Improvements to the processes for the preparation and the use of active dry yeast powder, and in such a yeast

摘要

An active, dry, powdery yeast is prepared by subjecting a concentrated suspension of yeast to spray drying in the presence of one or more compounds which have osmotic action on the yeast cell and do not inhibit the fermentation ability of the yeast. Compounds having osmotic action are added in proportions ranging from 2 to 40 g based on 1Kg of the wet yeast and include the alkali metal salts of hydrochloric acid, phosphoric acid, nitric acid and sulphuric acid (e.g. sodium or potassium chloride, and potassium nitrate); the alkali metal salts of organic acids such as acetic acid, propionic acid, lactic acid, succinic acid, malic acid, fumaric acid and glycollic acid (e.g. sodium or potassium acetate, or sodium lactate); polyhydric alcohols such as glycerine, sorbitol and propylene glycol; nonfermentable saccharides for the yeast such as lactose and xylose; and urea. Ammonium sulphate is stated to be unsuitable because the fermentative ability of the yeast is lowered so greatly. The activity of the yeast may be stabilized by the addition to the yeast suspension of such subsidiary agents as guar gum, lecithin, carboxymethyl cellulose, methyl cellulose, dibutyl hydroxytoluene, polyphosphates (e.g. potassium tripolyphosphate), ascorbic acid, sodium alginate, sodium erythorbate and sodium metaphosphate, which are added within specified ranges of proportions. Examples 1 to 7 relate to the spray drying of yeast suspensions containing specified compounds having osmotic action and subsidiary agents; and employing spray drying inlet temperatures of 100 DEG and 120 DEG C. and outlet temperatures of 65 and 67 DEG C., respectively. The active, dry, powdery yeast may be included in sponge and dough and in straight dough formulations for making bread (Examples 8 and 9).ALSO:An active, dry, powdery yeast is prepared by subjecting a concentrated suspension of yeast to spray drying in the presence of one or more compounds which have osmotic action on the yeast cell and do not inhibit the fermentation ability of the yeast. Compounds having osmotic action are added in proportions ranging from 2 to 40 g based on 1 Kg of the wet yeast and include the alkali metal salts of hydrochloric acid, phosphoric acid, nitric acid and sulphur acid (e.g. sodium or potassium chloride, and potassium nitrate); the alkali metal salts of organic acids such as acetic acid, propionic acid, lactic acid, succinic acid, malic acid, fumaric acid and glycollic acid (e.g. sodium or potassium acetate, or sodium lactate); polyhydric alcohols such as glycerin, sorbitol and propylene glycol; non-fermentable saccharides for the yeast such as lactose and xylose; and urea. Ammonium sulphate is stated to be unsuitable because the fermentative ability of the yeast is lowered so greatly. The activity of the yeast may be stabilized by the addition to the yeast suspension of such subsidiary agents as guar gum, lecithin, carboxy methyl cellulose, methyl cellulose, dibutyl hydroxytoluene, polyphosphates (e.g. potassium tripolyphosphate), ascorbic acid, sodium alginate, sodium erythorbate and sodium metaphosphate, which are added within specified ranges of proportions. Examples 1 to 7 relate to the spray drying of yeast suspensions containing specified compounds having osmotic action and subidiary agents, and employing spray drying inlet temperatures of 100 DEG to 120 DEG C. and outlet temperatures of 65 DEG and 67 DEG C., respectively. The active, dry, powdery yeast may be included in sponge and dough and in straight dough formulations for making bread (Examples 8 and 9).