Freeze concentration of dairy products Phase 2. Final report

Abstract

DISTRIBUTION OF THIS DOCUMENT 1s M m , , TEWand used to formulate products such as ice cream, cream cheese, milk chocolate and other products for consumer evaluation. Freeze-concentrated skim milk powder was reconstituted and compared against fresh skim milk as well as skim milk reconstituted from commercial liquid concentrate and nonfat dry milk powder for organoleptic quality and consumer acceptability. RESULTS The Niro PDU was successfully installed at Galloway West and brought up to 3-A processing standards. The GRAS status of freeze-concentrated milk ingredients was affirmed by an expert safety panel. The semi-commercial unit was used to freeze concentrate skim milk and whey protein concentrate. Continuous runs of up to 51 0-hours were achieved. Projected energy costs are higher for freeze concentration than they are for other concentration technologies currently in use by the dairy industry. However, a full evaluation of the operating, cleaning and energy utilization costs that differentiate freeze concentration from other evaporation technologies indicate that commercial-scale freeze concentration should be more economical than current evaporation technologies. This is due primarily to the lower product losses incurred with freeze concentration. Consumer evaluations documented that the functional and organoleptic properties of freeze-concentrated skim milk are as good as or better than those of fresh skim milk, current skim milk concentrates or nonfat dry milk powders. The semi-commercial scale production undertaken on the PDU did encounter problems with inconsistent product quality (primarily involving product oxidation) but these were not considered to be serious obstacles to commercialscale production. The results suggest that, once commercialized, freezeconcentrated milk powders and concentrates should fill significant added-value market niches in both domestic and international markets. 4-6 1-2 EXECUTIVE SUMMARYFreeze concentration is a process for removing water from food systems by crystallizing the water as ice and subsequently removing the ice crystals from the food system. Initial calculations indicated that the removal of water from foods by crystallization should be more energy efficient than its removal by evaporation. In addition, freeze concentration offers the advantage of minimizing the heat-abuse of sensitive milk components (such as proteins and flavors) and consequently an opportunity for producing dairy ingredients with enhanced functional and organoleptic qualities. Freeze concentration is already used commercially for concentrating juice, beer and coffee products.The feasibility of freeze-concentrating milk was demonstrated on a pilot-plant scale during Phase I of a project undertaken by a consortium comprised of the Electric Power Research Institute (EPRI), Dairy Research Foundation, and Niro (formerly Grenco). The U.S. Department of Energy joined the consortium for phase II. The objective of the Phase II study was to prove the technical feasibility of, the economics of, an...

Review: Freeze Concentration Technology Applied to Dairy Products

“…On the other hand, it was found that lactose had only a slight effect on the critical subcooling temperature for contact nucleation. The observation that whey proteins affect the rate of growth of ice crystals explains the results obtained by Best and Vasavada (1993) with whey permeate. If the critical subcooling temperature increases, it may also affect the microscropic structure of the crystal surface.…”

“…Two other lines of research, important for the application of cryoconcentration of dairy products, are the development of new equipment (Dickey et al, 1995;Zhang and Hartel, 1996;Habib and Farid, 2007) and the study of the influence of cryoconcentration on the proteins and lactose present in dairy products (Hartel and Chung, 1993). Best and Vasavada (1993) report the freeze concentration of skim milk, whole milk, sweet whey, whey protein concentrate and whey permeate using a single-stage configured Niro pilot plant unit ( Figure 1).…”

“…Sensory quality of freeze-concentrated milk has been reported to meet the quality of fresh skim milk and it exceeds those of conventionally concentrated and powdered skim milk when reconstituted as a beverage or when used as an ingredient in the development of cream cheese, frozen dessert, sour cream, salad dressings, whipped toppings and other products (Best and Vasavada, 1993).…”

Freeze concentration techniques as alternative methods to thermal processing in dairy manufacturing: A review

“…In 1993, Best and Vasavada's (1993) pioneer study on SFC equipment allowed to concentrate whole milk, skimmed milk, whey protein, and whey permeate. Due to the variable total soluble solids content of these dairy products, the maximum concentration (w/w) reached was 51% for whey permeate, 46.5% for whey protein, 44% for whole milk, and 40% for skimmed milk.…”

Review on Progressive Freeze Concentration Designs

“…FC also offers an advantage in dairy processing by minimizing the heat abuse of sensitive milk components such as proteins and flavours (Sánchez et al, 2011b). Best and Vasavada (1993) have carried out an evaluation of FC in dairy processing. It has been reported that the organoleptic quality of freeze-concentrated milk fulfilled the quality of fresh skim milk and exceeded those of conventionally concentrated and powdered skim milks when reconstituted as a beverage or when used as an ingredient in the developing of cream cheese, frozen dessert, sour cream, salad dressings, whipped toppings and other products.…”