| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 842.07 KB | Adobe PDF |
Orientador(es)
Resumo(s)
Tannins are a class of phenolic compounds commonly found in plants and studied for their in vitro bioactive
and enzyme inhibitory properties [1,2]. Cytinus hypocistis (L.) L. is a wild edible parasitic plant on various
Cistaceae family members, which biological properties (antioxidant, anti-tyrosinase, anti-inflammatory,
and antimicrobial) have been correlated with its high tannin content. Thus, studying the extraction
optimisation of tannins from C. hypocistis will give comprehensive clues for the enhanced recovery of
these high added- value bioactive compounds and their potential cosmeceutical applications [2].
The present work used Response Surface Methodology (RSM) to optimise tannins extraction using both
a conventional (Heat-Assisted Extraction – HAE) and a sustainable extraction method (Ultrasound-
Assisted Extraction – UAE). Two three-factor Rotatable Central Compound Designs (RCCDs) were
applied to evaluate the linear, quadratic, and interactive effects of the independent variables X1 [t: time
(min)], X2 [T: temperature (°C) or P: ultrasonic power (W)], and X3 [S: solvent ratio (% of ethanol/water,
v/v)]. The software Design-Expert v11 was used to generate the 20 experimental runs by entering the
factor ranges in alphas (α = 1.68). Each variable to be optimised was coded at five levels: -1.68, -1, 0, +1,
and +1.68.
The constructed polynomial models were statistically validated based on high R2 values and nonsignificant
lack-of-fit and used to predict the optimal extraction conditions. The obtained results from
both extraction systems revealed higher ethanol percentages as the critical factor for increasing the final
response (mg total tannins/g extract). The optimum global processing conditions predicted by the models
were 95 min, 46 °C, and 74% ethanol for HAE, and 18 min, 327 W, and 69% ethanol for UAE. Following
these conditions, 234 mg and 175 mg of total tannins per g of extract were recovered using HAE and
UAE, correspondingly.
Even though the HAE technique presented a higher final response, the UAE offers sustainable and
economic advantages in time and energy consumption. These results confirm the scale-up potential of C.
hypocistis as a valuable source of a tannin-rich extract.
Descrição
Palavras-chave
Cytinus hypocistis (L.)
Contexto Educativo
Citação
Silva, Ana Rita; Pinela, José; Ferreira, Isabel C.F.R.; García, Pablo; Barros, Lillian (2021). Optimisation of a tannin-rich extract using response surface methodology. In 1st Natural products application: health, cosmetic and food: book of abstracts. Bragança: Instituto Politécnico. ISBN 978-972-745-286-6