Effect of traditional oriental soy products on iron absorption.

The effect of a variety of traditional oriental unfermented and fermented soy products on iron absorption was evaluated in 242 Indian women. When compared with a soy-flour meal containing an equal amount of protein, iron absorption was found to be significantly improved with silken tofu, natto, tempeh, rice miso, barley miso, and soybean miso. This improvement could not be adequately explained except with reference to changes in the protein composition of the products. The protein fraction profiles of the soy products were obtained by size-exclusion high-performance liquid chromatography. An inverse relationship between food iron absorption and the high-molecular-weight fraction of the soy products was demonstrated (r = 0.66, p = 0.01). However, anomalous results obtained with three products (sufu, tempeh, and fully hydrolyzed isolated soy protein) did not make it possible to reach firm conclusions concerning the effect of the protein fraction of soy on iron bioavailability.

The effect of dimethyldicarbonate on vegetative growth and ascospores of Byssochlamys fulva suspended in apple juice and strawberry nectar.

The effect of dimethyldicarbonate (DMDC) on vegetative growth elements as well as ascospores of two strains of Byssochlamys fulva was investigated. Using apple juice as the suspending medium, vegetative growth was found to be sensitive to the compound at concentrations of 25 to 75 mg/l; temperature had a marked influence on lethality, with treatment at higher temperature being far more lethal than low temperature treatment; ascospores were highly resistant to the compound, with no evidence of any lethal effects being found even at the highest concentration used (1,000 mg/l). An inoculated pack study, designed to simulate the use of DMDC in fruit juices under practical conditions, was performed using commercially packaged apple juice or strawberry nectar as the suspending media. Packs, equilibrated to temperatures of 10 degrees C or 30 degrees C, were aseptically inoculated with low numbers of either vegetative elements or ascospores and were treated with varying levels of DMDC. Mould development was monitored over a four week period. Whereas vegetative growth was controlled at DMDC concentrations of 50 to 100 mg/l at a treatment temperature of 30 degrees C, ascospores displayed a great tolerance to the compound and survived exposure even in low numbers to high DMDC concentrations.

Effect of Ionizing Radiation on Ascospores of Three Strains of Byssochlamys fulva in Apple Juice.

Radiation inactivation of the ascospores of three strains (M 68-79), NRRL 1125 and NRRL 2614) of the heat resistant mold Byssochlamys fulva suspended in apple juice, was investigated. Whereas the ascospores of strain M 68-79 were significantly more sensitive to ionizing radiation, those of strains NRRL 1125 and NRRL 2614 did not differ significantly from one another in this respect. High numbers of ascospores of the more resistant strains required an absorbed dose of approximately 7.2 kGy (95% confidence interval 6.7 to 7.9 kGy) for inactivation; a decimal reduction dose (D10) of approximately 1.2 kGy was estimated for these strains. Ascospores of strain NRRL 2614 were confirmed as more radiation resistant when a small proportion survived an absorbed dose of 5 kGy and spoiled apple juice within a 3-month storage period. Although it was possible to inactivate B. fulva ascospores at absorbed doses of <10 kGy, it is probable that flavor impairment of apple juice, as well as cost currently limit the feasibility of this process.