Authors:ZS. Kiss, B. Vecseri-Hegyes, G. Kun-Farkas, and Á. Hoschke
In the course of our work we aimed to develop a product from gluten-free raw materials (millet, sorghum and buckwheat) that is similar to beer made of barley malt but is consumable by coeliacs. Our measurements were started by qualification of cereal/pseudo-cereal grains. Next malts were made of them with different steeping, germination and kilning parameters, and their most important quality characteristics were determined. Qualification of grains were done by grading, determination of thousand-kernel and hectolitre weight, and protein content, while malts were examined with congress mashing, Hartong mashing and lauter test, as well. Gelatinization point of the starch found in grains and malts were determined by Brabender amyloviscograph which helped to set the temperature of β-amylase rest in future mashings. The gelatinization points were higher in our samples, than in the barley’s starch.Optimization of mashing was continued with malts that fulfilled requirements needed for brewing. Mashing programs were written for each raw material with the help of our laboratory mashing equipment, and resulting worts were analysed (for extract content), then carbohydrate content was measured by HPLC, α-amylase activity by Phadebas test, and free α-amino nitrogen (FAN) content by the ninhydrin method. Those worts were selected for further fermentation tests that had the highest extract and FAN content, best filtration time and appropriate sensory characteristics. Optimal malting temperatures and time periods, aeration and water uptake were determined, and then the duration and temperature of protein and enzyme rests of mashing were set.The malting process that proved to be the most suitable for brewing requirements (high extract content, good lautering characteristics, high FAN content) has the following parameters: steeping with 25 °C water for 18 h with aeration in every 5 h; germination at 15 °C for 84 h; kilning at 50 °C for 48 h.
Authors:D. Živković, S. Šobajić, M. Perunović, and S. Stajić
The influence of seasonal variations on the chemical composition and composition of fatty acids in five commercially important freshwater fish species from the Danube: white bream, bream, vimba, zope, and Prussian carp, during May, July and September was determined. Changes in the chemical composition of meat of all examined species had the same tendencies. Water and protein content in the meat decreased, while fat content increased. The most frequent fatty acids in the meat of all the examined fish were the following: 18:1 n-9 (oleic), 16:0 (palmitic), 16:1 (palmitoleic), 18:2 n-6 (linoleic), 20:1 (eicosenoic), 20:5 n-3 eicosapentaenoic acid (EPA), 20:4 n-6 arachidonic acid and 22:6 n-3 docosahexaeonic acid (DHA). The content of saturated fatty acids (SFA) ranged from 25.03% to 32.43% and displayed a tendency to increase during the observed period. The total content of the n-6 group in the meat of Prussian carp was higher than in other species, which was probably a consequence of specific diet. The total content of n-3 fatty acids in the meat of white bream, bream, vimba and zope was the highest in May, and it declined during July-September. We can conclude that the meat of white bream and vimba contains high nutritional values in terms of EPA and DHA content. The n-3/n-6 ratio was also very favourable: 0.9 to 2.0 in the meat of white bream, bream, vimba and zope, with a clear downward tendency in the observed period.
Authors:J. Csapó, J. Schmidt, Zs. Csapó-Kiss, G. Holló, I. Holló, L. Wágner, É. Cenkvári, É. Varga-Visi, G. Pohn, and G. Andrássy-Baka
In the past years several methods have been developed for the determination of the proportion of the nitrogen-containing substances of microbial origin passed from the rumen into the abomasum or the small intestine. Recently, on examining the D-amino acid content of foodstuffs, particularly milk and milk products, it has been observed that, in addition to D-Ala, D- glutamic acid (D-Glu) and D-aspartic acid (D-Asp) can also be detected in similar quantities, primarily in products which have links with bacterial activity. This gave rise to the idea of examining the diaminopimelic acid (DAPA), D-Glu and D-Asp content of bacteria extracted from the rumen of cattle and that of chyme from the same cattle, in order to determine the type of relation existing among these three components, and to establish whether D-Asp and D-Glu can be used in the estimation of protein of bacterial origin. On determination of the DAPA, D-Asp and D-Glu content by means of amino acid analyser and high performance liquid chromatography of duodenal chyme from five growing bulls and of ruminal bacteria from the same bulls, the following values were established. For chyme (and, in brackets, for ruminal bacteria) r value calculated by means of linear regression was 0.78 (0.76) between DAPA and D-Asp, and 0.70 (0.81) between DAPA and D-Glu. The r values between the crude protein content of ruminal bacteria and the markers examined were found to be the following: DAPA, 0.74; D-Asp, 0.73; D- Glu, 0.61. In the model experiment performed for the re-obtaining of values for protein of bacterial origin the theoretical values were determined on the basis of D-Asp and D-Glu and values approximately 10% higher than the theoretical value on the basis of DAPA. It is therefore recommended that in addition to DAPA these other two amino acids be included among the bacterial protein markers.
Engenharia de Alimentos da Universidade Estadual de Campinas, S. P. Brasil.
Finney, K. F. & Barmore, M. A. (1948): Loaf volume and proteincontent of hard winter and spring wheats. Cereal Chem. , 25 , 291
Authors:G. Šimić, A. Lalić, D. Horvat, I. Abičić, and I. Beraković
, G.P. , Chen , J.X. , Dai , F. , Wang , J.M. & Wu , F.B.
2006 : The effect of cultivar and environment on ß-amylase activity with the change of proteincontent in barley grains . J. Agron. Crop Sci. , 192
Institution, MSZ 20501-1:2007, 4.1., pp. 6–8.
ISO/TS 16634-2:2009 (2009): Food products — Determination of the total nitrogen content by combustion according to the Dumas principle and calculation of the crude proteincontent