Because of the lack of data that convincingly show immunomodulatory properties of lactic acid bacteria in humans, a study was performed in which healthy volunteers were divided into two groups and given a fermented milk product supplemented with Lactobacillus acidophilus strain La1 or Bifidobacterium bifidum strain Bb 12 for 3 wk. Blood was sampled throughout the study to assess changes in lymphocyte subsets or leukocyte phagocytic activity following consumption of the fermented products. No modifications of lymphocyte subpopulations were detected. In contrast, phagocytosis of Escherichia coli sp. in vitro was enhanced after the administration of both fermented products. The increment in phagocytosis was coincident with fecal colonization by the lactic acid bacteria and persisted for 6 wk after ingestion of the fermented products. By this time, the fecal lactobacilli and bifidobacteria had returned to concentrations prior to consumption. Nonspecific, anti-infective mechanisms of defense can be enhanced by the ingestion of specific lactic acid bacteria strains. These strains can be used as nutritional supplements to improve the immune function of particular age groups, i.e., the neonate or the elderly, for which these functions are diminished.

The purpose of this study was to determine the effect of a fermented milk product containing Lactobacillus johnsonii La1 (formerly known as Lactobacillus acidophilus La1) on the phagocytic activity of peripheral blood leukocytes in healthy adult volunteers. Furthermore, we sought to define the effective doses of the bacteria, examine the effect on respiratory burst activity, and, finally, examine the contribution made by the starter culture to the biological effects. Volunteers were randomly distributed among three groups; each subject received one pot (150 ml) of fermented milk each day for 3 wk. The first two groups received a freshly prepared product fermented by Streptococcus thermophilus (group A) alone or S. thermophilus and 10(7) cfu/ml L. johnsonii La1 (group B). Group C received a product stored for a period of 21 to 28 d and that contained S. thermophilus and 10(6) cfu/ml of L. johnsonii La1. Ingestion of L. johnsonii La1 did not significantly increase fecal lactobacilli counts. However, L. johnsonii La1 was able to survive intestinal transit and was only recovered from the feces of the volunteers of groups B and C. The fermented base alone showed a weak effect on respiratory burst but not on phagocytic activity. However, the product containing 10(7) cfu/ml L. johnsonii La1 significantly enhanced both functions. The product containing 10(6) cfu/ml of L. johnsonii La1 had no significant effect on either function. These results suggest that fecal persistence may not necessarily reflect in vivo colonization and may not be a prerequisite for all forms of immune reactivity.

Positional distribution of fatty acyl chains of triacylglycerols (TGs) in vegetable oils and fats (palm oil, cocoa butter) and animal fats (beef, pork and chicken fats) was examined by reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to atmospheric pressure chemical ionization using a quadrupole mass spectrometer. Quantification of regioisomers was achieved for TGs containing two different fatty acyl chains (palmitic (P), stearic (S), oleic (O), and/or linoleic (L)). For seven pairs of 'AAB/ABA'-type TGs, namely PPS/PSP, PPO/POP, SSO/SOS, POO/OPO, SOO/OSO, PPL/PLP and LLS/LSL, calibration curves were established on the basis of the difference in relative abundances of the fragment ions produced by preferred losses of the fatty acid from the 1/3-position compared to the 2-position. In practice the positional isomers AAB and ABA yield mass spectra showing a significant difference in relative abundance ratios of the ions AA(+) to AB(+). Statistical analysis of the validation data obtained from analysis of TG standards and spiked oils showed that, under repeatability conditions, least-squares regression can be used to establish calibration curves for all pairs. The regression models show linear behavior that allow the determination of the proportion of each regioisomer in an AAB/ABA pair, within a working range from 10 to 1000 microg/mL and a 95% confidence interval of +/-3% for three replicates.

The working group of the International Office of Cocoa, Chocolate and Sugar Confectionery (IOCCC) performed a sequence of five ring tests to improve the agreement of the standard method for measuring viscosity of chocolate between laboratories. Reporting shear stress measurements instead of using the Casson equation improved the agreement, as did standardising the method of cleaning the concentric cylinder and calibrating the viscometers. In the revised method, the standard deviation for shear stress measurement at shear rates greater than 5 s−1 from 23 laboratories was less than 8%. However, the Casson yield values had a seven‐fold range and the Casson plastic viscosity a two‐fold range, which was unacceptably high. A new method (IOCCC 2000) has been published as a result of this work and is available from CAOBISCO in Bruxelles, Belgium.

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