Composition in sugars of white and black garlic from different origins
Conference Paper
Overview
Overview
abstract
Allium sativum L., commonly known as garlic, has been used by populations for dietary
purposes and also for its medicinal interest, since antiquity. Garlic presents an interesting
nutritional profile as well as bioactive compounds related to its medicinal properties:
antimicrobial, antiseptic, antiviral, antioxidant, anticancer, immunostimulatory,
cardioprotective and hypoglycemic [1).
This study has tested (i) three samples of fresh white garlic, from different origins: Spain
(commercial variety), Tn3s-os-Montes and Algarve, Portugal (both traditional cultivated
varieties); (ii) and a sample of black garlic. Black garlic is the result of a thermic treatment
in which garlic bulbs are subjected to controlled temperature and humidity, resulting in
organoleptic changes such as colour and flavour. Nutritional and chemical compositions
also suffer changes in this process [2] . The samples were tested to determine free sugars
content, using high performance liquid chromatography coupled to a refraction index
detector (HPLC-RI).
Four different sugars were identified: fructose, sucrose, xylose and glucose. Fructose was
the most abundant sugar in black garlic (BG), while sucrose was the most abundant in
commercial garlic (CG), followed by the traditional cultivated garlic from Algarve (TGA) and
traditional cultivated sample from Tras-os-Montes (TGTM). Xylose was only detected in
BG sample. Sucrose was found in higher concentration in TGA sample and at lower levels
in BG sample. The highest content of glucose and fructose was found in BG, while the
lowest content was observed in TGA. Total sugars content was significantly higher in BG
sample (33.55 g/1 00 g of fresh weight), than in the other samples: CG (1.32 g/1 00 g fw),
TGA ( 1 .48 g/1 00 g fw) and TGTM (0. 70 g/1 00 g fw).
These results show some variability on the sugars content, less relevant between the
white garlic samples when compared to the black garlic sample. This study shows the
possible variations in the sugars' profile accordingly to various factors, such as variety or
processing treatments. Therefore, these experiments are highly important to have a better
understanding of the products used in our diet.
The authors are grateful to the Foundation for Science and Technology (FCT, Porlugal) and FEDER
under Program PT2020 for financial supporl to CIMO {UID/AGR/00690/2013), A.F grant (SFRH/BPD11475312016) and L. B contract.
