Comparison of Two Cultures for Use in Preacidified Skimmilk for Cottage Cheese Manufacture

Curd formation in a cultured dairy product is brought about by the addition of a bacterial culture capable of producing lactic acid from lactose. The primary function of this culture is to produce sufficient lactic acid to cause coagulation of the caseinate system of skimmilk. A secondary function of the culture is the production of flavor compounds considered to be desirable in these products. The flavor compounds produced by the normal growth of citric acid fermenting organisms are water soluble, and are largely removed during washing of the Cottage cheese curd. Therefore, flavor compounds are normally added to the cheese in the creaming mixture. Because of the many factors involved in the preparation and use of lactic starter or culture bacteria, it would be advantageous to develop a procedure relying less on the lactic starter for production of lactic acid. The acid producing function of a starter can be replaced by the direct addition of acid to skimmilk. In doing so, the milk must be acidified in such a way that a definite curd structure is developed. The possibility of direct addition of an acidulant to skimmilk has been explored by several research workers in the industry. This procedure does not make use of equipment presently available in the industry and as yet the product does not meet the Federal Standards of Identity for Cottage cheese. The purpose of this research was to modify the present short set Cottage cheese making procedure by the simultaneous use of a chemical acidulant and lactic starter to shorten the make time of Cottage cheese and increase product uniformity and quality. Since very little previous work has been done ·in this area. This investigation was undertaken to determine if preacidification of skimmilk for Cottage cheese production is feasible from economic and quality standpoints. In evaluating the feasibility of preacidification, the acid producing ability of cells, the increase or decrease in coagulation time, and the tension of the curd were the properties of particular interest