The production system, especially fertilisation has an important effect on yield and quality of strawberries. In the present study, plants were fertilized with different doses of nitrogen (0–100% recommended doses), calcium chelate, as well as nano fertilizer Lithovit. Strawberry cultivar ‘Clery’ yield and quality parameters (fruit color and firmness) including nutritional indicators (total soluble solids, sugars, organic acids, phenolic and volatile compounds) were monitored. Volatiles were identified and monitored using headspace solid phase microextraction and analysed using gas chromatograph-mass spectrometry (SPME/GC-MS) and sugars, organic acids, and phenolic compounds with high performance liquid chromatography. Organic acids and phenolic compounds were detected with mass spectrometer (HPLC/MS). Both nitrogen and calcium fertilisation had altered sugars, organic acids, volatile and phenolic contents in strawberry fruits. Fertilisation with higher doses of nitrogen and calcium increased the content of unpleasant aromas aldehydes hexanal (up to 3.8-fold) and (E)-2-hexen-1- (up to 3.7-fold). The content of fruity esters was uppermost in fruits fertilised with nano-fertiliser Lithovit (up to 2.3-fold). Fertilisation with N and Ca decreased the strength of ketone and terpenoids fruity aroma. The highest content of total phenols, as well as all individual hydroxycinnamic and hydroxybenzoic acid derivatives were obtained in the nano-fertiliser Lithovit treatment. Fertilisation, especially with nitrogen, had mostly negative impact on strawberry flavour while nano-fertilization with Lithovit improved strawberry phenolic content and aroma.

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.

The polyphagous brown marmorated stink bug (Halyomorpha halys Stål.) is an important pest in many countries. Recently it was noticed that it can feed on and cause damage to strawberries (Fragaria × ananassa Duch.). The metabolic response of strawberries to brown marmorated stink bug attacks was studied. Brown marmorated stink bugs attacked strawberry fruit which had 18% lower total sugar content compared to that of the control treatment. However, organic acid content had no significant difference among the three treatments, with the exception of shikimic acid, which had the highest content in the attacked fruit. Thirty-one phenolic compounds were identified. Results showed a strong effect on secondary metabolites due to H. halys attacks. Halyomorpha halys treatment had 27% higher total analyzed phenolic content compared to the indirect Halyomorpha halys treatment. The brown marmorated stink bug significantly increased total ellagic acid derivatives (33.1% to 37% higher), hydroxycinnamic acids (22.3% higher) and anthocyanins’ (39% higher) contents. Fruit attacked by Halyomorpha halys also had higher catechin and epicatechin content than that of the control treatments. This pest had a significant influence on the plant’s secondary metabolism, and this improved our understanding of how a strawberry plant reacts to the attacks of this very important pest. H. halys-infested fruit are not suitable for commercial production, due to the production of off-flavors.

Blueberry fruits have gained consumer attention in recent years due to their good taste and high nutritional value. However, the short shelf-life of the fruit is one of the main downsides in intensive blueberry production. Therefore, optimized storage technology with a modified atmosphere is necessary to prolong blueberry fruit quality on the market. The aim of this study was to investigate long-term storage of fruit of the highbush blueberry (Vaccinium corymbosum L.) ‘Liberty’ under the air control (0.5% CO₂, 19.5% O₂, 80% N₂) and controlled atmosphere conditions of: 5% CO₂, 5% O₂, 90% N₂; 15% CO₂, 5% O₂, 80% N₂; and 25% CO₂, 5% O₂, 70% N₂. Fruit sampling was performed four times during storage (17, 30, 44, 62 days). Evaluation was carried out for fruit weight, total and individual sugar and organic acid contents, sugar-to-organic acid ratio, and individual phenolics contents. After 44 days of storage, weight loss was highest with 15% CO₂ and lowest with 5% CO₂, with minor variations. The greatest breakdown of total sugars was seen for the air control, and the least for 25% CO₂. Organic acids were significantly reduced under all of these storage conditions. Consequently, a high sugar-to-organic acid ratio was maintained in fruit stored with 25% CO₂. The contents of all of the identified phenolics significantly decreased with 15% and 25% CO₂. After 62 days of storage with 5% CO₂, there were small decreases in flavan-3-ols and hydroxycinnamic acids, while flavonoid and anthocyanin contents were unchanged, or for some individual phenolics, content increased. These data show that 15% CO₂ or higher accelerates degradation of the phenolics. We can conclude that for maintenance of weight and nutritional quality of the blueberry fruit ‘Liberty’, the optimal controlled atmosphere under long-term storage is 5% CO₂, 5% O₂, and 90% N₂.

Short-term modified-atmosphere storage with an adjusted CO₂ and/or O₂ concentration could recover blueberry fruit infested with the larvae of quarantine pests. However, this could significantly affect the fruit quality. In our experiment we investigated the performance of highbush blueberry ‘Bluecrop’ fruit (firmness, peel color, individual phenolics, sugars, and organic acids) under four short-term storage regimes: (1) a regular atmosphere with 0.03% CO₂, 21% O₂, and 78% N₂ at 22 °C, i.e., the control; (2) a regular atmosphere with 0.03% CO₂, 21% O₂, and 78% N₂ at 2 °C; (3) a modified atmosphere with 10% CO₂, 5% O₂, and 85% N₂ at 2 °C; and (4) a modified atmosphere with 100% CO₂ at 2 °C. Fruit sampling took place after 24 h, 48 h, and 72 h. Fruit firmness was not significantly altered by storage regime or duration, while some significant, but minor, changes were detected in the color parameters. Regarding the primary metabolites, the sugar/organic acid ratio stagnated in the first 48 h in all storage regimes. The content of the majority of the individual phenolics was significantly higher in the fruit stored under control conditions. From our results, we can conclude that the short-term storage of highbush blueberry ‘Bluecrop’ fruit for 24 h in a cold atmosphere does not affect the phenolic content, and storage for 48 h does not affect the total sugar/organic acid ratio, regardless of the atmosphere composition.

Flavour is an important quality trait of food and beverages. As the demand for natural aromas increases and the cost of raw materials go up, so does the potential for economically motivated adulteration. In this study, gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) analysis of volatile fruit compounds, sampled using headspace-solid phase microextraction (HS-SPME), is used as a tool to differentiate between synthetic and naturally produced volatile aroma compounds (VOCs). The result is an extensive stable isotope database (IsoVoc—Isotope Volatile organic compounds) consisting of 39 authentic flavour compounds with well-defined origin: apple (148), strawberry (33), raspberry (12), pear (9), blueberry (7), and sour cherry (4) samples. Synthetically derived VOCs (48) were also characterised. Comparing isotope ratios of volatile compounds between distillates and fresh apples and strawberries proved the suitability of using fresh samples to create a database covering the natural variability in δ¹³C values and range of VOCs. In total, 25 aroma compounds were identified and used to test 33 flavoured commercial products to evaluate the usefulness of the IsoVoc database for fruit flavour authenticity studies. The results revealed the possible falsification for several fruit aroma compounds.