127 research outputs found
BERLIN CONSUMER PREFERENCES FOR QUALITY ATTRIBUTES OF FRESH VEGETABLES
Consumer/Household Economics,
Consumer Willingness to Pay for Improved Attributes of Fresh Vegetables: A Comparison Between Atlanta and Berlin
Crop Production/Industries, Food Consumption/Nutrition/Food Safety,
Changes in quercetin and kaempferol concentrations during broccoli head ontogeny in three broccoli cultivars
Three broccoli cultivars â spear broccoli âEmperorâ, crown broccoli âMarathonâ and violet broccoli âViolaâ â were harvested during head ontogeny from start of head development until over maturity stage (five stages) in three different years. The aglycones quercetin and kaempferol were analysed at optimised conditions of acid hydrolysis by HPLC. Heads of over maturity stage had the highest contents of quercetin and kaempferol. However, the genotype fundamentally determined the quantity and course of the increase in flavonols. Mini broccoli, as a new trend to market vegetables, has lower content of flavonols than the commercial stage, which indicates a reduction in health potentials. Harvesting broccoli heads of over maturity stage should be used as raw material, e.g. for the design of new functional foods
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The influence of phytochemical composition and resulting sensory attributes on preference for salad rocket (Eruca sativa) accessions by consumers of varying TAS2R38 diplotype
Seven accessions of Eruca sativa (âsalad rocketâ) were subjected to a randomised consumer assessment. Liking of appearance and taste attributes were analysed, as well as perceptions of bitterness, hotness, pepperiness and sweetness. Consumers were genotyped for TAS2R38 status to determine if liking is influenced by perception of bitter compounds such as glucosinolates (GSLs) and isothiocyanates (ITCs). Responses were combined with previously published data relating to phytochemical content and sensory data in Principal Component Analysis to determine compounds influencing liking/perceptions. Hotness, not bitterness, is the main attribute on which consumers base their liking of rocket. Some consumers rejected rocket based on GSL/ITC concentrations, whereas some preferred hotness. Bitter perception did not significantly influence liking of accessions, despite PAV/PAV âsupertastersâ scoring higher for this attribute. High sugar-GSL/ITC ratios significantly reduce perceptions of hotness and bitterness for some consumers. Importantly the GSL glucoraphanin does not impart significant influence on liking or perception traits
Realizing Wardrop Equilbria with Real-Time Traffic Information
A Wardrop equilibrium for multiple routes requires equal travel time on each
path used. With real-time traffic data regarding travel times, it is important
to analyze how to use the information provided. In particular, can a Wardrop
equilibrium be realized? Simulations using the three-phase model on a two-route
example are presented to answer this question. One route (the main line) is a
two-lane highway with a stalled vehicle in the right lane and the other route
is a low-speed bypass. For a critical incoming flow, a phase transition between
free flow and congested flow near the stalled vehicle is observed, making this
a challenging example. In the first scenario, drivers choose routes selfishly
on the basis of current travel times. The result is strong oscillations in
travel time because of the inherent delay in the information provided. The
second scenario involves a hypothetical control system that limits the number
of vehicles on the main line to prevent the free-flow to congested-flow phase
transition by diverting sufficient flow to the bypass. The resulting steady
state is neither a Wardrop equilibrium nor a system optimum, but an
intermediate state in which the main-line travel time is less than on the
bypass but the average for all vehicles is close to a minimum. In a third
scenario, anticipation is used as a driver-advice system to provide a fair
indicator of which route to take. Prediction is based on real-time data
comparing the number of vehicles on the main line at the time a vehicle leaves
the origin to the actual travel time when it reaches the destination. Steady
states that approximate Wardrop equilbria, or close to them, are obtained.Comment: 50 pages, 24 figure
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Rocket science: a review of phytochemical & health-related research in Eruca & Diplotaxis species
Rocket species (Eruca spp. and Diplotaxis spp.) are becoming increasingly important leafy salad crops across the world. Numerous scientific research papers have been published in recent years surrounding the potential health benefits associated with phytochemicals contained in leaves, such as flavonoids and isothiocyanates. Other research of note has also been conducted into the unique taste and flavour properties of leaves, which can be hot, peppery, bitter, and sweet depending upon the genotype and phytochemical composition. While research into these aspects is increasing, some studies lack cohesion and in-depth knowledge of commercial breeding and cultivation practices that makes interpretation and application of results difficult. This review draws together all significant research findings in these crops over the last five years, and highlights areas that require further exploration and/or resolution. We also advise on experimental considerations for these species to allow for more meaningful utilisation of findings in the commercial sector
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Taste and flavour perceptions of glucosinolates, isothiocyanates, and related compounds
Brassicaceae plants are renowned for their taste, aroma and trigeminal characteristics; predominantly bitter taste, sulfurous aroma and pungency. Compounds responsible for these sensations include the glucosinolates (GSLs) and their hydrolysis products, particularly isothiocyanates (ITCs), but also sulfurâcontaining volatile compounds. This article reviews the relative importance of taste and flavour perceptions resulting from such compounds; collating evidence from papers where findings are based on sensory analytical correlations, and those that have extracted specific compounds prior to sensory evaluation. Where specific GSLs impart bitterness and many ITCs impart pungency, this is clearly not true for all GSLs and ITCs. Designing crop improvement strategies for sensory traits based on total GSL content would be flawed, as it does not consider the relative differences in sensory characteristics of different GSLs and ITCs, nor contribution from other GSL hydrolysis products. In addition, some Brassicaceae plants are consumed raw, whilst others are cooked; this affects not only the hydrolysis of GSLs, but also the generation and release of sulfides. Therefore, in breeding new plant varieties it is prudent to consider the individual GSLs, the typical cooking conditions the plant is subjected to, enzyme stability, and resultant composition of both GSL hydrolysis products (including ITCs) and sulfides
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