rmsSpNe00476

=Yeast in the food industry.=

1. What is yeast? Yeast is a type of fungi

2. How big are yeast cells? They are usually invisible to the naked eye but large masses can be seen

3. What does yeast help make? Bread,beer,wine and liquor etc

4. What can you yeast for? used in the field of biotechnology.

5. Can you use yeast in the field of science? yes ecspically s. cerevisiae.

6. Is yeast also in tea? yes mainly in //[|kombucha]// a fermented sweet tea.

7. Does yeast reproduce? yes it does like all fungi, may have [|asexual] and [|sexual] reproductive cycles.

8. Is it yeast in the environment? Yeasts are very common in the environment, and are often isolated from sugar-rich materials.

9. Does yeast spoil? Yeasts are able to grow in foods with a low pH (5.0 or lower) and in the presence of sugars, organic acids, and other easily metabolized carbon sources.[|[][|97][|]] During their growth, yeasts metabolize some food components and produce metabolic end products. This causes the physical, chemical, and sensible properties of a food to change, and the food is spoiled.[|[][|98][|]] The growth of yeast within food products is often seen on their surfaces, as in cheeses or meats, or by the fermentation of sugars in beverages, such as juices, and semiliquid products, such as [|syrups] and [|jams].[|[][|97][|]] The yeast of the //Zygosaccharomyces// genus have had a long history as spoilage yeasts within the [|food industry]. This is mainly because these species can grow in the presence of high sucrose,ethanol, [|acetic acid], [|sorbic acid], [|benzoic acid], and [|sulphur dioxide] concentrations,[|[][|61][|]] representing some of the commonly used [|food preservation] methods. [|Methylene blue] is used to test for the presence of live yeast cells.[|[][|99][|]] In oenology, the major spoilage yeast is //[|Dekkera bruxellensis]//.

10. Can you use yeast in baking? Yeast, the most common one being //S. cerevisiae//, is used in baking as a [|leavening agent], where it converts the [|food]/fermentable sugars present in dough into the gas [|carbon dioxide]. This causes the dough to expand or rise as gas forms pockets or bubbles. When the dough is baked, the yeast dies and the air pockets "set", giving the baked product a soft and spongy texture. The use of potatoes, water from potato boiling, [|eggs], or sugar in a bread dough accelerates the growth of yeasts. Most yeasts used in baking are of the same species common in alcoholic fermentation. In addition, //Saccharomyces exiguus// (also known as //S. minor//), a wild yeast found on plants, fruits, and grains, is occasionally used for baking. In breadmaking, the yeast initially respires aerobically, producing carbon dioxide and water. When the oxygen is depleted, [|fermentation] begins, producing ethanol as a waste product; however, this evaporates during baking.[|[][|64][|]]

Yeasts cells

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