Characterization of new late-spring-frost-tolerant apricot hybrids: physical and biochemical fruit quality attributes, volatile aroma compounds / Caracterização de novos híbridos de damasco tolerantes a geadas tardias: atributos físicos e bioquímicos de qualidade do fruto, compostos aromáticos voláteis

Late spring frosts is one of the most important restricting abiotic stress factors of apricot growing worldwide. In this study; some physical, biochemical fruit quality characteristics and volatile aroma compounds were determined in fresh fruit samples of thirteen late spring frost tolerant apricot hybrids recently obtained from Turkish apricot breeding programme. A wide variation was reported among apricot genotypes in all of the evaluated physical and biochemical fruit characteristics and also volatile aroma compounds.Fruit size varied between 27.2 and 60.5 g, total soluble solids between 13.6 and 17.4 %, total carotene 26.6 and 42.8 (mg.100 g-1), and total phenolics content 354.2 and 673.1 (GAE.100 g-1). A total of 42 flavor components belonging to various flavor compound groups were identified. The main volatile aroma compound groups detected in the assessed apricot genotypes were; aldehydes, ketones, esters, alcohols, terpenes, acids, and other compounds. Among the detected compounds; Hexanal, 2-Hexenal, 1-Hexanol, 2-Hexen-1-ol, Limonene were the most abundant compounds in terms of concentration. Hexanal varied between 55.8 and 528.5 µg.kg-1, and 2-Hexen-1-ol changed between 25.7 and 297.9 µg.kg-1 fresh weight. Correlation analysis revealed significant correlations among some aroma compounds and biochemical fruit quality characteristics. Significant correlations were reported for esters with titratable acidity (r=0.79) and total carotene (r=-0.61) and aldehydes were found as highly correlated with total soluble solids (r=-0.69). The results of the study will be beneficial in terms of food analysis, cultivation, and breeding studies of apricot.

As geadas do final da primavera são um dos fatores de estresse abiótico restritivos mais importantes do cultivo de damasco em todo o mundo. Neste estudo, algumas características físicas e bioquímicas de qualidade da fruta e compostos aromáticos voláteis foram determinados em amostras de frutas frescas de 13 híbridos de damasco tolerantes à geada da primavera, recentemente obtidos do programa de melhoramento de damasco turco. Uma grande variação foi encontrada entre os genótipos de damasco em todas as características físicas e bioquímicas dos frutos avaliados e também nos compostos aromáticos voláteis. O tamanho dos frutos variou entre 27.2 e 60.5 g, sólidos solúveis entre 13.6 e 17.4 %, caroteno total 26.6 e 42.8 (mg.100 g-1) e teor de fenólicos totais 354.2 e 673.1 (GAE.100 g-1). Um total de 42 componentes aromatizantes pertencentes a vários grupos de compostos aromatizantes foram identificados. Os principais grupos de compostos aromáticos voláteis detectados nos genótipos de damasco avaliados foram: aldeídos, cetonas, ésteres, álcoois, terpenos, ácidos e outros compostos. Os compostos: Hexanal, 2-Hexenal, 1-Hexanol, 2-Hexen-1-ol e Limoneno foram os mais abundantes em termos de concentração. O hexanal variou entre 55.8 e 528.5 µg.kg-1, e o 2-Hexen-1-ol variou entre 25.7 e 297.9 µg.kg-1 demassa fresca . A análise de correlação revelou correlações significativas entre alguns compostos aromáticos e características bioquímicas de qualidade do fruto. Correlações significativas foram encontradas para ésteres com acidez titulável (r=0.79) e caroteno total (r=-0.61) e aldeídos foram encontrados como altamente correlacionados com sólidos solúveis totais (r=-0.69). Os resultados do estudo serão benéficos em termos de análise de alimentos, cultivo e estudos de melhoramento de damasco.

Segregation of apricot accessions on the basis of fruit quality attributes / Segregação de genótipos de damasco na base das características quantitativas do fruto

The objective of this study was to characterize the European apricot germplasm that was collected in Cacak and Smederevo region, Central Serbia. Fifteen physical, chemical and sensorial traits were investigated in this germplasm consisting 14 accessions during a two year period. High variations were recorded in fruit weight, soluble solids content, ripening index, index of sweetness and total mineral mater, whereas variations in stone weight, titratable acidity and total sugars were smaller. Most of the accessions had large fruits with weight ≥60 g; two accessions had a fruit weight ≥80 g. Generally, fruits had a good aroma, firm flesh, orange and yellow flesh and skin color, respectively, and sweet kernel taste. High correlations were found between some evaluated properties. The accessions were grouped into four clusters according to their potential. Using a principal component analysis, accessions were segregated into groups with similar physical, chemical and sensorial properties. These relationships may help in selection of a set of accessions with better fruit quality performances, which, in our study, were found in T-1, T-2, T-10, T-13 and T-14.

Antioxidant and antimicrobial activities of bitter and sweet apricot (Prunus armeniaca L. ) kernels

The present study describes the in vitro antimicrobial and antioxidant activity of methanol and water extracts of sweet and bitterapricot (Prunus armeniaca L.) kernels. The antioxidant properties of apricot kernels were evaluated by determining radicalscavenging power, lipid peroxidation inhibition activity and total phenol content measured with a DPPH test, the thiocyanatemethod and the Folin method, respectively. In contrast to extracts of the bitter kernels, both the water and methanol extracts ofsweet kernels have antioxidant potential. The highest percent inhibition of lipid peroxidation (69%) and total phenolic content (7.9± 0.2 μg/mL) were detected in the methanol extract of sweet kernels (Hasanbey) and in the water extract of the same cultivar,respectively. The antimicrobial activities of the above extracts were also tested against human pathogenic microorganismsusing a disc-diffusion method, and the minimal inhibitory concentration (MIC) values of each active extract were determined. Themost effective antibacterial activity was observed in the methanol and water extracts of bitter kernels and in the methanol extractof sweet kernels against the Gram-positive bacteria Staphylococcus aureus. Additionally, the methanol extracts of the bitterkernels were very potent against the Gram-negative bacteria Escherichia coli (0.312 mg/mL MIC value). Significant anti-candidaactivity was also observed with the methanol extract of bitter apricot kernels against Candida albicans, consisting of a 14 mm indiameter of inhibition zone and a 0.625 mg/mL MIC value.