Blood Parameters Modification at Different Ruminal Acidosis Conditions

This study evaluated the reliability of various blood parameters to assess the ruminal acidosis in cattle. Six whole heifers were fed three experimental rations in a 3 x 3 Latin square design. The diets had different starch levels: high (HS), medium (MS) or low (CT). Ruminal pH values were continuously measured using wireless sensors. To evaluate the severity of ruminal acidosis, the amount of time per day that the pH was below 5.8, 5.5 and 5.0 was recorded. Blood samples were analyzed for complete blood count, venous blood gas and biochemical profile at 8:00 and 12:00 h. The data were analyzed according to a mixed model. Feeding on CT, MS and HS led to significant differences in DMI (7.7 vs. 6.9 vs. 5.1 kg/d; P < 0.01) which modified the amount of time per day that the pH was below 5.0 (0 vs. 12 vs. 92 min; P < 0.10). Feeding MS and HS diets led to inflammation as indicated by the significant increment of white blood cells when compared to the CT ones and to blood concentration due to the osmotic pressure at ruminal level. Furthermore a significant decrease of bicarbonate level, CO2 partial pressure and oxyhemoglobin was observed as consequence of the activation of metabolic processes aimed to prevent metabolic acidosis. No differences were observed on blood sampling time, suggesting that one daily blood sample was enough to evaluate the metabolic variations related to ruminal acidosis

Blood Parameters Modification at Different Ruminal Acidosis Conditions

This study evaluated the reliability of various blood parameters to assess the ruminal acidosis in cattle. Six whole heifers were fed three experimental rations in a 3 x 3 Latin square design. The diets had different starch levels: high (HS), medium (MS) or low (CT). Ruminal pH values were continuously measured using wireless sensors. To evaluate the severity of ruminal acidosis, the amount of time per day that the pH was below 5.8, 5.5 and 5.0 was recorded. Blood samples were analyzed for complete blood count, venous blood gas and biochemical profile at 8:00 and 12:00 h. The data were analyzed according to a mixed model. Feeding on CT, MS and HS led to significant differences in DMI (7.7 vs. 6.9 vs. 5.1 kg/d; P < 0.01) which modified the amount of time per day that the pH was below 5.0 (0 vs. 12 vs. 92 min; P < 0.10). Feeding MS and HS diets led to inflammation as indicated by the significant increment of white blood cells when compared to the CT ones and to blood concentration due to the osmotic pressure at ruminal level. Furthermore a significant decrease of bicarbonate level, CO2 partial pressure and oxyhemoglobin was observed as consequence of the activation of metabolic processes aimed to prevent metabolic acidosis. No differences were observed on blood sampling time, suggesting that one daily blood sample was enough to evaluate the metabolic variations related to ruminal acidosis

COMPARISON OF TWO METHODS FOR THE DETECTION OF LISTERIA MONOCYTOGENES

The aim of this study was to compare the performance of the conventional methods for detection of Listeria monocytogenes in food using media Oxford and ALOA (Agar Listeria acc. to Ottaviani & Agosti) in according to the ISO 11290-1 to a new chromogenic medium "CHROMagar Listeria" standardized in 2005 AFNOR ( CHR – 21/1-12/01). A total of 40 pre-packed ready-to-eat food samples were examined. Using two methods six samples were found positive for Listeria monocytogenes but the medium "CHROMagar Listeria" was more selective in comparison with the others. In conclusion this study has demonstrated that isolation medium able to target specifically the detection of L. monocytogenes such as "CHROMagar Listeria" is highly recommendable because of that detection time is significantly reduced and the analysis cost is less expensive

Blood Parameters Modifi cation at Diff erent Ruminal Acidosis Conditions

Summary Th is study evaluated the reliability of various blood parameters to assess the ruminal acidosis in cattle. Six whole heifers were fed three experimental rations in a 3 x 3 Latin square design. Th e diets had diff erent starch levels: high (HS), medium (MS) or low (CT). Ruminal pH values were continuously measured using wireless sensors. To evaluate the severity of ruminal acidosis, the amount of time per day that the pH was below 5.8, 5.5 and 5.0 was recorded. Blood samples were analyzed for complete blood count, venous blood gas and biochemical profi le at 8:00 and 12:00 h. Th e data were analyzed according to a mixed model. Feeding on CT, MS and HS led to signifi cant diff erences in DMI (7.7 vs. 6.9 vs. 5.1 kg/d; P &lt; 0.01) which modifi ed the amount of time per day that the pH was below 5.0 (0 vs. 12 vs. 92 min; P &lt; 0.10). Feeding MS and HS diets led to infl ammation as indicated by the signifi cant increment of white blood cells when compared to the CT ones and to blood concentration due to the osmotic pressure at ruminal level. Furthermore a signifi cant decrease of bicarbonate level, CO 2 partial pressure and oxyhemoglobin was observed as consequence of the activation of metabolic processes aimed to prevent metabolic acidosis. No diff erences were observed on blood sampling time, suggesting that one daily blood sample was enough to evaluate the metabolic variations related to ruminal acidosis

Agricultural by-products with bioactive effects: A multivariate approach to evaluate microbial and physicochemical changes in a fresh pork sausage enriched with phenolic compounds from olive vegetation water

The use of phenolic compounds derived from agricultural by-products could be considered as an eco-friendly strategy for food preservation. In this study a purified phenol extract from olive vegetation water (PEOVW) was explored as a potential bioactive ingredient for meat products using Italian fresh sausage as food model. The research was developed in two steps: first, an in vitro delineation of the extract antimicrobial activities was performed, then, the PEOVW was tested in the food model to investigate the possible application in food manufacturing. The in vitro tests showed that PEOVW clearly inhibits the growth of food-borne pathogens such as Listeria monocytogenes and Staphylococcus aureus. The major part of Gram-positive strains was inhibited at the low concentrations (0.375–3 mg/mL). In the production of raw sausages, two concentrates of PEOVW (L1:0.075% and L2: 0.15%) were used taking into account both organoleptic traits and the bactericidal effects. A multivariate statistical approach allowed the definition of the microbial and physicochemical changes of sausages during the shelf life (14 days). In general, the inclusion of the L2 concentration reduced the growth of several microbial targets, especially Staphylococcus spp. and LABs (2 log10 CFU/g reduction),while the increasing the growth of yeasts was observed. The reduction of microbial growth could be involved in the reduced lipolysis of raw sausages supplemented with PEOVWas highlighted by the lower amount of diacylglycerols. Moisture and aw had a significant effect on the variability of microbiological features,while food matrix (the sausages' environment) can mask the effects of PEOVW on other targets (e.g. Pseudomonas). Moreover, the molecular identification of the main representative taxa collected during the experimentation allowed the evaluation of the effects of phenols on the selection of bacteria. Genetic data suggested a possible strain selection based on storage time and the addition of phenol compounds especially on LABs and Staphylococcus spp. The modulation effects on lipolysis and the reduction of several microbial targets in a naturally contaminated product indicates that PEOVW may be useful as an ingredient in fresh sausages for improving food safety and quality

Suscettibilit\ue0 alla fotossidazione del formaggio DOP Asiago d\u2019allevo vecchio. Risultati preliminari

Gli alimenti sono potenzialmente esposti all\u2019azione degradativa della luce durante tutta la loro vita commerciale. I fenomeni foto-ossidativi causano lo scadimento organolettico del prodotto, la perdita del valore nutrizionale e lo sviluppo di composti potenzialmente nocivi per la salute del consumatore. La presenza del packaging limita solo parzialmente tale fenomeno. Si \ue8 valutata la suscettibilit\ue0 alla fotossidazione del formaggio Asiago d\u2019allevo D.O.P. porzionato in preincarto mantenuto in condizioni di conservazione commerciale. La valutazione ha preso in considerazione l\u2019effetto dell\u2019origine (formaggio di montagna vs. formaggio di pianura), dell\u2019esposizione (buio vs. luce) e del tempo di conservazione (0\uf7336 ore) nei confronti del colore (misurato strumentalmente), contenuto di riboflavina e formazione di composti secondari dell\u2019ossidazione lipidica. Il formaggio di montagna presentava un maggior valore dell\u2019indice del giallo (P<0,001) e del rosso (P<0,001) mentre il contenuto dei riboflavina era significativamente maggiore in quello di pianura (P<0,001) che presentava anche una minore ossidazione dei lipidi (P<0,01). Luce e tempo di conservazione hanno comportato la progressiva riduzione dell\u2019indice del giallo (P<0,001 per entrambi gli effetti) e del rosso (P<0,001 per entrambi gli effetti) e la riduzione del contenuto di riboflavina (P<0,01 e P<0,001 rispettivamente). Lo sviluppo dei prodotti secondari dell\u2019ossidazione, invece, non sembra essere condizionato dall\u2019esposizione alla radiazione luminosa ma dalla presenza di ossigeno all\u2019interno della confezione (P<0,001). Il prodotto di montagna sembra essere maggiormente suscettibile. Ulteriori analisi dovranno essere condotte per valutare l\u2019effetto della radiazione luminosa e della presenza di ossigeno a carico delle vitamine liposolubili

A bacterial ecology study to improve shelf life of food products: meat microflora in swine fed with polyphenols from olive mill waste

Meat is an excellent substrate for bacterial growth and different factors (e.g. pH, redox potential, processing conditions) influence its microbial communities. Animal feeding strategy is the management factor most actively used as a quality control tool in meat production and the use of dietary antioxidants is recommended to preserve product quality. Olive mill wastes are sources of phenolic compounds with antioxidant and antimicrobial properties and a development of new bioremediation strategies is currently needed to overcome ecological problem. This study is an evaluation of the employment of polyphenols obtained from olive mill wastes in the swine productive chain to identify possible correlation among feedstuff enrichment and meat microbial quality. To obtain a comprehensive view of the meat microbial biodiversity a 16S rRNA pyrosequencing approach was used. RNA was extracted from nine meat samples conserved at 4\ub0C, collected at 12 days from slaughter and derived from three groups of diets (control, phenolic extract and phenolic extract plus PUFA feedstuff enrichment). cDNA was amplified with primers targeting the V3-V4 region of 16S rRNA gene and analyzed using the 454/Roche GS Junior technology. Subsequent analysis were carried out using the QIIME (Quantitative Insights Into Microbial Ecology) pipeline. Dietary enrichment resulted in a increased microbial \u3b1-diversity and richness. The enriched diets significantly decreased the relative abundances of Pseudomonas and Brochothrix genera. In particular, Pseudomonas spp. constituted 83.9% of OTUs in control samples and 38,6% in meat derived from animals fed with phenolic extract plus PUFA. These interesting effects are accompanied by a increased abundance of the Lactobacillales order in the treated samples. Phenolic extract clearly influences the composition of the swine meat microflora and seems to ameliorate flesh quality and shelf-life

Effect of ultrasound alone or ultrasound coupled with CO2 on the chemical composition, cheese-making properties and sensory traits of raw milk

This study aimed to evaluate the effects of different intensities and durations of ultrasound on the composition, oxidation, cheese-making properties and sensory traits of raw milk. Moreover, the effects of the addition of CO2 and HCl prior to the sonication were tested to determine whether these chemicals could reduce the production of off-flavours. Treating milk with ultrasound led to certain changes in milk composition. We observed significant increases in free fatty acid levels, oxidation, and decreases in somatic cell count and pH; improved coagulation traits were also observed. The results of sensory evaluations revealed a significant increase in a burnt off-flavour with increasing intensity and duration of the ultrasound treatment. The addition of CO2 appeared to significantly reduce the disruptive effect of ultrasound, the formation of oxidation products and the detection of the burnt off-flavour, whereas the sour flavour was increased. Industrial relevance: Among the new technologies that are used to improve milk sanitisation and shelf life, ultrasound treatment has been demonstrated to inactivate many bacterial species and to be a viable sanitisation procedure. In this study the milk coagulation properties of sonicated milk were dramatically improved following the ultrasound (US) treatments, indicating a possible use for US in the cheese-making industry. Moreover, despite the evident production of off-flavours caused by US in milk, the use of CO2 to reduce pyrolytic processes and thus the formation of oxidation products, appeared to be promising with respect to the increased use of sonication on food and other organic matrices

Minimum bactericidal concentration of phenols extracted from oil vegetation water on spoilers, starters and food-borne bacteria

The aim of the study was to assess the in vitro effect of phenols extracted from oil vegetation water (PEOW) on several food-borne strains. Antibacterial activity of PEOW was based on the minimum bactericidal concentration (MBC) on microtitre assay. The taxa tested were: Staphylococcus (n. 5), Listeria (n. 4), Escherichia (n. 2), Salmonella (n. 1), Pseudomonas (n. 3), Lactobacillus (n. 2) and Pediococcus (n. 1). S. aureus and L. monocytogens showed the lowest level of resistance to PEOW (MBC=1.5-3 mg/mL). In contrast, the Gram negative strains (e.g. S. Typhimurium and Pseudomonas spp.) were in some cases unaffected by the tested doses and the MBCs ranged between 6 to 12 mg/mL. Starter cultures were dramatically reduced on growth (e.g. Staphylococcus xylosus; 0.75 mg/mL MBC). The thresholds for pathogenic strains could be considered for further applications of PEOW in food models (e.g. shelf life or challenge test studies)