These veggie-packed brownies might just be the game-changer your diet needs!

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.Jan 8 2025

Replacing traditional ingredients with vegetable purees enhances the nutritional value of brownies but presents challenges in maintaining taste and texture preferences.

Study: Vegetable-Enriched Brownies: A Healthier Twist on a Classic Treat. Image Credit: AlexeiLogvinovich / Shutterstock.com

A recent Nutrients study modifies a traditional brownie recipe by replacing butter with plant-based ingredients and subsequently assesses its nutrient profile and sensory attributes.

Brownies: A high-fat traditional delight

Brownies are popular chocolate cakes made up of eggs, wheat flour, fat, sugar, and chocolate. This dessert is high in energy and low in dietary fiber; therefore, its frequent and high consumption is extremely unhealthy. In fact, previous studies have indicated that individuals who consume brownies at a high frequency are at a greater risk of developing non-communicable diseases (NCDs), such as cardiovascular problems, obesity, and type 2 diabetes.

Considering the widespread popularity of brownies, it is important to discover alternative raw materials to completely or partially replace ingredients that increase the risk of NCDs in this dessert.

Vegetables as alternative cake ingredients

Plant-based products are rich in various nutrients that promote good health upon regular consumption. In fact, the daily intake of vegetables improves overall health and reduces the risk of gastric ulcers, certain types of cancer, diabetes, and other chronic diseases.

Thus, incorporating vegetables into cake recipes could lead to the production of healthier desserts. For example, zucchini has high water content, vitamin C, and potassium, whereas spinach is rich in dietary fiber, carotenoids, flavonoids, magnesium, calcium, and vitamins A, C, and E. Thus, vegetables, such as spinach, sweet potato, beetroot, zucchini, red kidney beans, and pumpkin, can be easily blended into a puree and incorporated into brownies.

About the study

The current study replaced traditional ingredients in brownie recipes with vegetables and assessed their nutritional profile and sensory attributes. To prepare the classic brownie (CB), medium-size chicken eggs, 70% cocoa, high-fat butter, wheat flour, and white sugar were used.

For the modified brownie, pumpkin (Cucurbita pepo), baby spinach (Spinacia oleracea), red lentils (Lens culinaris), red beet (Beta vulgaris), sweet potato (Ipomoea batatas), zucchini (Cucurbita pepo), or red kidney beans (Phaseolus vulgaris) purees were added to the basic ingredients.

All brownie variations were prepared in three separate batches. Sensory attributes and the chemical profile of each cake were assessed after baking and cooling.

Study findings

CB had the lowest moisture content, whereas the beetroot brownie exhibited twice as much moisture as CB. Except for the spinach brownie (SB), all other brownie variants, including CB, had lower protein content. Macronutrients in vegetable-enriched brownies ranged between 7.48-8.39%, with the highest macronutrients levels present in lentil brownies (LB), followed by red bean brownies (RBB).  

CB had highest fat content as compared to all brownie variants. When vegetables were used instead of fat, the lowest fat content was present in pumpkin and spinach brownies.

CB exhibited lowest fiber content. Among plant-derived brownies, SB had lowest, while RBB and sweet potato brownies (SPB) had the highest fiber.

The lowest ash content was measured in the CB, whereas the highest estimates were reported in brownies containing pumpkin, red beans, and sweet potato. Among all brownie variants, the highest energy value was estimated in CB, followed by pumpkin and sweet potato brownies.

RBB and SPB exhibited similar or slightly higher hardness values. In the hardness analysis, beetroot brownie (BB) and pumpkin brownie (PB) were significantly softer, whereas zucchini brownie (ZB), LB, and SB were the softest.

The chewiness assessment revealed that CB was the least chewie and SPB was the most chewie. RBB, BB, ZB, and PB exhibited moderate chewiness, with LB associated with the lowest chewiness value.

CB and LB exhibited the lowest springiness, thus indicating limited elasticity, while SPB and SB exhibited higher springiness values. BB, ZB, RBB, and PB had moderate springiness as compared to CB.

Color is a vital sensory attribute that influences consumer perception, even before tasting. ZB maintained a color that closely resembled that of CB; however, SB and SPB exhibited a significant change in color with the highest lightness values as compared to CB.

For general appearance, CB scored highest followed by BB and SPB. LB and SB were ranked the lowest for their appearance. The aroma of BB and CB was similar; however, the lowest aroma score was provided to SPB.

BB scored highest in texture, followed by RBB and CB. The overall desirability results indicated that CB was most sought after, followed by BB. RBB and PB exhibited moderate desirability, while SB, LB, and ZB had the least desirability scores

Conclusions

The addition of plant-derived ingredients into brownie recipes effectively increases their nutritional profile as compared to CB. However, the incorporation of these components altered the organoleptic properties of the brownie, which might impact consumers perception. Therefore, further optimization is needed to improve sensory attributes for a positive increase in consumer acceptance of plant-derived brownies.