Sensorial analysis and Fruit Quality in Citrus sinensis (L.) Osbeck from Northern Italy (Piedmont)

The loss of genetic variability of fruit is a worldwide problem and the genetic erosion is recurrent. The identification, characterisation and valorisation of traditional genetic resources are becoming fundamental to avoid the loss of this precious germplasm. The citrus grown in particular environments represent an important genetic resource with traits (e.g. frost and diseases resistance) useful in breeding programs or for direct exploitation. The aim of the research was to assess the nutritional properties and consumer acceptability of some local Citrus sinensis (L.) Osbeck accessions from Northern Italy (Maggiore Lake, Verbano area). Physical (weight, size, juice percentage, peel thickness) and chemical (pH, titratable acidity TA, total soluble solids TSS and vitamin C content) parameters were studied on 15 accessions (3 Pigmented, 4 Navel and 8 Common oranges). On six of these accessions, chosen for their good morpho-biological characteristics, samples of fruit were analysed by a trained panel to evaluate their sensorial quality. The sensorial attributes studied were: odour during peeling, hardness, juiciness, flavour, aroma, astringency and overall judgment. Significant differences were found among the groups for TA, TSS/TA and vitamin C content ranging from 36.89 to 67.67 mg/100 mL. Positive correlations between TA and sourness, aroma intensity and the overall judgment, astringency and bitterness were evidenced. Even if these accessions occupy the northern distribution range of the citrus in Italy oranges have good quality and good sensorial traits. These results were important to define the traits of the local germplasm and support the development of economic activities (trade, rural tourism, nursery, and educational activities).