Variability of Cucurbita spp. Fruit Nutritional Quality and Yield

This study aimed to investigate the inter- and intra-species variability in squashes and pumpkins (Cucurbita moschata, Cucurbita maxima, and Cucurbita pepo), with respect to fruit flesh nutritional quality parameters (contents of dry weight, sugar, protein, carotenoid and total soluble solids, refractive index, and flesh juice pH) and agronomic yield (fruit weight, number of fruits per plant, and yield per plant). The study included a total of thirty phenotypically divergent Cucurbita spp. genotypes cultivated over two consecutive growing seasons (2021 and 2022). Significant differences were observed among the species and genotypes regarding all the analyzed parameters, except for the fruit flesh juice pH. The greatest variability was detected for the carotenoid content (45.2, 11.1, and 6.5 mg/kg fresh weight for C. maxima, moschata, and pepo, respectively) and fruit weight (7.6, 4.0, and 2.5 kg for C. maxima, pepo, and moschata, respectively). The seasonal variation was most pronounced in C. moschata, indicating its comparatively low tolerance to heat stress. The highest values for the investigated parameters of both nutritional quality (dry weight 16.5%, sugar content 25.5 mg/g fresh weight, protein content 4.1 mg/g fresh weight, and total soluble solids content 8.1 °Brix) and agronomic yield (20.6 kg per plant) were noted in C. maxima, which is therefore suggested as the best raw material for the production of pumpkin-based food and feed. The investigated parameters varied in the other two species as well, suggesting the potential for improvements through breeding and applicability for similar purposes. This study highlights the importance of raw material quality for nutrient extraction from Cucurbita spp. fruits. Effective cooperation between plant breeders and food technology engineers is essential to deliver high-quality pumpkin-based products while optimizing production and processing costs.