Rye Flour Extraction Rate Affects Maillard Reaction Development,Antioxidant Activity,and Acrylamide Formation in Bread Crisps

This report shows the effect of rye flour extraction rate on Maillard reaction, antioxidant activity, and acrylamide formation during toasting of rye bread crisps. Four rye flours with extraction rates of 70, 85, 95, and 100% were tested. Maillard reaction development was studied by measuring browning development, hydroxymethylfurfural (HMF), and glucosilisomaltol (GIM) formation, as well as antioxidant activity. Results showed that HMF and GIM concentrations in toasted bread crisps were higher as the flour extraction rate increases. Antioxidant activity increased during toasting as a consequence of antioxidant Maillard reaction product formation. Acrylamide concentration was clearly affected by free asparagine content of flour, while no effect of dietary fiber and natural antioxidant content of flours had an effect on acrylamide formation. Overall data suggest that the rate of Maillard reaction is higher in whole flours because of their higher free amino acid and protein content.     

Identification and quantification of stilbenes in fruits of transgenic tomato plants (Lycopersicon esculentum Mill.) by reversed phase HPLC with photodiode array and mass spectrometry detection

Reversed-phase high-performance liquid chromatography (RP-HPLC) with photodiode array (PDA) and mass spectrometry (MS) detection was employed to study the accumulation of stilbenes and other naturally occurring polyphenol intermediates of flavonoid pathway in tomato fruits of plants genetically modified to synthesize resveratrol. The transgenic tomato fruits were obtained by overexpression of a grapevine gene encoding the enzyme stilbene synthase in tomato plants (Lycopersicon esculentum Mill.). Stilbenes and flavonoids, either glycosylated or free, were simultaneosly identified by electrospray interface (ESI)-MS in negative ionization mode and were quantified by PDA detection at the wavelength corresponding to their maximum absorbance. The two detectors were coupled online with an HPLC system utilizing a narrow-bore C18 reversed-phase column, which was eluted by a multistep gradient of increasing concentration of acetonitrile in water containing 0.5% (v/v) formic acid. The results of these analysis revealed that the genetic modification of the tomato plants originated different levels of accumulation of four stilbenes (i.e., trans- and cis-piceid and trans- and cis-resveratrol) in their fruit depending on the stages of ripening. Either at immature or at mature stages of ripening the stilbenes were preferentially accumulated in the fruit peel as the glycosylated form. The highest amount of trans-piceid and trans-resveratrol were found in the peel of fruits harvested at mature stage of ripening. The variations in the levels of rutin, naringenin, and chlorogenic acid found in the samples extracted from the fruits of transgenic tomato plants, in comparison to that determined in the control lines, seemed to be related to the genetic transformation, whose effect on the flavonoid biosynthetic pathway needs to be elucidated by additional studies.     

Silicon and increased electrical conductivity reduce downy mildew of soilless grown lettuce

Downy mildew of lettuce, caused by Bremia lactucae, is difficult to control in soilless systems by using conventional methods of disease management because few chemicals are registered, while resistant cultivars face the problem of resistance break down; therefore other methods for disease control need to be investigated. The effect of silicon salt as well as increased electrical conductivities against downy mildew was evaluated in four experiments carried out in hydroponically systems, using the cultivar of lettuce “Cobham Green”, known for its susceptibility to the pathogen. Silicon, as potassium silicate, was added at 100 mg l⁻¹ of nutrient solution at three levels of electrical conductivity: 1.5–1.6 mS cm⁻¹ (EC1), 3.0–3.5 mScm⁻¹ (EC2, 0.70 g l⁻¹ NaCl) and 4.0–4.5 mS cm⁻¹ (EC3, 0.95 g l⁻¹ NaCl) respectively. Lettuce plants, grown for 14–20 (trials 1 and 2) and 36–45 (trials 3 and 4) days in the different nutrient solutions tested, were inoculated with B. lactucae conidia with a maximum of two inoculations before final disease assessment carried out 14–21 days after the inoculation able to give symptoms. EC and potassium silicate significantly influenced downy mildew incidence and severity, while their interaction was not a significant factor. The addition to the standard nutrient solution (EC1) of potassium silicate resulted in a significant reduction of downy mildew severity in trials 1 and 2 where plants were artificially inoculated 15 and 20 days after transplanting. This efficacy was slight on plants grown for 36 and 45 days before inoculation in a soil drenched with EC1 amended with potassium silicate. EC2 gave a significantly similar downy mildew reduction than EC2 added with potassium silicate in trial 3. Plants grown for 36 and 45 days at the highest electrical conductivity (EC3) showed a significant reduction in severity of downy mildew compared with that observed at EC2 level. The best results, in terms of disease control, were given by the addition of potassium silicate to the EC3 solution. This combination also led to a significantly increased plant biomass. The possibility and benefits of applying potassium silicate and increased EC amendments in practice is discussed.     

Genotypic variation in durum wheat root systems at different stages of development in a Mediterranean environment

Summary Glasshouse and field experiments were carried out to compare root growth of eight durum wheat genotypes at different stages of development with different moisture levels and in different soils. Genotypic differences were found, particularly at the stem elongation and heading stages of development, but the ranking of genotypes varied in relation to soil moisture level and fertility. Differences under optimal moisture level were mainly due to differences in tillering and disappeared by considering the root number and weight per culm. Drought caused an increase in the root-to-total-plant weight ratio (18.5 vs 14.3% at heading) but also an increase in absolute root weight. Karel, the genotype with the largest root mass under drought and the greatest proportion of roots in the upper soil layers (more than 50% in the 0–20 cm layer from heading onwards), showed the lowest yield reduction under severe stress. A large root system with a high density of roots in the upper layers of the soil profile may be beneficial in Mediterranean climates.Research supported by a grant of Ministero della Pubblica Istruzione (40%).     

Complexation of imazalil with beta-cyclodextrin,residue uptake,persistence, and activity against penicillium decay in citrus fruit following postharvest dip treatments

A method for the inclusion of imazalil (IMZ) in the beta-cyclodextrin (betaCD), structural characterization of the inclusion complex and its antifungal activity against Penicillium digitatum and P. italicum assessed by in vitro and in vivo tests are reported. According to the starting stoichiometry of betaCD with respect to IMZ, an equimolar ratio beta-cyclodextrin-IMZ (betaCD-IMZ) was detected by (1)H NMR. In vitro assays showed that the freshly prepared betaCD-IMZ was as effective as IMZ, although 1- and 4-day-old betaCD-IMZ mixtures were more effective. Studies on Star Ruby grapefruit showed no significant differences in residue uptake between treatments with an IMZ commercially available fungicide (Deccozil) or betaCD-IMZ when equal active ingredient (a.i.) concentrations (250 mg/L) and dip temperatures (20 or 50 degrees C) were used. By contrast, treatments of Tarocco oranges and Di Massa lemons with 250 mg/L betaCD-IMZ at 50 degrees C produced significant differences in residue uptake in comparison with 250 mg/L Deccozil treatments at 50 degrees C. The a.i. degradation rate in grapefruit during postquarantine and simulated marketing period (SMP) at 20 degrees C was not affected by the type of formulation used, whether at 20 or 50 degrees C. Conversely, IMZ in oranges and lemons had greater persistence when applied at 50 degrees C. All fungicide treatments showed a comparable efficacy against decay in grapefruit and oranges, whereas treatment in lemons at 250 mg/L a.i. of heated fungicides had higher suppressive effects against decay than unheated chemicals having equal a.i. concentrations and comparable activity at 1200 mg/L IMZ at 20 degrees C.     

Determination of geographical origin of olive oils using 13C nuclear magnetic resonance spectroscopy. I - Classification of olive oils of the Puglia region with denomination of protected origin

13C nuclear magnetic resonance spectroscopy was used to classify olive oils from the three production areas of the Puglia region labeled with the "denomination of protected origin" (DPO) Terra di Bari, Colline di Brindisi, and Dauno. High resolution (13)C spectra of 173 olive oil samples were measured, and the intensity data of triacylglycerol resonances were processed by using linear discriminant analysis, which was carried out stepwise for variable selection. The olive oil samples from the DPOs Colline di Brindisi and Terra di Bari were 90% correctly classified, whereas only 74% of "Dauno" DPO oils were classified in the true group. The performance of the discriminant model was verified by applying the cross-validation procedure based on the "leave one out" formalism. The discriminant model was evaluated against a blind test set of olive oils from the three DPO areas. All the oils used for the purpose were correctly assigned to their respective groups, with the exception of the Dauno oil samples based on the Coratina cv. They were misclassified as Terra di Bari oils because of a common monovarietal composition.     

Antimicrobial susceptibilities and population structure of Staphylococcus epidermidis associated with ovine mastitis

Intramammary infections are a serious problem for dairy sheep farms, and Staphylococcus epidermidis is one of the main etiological agents of ovine mastitis. In this work, 131 S. epidermidis isolates, collected from 2201 dairy Sarda sheep belonging to 14 flocks with high somatic cell count scores, were studied. The flocks were located in diverse geographical areas of Sardinia, Italy. The aim of study was to assess the susceptibility of isolates to 13 antimicrobial agents, many of which are frequently used in mastitis therapy. Oxacillin was used for detecting methicillin-resistant S. epidermidis (MRSE) by disk diffusion test. Thirty-eight percent of the isolates (n = 50) were resistant to penicillin, 7.6% (n = 10) were resistant to tetracycline, and 2.3% (n = 3) were resistant to both penicillin and tetracycline (PTRSE). Two isolates were resistant to five antimicrobials including methicillin. Analysis of staphylococcal cassette chromosome mec (SCCmec) elements showed that both MRSE isolates harbored SCCmec type IVa. Based on pulsed-field gel electrophoresis (PFGE) typing by SmaI macrorestriction, S. epidermidis isolates were grouped into four clusters at 75% similarity level. The two multi-drug resistant MRSE isolates displayed distinct PFGE patters. This study indicates that S. epidermidis isolates from sheep milk samples may accumulate resistance markers for different antimicrobial agents. Furthermore, the occurrence of PTRSE and MRSE suggests to adopt adequate hygienic measures when handling animals with intramammary infections, in order to prevent spreading PTRSE and MRSE strains to humans through direct contact and/or consumption of contaminated food.     

Molecular characterization of Corynebacterium pseudotuberculosis isolates using ERIC-PCR

Caseous lymphadenitis is an infectious sheep and goats disease caused by Corynebacterium pseudotuberculosis and characterized by abscesses in superficial and visceral lymph nodes. C. pseudotuberculosis strains isolated from these hosts have been shown to be very difficult to type by the existing methods. The aim of this study is evaluating the potential of the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis strains isolated in sheep. One hundred and twenty seven isolates of C. pseudotuberculosis were isolated from lesions suspected to have had caseous lymphadenitis collected from sheep at the slaughterhouse. Animals were from 24 flocks in 13 municipalities of the Minas Gerais State, Brazil. Species identification of the isolates was performed by routine biochemical tests and mPCR. Fingerprint was performed by RAPD using ERIC-1R, ERIC-2 and ERIC-1R+ERIC-2 primers. Seventeen different genotypes were generated by ERIC 1-PCR, 21 genotypes by ERIC 2-PCR and 21 genotypes by ERIC 1+2-PCR. Hunter-Gaston Discrimination Index (HGDI) found for ERIC 1, ERIC 2, ERIC 1+2 PCR were 0.69, 0.87, and 0.84, respectively. For most herds evaluated observed at most three different genotypes among isolates from animals of these property, in all ERIC-PCR assays. However a few flocks observed between four and nine genotypes per flock. The W Kendall value found for correlation among the three techniques of ERIC-PCR was 0.91 (P<5.0 x 10(-6)). The results show that ERIC-PCR has good discriminatory power and advantages over other DNA-based typing methods, making it a useful tool to discriminate C. pseudotuberculosis isolates.     

Farmed Gilthead Sea Bream (Sparus aurata) by-Products Valorization: Viscera Oil ω-3 Enrichment by Short-Path Distillation and In Vitro Bioactivity Evaluation

This study shows a pilot scale protocol aimed to obtain an omega 3-enriched oil after the processing of farmed gilthead sea bream viscera (SBV); this was oil was tested in vitro for bioactivity, attesting to the possibility to turn waste into profit The quality of the oil, in terms of requirements for animal and human consumption, was assessed by determining some chemical parameters, such as peroxide value (PV), thiobarbituric acid reactive substances (TBARS), ρ-anisidine (ρ-AV) content, total oxidation value (TOTOX), and phospholipids and free fatty acid (%), both in crude viscera oil (CVO) and refined viscera oil (RVO). Among the extraction conditions, the higher CVO yields were obtained at 60 °C for 10 min (57.89%) and at 80 °C for 10 min (67.5%), and the resulting oxidation levels were low when utilizing both extraction conditions. RVO, obtained from CVO extracted at 60 °C, showed the highest quality on the basis of the assessed parameters. The ethyl esters of the total fatty acid (TFA) contents extracted from RVO were enriched in the ω-3 polyunsaturated fatty acid fraction (PUFAE) up to almost 56% via short path distillation (SPD). Antioxidant activities and adipogenic properties were tested in vitro. PUFAE protected 3T3 L1 cells from oxidative stress and exerted an anti-adipogenic effect in Dicentrarchus labrax pre-adipocytes, attesting to the beneficial properties for both farmed fish and human health. These results could stimulate the adoption of solutions aimed to recover and utilize aquaculture by-products at a higher scale, turning “waste into profit” and indicating a strategy to reach more sustainable business models in aquaculture resource utilization according to the principles of the circular economy.     

Characterization of Fungal Biodiversity In Compost and Vermicompost

The ability of fungi to break down complex carbon sources makes them of vital importance in both the generation and application of compost. This paper illustrates the diversity and functions of the mycoflora of both a green compost (made solely thermophilically from plant debris) and a vermicompost (made mesophilically by the action of earthworms on plant and animal wastes). The soil dilution plate technique was applied on 3 media (PDA, CMC, PDA plus cycloheximide) and at 3 incubation temperatures (24°C, 37°C and 45°C) to isolate and identify fungal entities. Enzymatic activities (amylase, cellulase, chitinase, esterase, ligninase, pectinase, phosphatase, plastic degradation and xylanase) of most species from both composts were evaluated with a semiquantitative method on 15 substrates. There were substantial qualiquantitative differences in the species composition of the two composts. A total of 193 entities were isolated: 54 from green compost only, 77 from vermicompost only, 62 from both. This taxonomic diversity was reflected in the metabolic potential. Amilase, cellulase, protease and esterase activities were significantly higher in the green compost. Lignin and plastic polymer degradation were significantly higher in the vermicompost. Structural and functional characterization of this kind is of assistance in determining both the most appropriate application of composts and their hygienic quality.