Subchronic toxicity evaluation of potato protein isolates.

The protein content of potatoes has a high nutritional value on par with eggs and soybeans. As a result, processed potato protein isolates may have commercial value for addition to other food products to increase protein content. A manufacturing process has been developed to produce total potato (TP), as well as low (LMW) and high molecular (HMW) weight, protein isolates as food ingredients. To assess the safety of these isolates, groups of 10 Wistar rats/sex were administered dietary admixtures containing 15% HMW, 7.5% LMW or 15% TP protein isolates for a period of 90days. There was no effect of treatment on clinical signs, mortality, body weight and body weight gain. No biologically significant changes occurred in hematological and clinical chemistry parameters. No statistically significant changes in organ weights were recorded. Histopathological analyses revealed no clear, treatment-related changes. A slight increase in the incidence, but not severity, of vacuolation of the zona fasciculate of the adrenal gland was noted in males of the 15% HMW and 7.5% LMW groups. The finding was not considered adverse or ascribed any toxicological significance. Overall, HMW, LMW, and TP protein isolates were well-tolerated and without adverse effect. These data support the safety of potato protein isolates.

Reproductive performance and fetal growth in female mice from lines divergently selected on the basis of plasma IGF-1 concentrations.

Reproductive performance, mammary gland weight and plasma concentrations of insulin-like growth factor-1 (IGF-1) were examined in 18-day-pregnant mice from lines divergently selected on the basis of plasma IGF-1 concentration. Females of the high IGF-1 (H) line were 14% heavier than those of the low IGF-1 (L) line at mating but did not differ in conception rate during a 15-day mating period. H-line females produced significantly larger litters by an average of 1.5 fetuses (19%), heavier fetuses (7%), greater total fetal weight (30%), heavier placental discs (15%), greater total placental weight (35%) and heavier mammary glands (18%). Plasma IGF-1 values were 12% greater in H-line than L-line females at Day 19 of gestation but the line difference was not significant. It is concluded that differences between the lines in litter size and mammary gland weight are most likely due to differences in maternal bodyweight (which are in turn a consequence of selection for plasma IGF-1 at puberty). Whether the difference in fetal weight is a function of fetal capacity to grow in utero or ability of the dam to provide nutrients for fetal growth is yet to be determined.