Potential uses for cuphea oil processing byproducts and processed oils

Cuphea spp. have seeds that contain high levels of medium chain fatty acids and have the potential to be commercially cultivated. In the course of processing and refining cuphea oil a number of byproducts are generated. Developing commercial uses for these byproducts would improve the economics of growing cuphea. Oil fractions and byproducts were obtained from processed seeds of cuphea germplasm line PSR 23 (Cuphea viscosissima × Cuphea lanceolata). We investigated the employment of oil byproducts as growth regulators and solid residues as organic soil amendments on Calabrese broccoli (Brassica oleracea L, family Brassicaceae) seedling growth. Seed processing solid residue fractions, included presscake, bin trash, stem trash and seed trash. These fractions were ground and mixed into soil to obtain concentrations of 0, 0.5, 1, 3, and 10% (w/w). Ground presscake and bin trash could be employed as an organic soil amendment up to 1% without detrimental effects on broccoli. Ground seed meal (seed trash) was detrimental to seedling growth at all concentrations tested. Stem trash employed at 1% caused fresh and dry weights to increase 26.8 and 29.8%, respectively, compared to untreated broccoli seedlings. Stem trash could be employed up to 10% without a detrimental effect on broccoli seedlings. Solvent extraction to remove residual oils from residue fractions was also conducted to generate improved soil amendments. Generally, solvent extraction of seed-processing residue fractions improved the broccoli seedling growth responses. Administration of processed oils and their byproduct fractions as foliar sprays on broccoli seedlings was conducted at rates of 0, 10, 30, and 50 g L−1. Plants were evaluated 72 h after spraying. Refined and crude oils had no effect on broccoli seedlings; gums and soapstock sprays had no effect at 10 or 30 g L−1 concentrations but at 50 g L−1 it killed seedlings. Distilled fatty acid fraction sprays killed broccoli seedlings at all tested concentrations. Certain oil byproduct fractions from cuphea oil processing can be employed as “environmentally-friendly” herbicidal sprays. Calorific evaluation of cuphea ag-wastes were conducted and found to compare well to other biomass energy sources.

• Cuphea seed processing generates a number of bi-products such as oils, gums, presscakes, bin and bin trash. This paper investigates the different avenues to commercially utilize these.
• Solid seed residue fractions such as presscakes, bin trash and stem materials can be employed as soil amendments.
• High oil content associated with soil seed residue fractions reduces the effectiveness of these fractions as soil amendments at high concentrations to counteract this problem solvent extraction was conducted on these fractions.
• Solvent-extracted solid seed residue fractions were better than the original solid seed residue fractions in promoting broccoli seed growth.
• Solid seed residue fraction were evaluated for their calorific values and found to be comparable or superior to other agricultural biomasses suggesting that they could be employed as a bio-fuel.
• Processed cuphea oil fractions were tested for their bio-herbicidal activities. Oil fractions containing high levels of short chain fatty acids were found to have the highest herbicidal effects.