Buletinul Institutului Politehnic din Iași Secția Chimie și Inginerie Chimică ISSN: 2537-2947
ISSN-L: 0254-7104
2024, Volume 70(74), Issue 2 (June), pp. 41 - 52
The Pericarp of Citruses: Waste Product or Polyphenol Resource
IOSIF CIOANCA, Theoretical High School “Al. I. Cuza” Iași, Romania GEORGE-ALEXANDRU MARIN, Faculty of Pharmacy, “Grigore T. Popa” University of
Medicine and Pharmacy, Iași, Romania,
george17marin@gmail.com ȘTEFAN LUCA, Faculty of Pharmacy, “Grigore T. Popa” University of Medicine
and Pharmacy, Iași, Romania IONUȚ IULIAN LUNGU, Faculty of Pharmacy,
“Grigore T. Popa” University of Medicine and Pharmacy, Iași, Romania CLAUDIA-ADRIANA CHITIC, Theoretical High School “Al. I. Cuza” Iași, Romania
Abstract Citruses, members of the Rutaceae family, are globally
renowned for their nutritional and health benefits. While the edible parts
are widely consumed, the peels are often discarded despite their rich
polyphenol content, particularly flavonoids like hesperidin, naringin, and
quercetin. These polyphenols offer significant antioxidant,
anti-inflammatory, and antimicrobial properties. The aim of our study was to
evaluate the secondary metabolites profile and antioxidant potential of
peels from four citrus species: sweet oranges, mandarins, grapefruits, and
lemons. Fresh peels were cut and prepared for a microscopic identification,
then methanolic maceration extracts were obtained in a ratio of 1:20 (m/v).
The major group of active compounds were first screened by chemical
reactions with sodium hydroxide, aluminium chloride, Folin-Ciocâlteu Reagent
and by thin-layer chromatography (TLC). Total flavonoids, total polyphenols
and carotenoids were quantified with spectrophotometric tests. Moreover, the
antioxidant capacity was evaluated using 2,2-diphenyl-1-picrylhydrazyl
(DPPH•) assay. The obtained results indicated that although the chemical
composition varies depending on species, there is a similar chemical profile
for all samples. Nevertheless, lemon peel extracts exhibited the highest
antioxidant activity, followed by mandarins and oranges, with grapefruit
showing the lowest. The findings underscore the potential of citrus peels as
a valuable resource for bioactive compounds, advocating for their
utilization in nutritional and medicinal applications to promote
sustainability and reduce waste. Keywords: citrus peels, polyphenols,
flavonoids, antioxidant activity, sustainable utilization.