A spread containing bioactive milk peptides Ile-Pro-Pro and Val-Pro-Pro, and plant sterols has antihypertensive and cholesterol-lowering effects.

Lifestyle intervention is recommended as the primary treatment for mild hypertension and hypercholesterolemia. We studied the effects of a spread containing bioactive milk peptides IPP and VPP, as well as plant sterols, on cardiovascular risk factors in 104 hypertensive, hypercholesterolemic subjects in a randomised, placebo-controlled double-blind intervention. Middle-aged subjects consumed 20 g day⁻¹ of a spread containing 4.2 mg of IPP and VPP as well as 2 g of plant sterols for 10 weeks after a 2 week run-in period. Blood pressure was measured at home 3 times a week. Office blood pressure and 24 h ambulatory blood pressure measurements were performed at the end of the run-in and intervention periods. Blood samples were analysed for serum lipids, plasma glucose and inflammation markers. A significant decrease (-4.1 mmHg vs. -0.5 mmHg, p = 0.007) in systolic blood pressure was seen in the active group, compared to placebo at home measurements. Office blood pressure and 24 h nighttime or daytime ambulatory systolic or diastolic pressure did not differ between the groups. Total (-0.16 vs. 0.25 mmol l⁻¹, p = 0.005) and LDL cholesterol (-0.16 vs. 0.18 mmol l⁻¹, p = 0.006) decreased significantly in the active group compared to the placebo. No significant differences between groups were seen for plasma glucose or inflammation markers. The results thus suggest that milk peptides IPP and VPP and plant sterols, in a low-fat spread matrix, produce a clinically significant reduction in systolic blood pressure as well as serum total and LDL cholesterol without adverse effects. Functional foods that affect 2 major risk factors offer a safe and convenient way to reduce the risk of cardiovascular disease by supporting lifestyle intervention.

Growth and survival of selected pathogens in margarine-style table spreads.

Although margarine-style table spreads can have a pH above 4.6 and a water activity greater than 0.85, there is some question if such products can support the growth of pathogenic bacteria. The objective of this study was to evaluate the growth and survival of Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhi in 60-percent- and 70-percent-vegetable-oil, margarine-style, water-in-oil-emulsion table spreads stored at different temperatures. Samples of 25 grams of each table spread were inoculated with 1 x 10(3) cells of each bacterial mixture. The samples were stored at 5 degrees C, 7 degrees C, and 21 degrees C, and the microbial population in colony-forming units per gram (CFU/gram) was enumerated over time. In almost all storage conditions, bacterial levels were shown to decrease over time. Inactivation was observed in (listed from fastest to slowest, respectively) S. aureus, L. monocytogenes, E. coli O157:H7, and S. typhi. Growth was observed only for S. typhi in table spreads stored at 21 degrees C, but the rate of growth was extremely slow. Based on these findings, the table spreads evaluated in this study are not potentially hazardous foods, and cold temperature storage is not necessary from a food safety perspective.

Viability of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in yellow fat spreads as affected by storage temperature.

A study was conducted to characterize the survival and inactivation kinetics of a five-serotype mixture of Salmonella (6.23 to 6.55 log10 CFU per 3.5-ml or 4-g sample), a five-strain mixture of Escherichia coli O157:H7 (5.36 to 6.14 log10 CFU per 3.5-ml or 4-g sample), and a six-strain mixture of Listeria monocytogenes (5.91 to 6.18 log10 CFU per 3.5-ml or 4-g sample) inoculated into seven yellow fat spreads (one margarine, one butter-margarine blend, and five dairy and nondairy spreads and toppings) after formulation and processing and stored at 4.4, 10, and 21 degrees C for up to 94 days. Neither Salmonella nor E. coil O157:H7 grew in any of the test products. The time required for the elimination of each pathogen depended on the product and the storage temperature. Death was more rapid at 21 degrees C than at 4.4 or 10 degrees C. Depending on the product, the time required for the elimination of viable cells at 21 degrees C ranged from 5 to 7 days to >94 days for Salmonella, from 3 to 5 days to 28 to 42 days for E. coli O157:H7, and from 10 to 14 days to >94 days for L. monocytogenes. Death was most rapid in a water-continuous spray product (pH 3.66, 4.12% salt) and least rapid in a butter-margarine blend (pH 6.66, 1.88% salt). E. coli O157:H7 died more rapidly than did Salmonella or L. monocytogenes regardless of storage temperature. Salmonella survived longer in high-fat (> or = 61%) products than in products with lower fat contents. The inhibition of growth is attributed to factors such as acidic pH, salt content, the presence of preservatives, emulsion characteristics, and nutrient deprivation. L. monocytogenes did not grow in six of the test products, but its population increased between 42 and 63 days in a butter-margarine blend stored at 10 degrees C and between 3 and 7 days when the blend was stored at 21 degrees C. On the basis of the experimental parameters examined in this study, traditional margarine and spreads not containing butter are not "potentially hazardous foods" in that they do not support the growth of Salmonella, E. coli O157:H7, or L. monocytogenes.

Application of pulsed-field gel electrophoresis to the epidemiological characterization of Staphylococcus intermedius implicated in a food-related outbreak.

An outbreak of food intoxication involving over 265 cases in western United States occurred in October 1991. Staphylococcus intermedius was implicated as the aetiologic agent. Representative outbreak isolates (five clinical and ten from foods) produced type A enterotoxin. DNA fragments generated by four restriction endonucleases and analysed by pulsed-field gel electrophoresis (PFGE) provided definitive evidence that all isolates from nine different counties in California and Nevada were derived from a single strain. The PFGE pattern of these outbreak isolates was distinct from those of a heterogeneous collection of seven S. intermedius strains of veterinary origin and five unrelated S. aureus laboratory strains. The data show a significant PFGE pattern heterogeneity not only among members of different Staphylococcus species but also within members of the same species and even the same enterotoxin type. The results indicate that PFGE is a valuable strain-specific discriminator for the epidemiological characterization of S. intermedius. To our knowledge, this represents the first documented foodborne outbreak caused by S. intermedius. These findings suggest that the presence of S. intermedius and other species such as S. hyicus in food should be reason for concern.