Evaluation of freeze-thaw method on beetroot powder

Beetroot powder sounds appetizing? what comes to mind when you hear this word. No, it’s not from a beetle, like you’re thinking. Though there is a pigment from a beetle. That’s another story. Look up “beetle pigment” in Google. Yes, it’s beetroot in British english, and also known as garden beet, red beet, or golden beet. I prefer the yellow beet over the red beet; it gives a sweeter than earthy flavor.

Image credit: Unsplash by Christina Rumpf

Freeze-thaw method and drying

Freeze-thaw of beetroot is applied first before the product is dried, and turned to powder form. There are several methods that can be put to use. These methods provide advantages and disadvantages, but I think the manufacturer can decide the best method to produce an acceptable product. For example, freeze drying provided the lowest shrinkage rate, hardness, color change, and highest rehydration ratio. While the microwave vacuum drying (MVD) resulted in the highest flavonoid, and phenolic content. The study concluded that MVD was considered the most beneficial method for drying beetroot, as it provided the highest antioxidant level from any other freeze-thaw method. To note here, the method applies freezing and thawing. After this step, the drying method is applied. Though, the article doesn’t mention the beetroot powder in dried form, as it talks about pretreatment with the freeze-thaw methods. However, from the results, there is a possibility to use MVD to produce beetroot powder from freeze-thaw pretreated beetroots. I think there needs to be more research to determine the condition of the dried beetroot powder—physical and chemical changes—in the final product.

Natural ingredient, and uses

The powder is utilized in different products as a natural ingredient. This meets the demand of health-conscious consumers, and natural food industry. For example, beetroot powder can be used as a natural coloring to replace artificial flavors and colors. Therefore, improving the nutritional, and textural properties of the final product. Other uses include smoothies, sauces, and natural sweetener.

Food safety

Freeze-thaw drying the beetroot is the safest method due to its high moisture, and water content. The method helps reduce microbiological and food safety issues since water is removed. I would think that the drying would apply here, as well.

Reference

1. Liu, Yan et al. (2024). Beetroot (Beta vulgaris L. var. conditiva Alef.) pretreated by freeze-thaw: influence of drying methods on the quality characteristics. CyTA – Journal of Food, 22:1, pp 1-12. Website: https://www.tandfonline.com/doi/full/10.1080/19476337.2023.2295421