Authors:P. Mokrejs, F. Langmaier, D. Janacova, M. Mladek, K. Kolomaznik, and V. Vasek
The study deals with the effect of chemical and physical modifications on thermal properties and solubility properties of
films based on amaranth flour starch–protein hydrolysate. Biodegradable and edible films were prepared by casting a 25% (w/w)
solution of hydrolysate containing 20% glycerol and various additions of dialdehyde starch (0, 1 and 5%). After thermal exposure
of films at 65 and 95 °C (for 6 and 48 h), thermal properties of films were studied employing differential scanning calorimetry
and thermogravimetric analysis. Film solubility tests were performed in an aqueous environment at 25 °C. Chemical and physical
modifications of films markedly affect their thermal properties and solubility.
Authors:H. Kim, S. Choi, B. Lee, S. Kim, H. Kim, C. Cho, and D. Cho
In this study, the thermal properties of bio-flour-filled, polypropylene (PP) bio-composites with different pozzolan contents
were investigated. With increasing pozzolan content, the thermal stability, 5% mass loss temperature and derivative thermogravimetric
curve (DTGmax) temperatures of the bio-composites slightly increased. The coefficient of thermal expansion (CTE) and thermal expansion
of the bio-composites decreased as the pozzolan content increased. The glass transition temperature (Tg), melting temperature (Tm) and percentage of crystallinity (Xc) of the bio-composites were not significantly changed. The thermal stability, thermal expansion and Xc of the maleic anhydride-grafted PP (MAPP)-treated bio-composites were much higher than those of non-treated bio-composites
at 1% pozzolan content due to enhanced interfacial adhesion. X-ray diffraction (XRD) analysis confirmed the crystallinity
of pozzolan-added bio-composites. From these results, we concluded that the addition of pozzolan in the bio-composites was
an effective method for enhancing the thermal stability and thermal expansion.
Authors:K. Takács, E. Némedi, D. Márta, É. Gelencsér, and E. Kovács
Yellow pea flour contains very low quantity of prolamins, thus it could be a good alternative dietary source for individuals suffering from celiac disease or wheat allergy. Beside emulsifiers, enzymes can be used for developing noodle structure with high quality. Transglutaminase (TG) enzyme was tested in model systems for improving noodle structure by using beneficial cross-linking property of the enzyme. Sensory-and cooking properties and biochemical attributes of proteins were evaluated to characterize structure-function relationships in accordance with the concentration of the applied enzyme. The amount of water and salt soluble protein fractions was reduced meaningfully and the molecular weight distributions assessed by SDS PAGE were changed by addition of 50–200 mg kg
TG enzyme. At the same time, sensory properties were improved and high water uptake and low cooking loss were also observed. Forasmuch an increase has been expected in the amount of the cross-linked molecules, the cross-reactivity of prolamins with anti-gliadin antibody was also tested to reduce the risk related to gluten sensitivity. Finally, the possible contamination with wheat was controlled by DNA-based PCR.
Authors:Hee-Soo Kim, Byoung-Ho Lee, Sena Lee, Hyun-Joong Kim, and John R. Dorgan
]. Bamboo flour (BF) and wood flour (WF) have been used as reinforcing fillers in biodegradable polymer biocomposites. These fillers are completely biodegradable when used as natural flour in a wide range of environments. In particular, bamboo fiber and
Authors:Lucia Odochian, Viorica Dulman, M. Dumitraş, and A. Pui
The study is devoted to the characterization by both TG-DTG analysis and FTIR spectroscopy of beech flour, dyes and the sorbent-dyes
products obtained through retention of the dyes from aqueous solution on the beech flour, to the aim of obtaining information
on the nature of dyes’ retention, thermal behavior of the sorbent-dye materials as well as on their possible upgrading as
Thermal analysis led to the conclusion that the mechanism of thermo-oxidative degradation is specific and the retention of
dyes occurs on cellulose from beech flour. The nature of the bonds involved in dyes’ retention is also investigated by FTIR
analysis, which evidences that dyes retention on cellulose is realized through hydrogen bonding between the NH and, respectively,
OH groups from dye molecule and the oxygen atoms from cellulose. Involvement of the non-participating electrons of the nitrogen
and, respectively, oxygen atoms of these groups in the extended electronic conjugation with aromatic nuclei strongly influences
the capacity of the amino and, respectively, hydroxyl groups of forming hydrogen bonds, thus achieving dyes fixation on the
sorbent. DTA analysis led to the conclusion that an improvement in the quality of the sorbent-dye materials as fuels is possible,
as compared to untreated beach flour, as a result of the modification of the cellulosic fibers in the process of dyes retention.
Authors:I. Szedljak, K. Szántainé Kőhegyi, and M. Tóth
Millet (Panicum miliaceum L.) is more resistant to climatic and soil conditions but the yields are lower than in wheat (Triticum aestivum L.), therefore its cultivation was given up for decades in Hungary. Millet is a suitable raw material for the production of pasta products without using eggs and it has other advantageous physiological effects, therefore its cultivation in Hungary is expected again. Millet is a gluten free cereal so it is not able to create viscoelastic protein network. During the biochemical studies the activity of enzymes (peroxidase, polyphenol oxidase) influencing the colour of the flour, flour mixtures (T. aestivum L., Triticum durum L., P. miliaceum L.), and pasta products were examined. Oxidoreductases in wheat flour have always been of interest to cereal chemists. The effects of peroxidase (EC 184.108.40.206) (POX) are much less thoroughly documented, although they are reported to have a relatively high level of activity in different flours. These days there are also insufficient research data on how the millet in dry pasta modifies the enzyme activity and the storage stability and shelf life of dry pasta products.
The potential effect of combined salicylic acid and fish flour to improve plant tolerance to salt stress was investigated. This pre-treatment improved the growth of wheat seedlings under salinity when compared to control (untreated wheat seedlings). Moreover, combined pre-treatment improved significantly phenylalanine ammonia lyase (PAL) and peroxidase (POD) enzyme activities, also phenolic-flavonoid content in the shoots of salt stressed seedlings. One of the most important consequences of increase in salt stress is the oxidative tissue damage. In our study, salt stress increased lipid peroxidation levels (LPO) and also the loss of chlorophylls levels during stress might also be related to photo-oxidation resulting from oxidative stress. Whereas phenylalanine ammonia-lyase (PAL) activities of wheat shoots increased by a 2.1-fold under salt stress, the activities of shoots grown from seeds primed with salicylic acid and fish flour (SA + FF) increased by a 4-fold for 0.05 mM SA + FF, 4.8- fold for 0.1 mM SA + FF and 3.7-fold for 2.5 mM SA + FF combined pre-treatment under salt stress. Also, the combined salicylic acid + fish flour primed seedlings showed higher content of the scopoletin, and salicylic, syringic, vanilic and gallic acids under both salt and nonsalinity stress conditions.
Authors:M. Rakszegi, G. Balázs, F. Békés, A. Harasztos, A. Kovács, L. Láng, Z. Bedő, and S. Tömösközi
Damaged starch, protein and arabinoxylan (AX) content and composition have been related to water absorption (WA) in a large set of samples. We tested 20 modern bread wheat cultivars bred in Hungary, 20 old Hungarian landraces, and 17 cultivars with special biochemical/functional characteristics from all around the world, this last set for international comparison. Grain was field grown in the 2011 and 2012 harvest seasons. Alinear mathematical model has been developed to estimate WA from protein content, starch damage, AX content and the relative amount of soluble proteins with strong correlation (r2 = 0.65) between measured and estimated data. The introduction of a new parameter, related to the cultivar dependent quantitative composition of soluble proteins and determined by lab-on-a-chip (LOC) analysis, largely improved the predictability of WA. Based on the large variation among the level of AX and certain soluble protein components in wheat flour and their significant contribution toWA determination, it was concluded, that these properties could be appropriate target traits to alter them during wheat breeding programs to improve the WA of wheat flour.
To elucidate the physiological mechanism of salt stress mitigated by cinnamic acid (CA) and fish flour (FF) pretreatment, wheat was pretreated with 20, 50 and 100 ppm CA and 1 g/10 mL FF for 2 d and was then cultivated. We investigated whether exogenous CA + FF could protect wheat from salt stress and examined whether the protective effect was associated with the regulation of seed vigor, antioxidant defense systems, phenolic biosynthesis and lipid peroxidation. At 2 days exogenous CA did not influence seed vigor. Salt stress increased the phenolic biosynthesis, but the CA + FF-combined pretreatment enhanced the phenolic biosynthesis even more under salt stress and decreased lipid peroxidation to some extent, enhancing the tolerance of wheat to salt stress.