434 Die Nahrung 30 (1986) 3-4

[5] SCHWENKE:. K. D.. L. PRAHL, B. RAAB, K.-I>. ROBOWSKY and A. RUTKOWSKI, GDR-Pat. 206068 (1982). [6] SCHWENFE. K . D.. E. J. RAUSCHAL and K.-D. ROBOWSKY. Nahrung 27, 335 (1983). [I VOSE, J. R . , Cereal Chem. 57, 406 (1980).

Dr. sc. nat. C;. MUSCHIOLIK, Dr. CH. SCHNEIDER, Dr. M. SCHULTZ and Prof. Dr. H. SCHMANDKE, Central Institute of Nutrition, DDR-1505 Bergholz-Rehbriicke, Arthur-Scheunert-Allee 114-1 16; DipLIng. H. H ~ R S K E , Technical University. Department of Process Engineering, DDR-8027 Dresden, Munchener Str. 28

Die Nahrung 30 (1986) 3-4,434-436

Department of. Biochemistry and Food Technology (Head of the department: Prof. Dr. R. LASZTITY), Technical University Budapest, Hungary

Functional properties of some proteins used in meat processing

w. DUDONIS dnd R . LASZTlTY

The application of non meat protein preparations (meat extenders) in the meat processing is increasing from year to year in many countries. A lot of papers and books discussing the problems connected with these additives were published in last period.

Nevertheless the elaboration of the best methods for the determination of functional properties of different proteins and the improvement of the technological process of the application needs further investigations.

Water holding capacity and emulsifying properties of the protein systems are the most important factors from practical point of view. Investigations summarized in this report include experiments connected with determination of water holding capacity, emulsifying properties and heat stability of emulsions and model experiments with sausages prepared with different meat extenders.

Material and methods

The following protein preparation were used in experiments : - Soya isolate PURlNA 500 E (protein content 90%) ~ Hungarian milk protein concentrate UF-75 (protein content 75 ",;) - Vital gluten (protein content 80%) - Egg protein (protein content 37 '?;) - Sunflower protein concentrate (Hungarian experimental product, protein content 7479.

The filter method published earlier [ I ] was used for the determination of water holding capacity. For the investigation of heat stability of emulsions 1 : 5 : 5 (emulsifier ~ fat ~ water) emulsions were prepared. The temperatureofmixingchanged between 20 and45 -C. Aftera heat treatment at 100 'C the stabilityofemulsions was measured by method described by REKASI et al. [2].

In model experiments sausages of Parisian art were produced using meat extenders and the properties of the products were tested organoleptically.

Results and discussion

It was stated that the filter test is a good method not only for the determination of water holding capacity but also for the detection of the exudative character of meat confirmed by cooking losses ofproducts prepared from meats of different quality, too.

DUDONIS/WSZTITY : Poster 435

M.3035.10 T Fig. 1. of emulsion containing UF 75 on

tJ M a flrnecrninl

Fig. 2. Dependence of stability of emulsion containing protein on process temperature

sunflower

f 5 44

3

2

1

0 Fig. 3. Dependence of stability of emulsion containing PURINA 500 E on process temperature

M

The results of the investigation of the emulsion stability (some characteristic results are summarized in Fig. I -3) showed significant differences between different protein preparations.

No emulsion can be obtained by the use of milk protein preparation UF-75 at temperatures of 20 "C to 35 "C. However a low-viscosity liquid emulsion developed at 45 "C which was stable even at 100 "C (Fig. I) . Using sunflower protein as emulsifier, a stable emulsion was obtained again at 45 "C only (Fig. 2).

Emulsion prepared from PURINA 500 E at temperatures below 45 "C have a limited stability (Fig. 3). Over 45 "C the stability is satisfactory.

Relating to consistency and organoleptic quality of experimental products it can be stated that good con- sistency was achieved by addition of PURINA 500 E, UF-75 and vital gluten. From point of view of sensory quality the same three meat extenders were the best.

436 Die Nahrung 30 (1986) 3-4

References

[I] DUDONIS, W , . V. Klss and L. KORMENDY, Fleischwirtschaft 64, 91-95 (1984). [2] REKASI. K - s < . I.. KORMENDY, G Y - ~ f . MIHALYI and H. HERRERA, Husipar-30, 111 (1981). [3] Kiss. V.. W. DUDONIS and L. KORMENDY, Husipar 32 (1984) 2.

WIESLAWA Duuouis and Prof, Dr. R. LASZTITY, Department of Biochemistry and Food Technology, Technical University Budapest. H-1521 Budapest, Pf. 91, Hungary

Die Nahrung 30 ( 1986) 3-4,436-437

Department of Biochemistry and Food Technology. Technical University of Budapest and College of Food Industry of Szeged. Hungary

Analysis of the relationship between flour quality and the electrophoretic protein spectrum F. ORSI, ATTILA PALLACI and R. LAsznTY

The quality of flour and that of bread and pastry products, prepared from flour, is determined in the first . place by the quantity and quality of the protein components of flour. In spite of this early recognition, with the exception of a few general correlations, the role ofprotein fractions, obtainable by electrophoretic methods, in the development of the quality of the above products is not known.

Increasing the number of the characteristics investigated, we attempted to use statistical methods suitable to find the variables producing the true relationships, the correlations of the variables, which cannot be directly investigated. This method is the principal component or factor analysis.

Six wheat varieties grown in the Research Institute of Cereal Cultivation were used in our investigations. The statistical processing of the results was done in more steps. The influence of harvest’s year and the varieties was studied by a two-way analysis of variance on the basis

of a linear additive model. In the next step correlations were investigated within the groups of variables investigated. To elucidate the

redundant relationships between the variables using the correlation matrix, principal component analysis was performed by the determination of the eigenvalue and eigenvector matrices.

t Y.807 - 5 0 d

J

-Is -;o -0:5 40 0-5 rb r:5

- 3

.-L-c 2.0

d

Fig. 1. Y = loaf volume cm3; d = canonical variable; R = correlation coefficient; S = standard deviation of calculated Y value; S, = standard deviation of slope; So = standard deviation of inter- cept; T = t value calculated from R wether R higher than zero ~ significant