Self-organizing maps based on chaotic parameters to detect adulterations of extra virgin olive oil with inferior edible oils

A nonlinear algorithm based on chaotic parameters (CPs) has been employed to determine the nature of different output signals obtained from UV–vis spectrophotometer (UV) measurements. These signals come from UV scans of adulterated samples of extra virgin olive oil (EVOO) with refined olive oil or refined olive pomace oil, or from pure samples of EVOO with white random or sinusoidal white random noises. The data collected from this equipment was used to calculate CP values. Then, a self-organizing map was used to detect different types of signals. Using this method, the signals can be identified and classified into five groups depending on their type, the percentage of noise added, and the concentration of adulterant agents, with a misclassification rate of less than 1.3%.     

Effect of eugenol and guaiacol application on tomato aroma composition determined by headspace stir bar sorptive extraction

BACKGROUND: The present work was carried out because there is only a small amount of literature on how the volatile composition of tomatoes can be modified by the effect of exogenous substances in contact with tomato plants. This work studies how eugenol and guaiacol, either by foliar application and/or in the surrounding atmosphere, can affect the volatile composition of this fruit. An important work of this study was also conduced to validate the analytical method [headspace stir bar sorptive extraction–gas chromatography–mass spectrometry (HS‐SBSE‐GC‐MS)] to determine the composition of the volatiles in tomato. RESULTS: Analytical method validation parameters such as linearity, limit of detection, limit of quantification, and recovery proved that this method is suitable for the analysis of tomato volatiles. Their eugenol and guaiacol content changed, with an increase of 200 and 35 times, respectively, when foliar treatment was used, and an increase of 10, in both cases, when plants were in contact with the contaminated atmosphere. As consequence of the treatments other volatile compounds changed considerably. CONCLUSION: For first time, a HS‐SBSE‐GC‐MS method was successfully validated for the study of volatiles in tomatos. Results suggests that exogenous compounds in contact with the plants, such as eugenol and guaiacol, can be absorbed changing the global volatile composition of fruits, which could produce a negative or positive effect in their aroma. © 2012 Society of Chemical Industry     

Infusion and decoction of wild German chamomile: Bioactivity and characterization of organic acids and phenolic compounds

Natural products represent a rich source of biologically active compounds and are an example of molecular diversity, with recognised potential in drug discovery. Herein, the methanol extract of Matricaria recutita L. (German chamomile) and its decoction and infusion (the most consumed preparations of this herb) were submitted to an analysis of phytochemicals and bioactivity evaluation. The antioxidant activity was determined by free radicals scavenging activity, reducing power and inhibition of lipid peroxidation; the antitumour potential was tested in human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture (non-tumour cells). All the samples revealed antioxidant properties. The decoction exhibited no antitumour activity (GI₅₀ > 400 μg/mL) which could indicate that this bioactivity might be related to compounds (including phenolic compounds) that were not extracted or that were affected by the decoction procedure. Both plant methanol extract and infusion showed inhibitory activity to the growth of HCT-15 (GI₅₀ 250.24 and 298.23 μg/mL, respectively) and HeLa (GI₅₀ 259.36 and 277.67 μg/mL, respectively) cell lines, without hepatotoxicity (GI₅₀ > 400 μg/mL). Infusion and decoction gave higher contents of organic acids (24.42 and 23.35 g/100 g dw). Otherwise, the plant methanol extract contained the highest amounts of both phenolic acids (3.99 g/100 g dw) and flavonoids (2.59 g/100 g dw). The major compound found in all the preparations was luteolin O-acylhexoside. Overall, German chamomile contains important phytochemicals with bioactive properties (mainly antitumour potential selective to colon and cervical carcinoma cell lines) to be explored in the pharmaceutical, food and cosmetics industries.     

Date palm by-products as a new ingredient for the meat industry: Application to pork liver pâté

Date palm is an interesting source of bioactive compounds that could be used as ingredient in meat products; thus a campagne type pork liver pâté was elaborated using fresh date by-products (0, 5, 10 and 15%). Physicochemical properties, pigment and lipid oxidation, residual nitrite level, texture and sensory analysis during 4 days after the elaboration process were evaluated. Date paste mostly incorporated moisture, fibre and phenolic compounds. Physicochemical parameters, myoglobin content and heme iron stability were not severely affected. Addition of 10% of date was enough to avoid lipid oxidation through all storage times. Colour was the most affected parameter; however, in terms of overall acceptability, panellists preferred samples with added date.     

β-Glucan administration to diabetic rats reestablishes redox balance and stimulates cellular pro-survival mechanisms

The mechanisms underlying the beneficial effect observed in diabetic rats after treatment with a commercially available β-glucan-enriched extract (BGEE) were examined. Multiple low-dose streptozotocin (STZ) diabetes was used (40 mg STZ/kg) as a model for type 1 diabetes. BGEE was administered daily (80 mg/kg) for 4 weeks, starting from the last day of the STZ treatment. In vitro and in vivo experiments suggest that significant free radical scavenging and antioxidant activities of BGEE were responsible for a systemic adjustment of the redox disturbance and reduction of DNA damage in the liver and kidney of diabetic rats. BGEE-treated diabetic rats also displayed increased Akt kinase activity and decreased pro-caspase-3 degradation, implying that BGEE mediates its beneficial effects through activation of the cellular pro-survival pathway. We conclude that β-glucan administration under diabetic conditions promotes a systemic improvement that can be expected to increase the organism’s resistance to the onset of diabetic complications.     

Stability and Quality Parameters of Probiotic Cantaloupe Melon Juice Produced with Sonicated Juice

The use of sonicated melon juice as substrate for Lactobacillus casei growth in cantaloupe melon juice and its effect on product quality were investigated. The survival of L. casei in the fermented juice, the product color, the post-acidification and other quality parameters were evaluated in the refrigerated product (4 °C) for a period of 42 days. Storage pH, color, sugar content, lactic acid concentration, biomass and viable cells count were determined. The caloric value of the product was also evaluated. During the refrigerated storage period, acidification and a slight reduction in the number of viable cells were observed. However, a sufficient number of viable cells were observed to guarantee the beneficial properties from probiotic consumption (>8 log CFU?ml^?1) throughout the storage period, for both stocked samples (with and without sugar addition). The product color was also preserved during storage. The developed product resulted in a low caloric product. The caloric value was reduced during the storage period due to sugar consumption by the remaining microorganisms.     

Effect of Cleaning Treatment on Adhesion of Streptococcus agalactiae to Milking Machine Surfaces

Streptococcus agalactiae is a common subclinical mastitis agent in dairy cattle. In this study, the influence of hygiene procedure time on the adhesion of S. agalactiae to rubber and silicone surfaces used in milking machines was evaluated. The effect of hygiene practices on the thermodynamic and microscopic features of both surfaces was also evaluated. The hydrophobicity of milking machines and bacterial surfaces was investigated by measuring the contact angle with a goniometer 0, 30, 90, and 180 days after a full hygiene procedure simulated using rubber and silicone coupons. As the time of cleaning procedures enhanced, there was a reduction in the adhesion of S. agalactiae to both surfaces. The rubber and silicone surfaces were hydrophobic in all treatments $ \left( {\Delta G_{\text{sws}}^{\text{TOT}}\; < \;0} \right) $ , while the bacterial surface presented hydrophilic behavior $ \left( {\Delta G_{\text{sws}}^{\text{TOT}}\; > \;0} \right) $ , which makes the adhesion process difficult. Photomicrographs showed rapid wear of both surfaces, pointing to damages caused by cleaning agents. However, the silicone was more resistant to cleaning and sanitizing treatments. Thus, this work shows that changes caused by hygiene procedures in the thermodynamic and in the morphology of milking surfaces have an enormous importance in the S. agalactiae adhesion and, consequently, in mastitis transmission between cattle herd.     

Biocomposite Films Based on κ-Carrageenan/Locust Bean Gum Blends and Clays: Physical and Antimicrobial Properties

The aims of this work were to evaluate the physical and antimicrobial properties of biodegradable films composed of mixtures of κ-carrageenan (κ-car) and locust bean gum (LBG) when organically modified clay Cloisite 30B (C30B) was dispersed in the biopolymer matrix. Film-forming solutions were prepared by adding C30B (ranging from 0 to 16 wt.%) into the κ-car/LBG solution (40/60 wt.%) with 0.3 % (w/v) of glycerol. Barrier properties (water vapour permeability, P _vapour; CO₂ and O₂ permeabilities), mechanical properties (tensile strength, TS, and elongation-at-break, EB) and thermal stability of the resulting films were determined and related with the incorporation of C30B. Also, X-ray diffraction (XRD) was done in order to investigate the effect of C30B in film structure. Antimicrobial effects of these films against Listeria monocytogenes, Escherichia coli and Salmonella enterica were also evaluated. The increase of clay concentration causes a decrease of P _vapour (from 5.34?×?10^?11 to 3.19?×?10^?11 g (m s?Pa)^?1) and an increase of the CO₂ permeability (from 2.26?×?10^?14 to 2.91?×?10^?14 g (m s?Pa)^?1) and did not changed significantly the O₂ permeability for films with 0 and 16 wt.% C30B, respectively. Films with 16 wt.% clay exhibited the highest values of TS (33.82 MPa) and EB (29.82 %). XRD patterns of the films indicated that a degree of exfoliation is attained depending on clay concentration. κ-car/LBG–C30B films exhibited an inhibitory effect only against L. monocytogenes. κ-car/LBG–C30B composite films are a promising alternative to synthetic films in order to improve the shelf life and safety of food products.