Journal of Geography & Natural Disasters
Libre accès
ISSN: 2167-0587
ISSN: 2167-0587
Marchionni Giuseppe
The whey is sanitized at a temerature of 80 ° C for 5 minutes. The sanitized item is set in a high-impact fermenter in which kluyveromices marxianus, a lactic yeast, develops utilizing lactose.
Maturation happens at a temperature of 30 ° C and pH 5.0. The utilization pace of the lactose substrate is as per the following: 6.0 kg of lactose every hour/cubic meter of fermenter.
The transformation yields are: kg of dry yeast per kg of lactose utilized kg 0.50 (yield half)
Since whey has 5.0% lactose (intended as an average value), there is the following production potential: Volume of fermented whey per cubic meter of fermenter per hour:mc 0.12
The fermented broth is centrifuged then the 30% dry yeast cream is separated. The cream is dried using a spray dryer to obtain the yeast flour. As an alternative to the production of yeast flour, the cream can be subjected to "enzymatic autolysis": in this process, the yeast proteins hydrolyze to form amino acids.
The hydrolyzate product is centrifuged to separate:
- amino acid solution;
- solid yeast cell walls.
The amino acid solution, after concentration in reverse osmosis, is dried in a spray drier to form “YEAST EXSTRACT”. Cell walls are used to produce GOS and glutathione.
Some critical phases of the process have been identified and overcome with adequate technology, particularly:
The stability of YEAST EXTTRACT ”over time.
The transfer of oxygen during fermentation: yeast has a high oxygen demand for which a bioreactor is required which induces a high oxygen / liquid broth transport coefficient (Kla).
The stability of the fermentation medium in terms of yield, contamination and growth rate.
Conclusions
The described technology allows:
To use a poor material to produce high value added yeast and yeast extracts.
The production of yeast extracts currently in the world takes place from saccharomyces; in this process yeast extract is produced from lactic yeasts with equivalent nutritional and flavor characteristics.
The demand for yeast extract in the world is growing sharply as it is also used as a substitute for glutamate, which has been declared carcinogenic.
Cook's yeast is the normal name for the strains of yeast usually utilized in preparing bread and pastry shop items, filling in as a raising specialist which makes the bread rise (grow and get lighter and milder) by changing over the fermentable sugars present in the mixture into carbon dioxide and ethanol. Bread cook's yeast is of the species Saccharomyces cerevisiae, and is similar species (yet an alternate strain) as the caring ordinarily utilized in alcoholic maturation, which is called brewer's yeast. Baker's yeast is likewise a solitary cell microorganism found close by the human body.
The usage of steamed or percolated potatoes, water from potato bubbling, or sugar in a bread player offers food to the advancement of yeasts; regardless, a great deal of sugar will dry out them. Yeast advancement is upset by both salt and sugar, yet more so by salt than sugar. A few sources state fats, for instance, spread and eggs, thwart yeast development, others express the effect of fat on combination remains jumbled, presenting confirmation that restricted amounts of fat are productive for warmed bread volume.
Saccharomyces exiguus (in any case called S. minor) is a wild yeast found on plants, grains, and common items that is now and again used for planning; regardless, when in doubt, it isn't used in an unadulterated structure yet comes from being spread in a sourdough starter.
Yeast isolates involve the telephone substance of yeast without the telephone dividers; they are used as food added substances or flavorings, or as enhancements for bacterial culture media. They are as often as possible used to make dazzling flavors and umami taste sensations, and can be found in a huge variety of packaged food, including frozen dinners, saltines, snack sustenances, sauce, stock and that is only the start.