Search

Sunflower meal (SFM), a byproduct of sunflower oil extraction, is a relatively inexpensive protein source with high potential for feed formulations. Dry fractionation methodologies are emerging as 'green' and affordable technologies with the potential to additionally enhance the nutritional quality of plant-based raw materials for animal feed, including sunflower meal. Following the optimization of a dry fractionation process in a previous study of the authors, this research aims to validate the defined parameters through the processing of three sunflower meals (SFM1, SFM2, and SFM3) with different characteristics. The dry fractionation process includes two-stage grinding using hammer mill and roll mill and fractionation of sunflower meal by sieving. The process successfully increased the protein content of sunflower meals in the range of 17.5% to 31.2%, reaching levels high enough to be categorized as "high protein" sunflower meals of first quality (42% as is). Exceptionally high fraction yields (76.5–78.9%) were obtained for all three sunflower meals. The lowest energy consumption was recorded for SFM1 (8.44 Wh/kg), while slightly higher values were observed during the processing of SFM2 and SFM3 (9.30 and 9.93 Wh/kg, respectively). Relative amino acid enrichments ranging from 13.35% to 26.64% were achieved, with lysine enrichment ranging from 18.9% to 36% and methionine from 30.6% to 44.1%. [ABSTRACT FROM AUTHOR]

Sunflower meal, a by-product of oil extraction from sunflower seeds, is an important protein source in domestic as well as European feed industry. There is a common interest for the proper utilization of sunflower meal and for the development of an effective fractionation process in order to obtain a nutritionally improved sunflower meal. This paper proposes and compares two dry fractionation processes for the improvement of sunflower meal protein content on a laboratory scale. The first phase of both processes included two step milling using a hammer and roller mill. In the second phase, the ground sunflower meal was fractionated by sieving or by air classification. Results indicated that the implementation of any of the suggested processes improved protein content of the starting sunflower meal to a level sufficient to categorize it as "high-protein" according to current national regulation on animal feed quality, with the fraction yields over 50%. For the air classification process the most promising result was achieved for air flow of 7 m3 /h (12.8% relative protein enrichment, 56.42% fraction yield). For the fractionation process with sieving as a separation step, when fractions smaller than 350 µm were conjoined, relative protein enrichment of 28.5% and fraction yield of 51.17% were achieved. The high protein content (48.81% on dry basis) of the joined fraction enables enough space for optimizing the protein content - fraction yield ratio of obtained sunflower meal. By applying sieves with larger aperture, it is possible to obtain higher yields of sunflower meal categorized as high-protein on account of a slight decrease in protein content, which gives this process a certain flexibility and potential for application on a larger scale.

Summary: Sunflower meal, as a high protein source, is usually utilised in animal feed, but other means of valorisation of this byproduct should be investigated in order to increase sunflower meal industrial functionality and therefore economic value. High protein content could suggest potential ability to stabilise food emulsions. Current study investigated the influence of sunflower meal protein content and particle size distribution in stabilisation of oil‐in‐water emulsions. Sunflower meal samples were characterised in terms of chemical and amino acid content and FTIR spectroscopy, while in the obtained emulsion samples creaming index, droplet size, droplet size distribution and zeta potential were determined. A relatively equal distribution of hydrophilic/hydrophobic amino acids (46% and 54%, respectively) was determined indicating a strong amphiphilic character of proteins and potentially effective emulsion‐stabilising properties. Further results suggested a positive influence of higher protein content (increasing from 16.78% to 42.56%) on lower creaming index values (lowering values from 84% to 32%, respectively). Protein content and particle size distribution strongly affected emulsion droplets sizes (ranging from 77.32 to 238.61 μm) and zeta potential values. Therefore, the evaluation of the obtained results suggested that high protein sunflower meal can be applied for the stabilisation of oil‐in‐water emulsions. [ABSTRACT FROM AUTHOR]

In this study, dry fractionation process was proposed in order to obtain protein-enriched sunflower meal fractions. The process includes two-stage grinding using a hammer mill and a roll mill, and fractionation of sunflower meal by sieving. Central composite design (CCD) with four variables on three levels within response surface methodology was applied in order to estimate the influence of grinding parameters (sieve openings diameter of the hammer mill: 2, 4, and 6 mm, roll gap: 0.15, 0.2, and 0.25 mm, feed rate: 0.1, 0.175, and 0.25 kg/cm min, and roll speed: 400, 500, and 600 rpm) on responses (protein content, fraction yield and grinding energy consumption). Sieve openings diameter expressed the highest impact on fraction yield while roll gap expressed the most dominant influence on protein content in the fraction and grinding energy consumption. The highest protein content obtained was 48.06%(dm) with fraction yield of 77.22%. A multi-response optimization procedure was performed and optimal values were: sieve openings diameter of 2 mm, roll gap of 0.25 mm, feed rate of 0.2 kg/cm min, and roll speed of 400 rpm, while predicted values for a desired range of responses were: protein content 45.5%(dm), fraction yield 77.89%, and grinding energy consumption 8.31 Wh/kg. [ABSTRACT FROM AUTHOR]