Flavonoids in baby spinach (Spinacia oleracea L.): changes during plant growth and storage

The variation in flavonoid concentration and composition was investigated in baby spinach (Spinacia oleracea L.) cv. Emilia sown on three occasions, each harvested at three growth stages at 6-day intervals. After harvest, leaves were stored in polypropylene bags at 2 or 10 degrees C. Flavonoids were analyzed by reversed phase HPLC. Twelve flavonoid peaks were detected. The main flavonoid, making up on average 43% of the total flavonoid concentration, was identified as 5,3',4'-trihydroxy-3-methoxy-6:7-methylenedioxyflavone-4'-glucuronide. Four other flavonoids each contributed 7-12% of the total flavonoid content. Total flavonoid content was relatively stable during normal retail storage conditions, although some of the individual flavonoid compounds showed considerable variation. The youngest plants had the highest flavonoid concentration, indicating that by harvesting the baby spinach a few days earlier than the current commercial stage of harvest, the flavonoid concentration in the product may be increased and the content of potentially health-promoting compounds enhanced.     

Chemical composition and antioxidant, antimicrobial, and antifungal activities of the essential oil of Achillea ligustica all

The chemical composition of the essential oil from flowering tops of Achillea ligustica All. was studied. Samples were collected in different localities of Sardinia (Italy) and hydrodistilled both with Clevenger-type and with simultaneous distillation-extraction apparatus. The yields ranged between 0.88 +/- 0.06 and 0.43 +/- 0.02% (vol/dry wt). The essential oils were analyzed by GC-MS, and a total of 96 components were detected. From a qualitative point of view, irrelevant differences between samples were observed. Strong chemical variability depending on the origin of the samples was observed. The major compounds found were santolina alcohol (6.7-21.8%, for the first time detected in A. ligustica), borneol (3.4-20.8%), sabinol (2.1-15.5%), trans-sabinyl acetate (0.9-17.6%), alpha-thujone (0.4-25.8%), and, among sesquiterpenes, viridiflorol (0.7-3.6%). No significant differences were detected between essential oils extracted by hydrodistillation and simultaneous distillation-extraction with CH2Cl2 and n-hexane. Antioxidant activity as DPPH radical scavenging activity was expressed in TEAC and ranged between 0.40 and 0.88 mmol/L. The antimicrobial and antifungal activities were investigated on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Penicillium commune, Fusarium oxysporum, Rizoctonia solani, and Aspergillus flavus, showing low activity.     

Changes in food resources and conservation of scarab beetles: from sheep to dog dung in a green urban area of Rome (Coleoptera, Scarabaeoidea)

The aim of the research was to show how a change in land use influences the structure of a dung beetle assemblage and affect its conservation. In the Pineto Urban Regional Park (Rome), dog dung is the sole food resource currently available for scarab dung beetles, after the recent removal of wild and domestic herbivores. A one-year sampling was conducted to study the scarab assemblage in dog scats (1999) and to compare it with the previous assemblage associated with sheep droppings (1986). Richness, evenness and similarity parameters were compared between the two allochronic assemblages. From sheep to dog dung, an impoverishment of the total richness was observed (from 19 to 9 species) together with an increase of individuals (by 7 times). Dog dung harboured 20% of the current scarab dung beetle fauna of Rome, probably as a consequence of the dog mixed diet, rich in cellulose. Both the communities showed a high percentage of tunnellers, probably because of the food shortage and, for dog scats, of the high dehydration rate. A comparison with other Roman scarab communities enhanced that: (1) the change in food resource determined a higher difference in species composition respect to other parameters (size and habitat diversity); (2) dog dung provided a temporary refuge for species that otherwise may encounter local extinction in urban environments.     

Genetic diversity and structure of Ethiopian,Yemen and Brazilian C<Emphasis Type="Italic">offea arabica</Emphasis> L. accessions using microsatellites markers

Genetic diversity among 115 coffee accessions from the Coffea Germplasm Collection of IAC was assessed using SSR markers. The germplasm represents 73 accessions of Coffea arabica derived from spontaneous and subspontaneous plants in Ethiopia and Eritrea, species center of origin and diversity, 13 commercial cultivars of C. arabica developed by the Breeding Program of IAC, 1 accession of C. arabica cv. ‘Geisha’, 13 accessions of C. arabica from Yemen, 5 accessions of C. eugenioides, 4 accessions of C. racemosa and 6 accessions of C. canephora. Genetic analysis was performed using average number of alleles per locus (A), proportion of polymorphic loci (P), Shannon’s genetic index (H′ and G′_ST) and clustering analysis. All evaluated species were distinguished by a cluster analysis based on Jaccard’s coefficient. Differentiation between the cultivated plants of C. arabica and accessions derived from spontaneous and subspontaneous plants was observed. Spontaneous and subspontaneous accessions from Ethiopia were separated according to the geographical origin: east and west of the Great Rift Valley. Cultivated plants showed a low genetic diversity with a division in two groups: accessions from Yemen (H′=0,028) and Brazilian commercial cultivars (H′=0,030). The results agreed with previously reported narrow genetic basis of cultivated plants of C. arabica and supported the hypotheses about domestication of the species. This study also showed a significant genetic diversity among accessions from Ethiopia and Eritrea present in the Germplasm Collection of IAC. This diversity is specially observed in accessions from Sidamo (H′=0,143), Kaffa (H′=0,142) and Illubabor (H′=0,147) indicating their importance as source of genetic variability for coffee breeding programs.     

Maximum daily trunk shrinkage and stem water potential reference equations for irrigation scheduling of lemon trees

Measurements of midday stem water potential (ψ_stem) and maximum daily trunk shrinkage (MDS) were done over a 3-year period in adult Fino lemon trees (Citrus limon (L.) Burm. fil.) grafted on sour orange (C. aurantium L.) rootstocks. Plants were irrigated daily above their water requirements in order to obtain non-limiting soil water conditions. The results indicated that reference equations can be obtained for MDS and ψ_stem by pooling data across several seasons using crop reference evapotranspiration (ETo), daily mean vapor pressure deficit (VPD_m) and mean daily air temperature (T _m) in the case of MDS, and ETo in the case of ψ_stem. The best predictor of MDS under non-limiting soil water conditions was T _m, suggesting that MDS reference values can be obtained by means of easy and cheap measurements. MDS and ψ_stem values were not influenced significantly by yield or crop load variations between years. A negative linear relationship between MDS and ψ_stem was found, pointing to an unchanging radial hydraulic conductivity in the bark tissues and suggesting that the MDS is controlled by water potential.     

The impact of various parameters on the carbon footprint of milk production in New Zealand and Sweden

The carbon footprint (CF) of milk production was analysed at the farm gate for two contrasting production systems; an outdoor pasture grazing system in New Zealand (NZ) and a mainly indoor housing system with pronounced use of concentrate feed in Sweden (SE). The method used is based on the conceptual framework of lifecycle assessment (LCA), but only for greenhouse gas (GHG) emissions. National average data were used to model the dairy system in each country. Collection of inventory data and calculations of emissions were harmonised to the greatest extent possible for the two systems. The calculated CF for 1 kg of energy corrected milk (ECM), including related by-products (surplus calves and culled cows), was 1.00 kg carbon dioxide equivalents (CO₂e) for NZ and 1.16 kg CO₂e for SE. Methane from enteric fermentation and nitrous oxide emissions from application of nitrogen (as fertiliser and as excreta dropped directly on the field) were the main contributors to the CF in both countries. The most important parameters to consider when calculating the GHG emissions were dry matter intake (DMI), emission factor (EF) for methane from enteric fermentation, amount of nitrogen applied and EF for direct nitrous oxide emissions from soils. By changing one parameter at a time within ‘reasonable’ limits (i.e. no extreme values assumed), the impact on the total CF was assessed and showed changes of up to 15%. In addition, the uncertainty in CF estimates due to uncertainty in EF for methane from enteric fermentation and nitrous oxide emissions (from soil and due to ammonia volatilisation) were analysed through Monte Carlo simulation. This resulted in an uncertainty distribution corresponding to 0.60-1.52 kg CO₂e kg⁻¹ ECM for NZ and 0.83-1.56 kg CO₂e kg⁻¹ ECM for SE (in the prediction interval 2.5-97.5%). Hence, the variation within the systems based on the main EF is relatively large compared with the difference in CF between the countries.     

Role of different factors affecting the formation of 5-hydroxymethyl-2-furancarboxaldehyde in heated grape must

The influence of concentration and water activity (a(w)) on the formation of 5-hydroxymethyl-2-furancarboxaldehyde (HMF) in thermally treated grape must was evaluated. Must was cryoconcentrated and then heated to study the pure effect of sugar concentration. Moreover, NaCl was added to the must to lower a(w), maintaining the same sugar concentration, with the purpose of evaluating the pure effect of a(w). Finally, the influence of minimal pH changes on the formation of HMF was evaluated by means of a model solution. The results showed that a(w) and sugar concentration are both determinant in the formation of HMF in grape must. Sugar concentration influences the reaction by supplying substrates; low a(w) enhances the formation of HMF by changing the equilibrium in the dehydration step of the reaction.     

Freshness and quality criteria of iced farmed Senegalese sole (Solea senegalensis)

Senegalese sole (Solea senegalensis) is a high-value commercial species with increasing importance in aquaculture. The aim of this work was to study the quality changes of this species during chilled storage under refrigeration, through sensory and chemical methods. In particular, the optimization of a quality index method (QIM) scheme was proposed as well as the definition of sensory and chemical quality criteria. A shelf life of 15 days was reported, and a QIM scheme based on a total of 22 demerit points (dp) was proposed. Biogenic amines were never detected, and the usual spoilage indicators, such as TVB-N and TMA-N, were not significantly produced during the period of sensory-acceptable quality (15 days). On the basis of the significant correlations (p<0.001) between sensory data and Ki values, a quality index (QI) 19 dp and a Ki>40% indicate unacceptable quality of iced Senegalese sole.     

Cocoa-enriched diet enhances antioxidant enzyme activity and modulates lymphocyte composition in thymus from young rats

Cocoa is a rich source of flavonoids, mainly (-)-epicatechin, (+)-catechin, and procyanidins. This article reports the effect of continuous cocoa intake on antioxidant capacity in plasma and tissues, including lymphoid organs and liver, from young rats. Weaned Wistar rats received natural cocoa (4% or 10% food intake) for three weeks, corresponding to their infancy. Flavonoid absorption was confirmed through the quantification of epicatechin metabolites in urine. Total antioxidant capacity (TAC) and the activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase, were examined. Cocoa intake enhanced TAC in all tissues especially in thymus. Moreover, thymus SOD and catalase activities were also dose-dependently increased by cocoa. It was also analyzed whether the enhanced antioxidant system in thymus could influence its cellular composition. An increase in the percentage of thymocytes in advanced development stage was found. In summary, cocoa diet enhances thymus antioxidant defenses and influences thymocyte differentiation.     

Early detection of fungal growth in bakery products by use of an electronic nose based on mass spectrometry

This paper presents the design, optimization, and evaluation of a mass spectrometry-based electronic nose (MS e-nose) for early detection of unwanted fungal growth in bakery products. Seven fungal species (Aspergillus flavus, Aspergillus niger, Eurotium amstelodami, Eurotium herbariorum, Eurotium rubrum, Eurotium repens, and Penicillium corylophillum) were isolated from bakery products and used for the study. Two sampling headspace techniques were tested: static headspace (SH) and solid-phase microextraction (SPME). Cross-validated models based on principal component analysis (PCA), coupled to discriminant function analysis (DFA) and fuzzy ARTMAP, were used as data treatment. When attempting to discriminate between inoculated and blank control vials or between genera or species of in vitro growing cultures, sampling based on SPME showed better results than those based on static headspace. The SPME-MS-based e-nose was able to predict fungal growth with 88% success after 24 h of inoculation and 98% success after 48 h when changes were monitored in the headspace of fungal cultures growing on bakery product analogues. Prediction of the right fungal genus reached 78% and 88% after 24 and 96 h, respectively.