Biological production of acrylic acid from cheese whey has been demonstrated. Lactose in sweet whey fortified with yeast extract was first converted to a stoichiometric mixture of propionic and acetic acids in 70 h by a coculture of Lactobacillus bulgaricus and Pro‐pionibacterium shermanii. Further conversion of propionate to acrylate was accomplished by resting cells of Clostridium propionicum in systems in which methylene blue acted as an electron acceptor. A maximum acrylate yield of 0.133 mmol/g of wet cell was achieved for periods of 6 h, after which resting cell activity declined substantially. Bio‐conversion of propionate to acrylate could also be carried out by cells immobilized in calcium alginate beads with no decrease in cell productivity or initial reaction rate.

Thermostable lipase from Thermomyces lanuginosus was immobilized in untreated microporous membranes. Melted tallow pumped through the membrane did not wash the enzyme out. From 0.4 to 0.9% of the soluble activity remained after immobilization with half-lives of 1-2 months or more at 50 degrees C. Membranes can be acid/base washed and reloaded with enzyme with no adverse effects. Buffer was required for a long half-life, and recycling the buffer improved the mass transfer of glycerol out of the immobilized lipase reactor. Immobilized activity was unaffected when the pH of the aqueous product changed from 5.5 to 6.5.

There is substantial evidence that controlled dehydration of bacon products to a water activity of 0.92 or below should allow control of spore outgrowth and toxin production by Clostridium botulinurn and permit reduction of added nitrite levels. This study presents sorption data necessary for the development of a practical dehydration technique for bacon. Variations in fat/lean ratio, storage temperature, sorption mode, and drying method result in changes to the moisture sorption isotherms. Of these parameters only fat/lean variability of bacon significantly affects the isotherms at water activity levels above 0.90. Empirical equations for the isotherms were derived and used to establish differences in the isotherms due to variation in the parameters studied.

Processes are described for obtaining a low moisture, free-flowing protein powder of high nutritional value through the high temperature (120°C) heat coagulation of cottage cheese whey protein in a constant stirred reaction vessel using steam injection heating. Dried protein concentrates produced by the suggested alternative processes contain 65%, 85% and 95% protein, respectively. Essentially all the coagulable protein can be removed in 8 min of holding time in a $H range of 5.5-6.5. Increasing coagulation temperature to above that of conventional methods (SS-1OO'C) significantly decreases processing time without adversely affecting product quality. The highly nutritious protein fraction produced has potentially wide application in the protein fortification of foods not requiring the normal functional properties of whey protein.