Kalapuolisäilykkeiden säilyvyys

A literature review is presented over the factors that limit the quality of fish semi-preserves. The most important are the changes in fat, microbiological spoilage, and excessive proteolysis. It is possible to reduce the oxidative changes in fats by anti-oxidants and exclusion of oxygen from barrels and retail packs. The carbonyl compounds are mainly formed after the packs are opened. The high salt content and the anaerobic conditions in barrel-salted fish inhibit the growth of most microbes. After processing the pH of semi-preserves decreases and the microbial flora consists mainly of representatives of the family Lactobacillaceae. The shelf life of the products is prolonged by preservatives. The amino acids and soluble peptides which are liberated by enzymatically catalyzed proteolysis diminish the effect of preservatives, possibly by a reaction of the amino groups. A promising preservative is tylosin lactate which has been found very suitable for fish semi-preserves. Excessive proteolysis which softens the muscle tissue too much may prove to be the most harmful effect. From the quality point of view the muscle tissue has to contain an adequate amount of free amino acids. However, the amino acids may accelerate the enzymatic proteolysis by raising the pH. A high content of salt and acid retards the proteolysis but also weakens the quality. To prolong the shelf life of fish semi-preserves new methods will have to be developed

Avomaakurkkujen pektolyyttisistä muutoksista korjuukauden aikana

Tutkimuksessa pyrittiin selvittämään avomaankurkun pektiinin ja pektolyyttisten entsyymiaktiivisuuksien muutoksia kurkun kasvun aikana sekä näiden suhdetta konsistenssiin. Mittauksia suoritettiin kahden satokauden eri kokoisista Superb OE kurkuista sekä suppeammin kuudesta muusta avomaankurkkulajikkeesta. Näytteistä määritettiin kokonaiskuiva-aine, pektiinipitoisuus sekä esteröitymisaste, pektiinimetylesteraasiaktiivisuus, polygalakturonaasia inhiboiva vaikutus sekä kiinteys. Selvimmät todetut muutokset olivat metylesteraasiaktiivisuuden ja kiinteyden aleneminen kurkun koon kasvaessa. Polygalakturonaasia inhiboiva vaikutus vaihteli melkoisesti eri lajikkeilla, mutta sen kasvukautiset muutokset olivat vähäisiä. Olosuhteiltaan toisistaan poikenneet satokaudet heijastuivat myös näytteiden tutkittuun koostumukseen. Tutkittujen entsyymiaktiivisuuksien sekä inhibition osuus kurkkusäilykkeiden pehmenemisessä arvioidaan tutkimuksen perusteella vähäiseksi

A Novel Approach to Detect Malicious User Node by Cognition in Heterogeneous Wireless Networks

Cognitive Networks are characterized by their intelligence and adaptability. Securing layered heterogeneous network architectures has always posed a major challenge to researchers. In this paper, the Observe, Orient, Decide and Act (OODA) loop is adopted to achieve cognition. Intelligence is incorporated by the use of discrete time dynamic neural networks. The use of dynamic neural networks is considered, to monitor the instantaneous changes that occur in heterogeneous network environments when compared to static neural networks. Malicious user node identification is achieved by monitoring the service request rates generated to the cognitive servers. The results and the experimental study presented in this paper prove the improved efficiency in terms of malicious node detection and malicious transaction classification when compared to the existing systems

Kalapuolisäilykkeiden säilyvyys

vokkirjasto Aj-KThe Shelf life of fish semi-preserve