A Method for Manufacturing a High-Nitrogen–Low-Lactose Product from Whey1,2

Abstract

Summary A method of increasing the total nitrogen of Cheddar cheese whey from a normal content of approximately 0.15 to 0.80% has been devised. The method involves the fermentation of cheese whey with Lactobacillus bulgaricus, followed by subsequent treatment of the whey with anhydrous ammonia to neutralize the lactic acid formed during fermentation. Both intermittent and continuous systems of ammoniation were investigated. Concentration of the ammoniated whey was carried to approximately 40, 50, 60, 80, and 90% total solids. Analyses for the concentrated wheys included fat, lactose, ash, and lactic acid. The nitrogen loss during concentration ranged from 4.33 to 8.93% of the total nitrogen present. Nitrogen stability of the concentrated whey stored at room temperature for 153 and 365 days was satisfactory, with a maximum loss of 1.0% nitrogen for 365 days. The concentrated product is syrupy in consistency, salty or acid to the taste, with a color ranging from brown to reddish-brown. Odor descriptions of the concentrated product are silage-like, molasses-like, bouillon-like, and pungent. All concentrations of the ammoniated whey are completely and readily water-soluble. The principal product formed in the process probably is ammonium lactate. Use of nitrogenous bases other than ammonia as lactic acid neutralizers in the process appears feasible; however, this study was limited to an evaluation of ammonia.