**2.3. Pumpkins (***Cucurbita moschata***)**

varieties, while *trans*-β-carotene was found the major carotenoid in all of the raw potatoes. Boiling resulted in an increase in *cis-*β*-*carotene and a decrease in the *trans-*isomer contents. The use of Kamalsundari and BARI SP-5 orange-fleshed sweet potatoes was proposed as

Sweet potatoes have been the aim of research over the years due to their functional and nutritional properties. Carbohydrates, proteins, lipids, carotenoids, anthocyanins, phenolic acid conjugates, and minerals constitute versatile nutrients in different parts (tubers, leaves, stems, and stalks) of sweet potato. The unique composition of sweet potato provides various beneficial effects such as antioxidant, hepatoprotection, anti-inflammatory, anticancer, antidiabetic, antimicrobial, anti-obesity, and antiaging activities. Factors which affect the nutritional composition and bio-function of sweet potatoes include the varieties, parts of the plants, extraction time and solvents, post-harvest storage and processing. Differences between the *in vitro* and *in vivo* assays employed for bio-function evaluation also lead to variations in results from different studies, which makes direct comparisons inadequate or difficult. Leaves, stems, and stalks from sweet potatoes are still commercially underutilized. Results from several studies point out that sweet potato can be developed as a sustainable crop for different nutritionally enhanced and value-added food products aiming at the promotion of human health [30].

Sweet potato (*Ipomoea batatas* (L.) Lam) is one of the most popular and ancient roots in Brazil, which is consumed cooked, baked or as sweets, cooked in boiling water. Cooking can result in physicochemical transformations which modify its nutritional properties. Vizzotto et al. [31] evaluated physicochemical characteristics, bioactive compounds, and the antioxidant activity of 12 genotypes of raw and roasted sweet potato, with different pulp colors: cream pulp, orange pulp, and purple pulp. Total soluble solids, acidity, sugars, carotenoids, anthocyanins, phenolic compounds contents, and antioxidant activity show a wide variation of these parameters for both forms of preparation. Antioxidant activity varied considerably amongst the genotypes, from 210.29 to 7870.57 μg trolox equivalent.g−1 for pulps *in natura* and from 773.26 to 17,306.22 μg trolox equivalent g−1 for baked pulps. Contents of soluble solids, acidity, sugars, and bioactive compounds as well as total antioxidant activity were higher while the levels of carotenoids were lower in baked sweet potatoes than *in natura*. Genotype and color of sweet potatoes influenced their chemical composition. Cultivars Amelia and *Beauregard* stood out with respect to the amount of soluble solids and carotenoids, respectively. Selections of purple have to be recommended as sources of anthocyanins. Thermal processing influenced the concentration of antioxidant compounds and affected some of the

Yellow sweet potato is mostly produced in small scale by farmers. It is a source of energy and carotenoids in the human diet; however, it is a highly perishable crop. To increase its industrial use, yellow sweet potato flour was produced for use in bakery products. Nogueira et al. [32] evaluated the technological quality and the carotenoid content in sweet breads produced by replacing wheat flour with 0, 3, 6, and 9% yellow sweet potato flour. The increase in yellow sweet potato flour concentrations in bread resulted in a decrease of specific volume and firmness and an increase in water activity, moisture, orange coloring, and carotenoids. Storage led to the most significant changes after the 5th day, with a reduction in intensity of

potential food-based supplements to reduce vitamin A deficiency.

112 Progress in Carotenoid Research

physicochemical characteristics.

A great number of pumpkin varieties, each of which contains a different amount of carotenoids, are cultivated worldwide [33]. In several Brazilian regions, *C. moschata* cultivars are known to contain a particularly high amount of α- and β-carotene. The β-carotene has 100% pro-vitamin A activity, and α-carotene has 53% pro-vitamin A activity [34–37].

Carotenoids have antioxidant activity, but few are converted in retinol (an active form of vitamin A) by the human body. Among more than 600 carotenoids which have pro-vitamin A activity, the most known are α- and β-carotene, and these are susceptible to degradation (isomerization and oxidation during the cooking process).

There are various studies about carotenoids from pumpkins, mainly β-carotene, and the large diversity of landraces and cultivars, among them the *Cucurbita maxima, Cucurbita moschata,* and *Cucurbita pepo.* The differences in carotenoids and β-carotene contents in these three species are important in order to choose the best one for cultivation and biofortification [19]. For instance, studies carried out by Carvalho et al. [19] revealed a large range of contents of carotenoids among samples of the same species of *Cucurbita moschata*. The total carotenoids content varied from 124.87 to 557.20 μg g−1 and others were above 60 μg.g−1.

Priori et al. [38] evaluated the genetic variability for the synthesis of bioactive compounds, total phenolic compounds, carotenoids, antioxidant activity, and minerals of 10 accesses of pumpkin (*C. moschata*) landraces. They found a high genetic variability for the synthesis of phenolic compounds, carotenoids, antioxidant activity, and minerals, with the most promising C52 and C389 accessions, due to their high levels of total carotenoids.
