There are not many exhaustive works emphasizing the amount of genetic diversity among the strawberry tree (Arbutus unedo L) genotypes in Morocco. This work aims to assess the biochemical composition of strawberry tree fruits, as well as to establish the variation of this composition among them. In this study, total phenols (TP), total flavonoids (TF), condensed tannins (CT) and hydrolyzable tannins (HT), total anthocyanins (TA), and free radical scavenging activity through ABTS were investigated in strawberry tree fruits. Furthermore, qualitative and quantitative analyses of individual phenolic compounds by high-performance liquid chromatography (HPLC) were carried out. Color parameters such as lightness (L *), Chroma (c *), and hue angle (h°) were also investigated. All studied variables showed highly significant differences among all samples with the exception of hydrolyzable tannins and chromatic coordinates. TP varied from 22.63 ± 1.74 to 39.06 ± 2.44 mg GAE/g DW, TF varied from 3.30 ± 0.60 to 8.62 ± 1.10 mg RE/g DW, and TA ranged between 0.12 ± 0.06 and 0.66 ± 0.15 mg cya-3-glu/100 g DW. In addition, CT and HT amounts were in the range of 10.41 ± 1.07–16.08 ± 1.50 mg TAE/g DW and 4.08 ± 2.43–6.34 ± 3.47 TAE/g DW, respectively. Moreover, the IC50 value (ABTS) ranged between 1.75 and 19.58 mg AAE/g DW. 17 phenolic compounds were detected in strawberry tree fruits. Gallocatechol and catechin were the most abundant phenolic compounds. Matrix of correlations revealed significant positive and negative correlations among variables particularly c *, a *, and b *. Principal component analysis (PCA) showed that the first three components formed than 68% of the total inertia. The following variables gallic acid, protocatechuic, gallocatechin, gallic acid derivative, chlorogenic acid, syringic acid, ellagic acid derivative II, L *, and h * were the most involved in the total variance explained. Hierarchical clustering classified samples into one main cluster, with a single branch. The results highlight a high biochemical diversity within studied strawberry genotypes, which is probably more genetically related.

This study aimed to explore the main biochemical components and the antioxidant capacity of five strawberry tree fruits using three antioxidant essays within the ecotypic comparison scheme, to find out the most valuable fruit presenting disease-preventing properties. Total phenols, total flavonoids, total anthocyanins, antioxidant activity (DPPH, ABTS, and β-Carotene bleaching assays), pH, titratable acidity, soluble solids, and moisture content were investigated in five strawberry tree genotypes belonging to several areas in Morocco. Phenolic compounds were also identified using high performance chromatography (HPLC), with a diode array detector (DAD). High significant differences (p ˂ 0.05) were revealed among the examined genotypes regarding their total phenols (25.37–39.06 mg gallic acid equivalents (GAE)/g Dry weight (DW), total flavonoids (3.30–7.07 mg RE/g Dry weight (DW), total anthocyanins (0.15–0.64 mg cya-3-glu/100g Dry weight (DW), pH (2.44–3.92), titratable acidity (0.65–1.01 g malic acid/100g Fresh weight (FW), and soluble solids (14.83–18.53%). The average radical scavenging capacity, assessed using three methods, exhibited the following concentration ranges: 3.33–21.08, 2.25–19.58, and 1.08–13 mg Ascorbic Equivalent (AAE/g Dry weight(DW) for the DPPH scavenging test, ABTS, and β-carotene bleaching, respectively. Seventeen phenolic compounds were identified in sampled cultivars. Gallocatechol and catechin were found to be the major phenolic compounds. The correlation matrix revealed significant correlations among investigated variables, particularly ABTS and DPPH. The principal component analysis showed that the first three components formed 90.25% of the total variance. The following variables: chlorogenic acid, ellagic acid derivative, ellagic acid, rutin, and cyanidin−30.5-diglucoside, were the most involved in the total variance. The results revealed highly promising physico-biochemical profiles within the studied strawberry tree genotypes.

Wild edible fruits have been used centuries by local people mainly for nutrition purposes and they have attracted the attention of researchers in the last decade throughout the world. Among wild edible fruits, the strawberry tree (Arbutus unedo) is widely distributed mainly in Mediterranean countries. However, the lack of information about strawberry tree genetic resources in Mediterranean countries is a major cause of its low exploitation by breeders. For a practical use and exploitation of the strawberry tree native germplasm, phenological, morphological, and biochemical characterization of the plant is essential. In this study, some important phenological, morphological, and biochemical characteristics of sixteen local strawberry tree genotypes were determined. Significant variations (p < 0.05) were observed in most of the investigated phenological, morphological, and biochemical traits of the genotypes. The genotypes were harvested between 2–21 November. The fruit weight and the number of fruits per cluster of the genotypes varied from 3.89 to 6.86 g and 3.61 to 7.94, respectively. Vitamin C and total dietary fiber contents of genotypes were found quite variable, ranging from 58 to 93 mg/100 g and 7.04 to 12.36 g/100 g, respectively. The fruits of the strawberry tree include mainly fructose and glucose rather than sucrose. Local strawberry tree genotypes are found to be promising for further valorization through horticultural characteristics for breeding. Some genotypes had significantly higher fruit weight, vitamin C concentrations, total dietary fiber, and total phenolic concentration and may be good selections for producing health products.

The phenotypic diversity of the strawberry tree (Arbutus unedo L.) has largely gone unheeded for many reasons, some of which have to do with its wild aspect, since it still naturally grows in the mountains and remains poorly exploited. In this regard, this study aims to investigate the phenotypic diversity within strawberry tree genotypes widely grown in Morocco, based on their physico-morphological properties and volatile compounds. Significant variability was observed among investigated genotypes for all traits with the exception of the peduncle weight. Fructose content was 20.40 g/100 g, while glucose and sucrose averaged 15.74 and 17.83 g/100 g dry weight, respectively. Headspace solid phase microextraction coupled with gas chromatography−mass spectrometry analysis identified a total of 28 volatile compounds in strawberry tree fruits. Chemometric evaluation using the principal component analysis model was used to determine the most discriminant traits among the data set. Regarding morphological attributes, fruit geometric traits (length, width, and weight), leaf weight, flower length, blade, and leaf length had the highest contribution the total variance explained; whereas, soluble solids and pH were the greatest contributors of physicochemical attributes to the model. Finally, among volatile compounds, dodecanoic acid, tetradecanoic acid, N-ethyl-1,3-dithioisoindoline, 1Hindole, and phenol captured the highest variance in the model. The combination of physico-morphological traits and volatile compounds proved to be efficient for strawberry tree discrimination and classification.

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