Organic acids, tocopherols and antioxidant activity of white and black garlic samples
Conference Paper
Overview
Overview
abstract
Garlic (Allium sativum L.) hás been used worldwide not only for its dietary interest, but also for
medicinal purposes, in prophylaxis and treatment of diverse pathologies. Garlic presents an
interesting nutritional profile as well as bioactive compounds, responsible for its biological properties,
namely, antioxidant, antimicrobial, immunostimulatory, hypoglycemic, among others [1].
The present work aimed to study bulbils (cloves) of white garlic (WG) and black garlic (BG). Both
white and black garlic samples were supplied by local producers from Trás-os-Montes region. Black
garlic samples were obtained by applying a dehydratation procedure to /t. sativum bulbs with
controlled humidity and temperature. Ali samples were studied regarding their chemical composition
in organic acids, analysed by High Performance Liquid Chromatography (HPLC) coupled to a Diode
Array Detector, and tocopherols determined by HPLC-fluorescence. Furthermore, their antioxidant
activity was evaluated through DPPH (2, 2-diphenyl-l-picrylhydrazyl) radical scavenging activity,
reducing power, p-carotene bleaching inhibition and TBARS (tiobarbituric acid reactive substances)
formation inhibition assays.
a-Tocopherol was the only vitamer identified in the studied samples, being quantified in BG samples
at the highest concentration. These samples presented oxalic, malic and pyruvic acids, while WG
samples showed also citric and fumaric acids, besides the ones previously mentioned. Malic and
pyruvic acids were the main compounds present in BG and WG, respectively. BG samples presented
higher antioxidant activity than WG samples, in ali the assayed methodologies.
The knowledge on the chemical and bioactive composition of natural matrices is of great importance
in the formulation of novel products. Therefore, the present study highlights that the processed garlic
(BG), an innovative product, presented higher antioxidant properties than WG, and could be explored
for bioactive purposes.
The authors are graleful to lhe Foundation for Science and Technology (FCT, Portugal) and
FEDER under Program PT2020 for financiai support to CIMO (UID/AGR/00690/2013), A.F grant
(SFRH/BPD/114753/2016) and L.B contract.
