Pumpkin, Cucurbita pepo (Cucurbitaceae)

The pumpkin, derived from Cucurbita pepo and belonging to the family Cucurbitaceae, is one of the most widely cultivated and versatile horticultural species. Originating from the Americas, it has been grown for centuries across temperate and warm-temperate regions worldwide. Numerous cultivars exist, selected for culinary use, ornamental purposes, or for the production of edible seeds. Pumpkin is valued for its sweet, carotenoid-rich flesh and for its high agronomic productivity.

Morphologically, Cucurbita pepo exhibits trailing or bushy stems, often equipped with tendrils, along with broad, lobed leaves covered in fine pubescence. The large, funnel-shaped yellow flowers clearly distinguish male from female blossoms, a hallmark of cucurbit species. The fruits show remarkable variability in shape, colour, and size: they may be spherical, elongated, cylindrical, or flattened, with smooth, warty, or striped rinds in shades ranging from green to deep orange-yellow. The inner flesh, thick and succulent, is abundant in carotenoids, responsible for the orange pigmentation in many cultivars.

Ecologically and agronomically, pumpkin thrives in temperate and warm-temperate climates, requiring abundant light, mild temperatures, and well-drained soils rich in organic matter. Its root system is shallow but wide-spreading, benefiting from regular irrigation, especially during flowering and fruit enlargement. Although generally robust, the crop can be susceptible to fungal and viral diseases, requiring careful crop management, particularly in intensive production systems.

From a phytochemical perspective, pumpkin flesh contains significant amounts of carotenoids (notably β-carotene), vitamin C, soluble fibre, simple sugars, and moderate levels of minerals such as potassium and magnesium. Carotenoids impart antioxidant activity and contribute to vitamin A formation in the human body. Its low caloric content makes pumpkin an advantageous ingredient in balanced, energy-controlled diets.

Nutritionally, pumpkin is recognised as a health-promoting and versatile food, offering a combination of fibre, vitamins, and natural antioxidants. Dietary fibre supports intestinal regularity, while the vitamin and carotenoid profile contributes to immune function, cell protection, and visual well-being. Its high water content and low calorie density make pumpkin easy to digest and suitable for a wide range of dietary needs.

Culinarily, pumpkin is extremely versatile and widely used in:
– soups, purées, and creamy dishes;
– fillings for pasta or baked preparations;
– steamed vegetable sides;
– desserts, cakes, and baked goods;
– industrial production of flours and purées.

Botanical classification (APG IV system)

Indicative nutritional values per 100 g (raw fresh pumpkin flesh)

Nutritional considerations

• A low-calorie vegetable due to its high water content.

• Excellent source of carotenoids (especially β-carotene → vitamin A).

• Very low lipid content, with SFA, MUFA, and PUFA present only in trace amounts.

• Suitable for both sweet and savory dishes: soups, purées, risottos, gnocchi, baked goods.

Production process

“Pumpkin” generally refers to several cultivated species of the genus Cucurbita (mainly C. maxima, C. moschata, C. pepo), grown in temperate and subtropical regions. The plants prefer well-drained soils, good water availability and warm conditions, with sowing in spring and harvest in autumn.

Fruits are harvested when the rind is hardened and the stem begins to dry and lignify, indicating physiological maturity. After harvest, pumpkins are cleaned and, in quality-oriented production, often cured for several days to about two weeks in warm, dry, well-ventilated conditions. This curing step helps heal minor skin injuries and improves storage life.

In industrial processing, pumpkins can be: peeled, seeded and cut into cubes for freezing; cooked and concentrated into puree for soups, baby food, fillings and baked goods; or processed into ready-to-use sauces and mixes. Seeds are separated as a by-product and may be used as edible seeds or for pumpkin seed oil.

Applications

Pumpkin is highly versatile in the kitchen:

• In home cooking, it is used in soups, purees, risottos, gnocchi, stuffed pasta, savoury pies and baked side dishes, as well as in sweets (cakes, muffins, pies, jams).

• In the food industry, it appears in ready soups and purees, frozen vegetable mixes, baby foods, ready meals and sweet or savoury bakery products.

• In some traditions it is used in chutneys, relishes and vegetable spreads.

Because of its high water content and relatively low calorie density, pumpkin is well suited to large-volume but low-energy dishes.

In animal feeding, by-products (peel, residual pulp, downgraded fruits) can be used, where permitted, as part of feed or forage.

In cosmetics, pumpkin fruit extracts and pumpkin seed oil are used in products for dry skin, in gentle exfoliating formulations (thanks to sugars and organic acids) and in nourishing body products.

Nutrition & health

Fresh pumpkin has a low energy content: most data place it around 20–40 kcal per 100 g of raw flesh, depending on variety and composition. A typical value often cited is about 25–30 kcal/100 g. It is largely water, with modest amounts of carbohydrates (mainly simple sugars and a small portion of fibre), and very little fat and protein.

Nutritionally, pumpkin is valued as a source of:

• Provitamin A (beta-carotene), especially in deep orange-fleshed varieties.

• Some B vitamins and vitamin C, in variable amounts.

• Potassium and other minerals in moderate quantities.

Within a balanced diet pumpkin can:

• Contribute fibre and micronutrients with limited calorie impact.

• Help create filling, low-energy dishes.

• Provide carotenoids that contribute to overall provitamin A intake.

The overall effect on glycaemic balance is generally favourable when pumpkin is part of balanced meals, although dishes very rich in added sugar or fat (cakes, fried preparations) obviously alter the final nutritional profile.

Portion note
A typical household portion of cooked pumpkin as a side dish or main vegetable component is about 150–200 g of flesh (cooked weight or equivalent raw), adjusted according to the rest of the meal.

Allergens and intolerances

Pumpkin is not listed among the major mandatory allergens in common regulations. True allergy is rare but possible, particularly in people with multiple sensitisation to pollens or to other cucurbits.

Potential issues include:

• Occasional individual allergy or intolerance to pumpkin flesh or seeds.

• Possible cross-reactivity in sensitive individuals with allergies to other Cucurbitaceae (certain squashes, melons, courgettes, cucumbers).

In composite products (soups, ready meals, baked goods), major allergenic risk usually comes from other ingredients (gluten, milk, eggs, soy, nuts), which must always be checked on the label.

Storage and shelf-life

Whole, mature pumpkins with intact rind generally have good keeping quality:

• Store in a cool, dry, well-ventilated place, away from direct sunlight.

• Avoid impacts and wounds that would favour rot.

Under appropriate conditions, some varieties can be stored for several weeks to a few months, depending on species, cultivar and environment.

Cut pumpkin (halves, slices, cubes) should be refrigerated in closed containers or food-grade wrap and used within a few days. Cooked pumpkin (baked, steamed, pureed) should generally be consumed within 2–3 days if kept in the refrigerator.

Pumpkin can also be frozen, after blanching or pre-cooking as cubes or puree, which significantly extends shelf-life.

Safety and regulatory aspects

Pumpkin is regarded as a conventional vegetable and is covered by standard fruit and vegetable safety rules:

• Limits for pesticide residues, heavy metals and other contaminants.

• Hygiene and microbiological quality along the production chain.

• Application of GMP (Good Manufacturing Practices) and HACCP in industrial processing.

Occasionally, cases of pumpkins or squashes with a markedly bitter taste have been reported, due to high levels of cucurbitacins, bitter compounds that can be toxic and cause “toxic squash syndrome”. If pumpkin flesh tastes clearly and strongly bitter, it should not be eaten; bitterness is a key warning sign.

Any nutrition or health claims (e.g. “source of vitamin A”) on processed products must be supported by actual nutrient content and comply with regulations on authorised nutrition and health claims.

Labeling

For fresh produce, labels or display cards typically state:

• The product name (e.g. “pumpkin” plus cultivar name where relevant).

• Country of origin.

• Quality class or category, where required.

In processed products (soups, purees, ready meals, frozen mixes, baby food), the ingredient will appear as “pumpkin” or under specific terms such as “pumpkin puree”, listed in descending order of weight. A nutrition declaration is mandatory, and any allergens present in the composite product must be emphasised according to local rules.

In cosmetics, pumpkin-derived ingredients appear under INCI names such as Cucurbita Pepo Fruit Extract, Cucurbita Pepo Fruit Juice or similar, depending on the extract type.

Main INCI functions (cosmetics)

In cosmetics, pumpkin-derived ingredients (especially fruit extracts and seed oil) can play roles such as:

• Emollient / skin conditioning (particularly pumpkin seed oil).

• Nourishing and soothing in body products for dry or dehydrated skin.

• Components of mild exfoliating formulations, in combination with other actives, thanks to the presence of sugars and organic acids in fruit-based extracts.

Conclusion

Pumpkin is a low-calorie vegetable with high water content and a meaningful contribution of carotenoids, fibre and certain minerals, making it especially suitable for dishes that are voluminous yet relatively light. Its culinary versatility spans savoury and sweet preparations, both in home cooking and industrial products, and it fits easily into omnivorous, vegetarian and vegan eating patterns.

Good control of cultivation, harvest timing, curing, storage and processing helps maintain desirable sensory and nutritional qualities while minimising waste and spoilage. When included as part of a varied diet, pumpkin is a valuable way to increase vegetable intake, adding colour, flavour and micronutrients with limited energy impact.

Studies

The fruit flesh is rich in carotenoids, tocopherols, polysaccharides, carbohydrates and minerals which endow pumpkin with medical functions including antidiabetic, antihypertensive, antitumor, antioxidant, immunomodulation, antibacterial, antihypercholesterolemia, intestinal antiparasitia, anti-inflammation and antalgic activities (1).

The seed contains fatty acids (≤64% linoleic acid), specific delta-7-sterols, tocopherols and micronutrients (2).

Potential health benefits

The oral administration of high doses of pumpkin seeds and pumpkin seed oil reduced prostate weight in experimental animal models of prostate growth (3).

Pumpkin seed oil is considered a preventive agent for various pathologies, particularly prostate diseases. These properties are related to its high content of carotenoids and liposoluble vitamins. In this study the carotenoid (lutein and zeaxanthin), vitamin E (α- and γ-tocopherol) and fatty acid contents (4).

This study validates the hypoglycemic and antidiabetic effect of Cucurbita maxima seed extract and therefore this extract could be further explored for development as a new anti-diabetic agent (5).

Pumpkin seed studies

Mini-glossary

• SFA – Saturated fatty acids; fats that, when consumed in excess, are associated with higher LDL (“bad”) cholesterol and increased cardiovascular risk.

• MUFA – Monounsaturated fatty acids; fats that can improve blood lipid profiles when they replace saturated fats in the diet.

• PUFA – Polyunsaturated fatty acids; include omega-3 and omega-6 families, important for cell membranes, inflammation modulation and cardiovascular health.

• INCI – International Nomenclature of Cosmetic Ingredients; the international system used to name cosmetic ingredients on product labels.

References_______________________________________________________________________

(1) Caili F, Huan S, Quanhong L  A review on pharmacological activities and utilization technologies of pumpkin. Plant Foods Hum Nutr. 2006 Jun; 61(2):73-80.

Abstract. Dietary plants and herbal preparations have been traditionally used as medicine in developing countries and obtained a resurgence of use in the United States and Europe. Research carried out in last few decades has validated several such claims of use of traditional medicine plants. Popularity of pumpkin in various systems of traditional medicine for several ailments (antidiabetic, antihypertensive, antitumor, immunomodulation, antibacterial, antihypercholesterolemia, intestinal antiparasitia, antiinflammation, antalgic) focused the investigators' attention on this plant. Considerable evidence from several epidemiological studies concerning bioactivities leads have stimulated a number of animal model, cell culture studies and clinical trials designed to test this pharmacological actions. In addition, it was found that technologies such as germination and fermentation could reduce antinutritional materials and affect the pharmacological activities of pumpkin. This review will focus on the main medicinal properties and technologies of pumpkin, and point out areas for future research to further elucidate mechanisms whereby this compound may reduce disease risk.

(2) Strobl M, Patz B, Bracher F: Kürbissamen bei Störungen der Blasenfunktion. DAZ 2004;144:4010-4014.

(3) Vahlensieck W, Theurer C, Pfitzer E, Patz B, Banik N, Engelmann U. Effects of pumpkin seed in men with lower urinary tract symptoms due to benign prostatic hyperplasia in the one-year, randomized, placebo-controlled GRANU study. Urol Int. 2015;94(3):286-95. doi: 10.1159/000362903. Epub 2014 Sep 5.

Gossell-Williams M, Davis A, O'Connor N: Inhibition of testosterone-induced hyperplasia of the prostate of Sprague-Dawley rats by pumpkin seed oil. J Med Food 2006;9:284-286.

Abstract. The oil from the pumpkin (Cucurbita pepo) seed is claimed to be useful in the management of benign prostatic hyperplasia. This investigation seeks to examine the effect of pumpkin seed oil on testosterone-induced hyperplasia of the prostate of rats. Hyperplasia was induced by subcutaneous administration of testosterone (0.3 mg/100 g of body weight) for 20 days. Simultaneous oral administration of either pumpkin seed oil (2.0 and 4.0 mg/100 g of body weight) or corn oil (vehicle) was also given for 20 days. The weights of the rats were recorded weekly, and the influence of testosterone and pumpkin seed oil on the weight gain of the rats was examined. On day 21, rats were sacrificed, and the prostate was removed, cleaned, and weighed. The prostate size ratio (prostate weight/rat body weight) was then calculated. Neither testosterone nor pumpkin seed oil had any significant influence on the weight gain of the rats. Testosterone significantly increased prostate size ratio (P < .05), and this induced increase was inhibited in rats fed with pumpkin seed oil at 2.0 mg/100 g of body weight. The protective effect of pumpkin seed oil was significant at the higher pumpkin seed oil dose (P < .02). We conclude pumpkin seed oil can inhibit testosterone-induced hyperplasia of the prostate and therefore may be beneficial in the management of benign prostatic hyperplasia.

Kim SH, Jung KI, Koh JS, Min KO, Cho SY, Kim HW: Lower urinary tract symptoms in benign prostatic hyperplasia patients: orchestrated by chronic prostatic inflammation and prostatic calculi? Urol Int 2013;90:144-149.  DOI: 10.1159/000342643

(4) Procida G, Stancher B, Cateni F, Zacchigna M. Chemical composition and functional characterisation of commercial pumpkin seed oil.  J Sci Food Agric. 2013 Mar 30;93(5):1035-41. doi: 10.1002/jsfa.5843. Epub 2012 Aug 30.

(5) Kushawaha DK, Yadav M, Chatterji S, Srivastava AK, Watal G. Evidence based study of antidiabetic potential of C. maxima seeds - In vivo.   J Tradit Complement Med. 2017 Jan 17;7(4):466-470. doi: 10.1016/j.jtcme.2016.12.001