Selective Extraction of Sinapic Acid Derivatives from Mustard Seed Meal by Acting on pH: Toward a High Antioxidant Activity Rich Extract

Abstract

The aim of this paper is to study the effect of the pH on the extraction of sinapic acid and its derivatives from mustard seed meal. Solutions of acidic pH (pH 2), basic pH (pH 12) and distilled water (uncontrolled pH ~ 4.5) were tested at different percentages of ethanol. The maximum extraction yield for sinapic acid (13.22 µmol/g of dry matter (DM)) was obtained with a buffered aqueous solution at pH 12. For ethyl sinapate, the maximum extraction yield reached 9.81 µmol/g DM with 70% ethanol/buffered aqueous solution at pH 12. The maximum extraction yield of sinapine (15.73 µmol/g DM) was achieved with 70% ethanol/buffered aqueous solution at pH 2. The antioxidant activity of each extract was assessed by DPPH assay; the results indicated that the extracts obtained at pH 12 and at low ethanol percentages (<50%) exhibit a higher antioxidant activity than extracts obtained at acidic conditions. Maximum antioxidant activity was reached at pH 12 with buffer solution (11.37 mg of Trolox Equivalent/g DM), which confirms that sinapic acid-rich fractions exhibit a higher antioxidant activity. Thus, to obtain rich antioxidant extracts, it is suggested to promote the presence of sinapic acid in the extracts.

A New Food Ingredient Rich in Bioaccessible (Poly)Phenols (and Glucosinolates) Obtained from Stabilized Broccoli Stalks

“…The quantitative profile of phenolics in broccoli stalks and sub-tissues is in agreement with what was studied in broccoli by-products, also stabilized by applying lyophilization processes and, thereby, exposed to similar deleterious effects, where there is also a predominance of sinapic acid and derivatives, as well as, to a lesser extent, feruloyl derivatives [ 1 , 27 ]. This preponderance is of special relevance because of the strong radical scavenging activity demonstrated for sinapic acid derivatives, as well as their capacity to interact with the membrane lipids and, thus, participate in the prevention of lipid peroxidation [ 29 , 30 ]. These molecular capacities allow the envisaging of the application of the materials obtained as functional ingredients.…”

Phenolics of mustard seeds: A review on composition, processing effect and their bioactvities

“…The pH of extracting solvents can greatly influence the electrostatic and stability of organic compounds. Chadni et al (2021) showed that sinapic acid was a pH‐dependent phenolic compound, in which the highest amount (13.22 ± 0.44 μmol/g of dry matter) was recovered from a buffered aqueous solution at pH 12. Galano et al (2011) previously confirmed the structural transformation of sinapic acid under the influence of pH using the computational stimulation method.…”

Highly efficient synthesis of sustainable bisphenols from hydroxycinnamic acids

“…[36][37][38] Hydroxycinnamic acids can be efficiently extracted from woody biomass with purities of up to 99%. Extraction can be conducted through alkaline [39][40][41][42] or enzymatic hydrolysis 43,44 followed by solvent extraction, 45,46 adsorption onto nanomaterials or membranes, 47,48 or counter-current chromatography (Fig. 1).…”