QHow will proposed changes to the Frozen Desserts Standard of Identity affect formulation practices?
Adoption of the proposed changes would expand the degree to which alternative dairy protein sources provide cost and quality benefits. As always, care is necessary when considering, selecting, and using any given combination of such ingredients.
Of special interest should be dairy protein concentrates. These include milk or whey protein concentrates (MPC, WPC), in which protein is concentrated up to 90% (dry basis), and milk or whey protein isolates (MPI, WPI), with protein at or above 90% (dry basis). These ingredients are commonly characterized by their protein level, e.g. MPC 55, WPC 75, etc. Concentration of protein is achieved by removing lactose and salts by ultrafiltration (See "Tharp & Young On Ice Cream,"Dairy Foods, August, 2003, p 49).
Because of lower lactose levels in these ingredients, changes proposed would make it possible to produce ice cream with lactose well below levels in current ice creams. Beyond a substantial reduction in the risk of sandiness and the relevance to consumer perceptions regarding lactose intolerance, there would be opportunities to reduce total "sugars" to ultra-low levels, help reduce calorie levels (with the aid of lower calorie ingredients) and provide benefits associated with higher freezing points.
The freezing point effects are illustrated by the compositions in Table 1. It includes a current 10% fat ice cream as a point of reference for three compositions using MPC 55 and/or WPC 50 to provide the minimum protein contemplated by the proposed changes. (Similar effects would be provided in varying degrees by other dairy protein sources.) Maltodextrin is used to maintain total solids parity. Sweetness (including that from lactose) is adjusted to be equivalent to that of the reference composition.
The effects of these formulation changes are substantial. The alternative compositions show a 2/3 reduction in lactose level, virtually eliminating the possibility of sandiness. Because of the higher freezing point, the water frozen at a typical draw temperature (22°F) is increased by about 20%, thereby extending textural shelf life by decreasing the average ice crystal size. Additional shelf-life extension is shown by Heat Shock Index (HSI) data. HSI is the amount of water that melts and refreezes (as larger ice crystals) during each temperature fluctuation in the range shown. The lower the HSI, the slower will be the ice crystal growth in the product. For the alternative compositions, reduction in HSI is near 20%, reflecting a significant positive influence on shelf life.
The nature of the protein system has a significant involvement in fat agglomeration. Since controlled fat agglomeration is desirable, it is important to keep the casein/whey protein ratio close to that in current ice cream; otherwise, the behavior of ice cream at the freezer and its eating qualities could be negatively affected. To avoid such difficulties it is recommended that the level of whey protein be no more than equal to that of casein, as in composition 4 in the table.
For in-depth coverage on the effects of the proposed changes in the ice cream standards including ingredient selection, formulation approaches, quality management, economics, and other considerations, plan to join us at the Tharp & Young On Ie Cream Short Course, Workshops and Clinics to be presented in Las Vegas Nov. 29 through Dec. 1. See www.onicecream.com for complete information.
