Association between rice consumption and risk of cancer incidence in the California Teachers Study.

PURPOSE: We evaluated the contribution of rice intake, a source of dietary arsenic, to cancer risk in a population of women with likely low arsenic exposure from drinking water and variable rice intake who participated in the California Teachers Study. METHODS: Rice consumption was categorized into quartiles (< 9.6, 9.7-15.6, 15.7-42.7, and ≥ 42.8 g/day). Multivariable-adjusted hazard ratios and 95% confidence intervals (95% CI) for incident cancer were estimated comparing rice consumption categories with bladder, breast, kidney, lung, and pancreatic cancer, with progressive adjustment for age, total calories, BMI, race, smoking status, physical activity, and cancer-specific covariates. RESULTS: The number of breast, lung, pancreatic, bladder, and kidney cancer cases was 7,351; 1,100; 411; 344; and 238, respectively. The adjusted hazard ratios (95% CI) comparing the highest versus lowest rice intake quartiles were 1.07 (1.00-1.15); 0.87 (0.72-1.04); 0.95 (0.66-1.37); 1.11 (0.81-1.52) and 1.07 (0.72-1.59) for breast, lung, pancreatic, bladder, and kidney cancers, respectively. Results were consistent when rice was modeled as a continuous variable and in analyses stratified by smoking status. CONCLUSION: Rice consumption was not associated with risk of kidney, lung or pancreatic cancer, except maybe a small excess risk for breast cancer and a small non-significant excess risk for bladder cancer, comparing the highest versus lowest quartile of rice intake. Due to lower consumption patterns in this cohort, future studies should involve populations for which rice is a staple food and use of an arsenic biomarker.

Attachment and Biofilm Formation by Selected Strains of Salmonella enterica and Entrohemorrhagic Escherichia coli of Fresh Produce Origin.

This study compared the abilities of selected Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) strains of fresh produce origin to form biofilms on polystyrene surface and to attach to alfalfa and bean sprouts. Each of the 7 S. enterica and 4 EHEC inocula (2 mL; 107 CFU/mL) was placed in 6 different broths in 24-well polystyrene tissue culture plates at 28 °C for 1 to 7 d. Developed biofilms were quantified using the crystal violet binding assay. In a separate experiment, alfalfa and mung bean sprouts (5 g) were exposed to 25 mL inocula (107 CFU/mL) of S. enterica or EHEC at 22 °C for 2 h with shaking at 40 rpm. Contaminated sprouts were thoroughly rinsed and homogenized in 0.1% peptone water, and bacteria attached to sprouts were enumerated. Biofilm mass accumulated on polystyrene surface increased with incubation time (P < 0.05). Among the microbiological media used, LB no salt (NaCl) broth better supported biofilm development (P < 0.05). Two EHEC strains formed more biofilms than the Salmonella and other two EHEC strains (P < 0.05). However, more Salmonella cells (5.66 log CFU/g) attached to sprouts than EHEC cells (3.46 log CFU/g). Both Salmonella and EHEC attached in higher numbers to mung bean, than alfalfa, sprouts (P < 0.05).

Survival of Probiotics in Hypromellose Capsules with Rice or Potato Maltodextrin Excipient.

There is currently no authorized or established therapeutic level/dose of probiotics for proposed health benefits; however, a daily probiotic consumption of 108 to 1010 CFU has been recommended. This study determined the survival of 5 individual probiotic strains, Lactobacillus rhamnosus, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus acidophilus, and Bifidobacterium lactis, along with a mixture of the 5 strains in hypromellose capsules with rice or potato maltodextrin at 4, 25, and 37 °C for 12 mo. Samples were collected monthly and plated on deMan-Rogosa Sharpe agar with 0.05% l-cysteine hydrochloride. Results showed that samples stored at 4 °C had an average count of 108 to 1011 CFU/g of probiotic cells during the 12 mo period, whereas at 25 °C, L. rhamnosus and L. paracasei had an average counts below 108 CFU/g during the storage period. L. rhamnosus was the most vulnerable strain used in this study, having the least viable counts at all 3 storage temperatures. Probiotics stored in rice maltodextrin, on average, had higher probiotic counts compared to those stored in potato maltodextrin. Study suggests that to provide consumers with 108 to 1010 CFU/d of probiotic cells, robust bacterial strains, suitable carriers, and a storage temperature of 4 °C are required.

Development of a Drinkable, Peanut-Based Dietary Supplement and Comparison of Its Nutritional and Microbiological Qualities with Commercial Products.

This study was undertaken to formulate, using peanuts as a major ingredient, a beverage which will benefit older adults who are at a high risk of protein-energy malnutrition and other health complications, and to compare its nutritional and microbiological qualities to commercial products. Peanuts, rice flour, and flaxseed meal in a ratio of 48.0:49.8:2.2 were mixed with water (20% solids) and cooked into gruel which was sequentially treated with BAN(®) , (480 KNU-B/g, 75 °C 1 h), Alcalase(®) (2.4 AU-A/g, 60 °C 1 h), and Flavourzyme(®) (1000 LAPU/g, 55 °C 1 h) to predigest starch and protein, respectively. The degree of hydrolysis and product viscosity during hydrolysis was measured. The nutritional and microbiological qualities of the product were compared to 10 commercial products. Results indicate that 60% of starch was hydrolyzed while a total of 1.62% protein hydrolysis was observed. Product viscosity reduced from 228.55 to 3.60 cP at the end of hydrolysis. The formulation had no cholesterol and low sodium which was a functional property that was absent in the commercial products. Results of this study suggest that the formulation can be further optimized into a unique product that could cater for the protein needs and other nutritional requirements of older adults.

Survival of four commercial probiotic mixtures in full fat and reduced fat peanut butter.

A well-documented health benefit of probiotics is their ability to reduce the incidence of diarrhea in young, malnourished children in the developing countries. This study was undertaken to determine whether peanut butter, a nutritious, low-moisture food could be a carrier for probiotics by observing the survivability of selected probiotic mixtures in peanut butter under different storage conditions. Commercial probiotic mixtures (B, U, N and S) comprising of multiple strains of Lactobacillus, Bifidobacterium, Streptococcus and Lactococcus were inoculated into full fat or reduced fat peanut butter at 10(7) CFU/g. Resulting products were stored at 4, 25 or 37 °C for 12 months. Populations of Lactobacillus, Bifidobacterium and Streptococcus/Lactococcus were determined periodically. The average viable cell counts of N and S were significantly lower than those of B and U (p < 0.05). In all probiotic products stored at different temperatures, Bifidobacterium had the greatest survivability, followed by Lactobacillus and Streptococcus/Lactococcus. The probiotics used in the study had different surviving patterns, and their survival was influenced by storage conditions. Fat content of peanut butter had no significant impacts on probiotic viability. Results suggest that peanut butter can be a vehicle to deliver probiotics for preventing diarrhea among malnourished children.

Survival of Lactobacillus rhamnosus GG as influenced by storage conditions and product matrixes.

Mortality resulting from diarrhea especially that occurs in children younger than 5 y of age ranks 3rd among all deaths caused by infectious diseases worldwide. Probiotics such as Lactobacillus rhamnosus GG are clinically shown to effectively reduce the incidence of diarrhea in children. A food substrate is one of the major factors regulating the colonization of microorganisms in human gastrointestinal tracts. Peanut butter is a nutritious, low-moisture food that could be a carrier for probiotics. In this study, we observed the influence of storage conditions and product matrixes on the survival of L. rhamnosus GG. Cells of L. rhamnosus GG were inoculated into full fat or reduced fat peanut butter at 10(7) CFU/g. Inoculated peanut butter was stored at 4, 25, or 37 °C for 48 wk. Samples were drawn periodically to determine the populations of L. rhamnosus GG. Results showed that there was no significant decrease in the viable counts of L. rhamnosus GG in products stored 4 °C. The survivability of L. rhamnosus GG decreased with increasing storage temperature and time. Product matrixes did not significantly affect the survival of L. rhamnosus GG except at 37 °C. Populations of L. rhamnosus GG were preserved at >6 logs in products stored at 4 °C for 48 wk and at 25 °C for 23 to 27 wk. At 37 °C, the 6-log level could not be maintained for even 6 wk. The results suggest that peanut butter stored at 4 and 25 °C could serve as vehicles to deliver probiotics.