17B-12 |
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M. C. VALDEZ1, V. B. Alvarez1, G. W. Chism, III1, and W. J. Harper. (1) Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007 Glucono-d-lactone (GDL), a slow hydrolyzing acid, has been established as one method for direct acidification of skim milk to produce cheese. Sodium acid sulfate (NaHSO4) is a fast hydrolyzing acid that is currently used in beverages, jellies, and dressings. However, its usefulness as a direct acidulant in cheese making is not known. The study’s objective was to evaluate the effects of NaHSO4 direct acidification of skim milk on curd development, curd texture, and whey composition. Pasteurized skim milk (4oC) was acidified by addition of 5g GDL or NaHSO4 (0.0300g/2minutes powder/granular or 3ml/2minutes 1% solution with and without 3ml/2minutes 1% CaCl2 solution) to pH 5.2. Further acidulant was then added to reach pH 4.6. The solutions then sat quiescently for 90 minutes at 28.3oC and then were refrigerated for 36 hours before texture analysis was completed. The Instron settings were as follows: 40% depth, 0.8333 mm/sec speed, 500N force, and a 34.7mm anvil probe were used. GDL samples formed a moderate strength gel with little synersis and had texture means of 0.12kgf hardness, 7.66mm springiness, and a 1.10 cohesiveness ratio. At pH 5.2 and 4oC, NaHSO4 samples produced a precipitate which formed a dome of gel beneath a white opaque liquid. At 28.3oC and pH 4.6, there was increased precipitation, significant synersis, and no gel formation. Protein content of the precipitates ranged from 30.377-38.082% protein. Investigations into using rennet to aid in gel formation and changes in whey composition are underway. NaHSO4 hydrolysis was accelerated by low pHs and heat, which resulted in significant precipitate formation but no gel. Therefore, the use of NaHSO4 alone to achieve gel formation for cheese curd production is insufficient. The addition of rennet and/or CaCl2 may be necessary to achieve gel formation.
Session 17B, Dairy Foods: General
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