Industrial Use of Oil Cakes for Material Applications - The Economic Utilisation of Food Co-Products - page 148

Table 7.2 Processes and biological consequences during the main steps of the
industrial extraction of sunflower oil.

Step Process Consequences

Flaking Plain flaking rolls Formation of 0.3 mm thick flakes

Hull break down
Contact area increase

d n 9 r 3 n g | 5

Cooking Steam cooking (80 1C) Setting of flakes moisture content

(3-5%)

Drying (110 1C) Decrease of oil viscosity

Increase of cell-wall plasticity
Protein denaturation
Sterilisation

d y y f n n 3 .

Pressing Shear/compression Cell-wall break down

Oil (and coproducts) expression

Extraction Solvent (hexane) Oil solubilisation

Desolvation Steam distillation (80 1C) Protein coagulation

Steam toasting (110-115 1C) Formation of phenolic/proteic

aggregates

Drying (95-100 1C) Setting of moisture content for

preservation

Table 7.3 SFOC composition. 52

Components Methods SFOC1 SFOC2 SFOC3

Moisture content (%DM) NF V 03-903 9.9 11.0 10.3

Proteins NF V 18-100 35.0 29.4 31.5

Cellulose ADF-NDF 18.3 24.2 25.1

Lignin 9.1 8.1 8.0

Hemicelluloses 10.9 15.4 12.5

Lipids NF ISO 0734-1 1.5 1.3 3.2

Chlorogenic acid UV spectroscopy

(Folin-Ciocalteu
reagent)

2.7 2.9 -

Phenolic compounds Estimated 4.5 4.9 -

Water-soluble
components

Boiled water 24.9 22.4 21.2

Ashes NF V 03-922 7.2 7.0 7.1

7.3.1.2 Composition of Sunflower Oil Cake
The composition of three SFOC batches is described in a recent paper 52 and is
shown in Table 7.3. The SFOC composition is considerably stable even if
intrinsic and extrinsic factors (genetic, climate, soil, and extraction process)
induce small changes in their composition. The main part of the SFOC is made
of cell-wall components such as lignocellulosic fibres (around 40%/dry matter).
The second major part is represented by protein fractions (around 30%/DM).
The other 30% is made up of many other components that contribute to the
matrix or to the fillers, many of which are water soluble.