The effects of microwave-assisted extraction, ultrasound-assisted extraction and water bath extraction on the antioxidant activity of apple polyphenols are reported in this short communication. This study evaluated these methods based on their effect on the antioxidant activity of apple polyphenols whereas previous studies focused only on the yield rate of the extraction methods. The oxidation induction periods of apple polyphenols were 6.11, 3.26 and 1.13 h for microwave-assisted extraction, ultrasound-assisted extraction and water bath extraction, respectively. This result indicates that from the perspective of antioxidant activity protection microwave-assisted extraction is much better than the other two methods. Hopefully, this study could attract researchers’ attention to the property of apple polyphenols in extraction and promote the development of natural polyphenols extraction methods.

Sour cherry is one of the most important horticultural crops in the Hungarian market. Its flavour combination makes it ideal for fresh consumption as well as canned products. The Hungarian and European markets have requested for new varieties to be introduced, making the evaluation of breeding and prebreeding material a crucial point. A total of 30 sour cherry accessions from the genebank collection were investigated for their potential inclusion into the breeding program. The main aim of the study was to identify candidates for future breeding programs, selecting their colour profiling and total polyphenolic content (TPC). This study follows the antioxidant activity of cherry species by determining the total content in polyphenols. Polyphenols are found in higher concentration in cherries when compared to other plants and have been identified as free radical scavengers, which are useful to prevent the occurrence of several diseases. Furthermore, TPC has been observed as a contributor of bitterness, acidity, colour, flavour, odour, and oxidative stability. The accessions were evaluated for their colour, fruit weight, flavour profile, firmness, and TPC. Colorimetric data were compared among four methods to illustrate to the Hungarian breeders which of the available approaches is the most accurate for sour cherry breeding. Results suggested that several accessions appear relevant for the breeding program, such as ‘Pipacs 1′, ‘Bosnyák’, ‘Hortenzia Királynője’, and ‘Mogyoródi Kései’. The total polyphenolic content was highest in ‘Pipacs1′ and lowest in ‘Kántorjánosi 3′. ‘Pipacs 1′ and ‘Hortenzia Királynője’ had interestingly high acidity content and light to very light fruit colours. ‘Bosnyák’ had a deep and dark colour with high soluble sugar content. ‘Mogyoródi Kései’ appears to have the biggest fruit. All mentioned varieties will be included in future breeding programs.

The Amfissis cultivar olive fruits grown in the region of Larissa, central Greece, were studied for the changes in total polyphenol content, phenolic fractions and antioxidant capacity during maturation period (four months). It has been established that the total phenol content and antioxidant capacity, change in broad ranges depending on the ripening stage of fruits. The content of total phenols in the Amfissis cultivar during maturation varied from 3.9 to 11.9 mg (GAE) g-1 FW. The highest content of total phenols has been found in the harvest stage (December). The content of flavonoid phenols ranges from 3.12 to 9.47 mg (GAE) g-1 FW. The highest content of flavonoid phenols was determined the time period of the harvesting. The content of non-flavonoid phenols during ripening of olive fruit ranges from 0.78 to 2.43 mg (GAE) g-1 FW. The highest content of NFP was determined the time period of the harvesting (black color). The inhibition concentration (IC50) of extract during maturation of the olive fruit in all stages ranges from (735 to 130) mg/l. The lowest inhibition concentration (highest antioxidant capacity) was observed in the collection stage of the olive fruits. The obtained results have a direct impact on the harvesting date of the table cultivar Amfissis, influencing the sensory properties and the quality of the olive fruit.