Ångsterilisering av morötter. Infekterade med Lactobacillus plantarum.

The purpose of the project was to exam steams ability to sterilize carrots infected withLactobacillus plantarum. The project was a cowork with Brämhults Juice AB. They hadobserved an increase of Lactobacillus in the production of carrot juice during the summer. Tokeep the flavour of fresh fruits, th...

Full description

Bibliographic Details
Main Author: Gjertz, Marcus
Format: Others
Language:Swedish
Published: Högskolan i Borås, Institutionen Ingenjörshögskolan 2008
Subjects:
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-18924
Description
Summary:The purpose of the project was to exam steams ability to sterilize carrots infected withLactobacillus plantarum. The project was a cowork with Brämhults Juice AB. They hadobserved an increase of Lactobacillus in the production of carrot juice during the summer. Tokeep the flavour of fresh fruits, the juice is treated carefully with heat. This means that thejuice only stays fresh for a few days, around two weeks for an unopened package and threedays for an opened package.In an attempt to remove the remaining Lactobacillus of the carrots, steam is tested as an extrastep in the production of juice. During the project it was found that it is difficult to reach thewanted temperature of above 100°C, when the steam is generated under pressure. When thesteam was released in normal pressure, a decrease in temperature occurred that were so largethat the steam had a temperature of only 40°C. At the second treatment the steam wasgenerated at 1,8 bar pressure and 130°C, the steam then decreased to 80°C.At the third and last treatment the steam was generated under normal pressure and atemperature of 90°C was reached. At this temperature an 96,5% sterilization occurred after 15seconds of steam treatment. This is not enough for Brämhults Juice, since they need only afew percent surviving Lactobacills after 6 seconds. === Uppsatsnivå: C