Jadwiga Sadowska

Natural fermentation of lentils : Influence of time, concentration, and temperature on the kinetics of hydrolysis of inositol phosphates

Lentil (Lens culinaris var vulgaris) flour was naturally fermented for 96 h at various conditions of concentration (79, 150 and 221 g litre -1 ) and temperature (28°C, 35°C and 42°C). The content of total inositol phosphates (IP-total) and individual inositol phosphates (hexa- (IP 6 ), penta- (IP 5 ), tetra- (IP 4 ) and tri- (IP 3 ) phosphates) were analysed to establish the changes of these compounds during natural fermentation of lentils. The preparation of the lentil suspension brought about 16-27% reduction of the total inositol phosphates. At the end of 96 h of natural fermentation maximum IP loss (70-75%) was achieved for an experiment carried out at minimum concentration. For IP 6 , the largest decrease was achieved at the highest temperature, the fermentation condition that also brought about the highest IP 5 content.

Natural fermentation of lentils. Functional properties and potential in breadmaking of fermented lentil flour

The effects of fermentation on functional properties of lentil flour and rheological properties of doughs and breads produced from blends of wheat and fermented lentil flour were studied. Lentil protein solubility was higher at neutral pH than acid pH; the lowest and highest protein solubility values were observed at pH 4.0 and pH 7.0, respectively. Water hydration capacity and fat binding capacity of fermented lentil flour (FLF) were always higher than those of non-fermented lentil flour (NFLF), irrespective of fermentation temperature (28-42 °C) and flour concentration (79-221 g/l). Emulsifying properties of NFLF were similar to the properties of other legume flours in the range used in experiment. In contrast, the emulsion capacity and stability of FLF were very low and flours fermented at 42°C did not even form emulsion. Rheological properties of doughs made from wheat-fermented lentil blends were similar to those from wheat flour with the addition of other legume flours such as pea and bean. Good quality breads were produced at 2.5 to 10% NFLF and FLF supplementation (except for bread with 10% FLF addition which was middle quality).

Drying Conditions and Processability of Dried Rapeseed

The possibility of using the oil-point and compression tests for evaluation of dried rapeseeds processability was examined. Seeds of initial moisture 10, 14, 18 and 22% (w/w) were dried at 60, 80, 100 and 120°C to a final moisture of 6.5% (w/w). The values of pressure (P 0 ), work (L 0 ) and strain (e 0 ) determined by the oil-point test, and pressure at strain e = 0.45 mm mm -1 (P e ) and degree of elasticity (D) determined by the compression test for bulk dried seeds differed markedly from those found for non-dried seeds. The P 0 , L 0 and P e values were strongly correlated with the initial moisture of rapeseeds and drying temperature. All the strain values (e 0 ) were lower than those for non-dried seeds, and their changes depended solely on the initial moisture of seeds. Changes in the degree of elasticity were irregular and did not reach the value characteristic for over-dried seeds, ie 100%. High correlation of the agglomeration test data (Δ 1-3 values) with those of the P 0 , L 0 and P e made it possible to develop appropriate equations that proved the usefulness of the variables for determining the dried rapeseed processability.

Digital Image Analysis — Essence and Application in Cereal Science

Sight is the most important sense of a human allowing him to perceive the surrounding world. Size, shape, structure and colour of examined objects are easily recognised by human eye and brain and simultaneously verify whether they correspond to the standard. Interpretation of images registered solely by the sight is somehow limited by the observer’s perception. Increased number of objects and their mobility resulted in difficulties of proper interpretation of human observations. Moreover, the eyes become tired quite fast, thus their ability to differentiate selected features of the object decreases.

The Effect of Seed Size and Microstructure on Their Mechanical Properties and Frictional Behavior

The seeds of grass pea were selected based on their size, hardness, and microstructure in order to examine their mechanical properties and friction coefficients versus mass. The size, shape, mass, and static friction coefficients of seeds were determined using adequate methods. Seed hardness was measured using compression methods, and it was described by typical and corrected fracture parameters. The microstructure of cotyledons and seed surfaces was viewed using scanning electron microscopy, and surface microimages were processed by digital image analysis. The length of the examined seeds ranged from 5.86 mm to 14.25 mm, their width ranged from 5.47 mm to 12.93 mm, thickness from 4.59 mm to 6.21 mm, mass from 0.110 g to 0.570 g, projected area from 28.55 mm2 to 148.73 mm2, and roundness from 1.060 to 1.126. The static friction coefficients for seeds of the examined accessions and varieties determined on steel, wood, rubber, and PVC surfaces were 23.4–33.3°, 24.4–37.2°, 29.6–50.4°, and 22.4–35.4°, respectively. For grass pea seeds of irregular size and shape, corrected fracture energy values (with regard to seed mass and volume) were proposed as a more robust parameter of seed hardness. The values of the static friction coefficient depend on both seed mass and the microstructural properties of seed surface digitalized with the involvement of image analysis techniques.