Nutritional Quality of Sorghum Seeds: Storage Proteins and Amino Acids

One sorghum commercial genotype (MASSA 03) and nine ICRISAT high-lysine genotypes from India were analyzed for storage protein content, distribution profile, and soluble amino acid concentrations. Storage proteins fraction were extracted and separated by SDS-PAGE. Soluble amino acids contents were determined by HPLC. Variations in intensity and appearance and disappearance of protein bands were observed among the sorghum genotypes suggesting genetic variability. Amino acid profile also indicated large variations in the amino acid concentrations. The high lysine and threonine soluble concentrations observed in the seeds of the sorghum genotypes encouraged the use of these genotypes as potential food source due to the better balanced amino acids profile.

Stabilization of an amylase from Neurospora crassa by immobilization on highly activated supports

The amylase from Neurospora crassa is an interesting enzyme, having higher stability than amylase from Aspergillus oryzea under a broad range of pH values. Moreover, the N. crassa enzyme may be immobilized on different supports with good retention of enzyme activity. The best stabilizations were achieved using Eupergit C 250 L or glyoxyl agarose, with which the enzyme remained fully active at 60C for 24 h while the soluble enzyme remained about 17%. The glyoxyl agarose immobilized enzyme had high thermostability, high optimal temperature (65C) and broad pH/activity profile, suggesting that this enzyme has potential for food and industrial applications for starch modification.

High pressure-sensitive gene expression in Lactobacillus sanfranciscensis

Lactobacillus sanfranciscensis is a Gram-positive lactic acid bacterium used in food biotechnology. It is necessary to investigate many aspects of a model organism to elucidate mechanisms of stress response, to facilitate preparation, application and performance in food fermentation, to understand mechanisms of inactivation, and to identify novel tools for high pressure biotechnology. To investigate the mechanisms of the complex bacterial response to high pressure we have analyzed changes in the proteome and transcriptome by 2-D electrophoresis, and by microarrays and real time PCR, respectively. More than 16 proteins were found to be differentially expressed upon high pressure stress and were compared to those sensitive to other stresses. Except for one apparently high pressure-specific stress protein, no pressure-specific stress proteins were found, and the proteome response to pressure was found to differ from that induced by other stresses. Selected pressure-sensitive proteins were partially sequenced and their genes were identified by reverse genetics. In a transcriptome analysis of a redundancy cleared shot gun library, about 7% of the genes investigated were found to be affected. Most of them appeared to be up-regulated 2- to 4-fold and these results were confirmed by real time PCR. Gene induction was shown for some genes up-regulated at the proteome level (clpL/groEL/rbsK), while the response of others to high hydrostatic pressure at the transcriptome level seemed to differ from that observed at the proteome level. The up-regulation of selected genes supports the view that the cell tries to compensate for pressure-induced impairment of translation and membrane transport.

Elucidation of the components involved in the antioxidant activity of honey

Canadian honeys were analyzed for sugar concentration, honey colour, total phenolic content, the level of brown pigments, and antioxidant activity in order to elucidate the main components involved in the antioxidant activity of honey. By employing size-exclusion chromatography in combination with activity-guided fractionation, it was demonstrated that the antioxidant components are of high molecular weight (HMW), brown in colour and absorb at both 280nm and 450nm. The presence of brown HMW antioxidant components prompted an investigation on the influence of heattreatment on the Maillard reaction and the formation of melanoid ins. Heat-treatment of honey resulted in an increase in the level of phenolics in the melanoidin fractions which correlated with an increase in antioxidant activity. The preliminary results of this study suggest for the first time that honey melanoidins underlie the antioxidant activity of unheated and heat-treated honey, and that phenolic constituents are involved in the melanoidin structure and are likely incorporated by covalent or non-covalent interaction.

Acción de organizaciones no gubernamentales frente a las semillas genéticamente modificadas en Colombia

Los efectos ambientales, económicos, sociales y culturales generados por las Semillas Genéticamente Modificadas-SGM y su control por empresas transnacionales como Monsanto, han incentivado la acción colectiva liderada por ONGs, tanto internacionalmente como en Colombia. El objetivo principal es analizar cómo la ONG “Semillas” ha incidido en las políticas colombianas relacionadas con la introducción y uso de SGM durante el periodo 2002-2013. Se centra en la Teoría de Redes Transnacionales de Defensa expuesta por M. Keck y K. Sikkink (1998). Además, se analiza el papel de las ONGs ambientales y las corporaciones transnacionales. El argumento central es que al crear vínculos con actores nacionales e internacionales y vincularse con redes y campañas con impacto transnacional, “Semillas” ha posicionado la lucha en contra de las SGM y ha logrado presionar al Estado influyendo parcialmente en sus políticas y leyes, al igual que en su posición y discurso frente al uso de SGM.

Use of PCR for detecting Aspergillus flavus in maize treated by gamma radiation process

The aim of this study was to verify the effects of gamma radiation process on the fungal DNA and the application of PCR in the detection of Aspergillus flavus in irradiated maize grains. The samples were inoculated with a toxigenic strain and incubated under controlled conditions of relative humidity, water activity, and temperature for 15 days. After incubation, the samples were treated with gamma radiation with doses of 5 and 10 kGy and individually analyzed. The use of PCR technique showed the presence of DNA bands of Aspergillus flavus in all irradiated samples that showed no fungal growth in agar medium.

Development and Biotechnological Application of a Novel Endoxylanase Family GH10 Identified from Sugarcane Soil Metagenome

Metagenomics has been widely employed for discovery of new enzymes and pathways to conversion of lignocellulosic biomass to fuels and chemicals. In this context, the present study reports the isolation, recombinant expression, biochemical and structural characterization of a novel endoxylanase family GH10 (SCXyl) identified from sugarcane soil metagenome. The recombinant SCXyl was highly active against xylan from beechwood and showed optimal enzyme activity at pH 6,0 and 45°C. The crystal structure was solved at 2.75 Å resolution, revealing the classical (β/α)8-barrel fold with a conserved active-site pocket and an inherent flexibility of the Trp281-Arg291 loop that can adopt distinct conformational states depending on substrate binding. The capillary electrophoresis analysis of degradation products evidenced that the enzyme displays unusual capacity to degrade small xylooligosaccharides, such as xylotriose, which is consistent to the hydrophobic contacts at the +1 subsite and low-binding energies of subsites that are distant from the site of hydrolysis. The main reaction products from xylan polymers and phosphoric acid-pretreated sugarcane bagasse (PASB) were xylooligosaccharides, but, after a longer incubation time, xylobiose and xylose were also formed. Moreover, the use of SCXyl as pre-treatment step of PASB, prior to the addition of commercial cellulolytic cocktail, significantly enhanced the saccharification process. All these characteristics demonstrate the advantageous application of this enzyme in several biotechnological processes in food and feed industry and also in the enzymatic pretreatment of biomass for feedstock and ethanol production. © 2013 Alvarez et al.

Pasteurization of Apple Cider with UV Irradiation

In a period of increasing concern about food safety, food poisoning outbreaks where unpasterurized apple cider or apple juice was found contaminated with Escherichia coli 0157:H7 reinforces the need for using the best technologies in apple cider production. Most apple cider is sold as an unpasteurized raw product. Because of their acidity, it was believed that juice products do not usually contain microorganisms such as E. coli 0157:H7, Salmonella, and Crytosporidium. Yet all of these foodborne pathogens are capable of being transmitted in unpasteurized juices. It is known that these pathogens can survive for several weeks in a variety of acidic juices. Although heat pasteurization is probably the best method to eliminate these pathogens, it is not the most desirable method as it changes sensory properties and also is very costly for small to mid-sized apple cider processors. Pasteurization of apple cider with Ultraviolet Irradiation (UV) is a potential alternative to heat pasteurization. Germicidal W irradiation is effective in inactivating microorganisms without producing undesirable by-products and changing sensory properties. Unpasteurized raw apple cider from a small local processor was purchased for this study. The effects of physical parameters, exposure time and dosage on the W treatment efficacy were examined as well as the effects of the UV light on apple cider quality. W light with principal energy at a wavelength of 254.7 nm, was effective in reducing bacteria (E .coli, ATCC 25922) inoculated apple cider. The W dosage absorbed by the apple cider was mathematically calculated. A radiation dose of 8,777 μW-s/cm2 reduced bacteria an average of 2.20 logs and in multiple passes, the FDA mandated 5-log reduction was achieved. Sensory analysis showed there was no significant difference between the W treated and non-treated cider. Experiments with W treated apple cider indicated a significant (p < 0.01) extension of product shelf life through inhibition of yeast and mold growth. The extension of the researched performed is applicable to other fruit juice processing operations.

The biotechnology of lactic acid bacteria with emphasis on applications in food safety and human health

Selostus: Terveyttä ja ruoan turvallisuutta edistävät maitohappobakteerien biotekniset sovellukset

Effect of Information about benefits of biotechnology on consumer acceptance of genetically modified food; evidence from experimental auctions in the United States, England, and France

This study investigates the effect of information about potential benefits of biotechnology on consumer acceptance of genetically modified (GM) foods. Consumer willingness to accept compensation to consume a GM food was elicited using an incentive compatible auction mechanism in three US states (California, Florida, and Texas) and in two European countries (England and France). Results indicate that information on environmental benefits, health benefits and benefits to the third world significantly decreased the amount of money consumers demanded to consume GM food; however, the effect of information varied by type of information and location. Consistent with prior research, we find that initial attitudes toward biotechnology have a significant effect on how individuals responded to new information.

Global and local implications of biotechnology and climate change for future food supplies

The development of improved technology for agricultural production and its diffusion to farmers is a process requiring investment and time. A large number of studies of this process have been undertaken. The findings of these studies have been incorporated into a quantitative policy model projecting supplies of commodities (in terms of area and crop yields), equilibrium prices, and international trade volumes to the year 2020. These projections show that a “global food crisis,” as would be manifested in high commodity prices, is unlikely to occur. The same projections show, however, that in many countries, “local food crisis,” as manifested in low agricultural incomes and associated low food consumption in the presence of low food prices, will occur. Simulations show that delays in the diffusion of modern biotechnology research capabilities to developing countries will exacerbate local food crises. Similarly, global climate change will also exacerbate these crises, accentuating the importance of bringing strengthened research capabilities to developing countries.

Factors underlying support or opposition to biotechnology among Australian food consumers and implications for retailer-led food regulation

Despite current findings that consumers, on average, have negative attitudes to biotechnologies such as cloning and genetic engineering, considerable variability can be found in the direction and strength of these attitudes. This paper presents a path analysis of attitudinal, motivational, demographic and behavioural variables that influence consumer dispositions towards biotechnology. Among these variables, those found to be most important were: consumers' level of motivation to find natural foods; the extent to which they were motivated by convenience; whether they did the shopping for their household on a regular basis; and their sex. In terms of direct effects on dispositions to biotechnology, motivation to find natural foods had a very strong negative effect while convenience had a very strong positive effect. Sex had a moderate direct effect with women less likely to be positively disposed towards biotechnology than men. In an apparent contradiction, taking responsibility for household shopping had an equally strong positive effect on both naturalness and convenience. However, sex also played a crucial role here with a very strong effect on motivation to find natural foods (women more motivated), a minor effect on convenience (women less motivated) and a strong effect on responsibility for household shopping (women more likely to shop). The policy implications of these findings are important, given the apparent oppositional trends of some sections of the food industry to endorse biotechnology, and of the supermarkets to deliver `clean and green' non-GM foods to consumers. (c) 2005 Elsevier Ltd. All rights reserved.