Six essential oils (EOs) from the Alliaceae family, namely garlic (Allium sativum), onion (Allium cepa), leek (Allium porrum), Chinese chive (Allium tuberosum), shallot (Allium ascalonicum) and chive (Allium schoenoprasum) were characterized by GC and GC-MS and evaluated for their functional food properties. Antibacterial properties were tested on five food-borne pathogens: Two Gram-positive Staphylococcus aureus (ATCC 25923), Listeria monocytogenes (ATCC 19115) and three Gram-negative Salmonella Typhimurium (ATCC 14028), Escherichia coli (ATCC 8739) and Campylobacter jejuni (ATCC 33291) bacteria. Antioxidant and radical-scavenging properties were tested by means of Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Garlic,
OPEN ACCESSMolecules 2014, 19
20035Chinese chive and onion EOs had the highest antibacterial activity whereas shallot and leek EOs were the strongest antioxidants. Heating caused a decrease in the antioxidant activity of these Eos, as shown in the Total Polar Materials (TPM) test. Suggestions on relationships between chemical composition and biological activities are presented. Results show that the EOs could be of value in the food industry as alternatives to synthetic antioxidants.
Maritime pine sawdust, a by-product from industry of wood transformation, has been investigated as a potential source of polyphenols which were extracted by ultrasound-assisted maceration (UAM). UAM was optimized for enhancing extraction efficiency of polyphenols and reducing time-consuming. In a first time, a preliminary study was carried out to optimize the solid/liquid ratio (6g of dry material per mL) and the particle size (0.26 cm(2)) by conventional maceration (CVM). Under these conditions, the optimum conditions for polyphenols extraction by UAM, obtained by response surface methodology, were 0.67 W/cm(2) for the ultrasonic intensity (UI), 40°C for the processing temperature (T) and 43 min for the sonication time (t). UAM was compared with CVM, the results showed that the quantity of polyphenols was improved by 40% (342.4 and 233.5mg of catechin equivalent per 100g of dry basis, respectively for UAM and CVM). A multistage cross-current extraction procedure allowed evaluating the real impact of UAM on the solid-liquid extraction enhancement. The potential industrialization of this procedure was implemented through a transition from a lab sonicated reactor (3 L) to a large scale one with 30 L volume.
There are more than 1300 articles in scientific literature dealing with positive impacts of Ultrasound-Assisted Extraction (UAE) such as reduction of extraction time, diminution of solvent and energy used, enhancement in yield and even selectivity, intensification of diffusion, and eliminating wastes. This present study aims to understand what are the mechanism(s) behind these positive impacts which will help to design a decision tool for UAE of natural products. Different microscopic observations (Scanning Electron Microscopy (SEM), Environmental Scanning Electron Microscopy (e-SEM), Cyto-histochemistry) have been used for spacial and temporal localization of metabolites in rosemary leaves, which is one of the most studied and most important plant for its antioxidant metabolites used in food industry, during conventional and ultrasound extraction. The study permits to highlight that ultrasound impacted rosemary leaves not by a single or different mechanisms in function of ultrasound power, as described by previous studies, but by a chain detexturation mechanism in a special order: local erosion, shear forces, sonoporation, fragmentation, capillary effect, and detexturation. These detexturation impacts followed a special order during ultrasound treatment leading at the end to the total detexturation of rosemary leaves. These mechanisms and detexturation impacts were identified in glandular trichomes, non-glandular-trichomes and the layer adaxial and abaxial cuticle. Modelling metabolites diffusion phenomenon during conventional and ultrasound extraction with the second Fick's law allowed the estimation of diffusivities and solvent penetration into the inner tissues and in meantime to accelerate the release of valuable metabolites.
This paper presents a comparison between manufactured food products using conventional and ultrasound-assisted procedures. Three different foam-type products, chocolate Genoise, basic sponge cake, and chocolate mousse were prepared using both methods with subsequent evaluation of the samples using both sensory and physicochemical methods. Ultrasound-assisted preparations were considered superior according to the sensory analysis, and physicochemical data confirmed this finding. This approach of applying an emerging piece of equipment, with potential industrial application to assist food preparation, consists of a new technique that could be of great interest for the development of not only other food products created by molecular gastronomy but also for practical work carried out by students.
This study aims total
valorization of rosemary for food applications,
moving toward developing an original biorefinery concept using solar
steam distillation (SSD) to extract essential oil while preserving
active compounds in the raw material, mainly antioxidants, for a further
extraction. The deodorization process is important to avoid the extraction
of antioxidants with strong aromas which limit their utilization for
food preservation. The SSD process was compared with conventional
steam distillation (CSD) for essential oil extraction as well as deodorization
of dried rosemary leaves. The treated leaves were recovered afterward
for the extraction of antioxidants by solvent extraction to recover
rosmarinic, carnosic, and ursolic acids. With standard protocol extraction
and analysis, the antioxidants seem to be mostly preserved by SSD
rather than by CSD. The Folin–Ciocalteu reagent was used to
determine the polyphenol content, whereas diphenylpicrylhydrazyl (DPPH)
was used to analyze the antiradical properties. It was found that
both the polyphenol content and antioxidant activity were preserved
after SSD. Scanning electron microscopy (SEM) and fluorescence microscopy
showed complete destruction of glandular trichomes for both processes,
which indicates that the extraction of essential oil was complete.
Overall, the results specify clearly that solar steam distillation
(SSD) is a green alternative, an efficient and economical process
for essential oil extraction and leaf deodorization.
In the effort of innovation towards green analytical chemistry concepts and considering the six principles of green extraction, the industrial turbodistillation process was downscaled into a laboratory apparatus turbo-Clevenger (TC) for the extraction of essential oils. Turbodistillation is used as an industrial purpose for the extraction of essential oils from hard matrixes such as wood, barks, seeds. In this work, a TC and the conventional technique of hydrodistillation (HD, Clevenger apparatus) are used for the extraction of essential oils from three spices with hard structures (Illicium verum, Schinus terebinthifolius, and Cinnamomum cassia) and are compared. This study shows that the essential oils extracted by TC in 30 min were quantitatively (yield and kinetics profile) and qualitatively (aromatic profile) similar to those obtained using conventional hydrodistillation in 3 h. This process, which gave a reduced extraction time, was perfectly adapted to the extraction of hard matrixes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.