Optimizing extraction conditions of crude fiber, phenolic compounds, flavonoids and antioxidant activity of date seed powder

Abstract

The objective of this study was to optimize the extraction conditions of crude fiber, phenolic compounds, flavonoids, and antioxidant activity from date seeds powder, using Response Surface Methodology. A central composite design with four independent variables; concentration of ethanol (X = 25, 50 and 75% v/v), solvent: sample ratio (X = 40:1, 50:1 and 60:1 v/w), temperature (X = 45, 55 and 65 °C), and extraction time (X = 1, 2 and 3 h) and a three level face centered cube design were used. A total of twenty nine experimental runs with five replicates at the central point were used to study the response variables using two extraction cycles. Maximum phenolic compound content (71.6 mg GAE/100 g) was extracted using 50% ethanol solution with 40:1 solvent: sample ratio for 1 h at 55 °C. While the maximum antioxidant activity (55.02 µmol Fe(II)/g) was obtained using similar ethanol concentration and solvent: sample ratio except at lower temperature (45 °C) for 2 h. On other hand, the maximum flavonoids content (455.77 mg CEQ/100 g) was reached by using 50% concentration, 50:1 solvent: sample ratio at 65 °C for 3 h. In contrast, the content of fiber was not affected by the different extraction conditions. Results indicate that using combination of extracted conditions, have a great potential for extracting all depending compounds except crude fiber.

Assessment of antioxidant and antibacterial activity of Phoenix dactylifera L. seed extracts: Perspective for the development of new foods

“…The yield extraction was 4.60 ± 0.03%. This result is different compared to that found in previous studies 38,39 .…”

“…Scherer and Godoy 31 defined the categories of values corresponding to the antioxidant activity index (AAI) and, according to these categories, P. dactylifera seed extracts tested in the present study presented a strong antioxidant activity (AAI = 5.25). In the last few decades, considerable research has been carried out on the antioxidant activity of different varieties of date seeds 38,55,[60][61][62][63] . Moreover, various studies have already confirmed that different varieties of date seeds constitute an important source of antioxidants and hence their potential use as an ingredient in functional food technology.…”

Valorization of quince peel into functional food ingredients: A path towards “zero waste” and sustainable food systems

“…Later, Afifi et al. [ 44 ] obtained a solid residue containing 79.4% crude fiber, resulting from a 3 h extraction with 25% ethanol at 55 °C; although the residue yield was relatively low, it was of high purity. These conditions also promote the recovery of total phenolics and flavonoids.…”

Phytochemicals of Conocarpus spp. as a Natural and Safe Source of Phenolic Compounds and Antioxidants

“…Three independent variables, X 1 -solvent concentration, X 2 -extraction temperature, and X 3 -extraction time, were studied, as shown in Table S10. For the three factors, a three-level face-centered cube design was applied, consisting of 15 experimental runs with three replicates at the central point [41,42]. All experiments were conducted in random order to eliminate error due to the extraneous factors.…”