Food systems containing lipids, i.e., fats or oils, have been the subject of much research to develop alternative versions that either contain "healthier" lipids or contain reduced lipid levels. Many commercialized versions of such food systems, however, fail to match the sensory characteristics of the original food systems they were intended to duplicate.
Many foodstuffs contain oils which are especially useful to impart flavor and taste characteristics. Most of the desirable, healthy oils, such as canola oil and safflower oil, are liquid at room temperature, whereas most of the undesirable, "unhealthy" oils, such as shortening and lard, have a plastic-like consistency. It is known that the viscosity and consistency of such liquid oils can be increased by addition of finely divided solids, e.g., highly dispersed silica or silica gel in industrial applications or high-melting fat crystals in edible foods. See, for example, U.S. Pat. Nos. 4,605,653, 4,652,458, and 4,375,483, all of which are incorporated herein by reference.
Unsaturated fatty acids present in natural vegetable oils which make up triacylglycerols are of a cis-fatty acid configuration. Due to the non-linearity of the cis-fatty oil compounds, vegetable oils are in liquid form. By means of the hydrogenation process, hydrogen atoms are added to the cis-double bond to produce straight-chain saturated fatty acids. This process, if carried out selectively, can also be used to transform the cis-configuration of the fatty acid to its trans-isomer, which in turn increases the linearity of the fatty acid chains and thus their melting points without altering the degree of saturation or fully saturating the hydrocarbon chain. Through the process of selectivity, hydrogenation can be controlled to minimize saturation and maximize the production of the transconfigurations of fatty acids (partial hydrogenation).
High melting fats, those which are saturated or have been partially hydrogenated, have important functions in a vast majority of food products. These fat crystals are added to liquid oils to impart structure/texture and plasticity by the interaction of many small fat crystals which restrict the flow of oil until some form of stress is applied. At rest the rheological properties of the fat are altered to produce conventional body and consistency found to be characteristic of shortening, margarine, etc. Another benefit of adding solid fats to liquid oils is that it increases the oxidative stability of liquid oil. Plastic fats are also useful in bakery applications to impart flakiness, body, and volume and to give aeration properties. Studies have shown that both fat types, saturated fats as well as those comprised of trans-fatty acids, raise the low density lipoprotein (LDL) cholesterol levels and lower high density lipoprotein (HDL) cholesterol, the "good cholesterol," which in turn increases the risk of coronary heart disease. Therefore, the need arises for alternative ingredients to texturize liquid fats which would have the same consistency and functionality as highly saturated fats or partially hydrogenated oils but which would be more healthful.
Further, U.S. Pat. No. 3,539,365 of Durand et al., incorporated herein by reference, discloses the use of conventional sodium carboxymethyl cellulose (CMC)-containing finely divided cellulose as a gelling agent, where water is required to activate the resulting composition. The CMC acts as a barrier dispersant, i.e., it functions as a barrier to prevent bonding of the colloidal cellulose particles during drying and acts to disperse the compacted cellulose particles during reconstitution, in aqueous systems. Whereas the compositions disclosed in the '365 patent are widely used in water-based food systems, they do not function well in non-aqueous systems since they require water to activate the soluble CMC portion.
Non-lipid-based food systems, i.e., water-based food systems that also contain lipids, have been the subject of significant effort to develop reduced fat or fat free versions that nevertheless possess the desirable sensory characteristics of the full fat food systems. Materials used to replace the caloric content or fat content of food systems are often termed "bulking agents"; powdered and microcrystalline cellulose have been utilized in reduced fat food products; see, e.g., U.S. Pat. No. 3,023,104 of Battista which describes the use of "cellulose crystallite aggregates" in reduced calorie foods and U.S. Pat. No. 3,067,037 of Herald et al. which describes foamable foods containing cellulose crystallite aggregates blended with a foaming agent.
The invention presented herein advantageously provides a new thickener, stabilizer, gelling agent for use in food systems, including in edible lipid food systems and in reduced fat food systems.