How do grinding and sieving impact on physicochemical properties, polyphenol content, and antioxidant activity of Hieracium pilosella L. powders?

Successive grinding and sieving as a new tool to fractionate polyphenols and antioxidants of plants powders: Application to Boscia senegalensis seeds, Dichrostachys glomerata fruits, and Hibiscus sabdariffa calyx powders

“…Indeed, particles of smaller size have greater specific surface area, thus they expose more bioactive molecules on their surface, leading to a higher oxidation rate of antioxidant molecules. Becker et al () and Becker et al () also described a loss of polyphenols during the grinding of Salix alba , Hypericum perforatum , and Achillea millefolium , the loss being more pronounced for smaller particles.…”

“…It is often observed that the smallest particles are richer in minerals, because fibrous plant parts, containing fewer minerals, are harder to grind, resulting in larger particles (Becker et al, ,; Zaiter, Becker, Karam, et al, ). Similar observations were made on Eucalyptus grandis powders.…”

“…Recently, alternation of drying and grinding process (ADG) and CDS extraction, that is, grinding and controlled differential screening, consisting in combinations of drying, grinding, and controlled sieving processes, has received increasing attention due to the raising desire to develop ecological extraction technologies of natural and active ingredients (Baudelaire, ; Becker et al, ,; Brewer, Kubola, Siriamornpun, Herald, & Shi, ; Karam, Petit, Zimmer, Djantou, & Scher, ; Li et al, ; Lucas‐González, Viuda‐Martos, Pérez‐Álvarez, & Fernández‐López, ; Zaiter, Becker, Baudelaire, & Dicko, ; Zaiter, Becker, Karam, & Dicko, ; Zaiter, Becker, Petit, et al, ). Indeed, the competitive advantage of plant powders in comparison with conventional bioactive molecules obtained from plants by solvent extraction mainly resides in the preservation of bioactive ingredients, and more especially of their bioactivity, for human interest.…”

“…The fine particles issued from the combination of drying, grinding, and sieving processes enable a better release of bioactive substances owing to their high specific surface area (Rosa, Barron, Gaiani, Dufour, & Micard, ; Zhao et al, ). Several recent studies have reported the link between particle size range of plant powders, bioactive ingredient contents, physicochemical properties, and functionalities (Becker et al, ; Sharma, Kadam, Chadha, Wilson, & Gupta, ; Zaiter, Becker, Karam, et al, ). With the increasing quantity and variety of powdered ingredients used in industry (Sharma et al, ), production of plant powders constitutes an important step for their valorization in various industrial sectors.…”

“…surface area, thus they expose more bioactive molecules on their surface, leading to a higher oxidation rate of antioxidant molecules Becker et al (2016). andBecker et al (2017) also described a loss of polyphenols during the grinding of Salix alba, Hypericum perforatum, and Achillea millefolium, the loss being more pronounced for smaller particles.The link between bioactive compound and total protein contents was investigated by calculating Pearson correlation coefficients (R). The correlation between polyphenol and flavonoid contents for all plant powders was highly significant (R = 0.97; p < 0.05), and a more anecdotic correlation was found between total polyphenols and total proteins (R = 0.51; p < 0.05).…”