Development of a Natural Preservative from Chestnut Flowers: Ultrasound-Assisted Extraction Optimization and Functionality Assessment

Ikbel ben Alaya,Eliana Pereira,José Pinela,Marina Kostić,Marina Soković,Cristina Caleja,Isabel C. F. R. Ferreira,Ricardo C. Calhelha,Maria Inês Dias,Lillian Barros,Faten Essid,Miguel A. Prieto

doi:10.3390/chemosensors9060141

Abstract

This study was carried out with the aim of optimizing the ultrasound-assisted extraction (UAE) of phenolic compounds from male chestnut flowers (C. sativa Mill) to develop a bioactive extract with potential to be used as a natural antioxidant preservative ingredient in the food industry. Time (t, 1–39 min), solvent concentration (S, 0–100%), and ultrasonic power (P, 5–500 W) were used as the independent variables for a 5-level experimental circumscribed central composite design (CCCD) coupled with response surface methodology (RSM) to optimize the extraction of phenolic compounds by UAE. Regarding the variables, the three showed a significant effect on the extraction of phenolic compounds. The content of phenolic compounds (including flavonoids and tannins) and the extraction yield (extract weight gravimetrically assessed) were the response criteria for the optimization. Based on the statistically validated predictive polynomial models, it was possible to reach a maximum content of phenolic compounds at the global optimal conditions of 24 ± 3 min, 259 ± 16 W, and 51 ± 7% ethanol. Additionally, pentagalloyl-glucoside and trigalloyl-hexahydroxydiphenoyl-glucoside were the major phenolic compounds identified. The optimized extract was then analyzed for their biological properties. The bioactive potential of the chestnut flower extract obtained under these optimized conditions was evaluated using in vitro assays for antioxidant, anti-inflammatory, and antimicrobial activity, as well as cytotoxicity and hepatotoxicity tests. The results revealed that the enriched extract has antioxidant, antitumoral, and anti-inflammatory activities without toxicity issues. Overall, this study allowed to define the optimal conditions for the extraction of phenolic compounds from chestnuts male flowers by UAE, to obtain an enriched extract with biological properties that could be further used as a natural antioxidant ingredient with applications on functional foods.

Highlights

IntroductionSome bioactive compounds present in the composition of these plants, namely, anthocyanins, flavonols, phenolic acids, and vitamins, when isolated or in combined extracts have antioxidant, anti-inflammatory, anticarcinogenic, cardioprotective, and antibacterial properties [1]
Theoretical Response Surface Models of the Used Response Criteria for the response surface methodology (RSM) Analysis and Nowadays, there are not studies about the optimal conditions maximizing the extraction of phenolic compounds from the flowers of C. sativa Mill
C. sativa Mill and other sources, and that describe the conditions used for their extraction have been described [22,23], the results from this study may depend on dissimilarities not found in these studies

Summary

Introduction

Some bioactive compounds present in the composition of these plants, namely, anthocyanins, flavonols, phenolic acids, and vitamins, when isolated or in combined extracts have antioxidant, anti-inflammatory, anticarcinogenic, cardioprotective, and antibacterial properties [1] In this sense, some authors ensure that these phenolic compounds may be used as potential natural additives. Male chestnut flowers have outstanding bioactive properties that can be combined by the great abundance of phenolic compounds present in their composition [4] In this sense, its application in the food industry appears as a promising application as a natural ingredient in the preservation of food [4,5] and with functional capacity acting in the health of consumers [6]

Methods

Results

Conclusion