Thermal mud maturation: organic matter and biological activity

Authors: Centini M (1) , Tredici MR (2) , Biondi N (2) , Buonocore A (1) , Maffei Facino R (3) , Anselmi C (1)
(1) Dipartimento di Biotecnologie, Chimica e Farmacia, University of Siena (2) Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente – Sezione di Microbiologia Agraia, University of Florence (3) Dipartimento di Scienze Farmaceutiche “Pietro Pratesi”, University of Milan
Source: Int J Cosmet Sci. 2015 Jun;37(3):339-47
DOI: 10.1111/ics.12204 Publication date: 2015 Jun E-Publication date: March 19, 2015 Availability: abstract Copyright: © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.
Language: English Countries: Italy Location: Saturnia spa Correspondence address: Marisanna Centini, Dipartimento di Biotecnologie, Chimica e Farmacia, University of Siena, Via della Diana 2, 53100 Siena, Italy. Tel.: +39 577 232072; fax: +39 577 232070; e-mail:


Article abstract


Many of the therapeutic and cosmetic treatments offered in spas are centred on mud therapy, to moisturize the skin and prevent skin ageing and rheumatic diseases. Thermal mud is a complex matrix composed of organic and inorganic elements which contribute to its functions. It is a natural product derived from the long mixing of clay and thermal water. During its maturation, organic substances are provided by the microalgae, which develop characteristic of the composition of thermal water.


The aim of this study was to identify methods for introducing objective parameters as a basis for characterizing thermal mud and assessing its efficacy. Samples of thermal mud were collected at the Saturnia spa, where there are several sulphureous pools. The maturation of the mud was evaluated by organic component determination using extractive methods and chromatographic analysis (HPLC, GC-MS, SPME). We also studied the radical scavenging activity of mud samples at different stages of maturation, in a homogeneous phase, using several tests (DPPH, ORAC, ABTS).


We identified several classes of compounds: saturated and unsaturated fatty acids, hydroxyl acids, dicarboxylic acids, ketoacids, alcohols and others. SPME analysis showed the presence of various hydrocarbons compounds (C(11) -C(17)) and long-chain alcohols (C(12) -C(16)). Six or seven months seemed appropriate to complete the process of maturation, and the main effect of maturation time was the increase of lipids. Six-month mud showed the highest activity. The hydrophilic extract was more active than the lipophilic extract.


The results indicate that maturation of thermal mud can be followed on the basis of the changes in its organic composition and antioxidant properties along the time. They also highlight the need to develop reference standards for thermal muds in relation to assess their use for therapeutic and cosmetic purposes.

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