Evolution of some fruit quality criteria during ripening of twelve new Moroccan apricot clones (Prunus armeniaca L.)

Abstract Apricot ( Prunus armeniaca L.) is one of the most widely spread Prunus species cultivated in the temperate zones and it is an important source of vitamins, sugars, and organic acids. Apricots also contain some phytochemicals that have beneficial effects on human metabolism. However, a little is known about the quality characteristics of important Moroccan local clones. The objective of this study is to evaluate the quality of twelve local clones and, therefore, to identify those that presenting important and interesting quality traits. Some quality parameters such as Soluble Solids content (SS), pH value, Total Acidity (TA) and the ratio (SS/TA) were evaluated and major carboxylic acid components of apricot fruits were detected and quantified. Principal component analysis (PCA) was performed to study correlation between fruit quality parameters and to evaluate maturity stage and clone effects which are considered as decisive factors in the quality of apricots fruits. The clones were analyzed during three maturity stages: semi-ripe (M1), commercially ripe (M2), and tree ripe (M3). The results showed that malic and citric acids were the predominant organic acids in all apricots. Among different maturity stages, it is found that malic acid ranged from 7.02 to 22.86 g/kg of fresh weights (FW) while citric acid varied from 6.36 to 23.28 g/kg FW. Quinic, fumaric, and ascorbic acids were also quantified in the apricot fruits. Significant levels of vitamin C ranged from 0.001 to 0.150 g/kg FW were detected in the analyzed apricots and a remarkable variation was observed in all quality parameters. Moreover, significant correlations were found between the variables pH, SS, SS/TA ratio and organic acids mainly citric and malic acids. A genetic diversity was found between apricots clones according to their quality characteristics. This variability can be an asset in the apricots sector development in the region of Marrakesh either for fresh consumption or their processing into different products.