Oilseed Cake Flour Composition, Functional Properties and Antioxidant Potential as Effects of Sieving and Species Differences

Oilseed cakes are produced as a by-product of oil pressing and are mostly used as feed. Their use for human consumption is due to the functional properties and benefits for human health. Herein, oilseed cake flours of eight species (flax, hemp, milk thistle, poppy, pumpkin, rapeseed, safflower, sunflower) were sieved into fractions above (A250) and below (B250) 250 µm. The chemical composition, SDS-PAGE profiles, colour, functional properties and antioxidant activities of these flours were evaluated. The B250 fractions were evaluated as being protein and ash rich, reaching crude protein and ash content ranging from 31.78% (milk thistle) to 57.47% (pumpkin) and from 5.0% (flax) to 11.19% (poppy), respectively. A high content of carbohydrates was found in the flours of hemp, milk thistle and safflower with a significant increase for the A250 fraction, with a subsequent relation to a high water holding capacity (WHC) for the A250 fraction (flax, poppy, pumpkin and sunflower). The A250 milk thistle flour was found to have the richest in polyphenols content (TPC) (40.89 mg GAE/g), with the highest antioxidant activity using an ABTS•+ assay (101.95 mg AAE/g). The A250 fraction for all the species exhibited lower lightness than the B250 fraction. The obtained results indicate that sieving oilseed flour with the aim to prepare flours with specific functional characteristics and composition is efficient only in combination with a particular species.

Comparative evaluation of the antioxidant, antimicrobial and nutritive properties of gluten-free flours

Gluten-free flours are interesting alternative to wheat flours. They could be by-products of oilseed processing, characterized by high content of bioactive compounds. Therefore the aim of the study was to determine the antioxidant, antimicrobial properties, amino acid and fatty acid profile of flours obtained as by-products from the oil industry. The highest total polyphenol content and antioxidant activity was found to have evening primrose flour. The widest spectrum of microbial growth inhibition was indicated for corn germ extract which showed no antimicrobial activity only against Bacillus subtilis. The highest protein content was found in pumpkin, peanut and almond flours (more than 50 g/100 g). The major abundant amino acids in all the analysed oilseed cake flours were aspartic acid, glutamic acid and arginine. The analysed gluten-free flours were found to be a good source of polyunsaturated fatty acids (PUFAs), which comprised mainly linoleic acid and α-linolenic acid, whereas the best source of PUFAs was evening primrose flour. The results suggest that the cold-pressed seed flours possess valuable chemical composition and may be considered for improvement of the nutritional properties of food products.

Bioethanol production from Jatropha seed cake via dilute acid hydrolysis and fermentation by Saccharomyces cerevisiae

The interest in using Jatropha curcas L. as a feedstock for the production of bio-diesel is rapidly growing. Available literatures holds [promise for the simultaneous wasteland reclamation capability and oil yields of the plant hence fueling the Jatropha bio-ethanol hopes. This research investigated the bioconversion of cellulose from press cakes of Jatropha oil seeds, which is a byproduct from a biodiesel plant, into ethanol by using the methods of acid pretreatment, hydrolysis and fermentation by Saccharomyces cerevisiae. The process includes the pretreatment method of the finely ground cellulosic solid oilseed cake with dilute sulphuric acid and heating the mixture at a high temperature to break the crystalline structure of the lignocellulose to facilitate the hydrolysis of cellulosic component by dilute acids. About 63.33% ethanol was recovered as confirmed by the infra-red spectroscopy and the investigated physicochemical parameters show that the produced bioethanol holds promise for its use as a possible candidate for replacement for petroleum diesel.

Performance of oyster mushroom (Pleurotus ostreatus) grown on different fingermillet husk substrates

Substrate type is one of the major factors affecting the growth and yield of oyster mushroom (Pleurotus ostreatus). Five substrates; Finger millet husk, Fingermillet husk + Molasses, Fingermillet husk + Rice bran, Fingermillet husk + Wheat bran, Fingermillet husk +Mustard oilseed cake, were evaluated for growth and productivity of oyster mushroom. The experiment was conducted in a completely randomized design with each treatment replicated seven times. Additives were added on finger millet husk @5% of its dry weight. Standard cultivation practice was followed with steam sterilization and spawning was done in poly bags containing 2.5 kg of wet substrate. Data were collected on time taken for full spawn run, fresh mushroom yield, biological efficiency and cropping duration upto three flushes. Molasses took the least duration (16.86 days) for full spawn run which was found to be statistically at par with wheat bran(17.13 days) and rice bran(17.75 days) whereas control treatment took the longest duration (21.62 days). Rice bran produced the highest fresh mushroom yield (793.04g/bag) with highest biological efficiency (137.92%), which was statistically at par with control, molasses and wheat bran. Similarly, rice bran had least cropping duration (66.62 days) followed by control (67.88 days), molasses (69.14 days), wheat bran (70.12 days) and mustard oilseed cake (73.86 days). The lowest fresh yield (521.84 g/bag) with lowest biological efficiency (90.75%) and the longest cropping duration (73.86 days) was observed on mustard oilseed cake supplementation. This study revealed that molasses, rice bran and wheat bran accelerated spawn run whereas mustard oilseed cake supplementation produced lowest fresh mushroom yield with least biological efficiency and highest cropping duration showing that it was ineffective for increasing yield and productivity of oyster mushroom.

Valorization Potential of Oilseed Cakes by Subcritical Water Extraction

The oil industry generates great quantities of oilseed cakes that remain after oil extraction. New technologies are required for their valorization, owing to their high nutritional value. Pumpkin, flax and hemp seed cakes were extracted by subcritical water under different conditions that included different gas atmospheres and homogenous catalysis, and for the first time their properties were directly compared. Extracts obtained in a nitrogen atmosphere, nitrogen atmosphere with the addition of a catalyst, and carbon dioxide atmosphere were chemically and nutritionally characterised. In the aqueous extracts obtained under different extraction conditions, the content of lipids, proteins and selected minerals (calcium, potassium, sodium and phosphorus) were determined. A detailed amino acid profile was determined by chromatographic analysis. The highest relative content of essential amino acids was observed in pumpkin seed extracts (51.49 ± 0.47 to 58.58 ± 0.45 mg/100 g dry extract), whereas hemp seed extracts were the richest in flavour amino acids aspartic acid, glutamic acid and alanine. Extraction in a carbon dioxide atmosphere or in nitrogen atmosphere with a HCl modifier released generally more minerals into the aqueous phase. Aqueous oilseed cake extracts demonstrated a favorable chemical composition and great nutritional value, opening new possibilities for exploitation of this biowaste. Based on the obtained results, oilseed cake extracts obtained by subcritical water have great potential to be used for the fortification of different food products, as well as in cosmetics.