Tuning the mechanical properties of pectin films with polyphenol-rich plant extracts.

The mechanical properties of pectin films enhanced with polyphenol-rich fruit extracts were investigated. The scavenging and reducing activity of plant extracts incorporated into the pectin films were determined using bench assays, and their antioxidant activity was correlated with a high presence of polyphenols, which were predominantly comprised of flavonoids and anthocyanins. The pectin films generated from the extracts exhibited a range of mechanical properties; tensile strength (4.99 MPa - 6.91 MPa), elongation at break (45.8 % - 52.3 %), and stiffness (1835 g mm-1 - 2765 g mm-1). To investigate the underlying relationships between plant extract composition and mechanical properties, Projection to Latent Structures (PLS) models were developed. The PLS models revealed that extracts containing high sugar and polyphenol content increase the tensile strength and moisture content of films. The elongation at break of the films was improved or diminished depending on the profile of sugar, acids, and polyphenols in the fruit extracts. Furthermore, the structures and concentration of anthocyanins and flavonoids were identified to strongly influenced the elongation at break differences. By modifying the concentration of sugars, organic acids, and polyphenols, the mechanical properties of pectin-based films can be tuned for tailored applications as food packaging materials.

Qualitative Analysis of Polyphenols in Glycerol Plant Extracts Using Untargeted Metabolomics.

Glycerol is a reliable solvent for extracting polyphenols from food and waste products. There has been an increase in the application of glycerol over benchmark alcoholic solvents such as ethanol and methanol for natural product generation because of its non-toxic nature and high extraction efficiency. However, plant extracts containing a high glycerol concentration are unsuitable for mass spectrometry-based investigation utilising electrospray ionization, inhibiting the ability to analyse compounds of interest. In this investigation, a solid phase extraction protocol is outlined for removing glycerol from plant extracts containing a high concentration of glycerol and their subsequent analysis of polyphenols using ultra-performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry. Using this method, glycerol-based extracts of Queen Garnet Plum (Prunus salicina) were investigated and compared to ethanolic extracts. Anthocyanins and flavonoids in high abundance were found in both glycerol and ethanol extracts. The polyphenol metabolome of Queen Garnet Plum was 53% polyphenol glycoside derivatives and 47% polyphenols in their aglycone forms. Furthermore, 56% of the flavonoid derivates were found to be flavonoid glycosides, and 44% were flavonoid aglycones. In addition, two flavonoid glycosides not previously found in Queen Garnet Plum were putatively identified: Quercetin-3-O-xyloside and Quercetin-3-O-rhamnoside.

Improved cognitive performance after dietary supplementation with a Pinus radiata bark extract formulation.

Dietary interventions may have the potential to counter age-related cognitive decline. Studies have demonstrated an improvement in age-related cognitive impairment in animals after supplementation with plant extracts containing flavonoids but there are few human studies. This double-blind, controlled study examined the effects on cognitive performance of a 5 week supplementation with Enzogenol Pinus radiata bark extract containing flavonoids, in 42 males aged 50-65 years, with a body mass index >25. Participants were supplemented for 5 weeks either with Enzogenol plus vitamin C, or with vitamin C only. A battery of computerized cognitive tests was administered, and cardiovascular and haematological parameters were assessed prior to and following supplementation. The speed of response for the spatial working memory and immediate recognition tasks improved after supplementation with Enzogenol plus vitamin C, whereas vitamin C alone showed no improvements. A trend in a reduction of systolic blood pressure was observed with Enzogenol plus vitamin C, but not with vitamin C alone. The blood safety parameters were unchanged. The findings suggest a beneficial effect of supplementation with Enzogenol on cognition in older individuals. Larger studies are needed to ascertain its potential as a preventive treatment for age-related cognitive decline.