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[en] The main objectives of the present study are to introduce new, ecologically safe, and natural compounds for controlling red flour beetle, Tribolium castaneum, and to understand the possible mode of action of these compounds. Therefore, the insecticidal and repellent activities of two phenylpropenes and six monoterpenes have been evaluated against the adults of T. castaneum. The inhibitory effects of these compounds on the activity of adenosine triphosphatases (ATPases) and acetylcholinesterase (AChE) were also tested. In fumigant toxicity assay, (−)-terpinen-4-ol (LC50 = 20.47 μl/l air) and α-terpinene (LC50 = 23.70 μl/l air) exhibited the highest toxicity without significant differences between them. Moreover, (−)-menthone and p-cymene showed strong toxicity, while (−)-citronellal, trans-cinnamaldehde, and eugenol were not active. In contact toxicity assay, the two phenylpropenes, trans-cinnamaldehde and eugenol, had the highest toxicity with same LC50 value of 0.02 mg/cm2. The monoterpenes and phenylpropenes showed pronounced repellent effect on the adults of T. castaneum at 0.001 mg/cm2 with (−)-menthone, trans-cinnamaldehyde, and α-terpinene being the most effective after 2 h of exposure. Repellent activity depended on compound, exposure time, and concentration. On the other hand, the tested compounds exhibited strong inhibition of ATPases form the larvae of T. castaneum as their IC50 values ranged between 1.74 and 19.99 mM. In addition, (−)-citronellal (IC50 = 9.82 mM) and trans-cinnamaldehde (IC50 = 23.93 mM) caused the highest inhibitory effect on AChE, while α-pinene (IC50 = 53.86) and p-cymene (IC50 = 68.97 mM) showed the weakest inhibitory effect. The results indicated that the tested phenylpropenes and monoterpenes had the potential to be developed as natural insecticides and repellents for controlling T. castaneum.
[en] Ethnic foods are healthy products interesting for the new societies. Mesquite flour offers another option for making gluten-free recipes as part of a diet for people with celiac disease. The physicochemical properties of mesquite flours (Prosopis laevigata) were characterized. The mesquite pods were dried at 60°C, 15% RH and 2 m/s airflow; then a grinding and sieving process were applied. The nutritional composition and the sorption isotherms were obtained at 30, 35, 40 and 45°C for water activities of 0.07-0.9. The particle-size distribution, morphology and thermal stability of the flours were determined by different methods. (Author)
[en] Rice flour gels with different amylose contents were subjected to instrumental compression cycles under artificial saliva-spraying conditions to simulate oral mastication and their structural breakdowns were evaluated in terms of rheological and tomographic characteristics. Both mechanical disruption of the gel structure by successive compressions and enzymatic degradation by artificial saliva featured in the simulated chewing process. Highly linear correlations (R2 > 0.95) were observed in the log plots of peak chewing force and time. The rice flour gels containing higher levels of amylose required high forces to be deformed by compression. Micro-CT analysis demonstrated that the rice flour gels with a weak cohesive texture were fragmented into smaller pieces by chewing, consequently providing channels for artificial saliva to penetrate inside the gel samples. The cohesive nature of foods appeared thus to play an important role in their disruption rate during chewing, probably influencing the masticatory performance with salvia and subsequent swallowing.
[en] For buckwheat noodle in which taste is important and its main material, buckwheat flour, the ordinary sterilization by heating or ozone cannot be applied. The number of the bacteria sticking to buckwheat flour is much more as compared with that of wheat flour, and is 105-107 per 1 g. The effective countermeasures are not yet found. Also noxious insects are apt to infect buckwheat flour. It has been known that radiation is effective for the sterilization of flavorings. In this study, the microorganism contamination of buckwheat flour and sterilization dose, the change of taste and properties after irradiation, and the capability of storage were examined, and the results are reported. The bacteria in buckwheat flour were mostly Erwinia which forms yellow colonies, and is plant-parasitic bacteria having sugar fermentation function, and also some Enterobacer, Klebsiella and Aspergillus were found. When gamma ray was irradiated on buckwheat flour, it was sterilized to less than 103 per 1 g bacteria at the dose of 5 kGy, and microorganisms were almost sterilized at 10 kGy. With the electron beam of 3 MeV, the effect of sterilization somewhat decreased. The noodle-making property of irradiated buckwheat flour, and the taste and storage capability of the noodle of irradiated flour were tested. (K.I.)
[en] The results are presented of a nation-wide survey programme aimed at determining the radioactivity in a widely used, inexpensive Brazilian food. Well-established nuclear techniques were employed to measure the specific activities of 226Ra, 228Ra, 40K, and 137Cs in fifty-six samples of manioc-root flour gathered in 20 Brazilian states. Whereas the activities for 40K were much the same as those found in other vegetables, the activities of radium proved to be in significant amounts: 0.2-7.2 Bq.kg-1 for 226Ra, and 0.3-34 Bq.kg-1 for 228Ra. Annual effective doses caused by the ingestion of manioc flour were also assessed taking into account the diet figures available for ten Brazilian states. For the adult public of those states, the radium (226Ra + 228Ra) present in manioc will be responsible for average doses ranging from 3 to 106 μSv.y-1. However, low-income people living in the states of Rio Grande do Norte, Ceara and Paraiba (northeast Brazil) could receive doses in the range from 28 to 893 μSv.yr-1. (author)
[en] A project was designed to evaluate the effect of different combinations of emulsifiers and gums on the quality of bread. Wheat variety AARI-11 was milled to get straight grade flour and mixed with the Emulsifiers (DMG and DATEM) and Gums (G.G and CMC) in a quantity of (0.3- 0.6 %). Both, straight grade flour as well as treated flour (combination with gums and emulsifiers) were subjected to proximate and rheological analysis. Results of the rheological study showed a significant change in water absorption, dough development time, dough stability time and dough viscosity i.e. W/A 61.33-62.93%, D.D.T 3.9-4.8 min, D.S.T 7-9.1 min and 818.33-950.00 BU, respectively. Breads prepared with both flours were also studied for their sensory attributes during storage after the interval of 24 h. The highest score was awarded to T1 (0.3% DATEM and 0.5% guar gum) on the bases of its excellent external attributes (colour of crust, volume, symmetry of form, evenness of bake and crust character) and internal characteristics (aroma, grain, texture, taste, mastication and colour of crumb). After the sensory and physicochemical analyses, it is concluded that with the addition of DATEM (0.3%) and guar gum (0.5%) resulted in good quality of bread. (author)