Novel acylflavones from Sideritis syriaca ssp. syriaca

In the framework of the detailed phytochemical analysis of the aerial parts of Sideritis syriaca, two novel acylflavones were isolated together with three acetylated flavone glycosides and acylated flavone glycosides. The novel acylflavones were identified as isoscutellarein 7-trans-p-coumarate and apigenin 7-,4′-bis(trans-p-coumarate). Their structures were elucidated by means of UV, 1D and 2D NMR, LC–DAD–MS and confirmed by HR-MS spectroscopy.     

The effects of a biocide and a surfactant on the detachment of Pseudomonas fluorescens from glass surfaces

Application of antimicrobial chemicals is a general procedure in the cleaning and disinfection of food-contacting surfaces. Adhesion to glass surfaces and chemically induced detachment of Pseudomonas fluorescens ATCC 13525(T) were studied in situ, under flow conditions, in a well-controlled parallel plate flow chamber (PPFC). Ortho-phthalaldehyde (OPA) and cetyltrimethyl ammonium bromide (CTAB) were applied separately, at several concentrations, to attached bacteria and their subsequent detachment was monitored. Following treatments the remaining adhered bacteria were characterized in terms of viability and cell size. Simultaneously, the planktonic cell surface was characterized in order to correlate PPFC results with thermodynamic approaches for adhesion evaluation, and surface free energy of chemically treated cells with adhesion strength. About 2.8x10(6) cells/cm(2) adhered to the glass surface after 30 min of bacterial flow, although thermodynamic analyses evidenced unfavourable adhesion. The independent application of OPA and CTAB promoted bacterial detachment to a small extent (16% of total cells). The remaining adhering bacteria were totally non-viable for OPA> or =0.75 mM and CTAB> or =0.25 mM, showing a lack of correlation between bacterial viability and detachment. The cellular size decreased as attachment proceeded and with chemical treatment. Both chemicals altered the cell surface properties, increasing the cell-glass adhesion strength, and promoting the emergence of polar characteristics. The overall results emphasize that OPA and CTAB were markedly ineffective in removing glass-attached P. fluorescens, demonstrating that bacteria can be non-viable but remain strongly attached to the adhesion surface.     

Nutritional composition and bioactive properties of commonly consumed wild greens: Potential sources for new trends in modern diets

Beyond the composition of the usual macronutrients and micronutrients, it is important to provide information on the composition of bioactive compounds and antioxidant capacity of foods, particularly of wild species to regain them for nowadays' dietary habits. Many greens are known as excellent sources of natural antioxidants, and consumption of fresh plants in the diet may contribute to the daily antioxidant intake. In the present study five leafy wild greens traditionally consumed (Borago officinalis, Montia fontana, Rorippa nasturtium-aquaticum, Rumex acetosella, Rumex induratus) were studied in order to document macronutrient, micronutrient and non-nutrient composition. R. induratus revealed the highest levels of sugars, ascorbic acid, tocopherols, lycopene, chlorophylls, flavonoids, and one of the highest antioxidant activity expressed as DPPH scavenging activity, β-carotene bleaching inhibition, and TBARS formation inhibition. R. nasturtium-aquaticum showed the healthier PUFA/SFA and n-6/n-3 ratios, and B. officinalis proved to be a source of γ-linolenic acid and other fatty acids from n-6 series that are precursors of mediators of the inflammatory response. The nutritional characteristics and antioxidant potential of these wild greens require reconsideration of their role in traditional as well as in contemporary diets. Furthermore, their extracts might find applications in the prevention of free radical-related diseases, as functional food formulations.     

Scapania nemorea liverwort extracts: Investigation on volatile compounds, in vitro antimicrobial activity and control of Saccharomyces cerevisiae in fruit juice

This study was focused on chemical characterisation of liverwort Scapania nemorea extracts and their antimicrobial activity against pathogenic and food-spoiling yeasts and bacteria. The chemical composition of three different extracts of the liverwort S. nemorea was determined by solid phase microextraction gas chromatography-mass spectrometry (SPME GC–MS). The dominant compounds in extracts were sesquiterpenes β-bazzanene (11%, 17.9% and 14.6%), isobazzanene (10.2%, 15.8% and 11.7%) and aromadendrene (8.8%, 12.9% and 10.6%) in the methanol, ethanol and ethyl acetate extracts, respectively. Antimicrobial potential of S. nemorea extracts against food spoiling yeasts and bacteria was determined in vitro by microdilution method. The Minimum Inhibitory Concentration (MIC) varied from 0.5 to 3 mg/mL for bacteria, and from 0.2 to 1 mg/mL for yeasts. Moreover, the combined effects of dry methanol extract of S. nemorea and heat processing on the survival and growth of a spoilage yeast in an apple/orange-based beverage, have been assessed through a Central Composite Design. Changes in color and flavor of the beverages were considered acceptable also after one week of storage at 25 °C. The results provide evidence of antimicrobial potential of S. nemorea extracts and suggest its potential as natural antimicrobial agent for food preservation.     

Exploring the anticancer properties of essential oils from family Lamiaceae

Lamiaceae is among the largest families of flowering plants with about 250 genera and over 7,000 species distributed around the world. It is considered as the important source of essential oils, for example, menthol, geraniol, eucalyptol, camphor and thymol. Therefore, it is imperative to study these economically important compounds under in vitro conditions for their sustainable and enhanced production. In addition to proven biological activities, essential oils from this family have recently been evaluated for anticancer activities and considered as a source of anticancer drugs. Mechanisms involved in the essential oils-mediated antiproliferative activity include cell cycle arrest, apoptosis and DNA repair mechanisms. Essential oils also act in the reduction of tumors, inhibiting metastasis and as anti-multidrug resistance molecules. The aim of this review is to assess the anticancer properties of essential oils obtained from different members of family Lamiaceae. The available reports on active components of essential oils and their effect on cancer type and cell line have been discussed. Biotechnological studies to improve the production of essential oils have also been highlighted. Various methods have been adopted to obtain essential oils under in vitro conditions from different plant species of family Lamiaceae, and their production is affected by culture conditions, cultivation mode, utilization of nutrient media and plant growth regulators. The literature survey suggests that essential oils obtained from family Lamiaceae have perspective for the development of new alternatives for disease treatment and prevention.     

Evaluation of Sample Preparation Procedures for Trace Element Determination in Brazilian Propolis by Inductively Coupled Plasma Optical Emission Spectrometry and Their Discrimination According to Geographic Region

Propolis is a complex mixture of substances collected by honeybees from buds or exudates of plants, beeswax, and other constituents, as pollen and sugars. The main purpose of this study was to evaluate two digestion procedures for determination of major, minor, and trace elements (Ba, Ca, Cd, Cr, Co, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn) in natura propolis samples by inductively coupled plasma optical emission spectrometry (ICP OES). The first procedure studied was an open-vessel digestion using HNO₃ + H₂SO₄ + H₂O₂ in a heating block and the second one was a microwave-assisted concentrated acid digestion using HNO₃ + H₂O₂. Both digestion procedures led to similar results and quantitative recoveries. The residual carbon contents (RCCs) for propolis sample digests were 0.269?±?0.012 % when using the first procedure with conventional heating and 0.458?±?0.023 % by microwave-assisted closed vessel digestion, demonstrating high efficiency of both procedures. Accuracy of the results was demonstrated using a certified reference material and by comparison with a recommended official method. The t test (unpaired) at 95 % confidence level showed that there was no significant difference between determined and certified values of all analytes under investigation, except Ca concentration employing conventional procedure. The optimized microwave-assisted digestion procedure led to recoveries around 89–103 % and precision better than 5 % for most samples. The second procedure was faster, safer, and more accurate than the one based on conductive heating. Additionally, principal component analysis (PCA) was applied for checking if there was correlation between inorganic composition and source of propolis samples collected around Bahia State in the Northeast of Brazil.     

Prevalence, distribution, and diversity of Listeria monocytogenes in retail environments, focusing on small establishments and establishments with a history of failed inspections

Despite growing concerns about cross-contamination of ready-to-eat foods with Listeria monocytogenes, our knowledge about the ecology and transmission of L. monocytogenes in retail establishments has remained limited. We conducted a cross-sectional study to characterize the prevalence, distribution, and subtype diversity of L. monocytogenes in 120 New York State retail deli establishments that were hypothesized to present an increased risk for environmental L. monocytogenes contamination (i.e., small establishments and establishments with a history of failed New York State Agriculture and Markets inspections). Analysis of these data along with previously reported data for 121 predominantly larger retail establishments in New York State identified establishment size, geographic location, and inspection history as significant predictors of L. monocytogenes presence and prevalence. The odds of an establishment being L. monocytogenes positive were approximately twice as high for large establishments, establishments located in New York City, or establishments with poor inspection history (as compared with establishments without these attributes), even though correlation between location and inspection history complicated interpretation of results. Within an establishment, L. monocytogenes was significantly more prevalent on nonfood contact surfaces than on food contact surfaces; prevalence was particularly high for floors and in floor drains, sinks, the dairy case, and milk crates. L. monocytogenes subtype diversity differed between sites, with lineage I isolates significantly associated with nonfood contact surfaces and lineage II isolates significantly associated with food contact surfaces. Isolates belonging to the same ribotype were often found dispersed across multiple sites within an operation.     

Effect of Blanching and Drying Temperature on Polyphenolic Compound Stability and Antioxidant Capacity of Apple Pomace

The effects of blanching and drying treatments on stability, physical properties, and antioxidant activity of apple pomace polyphenols were evaluated. Blanched and unblanched apples were extracted, and the pomace was dried in a cabinet dryer at a speed of 3 m/s at 50 °C, 60 °C, 70 °C, and 80 °C. The color, total phenolics, flavonoids, individual polyphenolic compounds, anthocyanins, and total antioxidant activity were analyzed. The blanching process caused a major retention in color, total polyphenolic content, and total flavonoid content for fresh apple pomace when compared with fresh unblanched pomace. Drying of either fresh blanched or fresh unblanched pomace caused a significant reduction (P < 0.05) in total polyphenol and flavonoid content leading to a reduction in the total antioxidant activity. When compared with the unblanched treatment, drying the blanched pomace at 80 °C resulted in a product with significant amounts of total phenolics, flavonoids, and antioxidant activity. The individual phenolic compounds were significantly increased (P < 0.05) in blanched pomace that was not dried when compared with unblanched samples. Drying blanched apple pomace did not cause a significant change in the concentration of individual polyphenolic compounds, but drying unblanched apple pomace caused a reduction in the concentrations of epicatechin and caffeic acid, with an important reduction in p-coumaric acid at temperatures higher than 60 °C. However, the drying process caused a significant reduction in the antioxidant capacity. Therefore, a combination of blanching and drying processes for apple pomace results in a product that maintains antioxidant capacity.     

Effect of sourdough fermentation on stabilisation,and chemical and nutritional characteristics of wheat germ

Lactic acid bacteria strains were identified from wheat germ by 16S rRNA partial sequencing, subjected to RAPD-PCR typing and screened. Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5 were used as starters to produce sourdough fermented wheat germ (SFWG). The chemical and nutritional characteristics of SFWG were compared to those of the raw wheat germ (RWG). Lipase activity in SFWG was ca. 2.6-fold lower than that found in RWG. As shown by SPME/GC/MS analysis, most of the volatile compounds derived from lipid oxidation during storage (40 days) were at markedly lower levels in SFWG compared to RWG. Fermentation of wheat germ increased of ca. 50% the concentration of free amino acids. Glu markedly decreased in SFWG, due to its conversion in GABA. The concentration of the anti-nutritional factor raffinose also decreased in SFWG. The in vitro protein digestibility, the concentration of total phenols, phytase and antioxidant activities were increased by fermentation.