Polyphenol bioaccessibility and antioxidant properties of in vitro digested spray-dried thermally-treated skimmed goat milk enriched with pollen

Food Chem. 2021 Jul 30:351:129310. doi: 10.1016/j.foodchem.2021.129310. Epub 2021 Feb 18.

Abstract

The aim of research was to determine polyphenols bioaccessibility and antioxidant properties of thermally-treated skimmed goat milk enriched with sunflower bee-collected pollen through in vitro digestion. HPLC analysis confirmed that pollen-enriched milk contained flavonols as the main phenolic fraction (80.7-76.2%) followed by phenolic acids (14.2-17.4%). Among individual compounds quercetin-3-O-glucoside (155.1-197.2 μg/L) and p-coumaric acid (29.5-30.7 μg/L) were the main quantified flavonols and phenolic acids, respectively. After digestion of milk/pollen sample, total polyphenols recovery was 30.71% with higher phenolic acids recovery (40.1%) compared to flavonols (28.3%) indicating strong interactions between caprine milk casein micelles and pollen polyphenols. Applied antioxidant assays (phosphomolybdenum, ABTS•+scavenging activity and ferrous-ion-chelating capacity) have confirmed complexity of prepared product- it had high ability to quench ABTS•+ radicals and to form chelating complexes with Fe2+ ions. Digestion provoked 20% reduction in total antioxidant capacity compared to the initial sample. TTSG milk/pollen powder could be good functional ingredient.

Keywords: Antioxidant properties; Goat milk/pollen powder; In vitro polyphenol bioaccessibility; Monofloral sunflower bee-collected pollen.

MeSH terms

  • Animals
  • Antioxidants / analysis*
  • Bees
  • Chromatography, High Pressure Liquid
  • Flavonols / analysis*
  • Glucosides / analysis
  • Goats
  • Milk / chemistry*
  • Pollen / chemistry*
  • Polyphenols / analysis*
  • Quercetin / analogs & derivatives
  • Quercetin / analysis

Substances

  • Antioxidants
  • Flavonols
  • Glucosides
  • Polyphenols
  • quercetin 3'-O-glucoside
  • Quercetin