Optimization of Betalain Pigments Extraction Using Beetroot by-Products as a Valuable Source

Abstract

(1) Background: This study is designed to extract the bioactive compounds from beetroot peel for future use in the food industry. (2) Methods: Spectrophotometry techniques analyzed the effect of conventional solvent extraction on betalains and polyphenolic compounds from beetroot peels. Several treatments by varying for factors (ethanol and citric acid concentration, temperature, and time) were applied to the beetroot peel samples. A Central Composite Design (CCD) has been used to investigate the effect of the extraction parameters on the extraction steps and optimize the betalains and total polyphenols extraction from beetroot. A quadratic model was suggested for all the parameters analyzed and used. (3) Results: The maximum and minimum variables investigated in the experimental plan in the coded form are citric acid concentration (0.10–1.5%), ethanol concentration (10–50%), operating temperature (20–60 °C), and extraction time (15–50 min). The experimental design revealed variation in betalain content ranging from 0.29 to 1.44 mg/g DW, and the yield of polyphenolic varied from 1.64 to 2.74 mg/g DW. The optimized conditions for the maximum recovery of betalains and phenols were citric acid concentration 1.5%, ethanol concentration 50%, temperature 52.52 °C, and extraction time 49.9 min. (4) Conclusions: Overall, it can be noted that the extraction process can be improved by adjusting operating variables in order to maximize the model responses.

A Comparative Study of Ethanol and Citric Acid Solutions for Extracting Betalains and Total Phenolic Content from Freeze-Dried Beetroot Powder

“…This conclusion applies to the time range covered in this work (5-30 min), which is expected given the ready solubility of the betalains in citric acid solution and cavitational effect of ultrasound to perform a quick and effective extraction [22]. Short extraction times will only have an effect if there are mass transfer limitations [17,21]. Long extraction times, such as over 50 min, can result in lower yields due to degradation of the extract caused by free radical formation in the presence of ultrasound [17,21].…”

“…Additionally, traditional extraction methods are energy-intensive. Hence, there is a growing interest in the development of extraction procedures using alternative solvents which are perceived to be greener, cleaner, safer, and easier to adopt [16], and the citric acid solution meets all of the aforementioned requirements to be a greener and cleaner solvent because it is easy to obtain, eliminate, and is safer and easier to handle [14,17,18]. In this context, citric acid solutions have been added to aqueous-ethanol solutions to extract betalains and total phenolic compounds.…”

“…In this context, citric acid solutions have been added to aqueous-ethanol solutions to extract betalains and total phenolic compounds. Lazăr et al (2021) [17] have used aqueous-ethanol acidified with citric acid; however, they did not control the pH of the solvent mixture, and the stability and extraction yield of betalains are known to be highly dependent on pH [19]. On the other hand, Singh et al (2017) [14] extracted betalains employing a similar mixture in the pH range 4-6 without varying the ethanol concentration.…”

Mycorrhizae set the stage for plants to produce a higher production of biomolecules and stress-related metabolites: a sustainable alternative of agrochemicals to enhance the quality and yield of beetroot (Beta vulgaris L.)

“…Beetroot is a biennial flowering plant that belongs to the Amaranthaceae family and originated in Asia and Europe (Avetisyan et al, 2022 ; Thakur and Singh, 2022 ). Approximately 1,400 species in 105 genera of beetroot have been reported worldwide to date (Lazǎr et al, 2021 ). Looking at the nutrient profile of the beetroot, it contains a variety of biomolecules and active ingredients such as highly active pigments, dietary fibers, vitamins, and secondary metabolites including carotenoids, polyphenols, flavonoids, and saponins (Chhikara et al, 2019 ).…”

Evaluation of Proximate Composition, Mineral Elements and Bioactive Compounds in Skin and Flesh of Beetroot Grown in Lithuania

“…Betalains are antioxidant and antiradical agents that can protect against disorders caused by oxidative stress. The functions of these compounds relate to the reduction of homocysteine levels, which regulate vascular homeostasis, vascular tone, and thrombotic activity while maintaining platelet function [9]. Other compounds present in this vegetable are fiber, proteins, and sugars with low energetic values [10].…”