Food for thought?--A UK pilot study testing a methodology for compositional domestic food waste analysis.

Recent media attention has amply demonstrated the need for changes in our society regarding waste. The cost of waste is rising, European legislation is driving forward waste reduction policies and industry is being made responsible for the waste that all products make. This legislation is also driving a reduction in biodegradable municipal waste. In general there are a number of factors ranging from the media, financial and political to environmental, that are driving forward an agenda to decrease both general waste and food waste going to landfill. A necessary requirement of such an agenda is a benchmark of the current composition and scale of both general waste and food waste. Hence, this can then be used as a measure to demonstrate improvement. A measurement methodology and the benchmark data already exists for general waste. However, there is little or no previous work about the compositional make up of food waste. This paper discusses the necessity for a compositional food waste analysis and the pros and cons of various food waste measurement methodologies. Results for a specific methodology are illustrated and suggestions for a revision of this methodology are proposed.

Content of free phenolic compounds in cultivars of potatoes harvested in Tenerife (Canary Islands).

Determination of free phenolic compounds in potato samples was optimized using a high-performance liquid chromatographic (HPLC) method with on-line diode array detection. This method was applied to samples of four cultivars of potatoes harvested in Tenerife (Canary Islands). The free phenolic compounds found in the potato samples were (+)-catechin, chlorogenic acid, caffeic acid, p-coumaric acid, and ferulic acid. Potato samples belonging to Colorada cultivar, ssp. andigena, had mean concentrations of total phenolic compounds and chlorogenic acid higher than those found for Kerr's Pink and Cara cultivars, ssp. tuberosum, and for Negra cultivar, S. x chaucha. In contrast, p-coumaric acid was not detected in any potato samples of the Colorada cultivar. Traditional potatoes presented a higher mean concentration of ferulic acid than recently imported potatoes. A significant and negative correlation was established between (+)-catechin and p-coumaric acid. A considerable contribution to the daily intake of flavonoids was observed with the actual consumption of potatoes.

Cluster analysis and artificial neural networks multivariate classification of onion varieties.

Eight cultivars of different colored onions (white, golden, and red) were evaluated for fresh bulbs cultivated and grown under the same environmental and agronomical conditions. Cluster analysis and principal component analysis, based on different flavonoids, total phenols, and pungency, data showed that the onions were not clustered according to variety (genetic similarity degree), whereas the color was the variable with the highest influence, ranging between 50 and 70%. Artificial neural networks were applied to study the possibility of discriminating among onion varieties. Characterization of the onion according to variety and procedence of the seeds was around 95-100%. Samples belonging to the Carrizal Alto procedence had an incorrect classification for 25% of the data.