Timing of onset of somatotropin supplementation on reproductive performance in dairy cows

The objective of this field trial was to determine whether delaying the start of recombinant bovine somatotropin (rbST) supplementation from 9 to 10 wk postpartum to 17 to 18 wk postpartum would improve reproductive performance in lactating dairy cows. Cows from nine herds (n = 798 cows; 766 Holsteins, 32 Jerseys) were assigned at random to receive rbST supplementation at 14-d intervals beginning during wk 9 to 10 (n = 399) or wk 17 to 18 (n = 399) after calving. Effects of herd, season of calving, parity, and onset of rbST supplementation (9 to 10 wk vs. 17 to 18 wk) on days to first service and days open were determined. In primiparous but not multiparous cows, there tended to be fewer days to first service and fewer days open when onset of rbST supplementation was delayed. Percentages of cows pregnant at 150, 200, and 250 d postpartum were also examined. Time of onset of rbST did not affect percentages of multiparous cows pregnant at 150, 200, and 250 d postpartum. However, there appeared to be a slight tendency for percentages of pregnant primiparous cows to be greater at 200 and 250 d postpartum for those receiving rbST supplementation beginning at 17 to 18 wk compared to those receiving rbST starting at 9 to 10 wk. In conclusion, delaying the start of rbST supplementation to wk 17 to 18 postpartum had no beneficial effect on reproductive performance of multiparous cows but tended to improve some measures of reproductive performance in primiparous cows.     

Physical and Antimicrobial Properties of Tapioca Starch-HPMC Edible Films Incorporated with Nisin and/or Potassium Sorbate

The antimicrobial effectiveness of nisin and potassium sorbate, incorporated individual and combined, in films made with tapioca starch and its mixtures with hydroxypropyl methylcellulose were studied. The combination of antimicrobials was more effective against Listeria innocua and Zygosaccharomyces bailii than their individual incorporation, with the added advantage of providing greater inhibitory spectrum. The effect of the formulation on some physical properties was also evaluated. The blended biopolymers-based films showed an increase of stress (σ _r) and elastic modulus (E) but a decrease of the strain at break (ε _r). In turn, the water vapour permeability and solubility in water were enhanced. In addition, these films were clearer than those made only with starch. It must be remark that, despite the antimicrobial agents modified films physical properties, producing a lower σ _r and E, a higher ε _r, solubility and darker films, they maintained a suitable behaviour as a packaging material.     

Characterisation and stability evaluation of bixin nanocapsules

The aim of this study was to produce bixin nanocapsules by the interfacial deposition of preformed poly-?-caprolactone (PCL). PCL (250 mg), capric/caprylic triglyceride (400 μL), sorbitan monostearate (95 mg) and bixin were dissolved in a mixture of acetone (60 mL) and ethanol (7.5 mL) under stirring (40 °C). This organic solution was added to the aqueous solution (130 mL) containing Tween 80 (195 mg). The size distributions in the formulations with bixin concentration from 11 to 100 μg/mL were evaluated periodically during 3 weeks of storage at ambient temperature. The optimal formulation (bixin concentration of 16.92 ± 0.16 μg/mL) was characterised in terms of particle size distribution, zeta potential, bixin content and encapsulation efficiency, and showed a volume-weighted mean diameter (D_4,3) of 195 ± 27 nm, around 100% of encapsulation efficiency and the nanocapsules were considered physically stable during 119 days of storage at ambient temperature.     

Bacterial community dynamics,lactic acid bacteria species diversity and metabolite kinetics of traditional Romanian vegetable fermentations

BACKGROUND: Artisanal vegetable fermentations are very popular in Eastern European countries. Fresh vegetables undergo a spontaneous fermentation in the presence of salt, which is mainly carried out by lactic acid bacteria (LAB). RESULTS: Culture‐dependent and culture‐independent analyses of end‐samples of various spontaneous vegetable fermentations carried out in houses of the Chiodju region (central Romania) revealed Lactobacillus plantarum and Lactobacillus brevis as the most frequently isolated LAB species. Leuconostoc mesenteroides and Leuconostoc citreum were also found. Furthermore, the community dynamics of spontaneous cauliflower and mixed‐vegetable (green tomatoes, carrots and cauliflower) fermentations revealed three steps: an initial phase characterised by the presence of Enterobacteriaceae and a wide LAB species diversity, encompassing Weissella species; a second phase from day 3 onwards wherein L. citreum and Lb. brevis occurred; and a final phase characterised by the prevalence of Lb. brevis and Lb. plantarum. Metabolite target analysis revealed that glucose and fructose were mostly depleted at the end of fermentation. The main products of carbohydrate metabolism were lactic acid, acetic acid, ethanol and small amounts of mannitol, indicating heterolactate fermentation. CONCLUSION: Given their prevalence at the end of vegetable fermentations, Lb. brevis and Lb. plantarum appear to be good candidate starter cultures for controlled vegetable fermentation processes. © 2012 Society of Chemical Industry     

Soybean extruded by-products as substrate for obtaining food ingredients containing probiotics

Extruded expeller meal (EEM) was widely used for feed production, but few exploited it as a food ingredient. Solid-state fermentation (SSF) was applied for obtaining food ingredients (FI) based on EEM containing Lacticaseibacillus casei. The FI were characterised physicochemically and functionally. The effect of the SSF on these characteristics as well as the effect of the expeller matrix on the survival capacity of L. casei in in vitro gastrointestinal digestion and on epithelial adhesion were analysed. In general, the SSF process did not produce significant changes on the nutritional and functional properties studied. Probiotic cells supported in the FI were stable for 42 days showing >10⁶ log (CFU g⁻¹) viable probiotic microorganisms. More than 60% of them survived to gastrointestinal simulated conditions. Expeller matrix interfered the adhesion of L. casei with the epithelium. The FI could be incorporated to a porridge for improving the nutritional profile and providing functionality.     

Polycyclic aromatic hydrocarbons in the indoor and outdoor air of three cities in the U.S

The indoor and outdoor concentrations of 30 polycyclic aromatic hydrocarbons (PAHs) were measured in 55 nonsmoking residences in three urban areas during June 1999-May 2000. The data represent the subset of samples collected within the Relationship of Indoor, Outdoor, and Personal Air study (RIOPA). The study collected samples from homes in Los Angeles, CA, Houston, TX, and Elizabeth, NJ. In the outdoor samples, the total PAH concentrations (sigmaPAH) were 4.2-64 ng m(-3) in Los Angeles, 10-160 ng m(-3) in Houston, and 12-110 ng m(-3) in Elizabeth. In the indoor samples, the concentrations of sigmaPAH were 16-220 ng m(-3) in Los Angeles, 21-310 ng m(-3) in Houston, and 22-350 ng m(-3) in Elizabeth. The PAH profiles of low molecular weight PAHs (3-4 rings) in the outdoor samples from the three cities were not significantly different. In contrast, the profiles of 5-7-ring PAHs in thesethree citieswere significantlydifferent, which suggested different dominant PAH sources. The signatures of 5-7-ring PAHs in the indoor samples in each city were similar to the outdoor profiles, which suggested that indoor concentrations of 5-7-ring PAHs were dominated by outdoor sources. Indoor-to-outdoor ratios of the PAH concentrations showed that indoor sources had a significant effect on indoor concentrations of 3-ring PAHs and a smaller effect on 4-ring PAHs and that outdoor sources dominated the indoor concentrations of 5-7-ring PAHs.     

Pasteurization of Apple Juice Contaminated with Escherichia coli by a Combined UV–Mild Temperature Treatment

The bactericidal efficacy of ultraviolet (UV) treatments to fruit juices is limited because of their low UV transmittance; therefore, it is necessary to design combined processes to improve their lethality. This investigation was carried out to determinate the lethal effect of UV-C treatments at mild temperatures (UV-H treatments) on the UV-resistant Escherichia coli strain Spanish Type Culture Collection (STCC) 4201 suspended in apple juice. A synergistic effect was observed and the optimum temperature for the combined process was established. Subsequently, the effect of the optimized treatment on the lethality of an E. coli cocktail (STCC 4201, STCC 471, American Type Culture Collection (ATCC) 27325, ATCC 25922, and O157:H7 Chapman strain) and on freshly squeezed apple juice quality was evaluated. A UV treatment of 20.33 J/mL reached 0.61?±?0.01, 0.83?±?0.07, 1.38?±?0.04, 1.97?±?0.06, 3.72?±?0.14, 5.67?±?0.61, and more than 6 log₁₀ cycles of inactivation at 25.0, 40.0, 50.0, 52.5, 55.0, 57.5, and 60.0 °C, respectively. The optimum conditions for exploiting the synergistic effects were UV doses of 27.10 J/mL, temperature of 55.0 °C, and 3.58 min of treatment time. This treatment guaranteed more of 5 log₁₀ reductions of the cocktail of five strains of E. coli without affecting pH, °Brix, and acidity of freshly squeezed apple juice. The UV-H treatment did not increase the loss of ascorbic acid compared to the same UV treatment at room temperature but approximately doubled the inactivation of polifenoloxidase.     

Synergistic antioxidant and antibacterial activity of rosemary plus butylated derivatives

Antioxidant and antibacterial activity of a methanol rosemary extract (RE) containing 30% carnosic acid (CA), 16% carnosol (COH) and 5% rosmarinic acid (RA) was studied in vitro alone and in combination with the antioxidant food additives butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). The antioxidant efficiency of the extract, CA, and RA, was determined by a kinetic analysis of the 2,2-diphenyl-2-picrylhydrazyl hydrate radical (DPPH·) scavenging activity. RE showed two different rate slopes in the reduction of DPPH· vs. time curve, which correlated with the distinct behaviours of RA and CA; pure RA reached the plateau more rapidly than CA. A synergistic antioxidant effect between RE and BHT was demonstrated by isobolographic analysis and a synergistic interaction of RE with BHA to inhibit Escherichia coli and Staphylococcus aureus growth was observed. Therefore, rosemary not only enhances the antioxidant efficiency of BHA and BHT, but also the antibacterial effect of BHA; allowing a decrease from 4.4 to17 folds in the amounts of the synthetic compounds used.