STORAGE RESULTS IN LOSS OF THE ANTIGENOTOXIC PROPERTIES OF LENTINULA EDODES (SHIITAKE MUSHROOM) AND DEVELOPMENT OF IN VIVO GENOTOXICITY

In this study, we have investigated the stability of the antigenotoxic properties of dried of Lentinula edodes (Berk.) Singer mushroom powder stored at room and at − 20C. Mice were pretreated by gavage for 15 consecutive days with 0.6 mL/day of an aqueous extract of dried L. edodes powder prepared at 60C. On day 15, the mice were intraperitoneally injected with 50 mg/kg N-ethyl-N-nitrosourea (ENU); 3 h later, peripheral blood was withdrawn from the animals and used to evaluate DNA damage using the comet assay. The mice were sacrificed 24 h after the ENU treatment and the bone marrow used to measure the frequency of micronucleated polychromatic erythrocytes. The results indicated that storage at both room temperature and at − 20C significantly reduced the antigenotoxic effects of the mushroom powder. In addition, whereas freshly dried mushroom powder was nongenotoxic, storage of the powder at − 20C resulted in genotoxic activity ( P <  0.05). Taken together, our data indicate that constituents of L. edodes powder are altered during storage, resulting in both genotoxicity and a reduction in antigenotoxicity.     

Fire and explosion hazards associated with milk spray drying operations*

Recent reports in the literature indicate that incidents involving fires and explosions in the spray drying of milk products are increasing in number. While milk powder is not highly explosible, the conditions for a dust explosion, apart from the ignition source, are almost always present in certain areas of a spray drying system during its normal operation. Self-ignition of deposits is known to be possible at the high temperatures in a spray drier. At best, this can cause product degradation and discoloration and at worst it can provide the source of ignition for an explosion. This paper is an attempt to draw together recent work on fire and explosion prevention and protection for milk powders.     

Effect of Marination upon Mineral Content and Tenderness of Beef

This study compared marinated and nonmarinated beef to determine differences in semimembranosus muscle tenderness and selected mineral content. The minerals analyzed were iron, zinc, magnesium and sodium. Marination resulted in a significantly more tender muscle, as determined by shear values and trained panel evaluations. Mineral content was significantly affected by marination with substantial losses of iron, zinc, and magnesium and increased sodium. Marination would be a feasible method of enhancing tenderness of more economical cuts of beef; however, the subsequent loss and/or gain of minerals should be considered.     

Spontaneous ignition of milk powders in a spray-drying plant

A company operating a spray-drying plant for skimmed milk and fat-filled powders asked the Fire Research Station for help in determining the cause of a series of fires. The subsequent investigation showed that the powders could undergo spontaneous ignition in certain circumstances. The thicknesses of powder deposit on the spray-drier walls necessary for there to be a risk of self-ignition were calculated. These were sufficiently close to those encountered in practice to suggest that self-ignition represents a real problem. Mechanisms for the occurrence of fires in the fluid-bed instantizers are also put forward. Preventive measures are suggested.     

RHEOLOGICAL BEHAVIOR OF CONCENTRATED INULIN SOLUTION: INFLUENCE OF SOLUBLE SOLIDS CONCENTRATION AND TEMPERATURE

Inulin is a storage polysaccharide present in more than 30,000 vegetable products, including chicory roots, that are considered suitable for industrial application. The objective of this work was to evaluate the influence of temperature and the soluble solids concentration on the rheological behavior of a concentrated inulin solution obtained from a centrifugation process from chicory roots, after freezing at − 24C. For all the evaluated soluble solids concentrations, inulin solutions showed a rheological behavior of a highly pseudoplastic fluid, with high resistance to flow at low strain rates followed by a breakdown of the structure when the shear rate increased. The effect of temperature on the apparent viscosity of inulin solutions can be represented by the Arrhenius equation. The rheological behavior of inulin solutions can be represented by the Herschel–Bulkley, Casson, Cross and Power Law equations, where the consistency index increases as temperature rises and the soluble solids concentration as well.

PRACTICAL APPLICATIONS

The main objective of this work was to analyze the rheological behavior of a concentrated inulin solution obtained from chicory roots, to check the possibility of its application to obtain powder inulin.
The concentrated inulin solution was obtained by diffusion in hot water, followed by concentration by evaporation and phase separation conducted by lowering the temperature (−24C) and centrifugation at a velocity of 10,000 rpm for a time interval of 15 min. However, this solution is still going to be processed. Therefore, it is important to know its rheological behavior.
The influence of temperature and the soluble solids concentration on the rheological behavior of the concentrated inulin solution was also studied.     

STARCH MOBILIZATION AND SUCROSE ACCUMULATION IN THE PULP OF KEITT MANGOES DURING POSTHARVEST RIPENING

Sugar is a determinant for the quality of mangoes, but information about its accumulation is scarce. Although starch can contribute to sugar production during ripening, not much is known about the enzymes involved. This work presents the changes in carbohydrate and enzymes during the development and ripening of Keitt mangoes. Starch disappearance was concomitant to a fivefold increase of sucrose, the most abundant sugar of the ripe fruits. The activities of α-amylase, β-amylase, phosphorylase and isoamylase were detected in the pulp, and while α-amylase increased parallel to the starch content, β-amylase presented a 20-fold increase during ripening. On the other hand, high phosphorylase activity was observed when fruits were still accumulating starch, and lowered during ripening. Isoamylase was detected during development and increased slightly during ripening, which would be in agreement to the expected role for isoamylases as acting on both subproduct of starch synthesis and degradation.

PRACTICAL APPLICATIONS

The present work reinforces our previous works that Keitt mangoes do not ripen when attached to the tree. This fact allowed us to study all the starch degradation after mango harvesting which does not occur with the other cultivars. Data obtained in this work reinforce the role of α-amylase, β-amylase and isoamylase rather than the starch phosphorylases on starch granule degradation in mangoes, and the subsequent soluble sugar accumulation.     

François Cointeraux and the School of "Agritecture" in Eighteenth-Century France

In eighteenth-century France, François Cointeraux was as an advocate of pisé , a provincial technique that rammed pure earth into artificial stones. Economical and sturdy, pisé could be used for a variety of rural constructions, ranging from sheds to silos. To share this knowledge, Cointeraux founded the "School of Agritecture," which combined agriculture ("agri-") with architecture ("-tecture"), and taught students how to work the land for food and shelter. Despite its practical benefits, the hybrid curriculum was not adopted elsewhere, for its agrarian values ultimately proved incompatible with the interests of industrial capitalism.