Partial replacement of pork fat by conjugated linoleic acid and/or olive oil in liver pâtés: Effect on physicochemical characteristics and oxidative stability

The effect of replacing pork fat in liver pâtés by an enriched conjugated linoleic acid oil (CLA-pâté), olive oil (OO-pâté), or the combination of both type of oils (CLA + OO-pâté) on the fatty acid profile, lipid oxidative stability, consistency and emulsion stability was studied and compared with a traditional liver pâté (C-pâté). Pâtés were analyzed at days 1, 6, 21 and 71 of refrigerated storage (4 °C). A enrichment in CLA was attained in CLA-pâté and CLA + OO-pâté. CLA-pâtés had the highest content in polyunsaturated fatty acids (PUFA) (p < 0.05) due to their content in CLA. A lower content in saturated fatty acids was achieved when using OO or CLA in pâtés (p < 0.05). OO-pâtés showed the highest levels of monounsaturated fatty acids (MUFA) (p < 0.05). No changes in the fatty acid profile and in lipid oxidation (mg malondialdehyde per kg of sample) throughout the storage of the products were found. Lower consistency and emulsion stability were obtained when using CLA or OO in the formulation. Consistency values (in N/cm²) tended to increase and emulsion stability to decrease throughout the storage in CLA or OO enriched pâtés.     

Efficacy of disinfectants to reduce Listeria monocytogenes on precut iceberg lettuce

The efficacy of water, chlorinated water (100 ppm), peracetic acid solution (0.05%), and commercial citric acid-based produce wash (0.25%) to reduce the population of Listeria monocytogenes on precut lettuce was tested. Samples were inoculated with a mixture of equal amounts of five L. monocytogenes strains at a level of 4.7 log CFU/g, and analyzed on the day of washing and after 3 and 6 days of storage at 6 degrees C. Sanitizer reduced the number of L. monocytogenes at maximum 1.7 log CFU/g and number of L. monocytogenes reached the inoculation level during 6 days of storage. Thus, disinfectants do not eliminate L. monocytogenes on precut lettuce and cannot be solely relied on in producing precut lettuce safely. The inoculated L. monocytogenes strains were recovered at different rates after 6 days of storage; one of these strains was not recovered at all. Thus, strain-specific differences exist in the ability of L. monocytogenes to survive the washing treatments of the lettuce.     

Characterization,differentiation and classification of aquatic humic matter separated with different sorbents: synchronous scanning fluorescence spectroscopy

Aquatic humic solutes were separated by the non-ionic macroporous XAD-8 and DAX-8 resins and a weakly basic DEAE cellulose anion exchanger from seven different fresh water sources. Synchronous fluorescence spectroscopy was applied for characterization, differentiation and classification of the different humic-solute aggregates. Fluorescence properties verified that humic-solute fractions isolated parallelly with the non-ionic XAD-8 and DAX-8 resins resembled very closely each other speaking strongly for their structural similarities. DAX-8 resin separated ca. 19% more aquatic humic matter than did the analogous XAD-8 resin. It was possible to tentatively differentiate the untreated water samples according to their fluorescent materials. Several distinct classes of chromophores were detected in both DOM and isolated humic fractions by the synchronous technique: lambda(ex)/lambda(em) 280/298, 330/348, 355/373, 400/418, 427/445, 460/478, 492/510 and 516/534 nm.     

A staining syringe for multiple em grids

In the EM-routine, the thin sections are usually attached onto round copper grids. The sections on these EM-grids are then stained either with a quite expensive automatic staining apparatus or by transporting the grids by hand from solution to solution. Here we will present a simple, inexpensive and truly reliable apparatus for staining and handling grids.     

A Seven-Year Study of Phenolic Concentrations of the Dioecious <Emphasis Type="Italic">Salix myrsinifolia</Emphasis>

In boreal woody plants, concentrations of defensive phenolic compounds are expected to be at a high level during the juvenile phase and decrease in maturity, although there is variation between plant species. Females of dioecious species, like most of the Salicaceae, are expected to invest their resources in defense and reproduction, while males are expected to be more growth-oriented. We studied age- and sex-dependent changes in leaf and stem phenolics, and in height and diameter growth in a dioecious Salix myrsinifolia plants over a seven-year time period. In addition, we registered flowering as well as rust damage in the leaves. From the first year and throughout ontogenetic development from juvenile to adult phases, there was no significant change in the concentrations of any of the studied compounds in the leaves of S. myrsinifolia. In the stems, the concentrations of six out of 43 identified compounds decreased slightly with age, which may be partly explained by dilution caused by the increment in stem diameter with age. The fairly steady chemistry level over seven years, accompanied by moderate genotypic phenolic variation, indicates important roles of chemical defenses against herbivory for this early-successional species.     

The effect of probiotic fermented milk and inulin on the functions and microecology of the intestine

We investigated the effects of a probiotic fermented milk and inulin on gastrointestinal function and microecology. The study was double-blinded and comprised 66 healthy adults (22 male, 44 female), mean age 40 years (range, 22-60 years). After a 12-d baseline period the subjects were randomized to consume, for 3 weeks, 3x200 ml daily of either (1) a fermented milk with probiotics (Bifidobacterium longum BB536, Bifidobacterium spp. 420 and Lactobacillus acidophilus 145), (2) a fermented milk with the same probiotics plus 4 g inulin, or (3) a control fermented milk. During the last 7 d of the baseline and the intervention periods, the subjects kept a record of their defaecation frequency and gastrointestinal symptoms, and collected all their faeces. Intestinal transit time, stool weight and faecal enzyme activities were measured. Thirty-nine subjects were randomized to give faecal samples for analysis of pH and microbes, including lactobacilli, bifidobacteria, coliforms, Escherichia coli, Bacteroides and Clostridium perfringens. Consumption of fermented milk with probiotics or with probiotics and inulin increased the faecal number of lactobacilli (P=0.009, P=0.003) and bifidobacteria (P=0.046, P=0.038) compared with the baseline. Compared with the control fermented milk, both active products increased lactobacilli (P=0.005, ANCOVA). Subjects consuming fermented milk with probiotics and inulin suffered from gastrointestinal symptoms, especially flatulence, more than the others (P<0.001). In conclusion, the probiotic fermented milk product had a positive effect by increasing the number of lactobacilli and bifidobacteria in the colon. Inulin did not alter this effect but it increased gastrointestinal symptoms.     

Persistence of probiotic strains in the gastrointestinal tract when administered as capsules, yoghurt, or cheese

Most clinical studies of probiotics use freeze-dried, powdered bacteria or bacteria packed in capsules. However, probiotics are commercially available in various food matrices, which may affect their persistence in the gastrointestinal tract. The objective of the study was to compare oral and faecal recovery during and after administration of a combination of Lactobacillus rhamnosus GG and LC705, Propionibacterium freudenreichii subsp. shermanii JS, and Bifidobacterium animalis subsp. lactis Bb12 as capsules, yoghurt, or cheese. This randomized, parallel-group, open-label trial (n = 36) included a 4-week run-in, 2-week intervention, and 3-week follow-up period. Participants consumed 10¹⁰ cfu/day of probiotic combination and provided saliva and faecal samples before, during, and after the intervention. Strain-specific real-time PCR was used to quantify the strains.L. rhamnosus GG was the only probiotic strain regularly recovered in saliva samples. During the intervention period it was recovered in the saliva of 88% of the volunteers at least once. No difference was found between the yoghurt and cheese groups. At the end of the intervention, L. rhamnosus GG and LC705 counts were high in faecal samples of all product groups (8.08 and 8.67 log₁₀ genome copies/g, respectively). There was no matrix effect on strain quantity in faeces or the recovery time after ceasing the intervention. For P. freudenreichii subsp. shermanii JS and B. animalis subsp. lactis Bb12, a matrix effect was found at the end of the intervention (P < 0.01 and P < 0.001, respectively) and in the recovery time during follow-up (P < 0.05 for both). Yoghurt yielded the highest faecal quantity of JS and Bb12 strains (8.01 and 9.89 log₁₀ genome copies/g, respectively). The results showed that the administration matrix did not influence the faecal quantity of lactobacilli, but affected faecal counts of propionibacteria and bifidobacteria that were lower when consumed in cheese. Thus, the consumption of probiotics in yoghurt matrix is highly suitable for studying potential health benefits and capsules provide a comparable means of administration when the viability of the strain in the capsule product is confirmed.