Tuesday 21 February 2017

Encapsulation of yarrow essential oil in hydroxypropyl-beta-cyclodextrin: physiochemical characterization and evaluation of bio-efficacies

CyTA - Journal of Food

Essential oil from yarrow (Achillea millefolium L. s. l.) has a broad spectrum of pharmacological activities. However, active chemical components of yarrow oil are sensitive to environmental factors such as, light, oxygen and temperature. Encapsulation of essential oil offers solutions for the limitation. Yarrow oil was encapsulated in hydroxypropyl-β-cyclodextrin (HPβCD) through freeze-drying technique with encapsulation efficiency of 45%. Inclusion complex formation was examined by scanning electron microscope, Fourier transformed infrared spectroscopy and UV–vis analysis and phase solubility study. Yarrow oil gave strong antioxidant activity of 72% DPPH scavenging at 50 μg/mL. HPβCD could protect active compounds of essential oil and retained antioxidant activity after sunlight exposure. Yarrow oil also exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli with the minimum inhibitory concentration (MIC) values of 250 μg/mL and 500 μg/mL, respectively. The antibacterial efficacy was much improved after encapsulation against both S. aureus and E. coli with the MIC value of 62.5 μg/mL.

Friday 10 February 2017

Vine Trimming Shoots as Substrate for Ferulic Acid Esterases Production

Applied Biochemistry and Biotechnology

Ferulic acid esterases (FAE) possess a large variety of biotechnological applications mainly based on their ability to release ferulic acid from lignocellulosic matrixes. The use of vine trimming shoots (VTS), an agricultural waste, as substrate for the generation of this kind of esterases represents an attractive alternative to change the consideration of VTS from residue to resource. Furthermore, xylanase, cellobiase, and cellulase activities were quantified. Six microorganisms were screened for FAE production by solid-state fermentation, and the effects of the additional supplementation and substrate size were also tested. Finally, the process was scaled-up to a horizontal bioreactor where the influence of aeration in enzymatic activities was evaluated. Thus, the optimal FAE activity (0.44 U/g dry VTS) was attained by Aspergillus terreus CECT 2808, in non-additional supplementation media, using the larger particles size of substrate (≤ 5 mm) and at a flow rate of 0.7 L/min.

Thursday 2 February 2017

A Critical Review of the Characterization of Polyphenol-Protein Interactions and of Their Potential Use for Improving Food Quality.

Curr Pharm Des. 2017;23(19):2742-2753. 

Interest in protein-phenol interactions in biological systems has grown substantially in recent decades.

The interest has focused largely on food systems in response to reports on the prominent roles of phenolic compounds in nutrition and health.

Phenolic compounds can have both favourable and adverse nutritional effects. Polyphenols are widely known for their antioxidant, anti-inflammatory, anticancer and antiaging properties; however, they have also been ascribed anti-nutritional effects resulting from interactions with some proteins and enzymes. Interactions between proteins and polyphenols can additionally influence food quality by altering some physical-chemical and sensory properties of foods. These effects may be useful to develop new products in food science and technology provided the nature of physical-chemical interactions between proteins and phenols is accurately elucidated. In this paper, we review the different possible modes of interaction between selected food proteins and phenolic compounds.

Existing knowledge on the mechanisms behind polyphenol-protein reactions, the structures of the resulting products and their potential uses is reviewed.