3,548 research outputs found
Sulfur and baking-quality of breadmaking wheat
It is well known in biological science that all factors applied to living organisms (light, water, warmth, fertilizers etc.) show an optimum, when their input is increased. Healthy organisms and sus-tainable systems are, on the long run, only achieved when care is taken not to destroy this equilibrium of factors producing an optimum. With regard to the baking quality of wheat breeders and cereal scientists obviously failed to achieve this aim by breeding their cultivars on the background of ample S depositions in the ecosystems. They (involuntarily) selected plants showing definite characteristics of S deficiency (higher proportions of HMW-glutenin, stronger gluten and dough) even under conditions of ample S supply. I suppose they also selected plants with a high warmth susceptibility as this also delivers firm protein structure. When this environ-mental pollution was stopped and S supplies returned to natural conditions, even with a non S craving plant like wheat, problems arose with the gluten structure as doughs turned out so strong that the baking volume decreased. So one may ask, particularly with regard to S, if the plant constitutions of our modern wheat cultivars are still harmonious and in balance. And as a consequence ot that also the nutritional quality of these cultivars is rather questionable
Lebensmittelchemie 2012
Neben der Identifizierung von Aromastoffen durch die molekulare Sensorik sind die Aufklärung ihrer ‧Biosynthese sowie ihre biotechnische Produktion ins Zentrum der Aromastoffforschung gerückt. Geruch und Geschmack vermitteln die Qualität eines Lebensmittels. Den Geruch bestimmen flüchtige Aromastoffe, die heute vielen industriell hergestellten Lebensmitteln zugesetzt werden, um herstellungsbedingte Verluste auszugleichen oder das Aroma abzurunden. Der Verbraucher akzeptiert dabei eher natürliche Aromen. Der Begriff „natürlich“ darf nach EU-Recht allerdings nur dann zur Bezeichnung eines Aromas verwendet werden, wenn es ausschließlich Aromaextrakte oder natürliche Aromastoffe enthält.1) Dazu zählen biotechnisch erzeugte Aromastoffe, die in puncto Nachhaltigkeit für Aromenhersteller eine Alternative sind zu den klassischen natürlichen Aromen aus pflanzlichen Rohstoffen wie ätherischen Ölen. Biotechnische Verfahren dienen vermehrt dazu, strukturell komplexe Aromastoffe billiger und in größeren Mengen herzustellen, als dies mit chemischen Synthesen oder durch Pflanzenextraktion möglich ist.2) Fortschritte in Enzymtechnik, Gentechnik, Bioprozess-Monitoring und Produktisolierung bieten viel versprechende Möglichkeiten für biotechnische Aromastoffproduktion.3) Spezifische Strategien sind hierfür aber nur dann weiterzuentwickeln, wenn Enzymologie und Regulation der Aromastoffbiosynthese auf molekularer Ebene verstanden sind. Daher ist die biochemische Forschung zur Aufklärung von Biosynthesewegen in Pflanzen ein wichtiger Bestandteil der Aromabiotechnik
A literature-based comparison of nutrient and contaminant contents between organic and conventional vegetables and potatoes
Purpose - The increasing demand for organic foods is explained mainly by consumers' concerns about the quality and safety of foods and their perception that organically produced foods are healthier and safer than conventional foods. Based on internationally available concentration data of organic and conventional vegetables (carrots, tomatoes, lettuce and spinach) and potatoes, the paper aims to investigate the scientific validity of nutrition claims as "no vegetable/potato has higher amounts of nutrient X than organic vegetables/potatoes" and "no vegetable/potato has lower amounts of contaminant Y than organic vegetables/potatoes".
Design/methodology/approach - Detailed nutrient and contaminant databases were developed for organic and conventional vegetables separately. Non-parametric (Mann-Whitney test) methods were used to detect significant differences between both types of vegetables. A chi-square test was used to compare the incidence of pesticide residues in organic and conventional vegetables.
Findings - From a nutritional and toxicological point of view, organic vegetables and potato in general are not significantly better than conventional vegetables and potatoes. For some nutrients and contaminants organic vegetables and potatoes score significantly better but for others they score significantly worse. Therefore, it becomes difficult to justify general claims indicating a surplus value of organic over conventional vegetables and potatoes. More data from controlled paired studies are needed to reconsider the use of claims for these organic plant foods in the future.
Research limitations/implications - Only a limited number of studies comparing the nutrient and/or contaminant concentration of organic and conventional vegetables are available ("paired studies"). Additionally, the majority of the studies are of moderate or poor quality. The implication is that more of those paired studies are heavily needed. Another limitation of the study is the fact that most pesticide residue data originated from the USA, the EU and Australia.
Originality/value - So far only few studies compared both nutrient and contaminant contents between organic and conventional plant foods. This paper covers therefore an important, not well-explored research sub area
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