Inactivation of Endogenous Rice Flour β-Glucanase by Microwave Radiation and Impact on Physico-chemical Properties of the Treated Flour

The apparent reduction of β-glucan (BG) molecular weight in rice-based gluten-free (GF) breads fortified with cereal BG concentrates reveals the presence of β-glucanase activity in rice flour. Inactivation of endogenous β-glucanase in rice flour thus seems to be a necessary step when developing GF breads enriched with BG of high molecular weight. The aim of this work was to study the thermal inactivation of endogenous β-glucanase in rice flour by means of microwave (MW) processing; rice flours preconditioned at four different moisture levels (13, 16, 19, 25 %) were treated by MW radiation at 900 W and five MW treatment times (ranging from 40 s to 8 min, applied stepwise at 20-s intervals). The effects of microwaves on starch crystallinity, pasting, and thermal properties of MW-treated rice flours were also explored. The β-glucanase activity in rice flours was assessed by the rate of decrease in specific viscosity of a dilute solution of a purified β-glucan preparation, upon addition of flour extracts. MW proved to be a useful alternative for thermal inactivation of endogenous β-glucanase in rice flours when applied to moistened samples. The inactivation process followed a first-order kinetic response and the apparent rate constant of thermal inactivation increased exponentially with the moisture content of the flour, M, according to the equation 0.0146·exp (0.212·M) (R ²?=?0.97). The MW time required for complete β-glucanase inactivation was only 4 min when the initial flour moisture increased to 25 %. Following MW treatment, the starch crystallinity was unaffected (p?>?0.05) and the side effects of the treatment on flour pasting and thermal properties were rather negligible.     

Effect of β-Glucan Concentrate on the Water Uptake,Rheological and Textural Properties of Wheat Flour Dough

The effects of the addition of β-glucan concentrate (2.5–10 g/100 g flour) and water (58–70 mL/100 g flour) on the rheological and textural properties of wheat flour doughs were studied. Various empirical (farinograph, extensograph, dough inflation, and dough stickiness) and fundamental rheological tests (oscillatory and creep-recovery) were employed to investigate composite dough structure and an attempt was made to correlate the data obtained from different instrumental measurements. The water absorption increased with the addition of β-glucan concentrate into wheat flour. An increase in mixing time and stability were recorded upon addition of β-glucan concentrate (≤ 5 g/100 g flour), and the extensibility decreased at similar condition. The composite dough exhibited predominating solid-like behavior. The mechanical strength, dough stickiness, the peak dough inflation pressure decreased with increasing water content but those parameters increased with β-glucan concentrate incorporation within the studied concentration range. Creep-recovery tests for 5 g β-glucan concentrate/100 g flour doughs recorded less resistance to deformation with an increase in water level and data were well described by the Burger model. Thermal scanning of doughs revealed that the protein denaturation peak was significantly influenced by water content, and the values were ranged between 110 and 124°C. Significant relationships between empirical and fundamental rheological testing methods were found.     

Effect of Germination on the Functional and Moisture Sorption Properties of High–Pressure-Processed Foxtail Millet Grain Flour

Foxtail millet is one of the commonly cultivated, nutritionally competitive source of protein, fibre, phytochemicals and other micronutrients, as compared to major cereals like wheat and rice. Considering the potential of these grains, the high pressure processed flours of germinated (GFMF) and non-germinated foxtail millet (NGFMF) grains were studied for its functional, moisture sorption and thermodynamic properties. Germination and high-pressure processing of foxtail millet grains significantly improved the functional properties of the flour. Apart from this, the moisture sorption isotherms of both the flours were determined at 10, 25 and 40 °C and the sorption data was fitted to Guggenheim-Anderson-De Boer (GAB) sorption model. The monolayer moisture content for NGFMF and GFMF ranged between 3.235–2.364 and 2.987–2.063 g g^?1, respectively. The isosteric heat of sorption ranged between ? 76.35 to ? 38.23 kJ mol^?1 for NGFMF and 172.55 to ? 34.02 kJ mol^?1 for GFMF at a moisture range of 0 to 36%, whereas, the integral entropy of sorption for NGFMF ranged between ? 0.404 and ? 0.120 kJ mol^?1 K^?1 and for GFMF between ? 0.667 and ? 0.383 kJ mol^?1 K^?1. Along with the validation of the compensation theory, the values of spreading pressures lied in the range of 0–0.078 J m^?2 for NGFMF and 0– 0.124 J m^?2 for GFMF, while, the glass transition temperatures ranged between 82.25 and 28.67 °C for NGFMF and from 51.11 to 11.83 °C for GFMF at all three temperatures.     

Microstructural evaluation of the mucin balls and their relations to the corneal surface—Insights by in vivo confocal microscopy

Purpose

The purpose of the current study was to observe and correlate the characteristics of mucin balls to the ocular surface properties, and furthermore, to report the effect of different mucin balls size and number on structural alteration of the anterior cornea.

Crops that feed the World 2. Soybean—worldwide production,use, and constraints caused by pathogens and pests

The soybean crop is one of the most important crops worldwide. Soybean seeds are important for both protein meal and vegetable oil. The crop is grown on an estimated 6% of the world’s arable land, and since the 1970s, the area in soybean production has the highest percentage increase compared to any other major crop. Recent increases in production coincide with increases in demand for meal and oil. Soybean production was 17 million metric tons (MMT) in 1960 and increased to 230 MMT in 2008. Future soybean production is expected to increase more than other crops, due to expanded production area and higher yields. There are a number of important abiotic and biotic constraints that threaten soybean production by directly reducing seed yields and/or seed quality. Abiotic constraints include extremes in nutrients, temperatures and moisture. These may reduce production directly, but also indirectly through increases in pathogens and pests. Biotic constraints tend to be geographically and environmentally restricted. Some diseases like soybean rust may be explosive by producing copious amounts of air-borne spores. This disease, more so than most, caused great concern when first found invading soybean production areas in Brazil and the United States of America. In contrast, red leaf blotch is a disease restricted to a few countries in Africa, but deserving attention since it has not been intensely studied and adequate management strategies, such as the use of resistant varieties, are not available. Significant losses in soybean yield beyond current levels may have implications for food security because of our dependence on the soybean crop, directly and indirectly for food products. In addition, because the crop is highly nutritious and versatile it offers resources to address world food issues through current and future utilization practices. Future soybean production is expected to increase in proportion to increased demand, and with application of newer genomic technologies, the crop has enormous potential to improve dietary quality for people throughout the world whether consumed as a vegetable crop or processed into various soybean food products.     

What's new in chicken egg research and technology for human health promotion? - A review

BackgroundChicken eggs are considered to be nature's perfect food. The egg white is an excellent natural source of high quality protein, which is rich in essential amino acids. The yolk is a source of antioxidants, aromatic amino acids, carotenoids, vitamins, phospholipids and proteins, which not only provide nutritional value but also act pro-health and might prevent eg. from heart diseases. In turn eggshell supplies well absorbed by the human body minerals, of which the most important is calcium.Scope and approachIn this review the new trends in chicken egg research are showed. The egg components which are the most important for human health are described. This study shows also the methods of isolating the most important health-promoting ingredients from chicken eggs.Key Findings and Conclusion: Eggs are not only a highly nutritious food, but also a rich source of diverse bioactive components also including nutraceuticals. Therefore, the current research trends focus on the new look at the egg as a material acting as health-promoting functions. Currently carried out research also concern the development of new technologies for the production of bioactive ingredients of chicken eggs.These new trends introduce a new era in egg science and technology and the future of eggs and egg ingredients remains bright.     

Whole wheat and white wheat flour— the mycobiota and potential mycotoxins

Mold growth has detrimental effects on the quality of flour and may result in mycotoxin contamination. The search for potential mycotoxins—almost 400 are known—is time-consuming and expensive. However, detailed knowledge about the mycobiota and especially the toxin producing fungi enables the effective search for these toxic fungal metabolites. Therefore, a whole wheat flour and a white wheat flour (type 405) were investigated for their total qualitative as well as quantitative mycobiota. Overall, 51 species belonging to 14 different genera could be isolated. Total fungal counts of the whole wheat flour amounted to 1833 molds while the white wheat flour contained 1730 cfu 2 g⁻¹. The mycobiota of both flours was dominated by Aspergillus spp. accounting for 84% and 77·3% of the isolations, respectively. Fungi of the genus Penicillium spp. occurred only to a minor degree: 8% of the isolations in whole wheat flour and 15% in white wheat flour. Aspergillus candidus was the most frequently encountered mold.Penicillium aurantiogriseum , Cladosporium cladosporioides, A. flavus, Eurotium herbariorum,P. griseofulvum , P. brevicompactum and P. viridicatum were isolated to a lesser degree. From the 3563 identified fungi 93·3% (32 species) belong to the group of toxigenic molds.     

Is authentication of the geographic origin of poultry meat and dried beef improved by combining multiple trace element and oxygen isotope analysis?

Data available on contents of up to 72 different trace elements and the oxygen isotope ratio of 78 poultry breast and 74 dried beef samples were analysed to determine whether the accuracy of the prediction of the geographic origin is improved by combining promising methods. Validation was performed by determining the origin of a smaller sub-group using a statistical model established from the data of the second, larger, sub-group. As expected, the combined data proved useful for the determination of the geographic origin of meat samples. However, combining data did not clearly reduce the percentage of incorrectly classified individual samples compared to the two approaches applied separately. In poultry, cross-validation and validation resulted in 83% and 50% correct classifications, respectively. The corresponding values in dried beef were 73% and 43%. In conclusion, compared to element signature data alone, combining both methods did not improve predictions of origin.     

Investigation of the Interaction Between Gallic Acid and α-Amylase by Spectroscopy

Gallic acid is one of the important polyphenols in plants and it inhibits α-amylase. The interaction between gallic acid and α-amylase was investigated by fluorescence quenching spectroscopy, UV-vis spectroscopy, synchronous spectroscopy, and the three-dimensional fluorescence spectroscopy under mimic physiological conditions. The result of the emission quenching at different temperatures revealed that there are static quenching of intrinsic fluorescence of α-amylase induced by gallic acid and a complex of gallic acid-α-amylase was formed. The results obtained from the evaluation of three-dimensional fluorescence spectra, UV-vis spectra, and synchronous spectra suggested that the association between gallic acid and α-amylase did change the molecular conformation of α-amylase. Gallic acid can enter the primary substrate-binding pocket and alter the microenvironment around tryptophan and tyrosine residues.     

Uptake and depuration of 4-nonylphenol by the benthic invertebrate Gammarus pulex: how important is feeding rate?

The major exposure and uptake route for soluble toxins by aquatic organisms is generally considered to be through the water column. In the case of hydrophobic chemicals, exposure and uptake through diet often take on greater importance as the chemicals adsorb onto organic sediments and food. A chemical that has recently come under close scrutiny because of its toxicity and possible endocrine disrupting effects in aquatic life is 4-nonylphenol (NP). It has been detected in environmental water and sediment samples and is a persistent and hydrophobic (log KOW = 4.48) contaminant in many aquatic systems. In this study, the relative importance of NP uptake through accumulation from diet and water was examined for the detritus-feeding freshwater shrimp Gammarus pulex. Using a bootstrap nonlinear regression technique, the level of toxin present in G. pulex at any time during or after initial exposure was estimated. Heterogeneity, together with assumptions on feeding rate, was shown to affect the determination of NP uptake substantially. Because of its lifestyle as a benthic organism, the main exposure route was at first assumed to be through sediments and food. However, the results suggest that major uptake may also occur through water. The statistical and modeling methodology may be applied to uptake and depuration assessments for any aquatic organisms exhibiting a variable feeding phase.     

What do you mean by hot? Assessing the associations raised by the visual depiction of an image of fire on food packaging

The images shown on food packaging play an important role in the processes of identification, categorisation and the generation of expectations, since the consumer uses the images to infer information about the product. However, a given image may convey different meanings (e.g. in a food package, “fire” may mean barbecued or spicy), so it is very important for producers and designers to understand the factors responsible for consumers inferring a specific meaning. This paper addresses this problem and shows experimentally that the consumer tends to infer the meaning from the image which is most congruent with the product it is displayed with. 65 participants carried out two speeded classification tasks which results show an interaction between the product (congruent vs. incongruent) and the image (with fire vs. without fire): products congruent with a meaning of fire were categorised more quickly when shown with fire than without it, while products incongruent with a meaning of fire were categorised more slowly when shown with fire than without it. In addition, the results show that stimuli were categorised more quickly when the interpretation of fire was literal (e.g. barbecue) than in those that were metaphorical (e.g. spiciness), indicating that the rhetorical style of the image (literal or metaphorical) influences the cognitive effort required to process it. These contributions improve our understanding of the effect of the images shown on packaging in the communication between packaging and consumers.     

Food stability determination by macro–micro region concept in the state diagram and by defining a critical temperature

In the 1950s the concept of water activity was proposed for determining food stability. This concept is now being used although it has some limitations. Indeed, these limitations mean that the concept is not universally applicable and in fact is invalid under certain conditions. In order to address the limitations of the water activity concept, the glass transition concept was proposed in the 1960s, although significant application of the concept only started in the 1980s. Recently, it has become evident that the glass transition concept is also not universally valid for stability determination in all types of foods when stored under different conditions. Currently in the literature the need is emphasized to combine the water activity and glass transition concepts since both concepts could complement each other. The glass transition concept was used to develop the state diagram by drawing another stability map using freezing curve and glass transition line. In this paper an attempt is made to review the published methods used to combine both concepts. These approaches are graphical plot of glass transition conditions and water content as a function of water activity, and macro–micro region concept in the state diagram. In addition, a new approach is proposed in this paper by defining a critical temperature for stability and then relating it with water content, and other hurdles affecting food stability. The water mobility concept is also reviewed to provide another dimension of food stability in order to determine a more complete picture.