How to preserve pumpkins

In this brief guide, we are going to answer the question “how to preserve pumpkins” and discuss the different methods of preserving pumpkins.

How to preserve pumpkins

Postharvest losses include any damage to the quantity and quality of produce from the moment of harvest until consumption. The magnitude of postharvest losses in fresh produce is estimated to be 5% to 25% in developed countries and 25% to 50% in developing countries. This enormous waste of food poses a significant economic, social, and ecological burden on humanity that prompts an urge to improve the current practices and develop new means to reduce the waste (1).

Pumpkins can be preserved by :

  • Properly storing raw uncarved pumpkins at room temperature.
  • Refrigerating, freezing, canning and dehydrating cut, blanched pumpkins.

How to preserve raw uncarved pumpkins

Raw uncarved pumpkins preserve well at room temperature. A properly stored raw, uncarved pumpkin can last for about 3 to 4 months. The following storage conditions preserve whole pumpkins for a longer time. During this period, weight and nutrient losses occur, due to the metabolism of the fruit. Harvested fruits and vegetables continue to respire and lose water to the environment, which cannot be replaced and weight loss occurs. β-carotene destruction occurs due to oxidation (2). 

  • Raw, whole pumpkins must not be refrigerated or frozen. Raw pumpkins must be stored in a cool, dark and dry place. Moisture will cause rapid spoilage of pumpkins.
  • Raw pumpkins must not be kept directly on the floor. Always keep them on a dry mat or a clean crate. Placing them directly on the floor may attract insects.
  • Place the pumpkins upside down so that the stalk is facing the floor.
  • Store  pumpkins in a dry (70% RH) and cool (50°F–60°F) place. Spread out the pumpkins rather than stacking them up. Decay is the main source of loss. Some good results have been obtained by curing pumpkins before storing. This was done by keeping them for 10 days at 80°F–85°F and a high relative humidity (80%–85%) (3)

How to clean and cut pumpkins for preservation

Pumpkins are large vegetables and cleaning a whole pumpkin takes a bit of time and effort.

To clean and cut pumpkins (5) :

  • Wash a pumpkin with water and blot dry with a paper towel.
  • Cut the pumpkin in half.
  • Use a spoon to remove the seeds and fibres. Pumpkin seeds are edible so save them for later use.
  • Peel the skin if needed and slice the pumpkin into desired thickness,

How to preserve pumpkins by refrigerating

Cold storage is the most frequently used practice to decrease metabolic activity (1). Cut pumpkins must always be refrigerated until they are used in cooking.  Minimal processing, such as peeling and cutting, favors quality losses due to the mechanical stress generated. This accelerates the rate of perspiration (water loss) and is a determining factor in the weight loss (fresh mass) of vegetables (6).

To refrigerate cut pumpkins:

  • Wrap the pumpkin piece with cling film.
  • Place it in the fridge and use it within 12 days weeks.

How to preserve pumpkins by freezing

The type of chemical changes that occur during frozen storage includes protein insolubilization, lipid hydrolysis and oxidation, natural pigment degradation, vitamin deterioration and brown pigment formation. Particularly in vegetables, textural changes throughout frozen storage can be attributed to structural alterations of protein membranes and disruption cellulosic cell wall by ice crystal growth (7).

Pumpkin can be frozen either as cubes or puree. It is recommended to blanch the pumpkins before freezing, This would inactivate enzymes, prevent freezer burn and retain the flavour and texture for a longer time.

Freezing preserves pumpkins for 6 to 12 months. Frozen pumpkins can be thawed by placing them in the fridge overnight or by defrosting in water at room temperature.

Frozen pumpkins can be used in both cooking and baking.

To freeze pumpkin cubes:

  • Take pumpkin slices and trim off the rind.
  • Remove any remaining seeds and strings from the inner part.
  • Dice the pumpkin into cubes of desired thickness.1-inch cubes are perfect for freezing.
  • Add the pumpkin cubes into boiling water for 2 minutes.
  • Transfer the pumpkin cubes into ice water for 2 minutes.
  • Strain the pumpkin cubes using a colander to remove the excess water.
  • Spread out the pumpkin cubes on a tray lined with parchment paper.
  • Freeze for a few hours.
  • After the pumpkin cubes have frozen, transfer them into a ziplock bag or an airtight container. 
  • Label and return to the freezer.

To freeze pumpkin puree:

  • Cut a pumpkin into quarters and remove the seeds and strings.
  • Place the pumpkin quarters in a baking tray with 1 inch of water. Make sure that the cut side is facing upwards.
  • Bake for 1 hour at 300 F until the pumpkin quarters become soft.
  • Remove the flesh of the pumpkin quarters and make a puree using a food processor. Add a bit of water to the puree if needed.
  • Transfer the puree into a ziplock bag, an airtight container or ice cube trays.
  • Label and place it in the freezer.

How to preserve pumpkins by canning

Pickling involves preserving foodstuffs under high acid concentration, enabling their preservation for over two years without refrigeration. By the unfermented pickles, the product is added with a concentrated brine (up to 16% salt) and acid and then pasteurized. By the fermented pickles, the product is added with dilute brine (2–5% salt) and left to ferment. Naturally occurring bacteria grow over 1–2 weeks to produce lactic acid, which then prevents the growth of food poisoning bacteria and other spoilage microorganisms (5).

Pumpkin cubes can be canned at home by using a pressure canner. It is not recommended to use a water bath for canning pumpkins as it will not destroy all the harmful microbes. 

The only ingredients required to can pumpkins are pumpkin cubes and water. Salt and spices may also be added to season the pumpkins.

Canned pumpkins have a shelf-life of 1 year at room temperature. Just make sure to keep the jars in a cool, dark place.

The only downside to canning pumpkins is that you need to have a pressure canner and follow the exact pumpkin canning instructions.

How to preserve pumpkins by dehydrating

Drying constitutes an alternative to the consumption of fresh fruits and vegetables, and allows their use during the off-season. It is one of the most widely used methods for food preservation, and its objective is to remove water from the food to a level in which microbial spoilage and deterioration reactions are greatly minimized (4).

Pumpkins can be dehydrated by sun-drying, using an oven or using a food dehydrator. Using a food dehydrator is the most efficient and preferred method to dehydrate pumpkins.

Dehydrated pumpkin will preserve well for about 1 year.

Pumpkin slices must be blanched before dehydration for best results.

To dehydrate pumpkins in a food dehydrator: 

  • Spread out the blanched pumpkin slices on a dehydrator tray.
  • Sprinkle with salt or spices if needed.
  • Dehydrate at 150°F-165°F, for 10-12 hours.
  • The pumpkin slices would be crispy once they are completely dehydrated.
  • Store the dehydrated pumpkins in an airtight container in a cool, dark place.

Other FAQs about Pumpkin that you may be interested in.

How to preserve uncarved pumpkins

Can you eat whole pumpkin seeds?

Conclusion

In this brief guide, we answered the question “how to preserve pumpkins” and discussed the different methods used to preserve pumpkins.

If you have any questions or comments, please let us know.

References

  1. Ziv, Carmit, and Elazar Fallik. Postharvest storage techniques and quality evaluation of fruits and vegetables for reducing food loss. Agronomy, 2021, 11, 1133.
  2. Stephens, James M. Pumpkin–Cucurbita Spp. University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS, 1994
  3. Rahman, M. A., et al. Effect of storage periods on postharvest quality of pumpkin. Bangladesh J Agri Res, 2013, 38, 247-255.
  4. Guiné, Raquel PF, Susana Pinho, and Maria João Barroca. Study of the convective drying of pumpkin (Cucurbita maxima). Food  bioprod process, 2011, 89, 422-428..
  5. Behera, Sudhanshu S., et al. Traditionally fermented pickles: How the microbial diversity associated with their nutritional and health benefits?. J Funct Foods, 2020, 70, 103971.
  6. Lima, Keila S., et al. Shelf life and quality of minimally processed pumpkins. Amazonian J Plant Res, 2019, 3, 336-342.