Chances are that if you’re growing pumpkins on your operation, you’re growing them mostly for aesthetic value. Visitors want to visit the pumpkin patch come autumn for family photos and front porch decorations.
But there’s more to a pumpkin than just a pretty rind.
Researchers from the University of Life Sciences and the University of Galati wanted to explore the utilization of pumpkin byproducts as a bioactive powder in the development of value-added yogurt. In this case, the byproduct was pumpkin peel.
According to their study, “pumpkin peel contains antioxidant components like phenolics, flavonoids and carotenoids, compounds characterized by high bioactivity.” Their study investigated the potential of incorporating pumpkin peel powder (PPP) into yogurt to enhance its nutritional value and sensory attributes.
There is growing demand among customers for better taste and higher nutrient intake in all kinds of foods, and adding fruits or vegetables to yogurt is an easy way to do both. Pumpkins offer beneficial supplies of carotenoids (beta-carotene), protein, pectin, dietary fiber, certain vitamins (A, B1, B2 and C), minerals (K, P, Mg, Fe and Se) and other nutrients.
The researchers noted that food waste – particularly from the processing of fruits and vegetables – offers a variety of natural pigments too, like carotenoids (yellow to orange), anthocyanins (blue to purple), chlorophylls (green) and betalains (dark red to pink), as well as natural additives to enhance the quality of food products.
According to the research team, the primary portion of pumpkins intended for processing and eating is the pulp. That means about 18% to 21% of the fruit (peel or seeds) is wasted or used as fertilizer or animal feed. The numerous phytochemicals and antioxidants found in these byproducts could be used as food additives, bioactive molecules or nutritional supplements, however.
(L – R) Images of the yogurt without PPP, with 2% PPP and with 4% PPP. Photos courtesy of University of Life Sciences
Pumpkin peels specifically are being used as an ingredient in the development of new value-added foods enriched in fiber and have shown to have a high level of antioxidant activity. (Exciting news for those who believe in “waste not, want not.”)
To see how they could be used in yogurt, the researchers freeze dried the peels of Cucurbita maxima ‘Golden Nugget’ and then powdered them. The PPP was added to traditional yogurt after the milk had been inoculated with starter cultures. Then, 48 taste testers evaluated flavor, color (which tended to be yellow), consistency, tongue feel, acidity and overall acceptability.
In this study, it seemed the PPP was a hit. Adding it generated a significant decrease in yogurt pH (which may be the result of acidity in the pumpkin pulp), but the taste testers didn’t note any difference in acidity. Adding PPP improved the yogurt’s antioxidant properties. And the addition of PPP made the yogurt more springy/thicker, which was associated with a better tongue feel. There was also a significant positive difference in the protein available to those trying the yogurt.
This isn’t a magic bullet for all the pumpkin peel out there, though. Low levels of PPP were added to the yogurt – only 2% and 4% of overall volume. The researchers determined the yogurt fortified with 2% PPP had the highest flavor score; that fortified with 4% PPP received the lowest. The 2% PPP also earned the best color and mouth feel scores.
The big picture results: The incorporation of PPP into yogurt resulted in improvements in nutritional composition, particularly in terms of beta-carotene and bioactive compounds. Additionally, utilizing PPP positively influenced the textural properties of the yogurt.
The research team concluded that this work shows PPP “could be a promising alternative for the food industry to provide carotenoid-enriched yogurts.” If you’re interested in being a pumpkin pioneer, it may be time to find a creamery to partner with.
