Consuming food that is rich in antioxidants reduces the risk of developing chronic diseases and oxidative stress. Fruits and vegetables are an excellent source of substances with antioxidant and pro-health properties. Such raw materials, characterized by a high content of polyphenolic compounds and antioxidant capacity, include pear fruits. In this study, the concentrations of bioactive compounds, as well as the antioxidant, anti-inflammatory, and antiproliferative activity in fruits of five selected pear cultivars were determined and compared. LC–MS and UPLC–PDA methods were used to determine the polyphenolic, carotenoid, chlorophyll, and triterpenoid profiles and content, and the antioxidant activity was analyzed using DPPH and ferric-reducing ability of plasma (FRAP) tests. The anti-inflammatory activity was determined against COX-1 and COX-2 enzymes. The cytotoxic activity of the test compounds was assessed against six tumor cell lines. The results showed that the major group of phenolic compounds in all cultivars was phenolic acids. In the group of chromoplastic pigments, chlorophyllide a and 9-cis-β-carotene were the major compounds, while in the triterpene group, ursolic acid was dominant. The antioxidant potential correlated with the content of polyphenols and carotenoids, and was the strongest for the ‘Radana’ cultivar. The highest antiproliferative activity in all varieties was established for bladder cancer.

The eating quality of nine new pear cultivars grown in Poland was investigated in 2008-2011. Fruits of two summer cultivars: ‘Alfa’ and ‘Radana’, as well as late season varieties: ‘Hortensia’, ‘Dicolor’, ‘Concorde’, ‘Uta’, ‘Xenia’, ‘Erika’ and ‘Verdi’ were compared to fruits of ‘Clapp’s Favorite’ and ‘Conference’, which were taken as cultivars of reference. Fruits of all cultivars were harvested from the Experimental Orchard of the Research Institute of Horticulture at the commercial maturity stage and stored at +2.5 °C or -0.5 °C in a normal atmosphere (NA) or at -0.5 °C in a controlled atmosphere (CA) (0.7% CO ₂ : 2% O ₂ ) for 6 to 16 weeks. At the end of storage, the fruits of each cultivar were subjected to an individual ripening schedule at 18 °C (up to 14 days), which generated samples of diversified quality attributes. Based on instrumental analyses and descriptive sensory assessment the quality attributes of each cultivar were examined. The gathered data on the dynamics of quality attribute changes during the ripening stage confirm that each new cultivar needs an individual strategy during storage and ripening in order to maximise their specific sensory attributes to increase potential market value. The obtained data leads to the conclusion that ‘Xenia’ and ‘Concorde’ fruits have the biggest chance to fulfil consumer expectations, as they were appreciated more than the reference ‘Conference’ cultivar. Among the others also ‘Hortensia’, ‘Verdi’ and ‘Dicolor’ were scored higher than ‘Conference’, but their advantages were not so evident.

The aim of this study was to examine the effects of tryptophan (L-TRP) sprays on calcium (Ca) distribution within mature ‘Red Jonaprince’ apple ( Malus domestica Borkh.) trees and on fruit quality. Trees were sprayed with L-TRP before flowering (at the green and pink bud stages and when 5% to 10% of flowers were open), after flowering (at petal fall and 14 and 28 days later), and both before and after flowering. In each spray treatment, 50 g of L-TRP per ha was applied. Other trees were sprayed with calcium chloride (CaCl ₂ ) six times during the growing season at rates ranging from 6 to 9 kg⋅ha ⁻¹ . Plants that were not sprayed with L-TRP or CaCl ₂ served as controls. The results found that the studied spray treatments did not affect yield, mean fruit weight, apple skin russeting and blush, seed set, mean seed weight, or acidity of fruit at harvest. Prebloom L-TRP sprays enhanced the concentrations of both free indole-3-acetic acid (IAA) in fruitlets (by ≈230% compared with those of the control plants) and Ca in fruitlets and fruit (on average by 18% compared with the control combination) but did not affect the leaf Ca concentrations. Apples from trees sprayed with L-TRP before flowering had lower starch index (SI) values at harvest than those of the control plants. Postbloom L-TRP sprays increased leaf Ca concentration, but had no effect on apple Ca concentration or fruit quality at harvest. Combined pre- and postbloom L-TRP sprays did not improve the effectiveness of this amino acid. Overall, preharvest CaCl ₂ sprays increased leaf and fruit Ca concentrations and decreased fruit SI. Apples sprayed with CaCl ₂ had lower soluble solids concentrations (SSCs) and were firmer than fruit from control trees. Prebloom L-TRP sprays are effective in improving apple Ca concentration, at least for triploid varieties that have small seed numbers.

The aim of this study was to evaluate the fruit quality of 13 Asian pear cultivars grown in climatic conditions of central Poland. The following cultivars were tested: ‘Chojuro’, ‘Hayatama’, ‘Hosui’, ‘Kosui’, ‘Yuan Huang’, ‘Nijisseiki’, ‘Dżin Li’, ‘Er Shi Shinge’, ‘Er Jang Li’, ‘Golden 20^th’, ‘Min Czi Li’, ‘San Li’, and ‘Shinseiki’. Pears were harvested in Experimental Orchard of Research Institute of Horticulture in Dąbrowice (near Skierniewice). Fruits were stored for 10 weeks at 0 °C in regular atmospheric conditions. Flesh firmness (FF), total soluble solids (TSS), and titratable acidity (TA) were measured at harvest and after the storage followed with 1 and 7 days of shelf life (SL) at 18 °C. After the storage, the sensory evaluation was also performed. Among the tested cultivars, ‘Min Czi Li’ and ‘San Li’ were the most firm (above 45 N) and ‘Kosui’ was the least firm (below 28 N) at harvest time. High amount of TSS (above 11% in both seasons and harvest dates) was observed in ‘Chojuro’, ‘Hayatama’, ‘Kosui’, ‘Yuan Huang’, and ‘Er Jang Li’ pears. Low TSS (not more than 10.6% at harvest) was observed in ‘Nijisseiki’, ‘Dżin Li’, and ‘Er Shi Shinge’ cultivars. The large differences among cultivars were observed in TA. High TA was observed in ‘Nijisseiki’ (above 0.32% in all terms of analyses) and low TA in ‘Hayatama’ and ‘Kosui’ (below 0.14%). All of the evaluated cultivars can be stored for 10 weeks at 0 °C in regular atmosphere without major negative impact on their quality characteristics. Fruits showed a slight (sometimes significant) decrease in FF after storage and a slight or no changes in TSS and TA. In sensory evaluations, ‘Chojuro’, ‘Hayatama’, ‘Hosui’, ‘Kosui’, ‘Yuan Huang’, ‘Er Jang Li’, ‘Er Shi Shinge’, and ‘Shinseiki’ (mostly cultivars characterized by high TSS) obtained highest scores for the overall quality (above 5.0 points in 10 points scale).

Temperature changes strongly affect apple development and quality. In this study, we analyze the relationships between the main factors modulating both of the aforementioned processes in the fruits of four apple cultivars. We assessed three-dimensional data concerning the expression profile (fold change) of eight genes related to fruit ripeness regulation (involved in the cell respiration process and sorbitol metabolism as well as encoding cell kinase receptors) and fruit parameters such as fruit weight, ethylene concentration, concentration of soluble solids and acidity, which are affected by seasonal temperature variations (2018–2020). We observed that low temperatures (before the apple ripening phase) promoted an increase in gene activity and improved the fruit quality of the following cultivars: early-flowering/mid-ripening ‘Pink Braeburn’ and ‘Pinokio’, early-flowering/late-ripening ‘Ligol’ and late-flowering/late-ripening ‘Ligolina’. We confirmed the positive effect of low temperatures on the activity of the AAAA1, AALA1, StG and AAXA genes and on the evaluated fruit quality parameters, and we confirmed their dependence on the genotype of the studied cultivars. The obtained results shed light on the complexity of the variability mechanism in fruit features and fruit harvest dates. This knowledge may improve breeding programs for the production of better-quality apples.