This study was carried out to determine the fatty acid composition, bioactive compounds, and mineral element content of standard hazelnut cultivars and accessions from the Eastern Black Sea region. A wide variation was determined in terms of the traits examined between hazelnut accessions and cultivars. Most of the accessions investigated had higher values of bioactive compounds, oleic acid, stearic acid, Na, and Ca than the standard cultivars. Among accessions investigated, S-1 had the highest total phenolics and antioxidants (557.3 mg/100 g and 0.53 mmol/100 g) while P-4 had the lowest (307.3 mg/100 g and 0.22 mmol/100 g). The highest oleic acid content was determined in P-2 (87.16%); the lowest was in H-1 (71.24%). Linoleic acid ranged from 4.35% (P-1) to 18.06% (H-1). P-2 (3349 mg/kg and 2464 mg/kg, respectively) had the highest K and P contents. The highest Mg content was found in S-1 (1787 mg/kg). The highest value of Ca and Na was determined in P-1 (2701 mg/kg and 412 mg/kg, respectively). Principal component analysis revealed that the traits studied could effectively explain the variability among hazelnut genetic sources. First, three components explained about 60% of total variation. PC1 was related to arachidonic acid and most of the mineral elements (P, K, Mg, Ca, Fe, Mn, Zn, Cu, B, Cd, Ni, and S), and explained 27.6% of the total variation. PC2 explained 18.3% of the total variation, and was mainly related to oleic, linoleic, and linolenic acid, as well as Ca. PC3 was related to total phenolics, total flavonoids, antioxidant activity, and palmitic acid, and explained 14.5% of total variation. The oleic acid had a strong negative correlation with linoleic acid (−0.99 ***) and linolenic acid (−0.95 ***). A strong positive correlation was determined between antioxidant activity and total flavonoids (r = 0.95 ***). K content showed a strong positive correlation with P (r = 0.92 ***) and Mg (r = 0.82 ***) contents. A strong positive correlation was also determined between P and Mg (r = 0.91***). These findings revealed that many of the accessions investigated were a good source of fatty acids and bioactive compounds. As a conclusion, most accessions with superior nutritional content can be evaluated as genetic material for the development of new cultivars in hazelnut breeding programs.

The aim of this study was to determine the quality characteristics and bioactive components of the local variety “Long Apple”. Although it is a very delicious and popular old apple variety, the knowledge about “Long Apple” is very insufficient. In this study, fruit quality parameters, organic acids, vitamin C, sugar components, phenolic compounds, and antioxidant capacity of the endemic apple “Long Apple” were determined as follows: chlorogenic acid, catechin, syringic acid, and o—coumaric acids, 117.68, 35.11, 22.71, and 15.54 mg kg⁻¹fw, respectively; vitamin c 135.67 mg L⁻¹, total sugar 196.29 g L⁻¹; malic, succinic, and citric acid 10.50, 2.88, and 2.13 g 100g⁻¹, respectively; fruit weight 139.11 g, hardness 8.27 kg cm⁻², shape index 1.42, and soluble solid content 16.70%; antioxidant capacity 3.30 µmol g⁻¹ TE were the highest. Except for fruit size and shape, the “Long Apple” genotypes outperformed Starking Delicious based on quality parameters and bioactive properties. The genotypes of “Long Apple” are separated by different parameters, but the genotypes 36K093, 36K094, and 36K106 are more prominent than others. In addition to its health benefits, the “Long Apple” has valuable properties for researchers. Therefore, increased research on “Long Apple” has been recommended.

Fruits is a scientific journal for original articles and reviews on fruit crops in temperate, Mediterranean, subtropical and tropical regions