Assessment of the Efficiency of a Nanospherical Gallic Acid Dendrimer for Long‐Term Preservation of Essential Oils: An Integrated Chemometric‐Assisted FTIR Study

Abstract

Essential oils (EOs) are volatile chemicals very popular in the food, cosmetic and pharmaceutical industry as aromas, fragrances and alternative therapeutic devices. EOs are susceptible to oxidative degradation, loss of quality and alterations of sensory and pharmacological properties with production of smelly or harmful compounds, responsible for allergic reactions. For preventing EOs’ spoilage, synthetic preservatives are adopted, but with poor efficiency and danger of health diseases. Natural polyphenols as gallic acid (GA) are proposed as safer alternatives, but the low compatibility with oils limits their efficacy. In this study, a hydrophobic, GA‐enriched antioxidant dendrimer (GAD), is advised as an innovative preservative, after due evaluations. Besides oxidation chemical indexes, the desired information was obtained by FTIR spectroscopy assisted by multivariate analysis. For further confirmation, FTIR data were interpreted by considering the area of some selected bands. Iodometric titration, was performed to determine peroxide value (PV), selected as chemical index. GAD showed a preservative power extraordinary better than that of GA and no pro‐oxidant action.

Development of a Fast, Low‐Cost, Conservative and Ecological Method for Quantifying Gallic Acid in Polymeric Formulations by FTIR Spectroscopy in Solution

“…GA attracts the interest of researchers mainly for its antioxidant capacity and ability in counteracting oxidative stress (OS) and correlated diseases as cancer, HIV, ulcer, inflammation, bacterial infections, fungi infections and neurodegenerative disorders …”

“…In the last decade, several natural or synthetic polymers, including acryloyldimethyl taurate with propylene glycol, polylactic‐co‐glycolic acid (PLGA), polyethylene glycol (PEG), chitosane, cyclodextrins, dextrane and dendrimers such as poly(amidoamine) (PAMAM) or polyester‐based ones have emerged as promising carrier systems for GA.…”

“…By reformulating GA in nanoparticles, it turned out to be possible to improve its efficiency and stability and consequently to revolutionize the treatment strategies of many diseases and to ameliorate GA industrial employments as preservative additive …”

“…As priorities, the method has to be fast, low‐cost in terms of consumables, simple to perform, ecological and conservative, for allowing the recovering of samples, which often are made of precious materials. FTIR spectroscopy, often associated to chemometric tools as PCA, is well‐known to be low‐cost, rapid, conservative and reproducible and is extensively employed for several kind of investigations …”

Reshaped as polyester-based nanoparticles, gallic acid inhibits platelet aggregation, reactive oxygen species production and multi-resistant Gram-positive bacteria with an efficiency never obtained

“…A study concerning the efficiency of the GAD as a preservative additive to prevent essential oil (EO) auto-oxidative spoilage conrmed its high performance as a radical scavenger and antioxidant. 73 It was shown to be a preservative additive far more potent than GA, with the ability to stop oxidative degradation thermally induced at very early stages thus improving the EO shelf life (Section S6 in the ESI †). Furthermore, different from GA, the GAD showed no pro-oxidant activity, even for prolonged exposure to heat, light and air.…”