FTIR-ATR Analysis: Tomentosum Extract Abolization
C. tomentosum extract proximal composition is shown in Table 1. The relatively higher ash proportion in seaweed extract (SE) (aprox. 74%) could largely be accounted for by the lower moisture content, and probably due to a hygroscopic nature of the SE (Blanco-Pascual, Montero, & Gómez-Guillén, 2014). The values of TPC and DPPH radical-scavenging activity are consistent with literature (Andrade et al., 2013; Valentão et al., 2010) (Table 1). POD and PPO activities in the presence of extract solution are indicated in Table 1, were it is possible to observe that the extract significantly inhibits booth enzymatic activities with a reduction of 7.5% and 70% respectively.
2.2. FTIR-ATR analysis
The FTIR …show more content…
A small contact angle (below 30°) shows a hydrophilic surface (Seyedi, Koocheki, Mohebbi, & Zahedi, 2014). The contact angle between water drop and films surface was analyzed (Table 2). For all films studied, the only reliable result of contact angle obtained was for chitosan films, on which the drop remained stable (θ=78°). Influences on contact angle values with SE incorporation was verified, with a significant decrease (P<0.05) of values in both types of films, which presented dissolution and revealing surface hydrophilic characteristics. The addition of SE produces noticeable changes in the properties of both polymers, such as surface instability in aqueous media. Surface properties of the films also give information regarding the phenomenon of wetting or non-wetting of a product surface by film forming dispersions (Vargas, Albors, Chiralt, & González-Martínez, 2009). Wettability is one of the most important properties when evaluating the capacity of a solution to coat a surface where higher values of wettability (lower contact angels) are considered the most suitable to coat the surface. An increase in contact angle is known to reflect lower wetting (relatively higher hydrophobicity) property of the film surface (Seyedi et al., 2014). The contact angle results are in good agreement with the results obtained in film solubility tests (Table 2). As mentioned before, films with higher moisture content had lower contact angles, indicating more ability to absorb water and thus explaining the high