Phytate, as a minor constituent of soybeans, has been reported to interfere with the dietary mineral absorption of mammals. Commercial soy protein isolate contains 2–3% tightly bound phytate. Practifrom soy protein materials. However, in this reported process, the phytate content was reduced to extremely low levels using commercially feasible processing techniques. The first step of this process was the extraction of water soluble components from soy flakes using routine commercial procedures. In the second step, the extract was adjusted to pH 11.6 at 28 C to insolubilize the phytate. The phytate was removed by centrifugation or vacuum filtration. Neutralization followed the phytate removal. The temperature and pH are critical for phytate removal but also must be carefully controlled to prevent protein degradation. Lysinoalanine was not detected nor was cysteine or other amino acids found to be degraded. The third step of this process was purification of the protein. In this case, the low phytate soy extract was purified by Ultrafiltration until permeate equivalent to 1/2 times the volume of the extract was collected. The phytate and phosphorus contents of the resulting soy protein isolate were 0.1 and 0.2%, respectively, compared to 2.6 and 0.8 for typical commercial soy protein isolate. The PER was significantly better than an acid isolate prepared from the same soy flakes or the commercial soy isolate tested. The retenate obtained after purification by Ultrafiltration was a translucent liquid with a protein content of 5–6%. This protein was in a very soluble form and was stable to heat.

Leaf protein concentrates were prepared by spray-drying the juice expressed from fresh alfalfa and pea vines. The concentrate was a

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Four commercial sterile milk-based dietetic products were inoculated aseptically with small concentrations of a commericial milk clotting enzyme derived from Mucor miehei and incubated at 30 C for 32 wk. One of the products, Sustacal, exhibited no observable changes in body and texture during storage. Enzyme concentrations of 1 x 10(-4) chymosin units per milliliter or higher induced undesirable changes in the body of the other three products, Enfamil Ready-to-Use, Enfamil Concentrate, and Metrecal Shape. None of the products was affected visibly by enzyme concentrations of 1 x 10(-5) chymosin units per milliliter or less. In-can sterilization of Enfamil Ready-to-Use at 126.1 C for 4.5 min and Enfamil Concentrate at 126.7 C for 4.23 min completely destroyed all measurable enzyme activity at concentrations (up to 5.5 x 10(-2) chymosin units per milliliter) in these experiments. However, 1 to 3 h between formulation and sterilization allowed time for the enzyme at concentrations of 1 x 10(-2) chymosin units per milliliter or more to cause coagulation during heat sterilization.