Inoculation Preparation Affects Survival of Salmonella enterica on Whole Black Peppercorns and Cumin Seeds Stored at Low Water Activity.

Salmonellosis has been increasingly associated with contaminated spices. Identifying inoculation and stabilization methods for Salmonella on whole spices is important for development of validated inactivation processes. The objective of this study was to examine the effects of inoculation preparation on the recoverability of Salmonella enterica from dried whole peppercorns and cumin seeds. Whole black peppercorns and cumin seeds were inoculated with S. enterica using one dry transfer method and various wet inoculation methods: immersion of spice seeds in tryptic soy broth (TSB) plus Salmonella for 24 h (likely leading to inclusion of Salmonella in native microbiota biofilms formed around the seeds), application of cells grown in TSB, and/or application of cells scraped from tryptic soy agar (TSA). Postinoculation seeds were dried to a water activity of 0.3 within 24 h and held for 28 days. Seeds were sampled after drying (time 0) and periodically during the 28 days of storage. Salmonella cells were enumerated by serial dilution and plated onto xylose lysine Tergitol (XLT4) agar and TSA. Recovery of Salmonella was high after 28 days of storage but was dependent on inoculation method, with 4.05 to 6.22 and 3.75 to 8.38 log CFU/g recovered from peppercorns and cumin seeds, respectively, on XLT4 agar. The changes in surviving Salmonella (log CFU per gram) from initial inoculation levels after 28 days were significantly smaller for the biofilm inclusion method (+0.142pepper, +0.186cumin) than for the other inoculation methods (-0.425pepper, -2.029cumin for cells grown on TSA; -0.641pepper, -0.718cumin for dry transfer; -1.998pepper for cells grown in TSB). In most cases, trends for reductions of total aerobic bacteria were similar to those of Salmonella. The inoculation method influenced the recoverability of Salmonella from whole peppercorns and cumin seeds after drying. The most stable inoculum strategies were dry transfer, 24-h incubation of Salmonella and spices in TSB (i.e., potential inclusion of Salmonella within native microbiota biofilms), and inoculation of Salmonella cells grown on TSA subsequent to drying. However, with the dry transfer method it was difficult to obtain the large amount of inoculum needed for inactivation studies.

Influence of emulsifying component composition on creams formulated with fractionated milkfat.

Dairy systems formulated with fractionated milkfat and milk-derived components have compositional differences that may affect functionality and nutritional aspects as compared to natural dairy products. The composition of 20% milkfat creams formulated with emulsifying components (skim milk, sweet buttermilk, and butter-derived aqueous phase) and low- or medium-melt fractionated butteroil was compared with natural cream. Cream separation temperatures (49 and 55 degrees C) and processing conditions (commercial and pilot plant) in obtaining emulsifying components were examined for effect on content of surface active agents. Individual fatty acids, lipids, cholesterol, phospholipids, protein levels, and types varied with components. Separation temperature influenced the cholesterol level in the aqueous phase. A commercially produced aqueous phase contained less total lipid, protein, cholesterol, and phospholipid than aqueous phase obtained in the pilot plant. Milkfat globule membrane concentration of emulsifying components affected phospholipid and cholesterol content of formulated creams. Butteroil type affected cholesterol levels and cream formulations.