Economic feasibility evaluation of microfiltration of milk prior to cheesemaking.
A nonlinear programming optimization model was used to evaluate the net revenues and potential profit-ability of microfiltration (MF) prior to cheesemaking in the 3-year period 1998 to 2000, using monthly milk price and composition data. The model identifies the optimal mix of milk resources and determines if MF cheesemaking produces a higher net revenue than conventional cheesemaking that uses NDM and condensed milk for fortification. This study demonstrates the potential of this model to evaluate new technologies in cheese manufacture and improve decision making in the cheese industry. The use of MF produced higher net revenues in 30 out of the 36 mo for both Cheddar and low-moisture, part-skim mozzarella, leading to an appreciable increase in net revenue (vs. conventional cheesemaking) for both cheeses. The benefit from MF in net revenue was greater when the cream price was high. The use of 3X MF yielded the same net revenue as 2X MF. An estimate of manufacturing costs of MF vs. conventional cheesemaking was also made. To this end, the yields of products were calculated by the optimization model, while the production cost of each product was estimated from data of two economic engineering studies and a MF cheesemaking trial. The manufacturing cost of MF Cheddar was slightly higher than the manufacturing cost of conventional Cheddar. However, the benefit in net revenue from the use of MF was estimated to be higher than the difference in manufacturing costs. Moreover, some advantages in the new coproducts of MF Cheddar could outweigh its higher manufacturing cost. The relationships between prices and recoveries of coproducts required to render MF profitable were identified.
Production of an 18% protein liquid micellar casein concentrate with a long refrigerated shelf life.
Our objective was to develop a process to produce a high-concentration liquid micellar casein concentrate (18% protein, MCC18) with a long refrigerated shelf life. The MCC18 is a novel milk protein ingredient produced by fractionating skim milk using microfiltration (MF). To achieve a long refrigerated shelf life, the processing of MCC18 was designed to maximize the removal of low-molecular weight compounds [e.g., lactose and nonprotein nitrogen (NPN)] that can be easily metabolized by microbes, while minimizing the microbial count in the final product. The production of MCC18 was done over a period of 5 d. The experiment was replicated 3 times in different weeks with a different batch of raw milk. Raw whole milk was pasteurized and separated to produce skim milk. Skim milk was ultrafiltered (UF) to remove more than half of the lactose and NPN. The UF milk retentate was diluted with water and then MF in 3 stages to remove approximately 95% of the serum protein and further remove lactose and NPN. The retentate from the last stage of MF was UF to concentrate the protein to 18% and batch pasteurized. The MCC18 was collected immediately after processing in sterile plastic vials and stored at 4°C. The average MCC18 contained 21.78% total solids, 18.27% true protein, 0.31% NPN, and 0.13% lactose. The MCC18 at the day of processing contained a mean aerobic bacterial count of 2.1 log cfu/mL and mean aerobic spore count of 2.3logcfu/mL. The MCC18 formed a solid gel at temperatures <22°C, but the MCC18 reverted back to a liquid when warmed from 4°C temperature to >22°C. This provides a unique opportunity in ingredient handling and packaging and eliminates the challenges encountered in reconstitution of dried milk protein ingredients. The MCC18 produced in this study maintained a bacteria count <20,000 cfu/mL for 16wk when stored at a refrigeration temperature of 4°C. Further study is needed to determine if changes occur in the organoleptic and functional properties of MCC18. We envision that the conversion of skim milk to MCC and its coproducts (serum protein concentrate and lactose concentrate) could be used as an alternative to the production of nonfat dry milk to balance milk production seasonality, specifically the components of skim milk portion.
THE PROCESS CHEESE INDUSTRY IN THE UNITED STATES: A REVIEW: II. RESEARCH AND DEVELOPMENT
Research and development ( R & D) in corporate laboratories of cheese processors and in other research facilities in the United States have contributed knowledge of analytical technology, microbiology, defects and their corrections, manufacturing techniques, equipment, emulsifiers, and the use of other ingredients. Methods of wrapping and protecting the product during distribution were improved. Cheese foods and spreads with higher moisture, lower fat, and altered consistency were developed. The technology of producing slices of processed cheese has been revolutionary. Packages of slices are replacing the original, and highly successful, 5-lb. loaf. Mechariically formed, individually wrapped, and sealed slices are produced at fantastic speeds. Trends of industry indicate greater production per plant, more low-fat, high proteiD cheese products, and use of vegetable fats and proteins, Trends of R & D indicate improvements in emulsifiers, packaging, keeping quality, new products, and more mechanization and automation for greater efficiency and improved protection of this valuable food and its related products. The industry provides opportunities for trained food scientists, engineers, marketing specialists, and business administrators. The original United States patents described the first research and development ( R & D) on process cheese in the United States. Most industrial R & D has occurred in the plants or laboratories of the processors. The numerous patents on products, emulsifiers, equipment, processes, and packaging show the productiveness and ingenuity of the workers. Organizations supplying ingredients, equipment, and supplies to processors have engaged in R & D which contributed directly to the progress and welfare of the industry (118, 217). Research in institutions or commercial research laboratories has often been initiated, · or supported, or both, by industry. The National Cheese Institute or its members have usually provided such support. All research which contributes to knowledge of cheese affects the process cheese industry directly or indirectly. This review will be limited of necessity to those developments which seem to us to be directed to the progress of the industry. A contribution from the College of Agriculture and Life Science, University of Wisconsin-Madison, Madison, Wisconsin 53700. TECHNICAL AND ANALYTICAL EVALUATIONS AND CONTR.OLS HECEIVINO • COHINO • MANIIFACTIIHI60 FAT QUALITY STANDARDIZING MOISTURE COMPOSITION COMPOSITION CHECK FILTER TEST CLASSIFICATION CONTROL ACTION