On Exact Evaluation of Path Integrals

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Concept paper on processing methods and their labelling

Accurate labelling is a very important part of the organic food concept. Therefore, the aspect of how to develop labelling concepts further down the line is important. Creative labelling solutions must be developed to enable consumers to understand the communication and to avoid additional labelling that leads to misunderstandings. Perhaps new types of labelling systems that guarantee that the product is, for example 'carefully processed' or 'hand-crafted' could also be considered

Convergence of Gradient Descent for Low-Rank Matrix Approximation

This paper provides a proof of global convergence of gradient search for low-rank matrix approximation. Such approximations have recently been of interest for large-scale problems, as well as for dictionary learning for sparse signal representations and matrix completion. The proof is based on the interpretation of the problem as an optimization on the Grassmann manifold and Fubiny-Study distance on this space

Effect of ozonated water on the microbiological physical and nutritional quality parameters of minimally processed lettuce during shelf-life

Since chlorine is not accepted for treatment of organic products, alternative sanitizing agents are needed to assure the safety and shelf-life of fresh-cut organic vegetables. Therefore, the effect of ozone on the microbiological, nutritional ands sensory quality of lettuce were studied during shelf-life at 4ºC in this project. Ozone gas was produced from extra dry oxygen by means of a corona discharge generator. After spinning, samples were packaged using 35 μm oriented PP bags and stored at 4ºC for 13 days. Sampling was done on days 0, 3, 8, 10, and 13. Analyses include aerobic plate count and psychrotrophic bacteria, vitamin C and sensory quality. One chlorine (100 ppm, 2 min) and one organic acid (0.25% citric acid plus 0.50% ascorbic acid, 2 min) disinfected sample were used as control samples during the shelf-life study, as chlorine is the generally used disinfecting agent in conventional processing and organic acids are one of the few alternatives that can be used for organic products. No significant difference was detected between the microbial quality of ozone, chlorine and organic acid disinfected lettuce samples. Although the vitamin C loss in 3 ppm ozone treated samples were significantly higher than the other samples, no significant difference was observed between chlorine washed and 1 ppm ozone treated samples. At the end of 10 days of storage, at a level of 5 %, no significant difference was observed between chlorine washed and the samples treated with 1 ppm ozone for 2 min

Pilot scale application of ozonated water wash - effect on microbiological and sensory quality parameters of processed iceberg lettuce during self-life

The aim of the study was to assess the effect of ozonated water wash on the microbiological and sensory quality parameters of minimally processed iceberg lettuce in pilot scale in comparison to aqueous chlorine wash. Alternative solutions for chlorine are needed, since its use is prohibited in organic food processing. Iceberg lettuce samples were washed with three different ozone solutions and the water wash and the 100 ppm chlorine wash were used as control. Ozone generator based on corona discharge was used to produce ozone at level 7 ppm. The samples (150 g) packed in oriented polypropylene pouches were stored for 10 days at +5C and the microbiological and sensory quality was analysed on days 1, 6 and 10. There was no significant difference between chlorine wash samples and the samples washed 1 min in a machine with ozonated water concerning the microbiological quality. Compared with the chlorine with lower concentrations of ozone it is possible to control the microbial load. Concerning the sensory quality all samples endured all of the treatments well except the treatment with 7 ppm ozone for 5 min. As a conclusion the bubbling gaseous ozone in water can be as effective disinfection method as chlorine wash when the following processing parameters are taken into account: concentration of ozone during the whole process, exposure time, water temperature and the amount and type of the organic material