.11% and in the pierced tissue of damaged fruits by 6.1% compared to control. A total of 44 individual phenolic compounds were identified, 21 of them increased in at least one cultivar after infestation. Huge increases in phenolic content were observed in both cultivars, particularly for flavones, secoiridoids, anthocyanins, and flavonols in the pierced tissue of damaged fruits. The most responsive individual phenolic compound in both cultivars was oleuropein. Its content in the pierced tissue of damaged fruits increased by 44.7% in the cultivar ‘Pendolino’ and for 82.6% in the cultivar ‘Istrska belica’.

Secondary metabolites, namely, phenolic and volatile organic compounds, contribute to the nutritional and organoleptic quality of the strawberry fruit. This study focuses on the changes in the content of phenolic compounds and volatile organic compounds during the ripening, from green to overripe fruit, of five strawberry cultivars (‘Asia’, ‘CIVN 766’, ‘Aprica’, ‘Clery’, and ‘Malwina’). Additionally, these changes are compared with the colour of the fruit and peroxidase and polyphenol oxidase activity. Our results show that the accumulation of secondary metabolites (phenolic and volatile organic compounds) significantly changed during the ripening process for all of the studied cultivars. As for phenolic compounds, flavanols and hydroxybenzoic acid derivatives comprised between 87 and 95% of the total phenolic compound content in unripe green fruit. In contrast, anthocyanins and hydroxycinnamic acid derivatives comprised between 64 and 77% of the total phenolic compound content in overripe fruit, except in the fruit of the cultivar ‘CIVN766’. When it comes to the aroma profile, the content of aldehydes decreased by 24–49% as the fruit ripened, and the accumulation of esters increased. Our study also shows that the ripening process differs among cultivars, and it is therefore necessary to define ripening indicators separately for each cultivar.

In the genus Phyteuma, the taxonomic delimitation of some species is difficult since a high variability of morphological traits, such as flower color, is present, probably due to high levels of hybridization. Historic descriptions and the morphological traits used in the taxonomic keys are sometimes unclear and lead to misinterpretations. Here, a detailed analysis of flower color variability in different populations of sympatric P. spicatum, P. ovatum, and P. persicifolium constitutes a new approach to clarifying the taxonomic statuses. The numeric analysis of color, providing colorimetric variables, together with the detailed description of the metabolic profiles of populations with different flower colors, constitute a unique chemical fingerprint that identifies species and subspecies with clear markers. This study is the most complete metabolic research on genus Phyteuma, since we identified and quantified 44 phenolic compounds using HPLC-MS, comprising 14 phenolic acids, 23 flavonols and flavones, and, for the first time in the genus, 7 anthocyanins involved in flower color variability. This approach contributes to clarifying the differences between species, which is particularly relevant in taxonomic complexes such as the present, where morphology fails to clearly differentiate taxa at specific and intraspecific levels.

The distribution of primary and secondary metabolites within a fruit can affect its nutritional and organoleptic quality, as fruit can vary in size and shape. This study investigated the differences in the distribution of the primary and secondary metabolites in the fruit of four strawberry cultivars (‘Asia’, ‘Clery’, ‘Frederica’, and ‘Sandra’) that were collected at one harvest point. The study included an analysis of the individual sugars, organic acids, phenolic compounds, and enzymes responsible for the degradation of phenolics. All of the studied cultivars showed a lower pH, higher total organic acid content, and lower glucose and fructose content in the outer part of the fruit. Differences were also observed in the total phenolic and anthocyanin contents, which were always higher in the outer part. The absolute differences in the total phenolic content ranged from 3723 to 6154 mg kg⁻¹ dry weight. Our results provide a basis for understanding the differences in the biosynthesis of these metabolites within this fruit and prove that it is essential to mix samples well before extractions to obtain results that are representative of the whole fruit.