Plant growth response to olestra as related to beneficial use of municipal sludge

Abstract

Consumer food ingredients may enter the terrestrial environment as constituents of municipal sludge which is used as a beneficial fertilizer source in land application. Evaluation of the plant/soil response to specific organic constituents, in the presence and absence of municipal sludge, is thus an important scientific component. Olestra is a consumer ingredient used in savory snacks to eliminate fat content and reduce calories in these foods. The fat substitute olestra is a mixture of hexa, hepta, and octaesters of sucrose with medium and long-chain fatty acids.

Experiments were conducted of plant response in olestra mixtures with soil or municipal sludge/soil over a range from 0–1,000 mg olestra/kg dry soil. The plants grown from seed were corn, fescue, wheat, and soybean, with the latter two continued to seed production maturity. The comparison of effects rationale used in this study requires some consistent response to be measured and removes emphasis from singular, statistically significant response. The investment in multiple measures of plant response, separate periods of time, and appropriate multiple controls are necessary to place emphasis on consistent trends for a comparison rationale. For olestra, the notion of consistent effects permits the conclusion that more highly saturated solid olestra did not impact plant growth at concentrations of 0–1,000 mg olestra/kg dry soil in soil alone or in sludge/soil mixtures. The absence of effects occurred with germination, height, and biomass parameters.