U.S. patent application number 09/424375 was filed with the patent office on 2002-03-14 for method for making reduced calorie cultured cheese products.
Invention is credited to WEIBEL, MICHAEL K..
Application Number | 20020031592 09/424375 |
Document ID | / |
Family ID | 23682401 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020031592 |
Kind Code |
A1 |
WEIBEL, MICHAEL K. |
March 14, 2002 |
METHOD FOR MAKING REDUCED CALORIE CULTURED CHEESE PRODUCTS
Abstract
A method is disclosed for making reduced calorie cultured
cheeses whereby the natural lipid content of milk is replaced with
colloidal forms of synthetic or chemically structured lipids
displaying low to no human digestibility. The colloidal dispersion
of modified lipids contained within the milk base is initially
stabilized by preferred combinations of polymeric and particulate
hydrocolloidal materials such as structurally expanded cellulose.
Such stabilization is important during formation of the curd to
ensure homogeneous distribution and maintenance of the lipid
dispersion throughout the coagulum yet allow effective
concentration of the coagulum solids by means of ordinary water
removal methods commonly used in the manufacture of conventional
cultured cheeses. The coagulum is then processed by means similar
to that employed for naturally fermented cheeses. The resulting
cultured cheese is a reduced calorie product with low to no
metabolizable fat content yet possesses organoleptic properties
similar to a full fat product.
Inventors: |
WEIBEL, MICHAEL K.; (WEST
REDDING, CT) |
Correspondence
Address: |
DANN DORFMAN HERRELL & SKILLMAN
SUITE 720
1601 MARKET STREET
PHILADELPHIA
PA
19103-2307
US
|
Family ID: |
23682401 |
Appl. No.: |
09/424375 |
Filed: |
November 23, 1999 |
PCT Filed: |
May 28, 1998 |
PCT NO: |
PCT/US98/10803 |
Current U.S.
Class: |
426/582 ; 426/36;
426/40; 426/42; 426/43; 426/519; 426/573; 426/585 |
Current CPC
Class: |
A23C 19/054 20130101;
A23C 19/055 20130101 |
Class at
Publication: |
426/582 ; 426/36;
426/40; 426/42; 426/43; 426/519; 426/573; 426/585 |
International
Class: |
A23C 019/00 |
Claims
What is claimed is:
1. A method for making a reduced-calorie cheese product,
comprising: (a) providing a milk base comprising low-fat, skim or
no-fat milk, or a mixture thereof, an edible,
nutritionally-diminished lipid-like substance and a stabilizing
agent comprising structurally-expanded cellulose; (b) homogenizing
said milk base; (c) subjecting said homogenized milk base to
conditions causing formation of a coagulum; (d) concentrating said
coagulum; and (e) aging the concentrated coagulum.
2. The method of claim 1, wherein said milk base is provided by
adding said stabilizing agent to a dispersion of said lipid-like
substance in said milk.
3. The method of claim 1, wherein said lipid-like substance
comprises a fat replacer.
4. The method of claim 1, wherein said lipid-like substance
comprises at least one sucrose polyester of long chain fatty
acids.
5. The method of claim 1, wherein said lipid-like substance
comprises a structured lipid.
6. The method of claim 1, wherein said lipid-like substance
comprises at least one polyol ester of short and long chain fatty
acids.
7. The method of claim 6, wherein said polyol ester is a glycerol
ester.
8. The method of claim 1, wherein said stabilizing agent includes a
colloid-forming material.
9. The method of claim 8, wherein said colloid-forming material is
selected from the group consisting of carboxymethyl cellulose, a
glucomannan, microcrystalline cellulose, xanthan gum, gellan gum,
and gum arabic.
10. The method of claim 1, wherein said stabilizing agent includes
a surfactant.
11. A cheese product prepared by the method of claim 1.
12. A composition for preparing a reduced calorie cheese product,
comprising milk selected from the group consisting of low-fat, skim
or no-fat milk, an edible, nutritionally-diminished, lipid-like
substance and a stabilizing agent comprising structurally expanded
cellulose.
13. The composition of claim 12, wherein said lipid-like substance
comprises a fat replacer.
14. The composition of claim 12, wherein said lipid-like substance
comprises at least one sucrose polyester of long chain fatty
acids.
15. The composition of claim 12, wherein said lipid-like substance
comprises a structured lipid.
16. A composition of claim 12, wherein said lipid-like substance
comprises at least one polyol ester of short and long chain fatty
acids.
17. The composition of claim 16, wherein said polyol ester is a
glycerol ester.
Description
BACKGROUND OF THE INVENTION
[0001] Cultured cheese products are nutritionally dense foods
containing 10 to 40% digestible lipid and 3 to 4 kcals/g. They are
produced by coagulation of raw or processed milk, concentration of
the coagulum solids by mechanical processes to express whey and
ageing. During ageing complex microbiological and enzymatic
development occur to generate flavor and textural characteristics
associated with various cheese types. Lipids per se are
biochemically considered to be highly reduced substances. Under the
anaerobic environment of the ageing process milk lipids do not
participate directly as substrates for metabolic events leading to
generation of flavor and aroma qualities of the resulting cheese.
However, lipids do have an important impact on the partitioning and
capture of volatile flavor and aroma components. Lipids further
have impact on the textural properties as well as meltability of
the resulting cheese product. Therefore in addition to their
nutritional contribution, lipids play an important role in the
flavor development, organoleptic characteristics and heat
responsiveness of cultured cheese products.
[0002] The development of reduced calorie cheese products has
evolved around lipid replacement strategies based on blending of
low fat or fat-free, skim milk cheese with fat substitutes or fat
mimetics to enhance organoleptic quality of the skim milk cheese
base. These products are designated processed cheeses. Imitation
cheeses are blended variations based on partial or total
replacement of milk derived protein with alternative protein
sources such as those derived from vegetable sources. Natural
cheese products are distinguished from blended products in that the
isolation and ageing of the coagulum is conducted in situ without
adulteration by subsequent blending of other materials.
[0003] The very nature of the cheese making process does not lend
itself to extraction of lipid from the intermediate or final
products of the process. Rather fractionation of the raw material
to remove or reduce lipid at the onset is the protocol of
commercial interest today. Low fat processed milk products are
readily available as starting raw materials for cultured and other
processed dairy products. However, cultured cheese products
prepared from skim or substantially reduced-fat milk suffer severe
deficiencies due to loss of a key organoleptic component which is
lipid. The resulting products are inferior in texture, flavor and
appearance and have poor meltability. In part these deficiencies
are due to enrichment of natural non-lipid composition with
attendant enhancement of their specific functionality, but also due
to the loss of unique lipid functionality. The result is an
imbalance of physical and organoleptic properties associated with
the consumer's expectation for performance of a specific cheese
product. Therefore a means has long been sought to reduce the
caloric content of cultured cheese products yet maintain high
organoleptic standards.
[0004] In the past two decades interest in fat substitutes has
spawned a host of technological developments in alternative
materials for replacement of natural lipids in foods; see for
example "Fat Mimetics in Low Fat Cheddar Cheese", J. Food Science,
61 (5) 1267-1270, 1288 (1996). Water and combinations of
hydrocolloidal materials, hydrated microparticulated materials
based on starch or proteins and synthetic lipids have been
reported. All of the above ingredients have been considered as
components in low fat or no fat processed cheese products.
Specifically, incorporation of structured polyol polyesters such as
sucrose polyesters, SPEs, have been reported as highly efficacious,
nutritionally unavailable additives for processed cheeses (U.S.
Pat. No. 5,585,132).
[0005] Insofar as is know, direct substitution of synthetic or
organically structured lipids for natural milk lipids prior to
coagulation has heretofore not been considered. Such materials are
of sufficiently different specific gravity and display such high
interfacial tension in milk based fluids that their colloidal
dispersions are not stable. This behavior leads to heterogeneous
accumulation and phase separation. Therefore, some means of
stabilizing the colloidal dispersed lipid state is required.
Stabilization components are characterized by the property that
they alone or in combination with other components of the system of
interest form structured networks throughout the continuous phase.
An important aspect of such stabilization is that the physically
compartmentalized microdomains are dimensionally similar in size to
that of the colloidal material to be physically constrained. Such
compartmentalization provides a barrier to translational migration
which leads to heterogeneous accumulation and ultimately
consolidation of the dispersed lipid domains. Such stabilizer
systems may be soluble, interactive polymeric materials which form
polymer gels or particulate reticulated material of supracolloidal
dimensions which becomes physically entangled to form particle
gels. Hybrid combinations of particulate and polymer gel forming
components specifically are particularly useful stabilizers in this
application.
[0006] While known polymer stabilizer systems, for example xanthan
gum or quar gum, could be expected to provide maintenance to some
degree of a dispersed exogenous colloidal lipid material in a milk
matrix, the very mechanism that leads to such phenomena usually
prevents effective water removal from the flocculated curd or milk
coagulum. This complication is a result of enhanced water
immobilization within the capillary and interstitial domains of the
dispersed system, a consequence of translational
compartmentalization by polymer gels. However, it has now been
found that various forms of structurally expanded celluloses can
form the basis of a highly effective stabilizer system for
synthetic or chemically modified lipids in either natural or
reconstituted low/no fat milk bases. Further, these materials allow
excellent control of drainage and water removal from the curd
enhancing processability. The use of structurally expanded
celluloses in the art of cheese making is believed to be new and
unique.
SUMMARY OF THE INVENTION
[0007] In practicing the method of the invention a
nutritionally-diminishe- d, lipid-like substance, such as sucrose
polyester (SPE), is dispersed into low fat, skim or no fat milk by
means of vigorous agitation. Next, a stabilizing agent, comprising
structurally expanded cellulose, prepared as described below, and
other optional hydrocolloids and surfactants, is added to the milk
containing the dispersed lipid-like substance to provide a milk
base. It should be understood, however, that the order of addition
of the above-mentioned ingredients is not essential to the
successful practice of the invention. The resulting milk base may
then be pasteurized prior to homogenization, or undergo direct
homogenization. Homogenization may be achieved by high pressure
impact discharge (Gaulin Homogenizer) or opposing, submersed jet
discharge (Microfluidics Homogenizer). Other preferred methods of
homogenization to produce colloidal forms of the lipid-like
substance from the dispersed state may be achieved by high shear
rotor-stator homogenization or colloid mill type disperators. The
colloidal dispersion of the lipid-like substance in the milk base
is then inoculated by the appropriate cheese specific
microorganism(s) to initiate curd coagulation and subsequent ageing
development. A variation may involve enzymatic addition for both
curd coagulation and subsequent flavor development, such as
proteases and lipases, which may be added along with the inoculum.
The resulting curd is cut and drained, salted and finally pressed
to individual cheese bricks which are then aged under anerobic
conditions for flavor and textural development.
[0008] The expression "nutritionally-diminished, lipid-like
substance" as used herein, includes both fat replacers, such as
SPEs, which provide the organic quality of a lipid but are
essentially non-metabolized, and structured lipids, such as
glycerol esters with mixed long/short chain fatty acids, which have
reduced calorie value upon oxidation as compared to milk fat.
DETAILED DESCRIPTION OF THE INVENTION
[0009] In order to appropriately define and distinguish
structurally expanded cellulose, SEC, from other forms of cellulose
and hydrocolloidal polymers and gums mentioned herein, it is
necessary to briefly examine cellulose structure and methods of
manipulation. For example, powdered cellulose is known in the art
of cheese manufacture as an anticaking agent for ground cheese
products. Carboxymethyl cellulose and other cellulose ethers have
been considered as useful additives to enhance texture and yield of
low fat skim and processed cheese products. Hence differentiation
of SEC from other types of "cellulose" known in the art of cheese
manufacture is important.
[0010] In chemical terms cellulose specifically designates a class
of plant derived linear, glucose homopolysaccharides with B 1-4
glycosyl linkage. It is the dominant structural polysaccharide
found in plants and hence the most abundant polymer known. The
function of cellulose is to provide the structural basis for the
supramolecular ensemble forming the primary wall of the plant cell.
Differentiation and aggregation at the cellular level are highly
correlated with cellulose biosynthesis and assembly. In combination
with associated proteins, lignin and heteropolysaccharides such as
pectin and hemicelluloses, the cellulosic containing primary cell
wall defines the shape and spatial dimensions of the plant cell.
Therefore cellulose is intimately involved in tissue and organelle
specialization associated with plant derived matter. Over time the
term "cellulose substance" or simply "cellulose" has evolved as a
common commercial describer for numerous non-vegetative plant
derived substances whose only commonality is that they contain
large amounts of B 1-4 linked glucan. Commercially, combinations of
mechanical, hydrothermal and chemical processing have been employed
to enrich or refine the B 1-4 glucan content to various degrees for
specific purposes. However, only highly refined celluloses are
useful substrates for structural expansion. Examples of highly
refined celluloses are those employed as chemical grade pulps
derived from wood or cotton linters. Other refined celluloses are
paper grade pulps and products used in food. The latter are
typically derived from nonwoody plant tissues such as stems, stalks
and seed hulls.
[0011] Refined cellulose can be considered a supramolecular
structure. At the primary level of structure is the B 1-4 glucan
chain. All cellulose is similar at this level. Manipulation at this
level would by necessity involve chemical modification such as
hydrolysis or substitution on the glycosyl moiety. However, as
outlined next this level of structure does not exist as an isolated
state in other than special solvent systems which are able to
compete with extremely favorable intermolecular association
energies formed between B 1-4 glucan chains.
[0012] In contrast to primary structure, a stable secondary level
of structure is formed from the nascent B 1-4 glucan chains which
spontaneously assemble into rodlike arrays or threads designated
the microfibril. The number of chains involved are believed to vary
from 20 to 100. The dimension of the microfibril is under the
control of genetic expression and hence cellulose differentiation
begins at this level. Pure mechanical manipulation is not normally
practiced at this level of organization. However, reversible
chemical modification is the basis for commercial production of
reconstituted forms of cellulose fibers such as rayon. Chemical
substitution by alkylation of the glycosyl moiety yields stable
ether substituted B 1-4 glycans which no longer self assemble. This
reaction forms the basis for the production of commercial forms of
cellulose ethers such as carboxymethyl (CMC), hydroxyethyl (HEC),
hydroxypropyl (HPC) and methyl or ethyl (MC & EC) cellulose.
One further modification at the secondary structural level involves
intensive acid hydrolysis followed by application of high shear to
produce colloidal forms of microcrystalline cellulose (MCC). This
modification is best deferred to the next level of structure as
most forms of MCC are partially degraded microfibril
aggregates.
[0013] The third level of cellulose structure is that produced by
the assemblage of microfibrils into arrays and ribbon like
structures to form the primary cell wall. As in the case of
secondary structure, tertiary structure is under genetic control
but additionally reflects cellular differentiation. It is at this
level that other structural polymeric and oligomeric entities such
as lignin and proteins are incorporated into the evolving
structure. Selective hydrolytic depolymerization and removal of the
non-cellulose components combined with application of sufficient
shear results in individually dispersed cellular shells consisting
of the cellulosic skeletal matrix. With the removal of strong
chemically and physically associated polymeric moieties which
strengthen the cellulose motif, structural expansion by mechanical
translation and translocation of substructural elements of
cellulose can begin to occur.
[0014] The process by which structural expansion occurs is that of
rapid anisotropic application of mechanical shear to a dispersed
phase. Particles of refined cellulose, consisting of cellular
fragments, individual cells or aggregates of a few cells, are
dispersed in a liquid. The continuous liquid phase serves as the
energy transduction medium and excess enthalpy reservoir. While the
individual forces maintaining secondary and tertiary structure of
the refined cellulose particles are largely noncovalent and hence
of relatively low energy, the domains of collective ensembles of
such interactions possess extraordinary configurational stability
due to the large number of interactions. only by application of
intense hydraulic gradients across a few microns and on a time
scale that precludes or minimizes relaxation to mere translational
capture, can sufficient energy be focused on segments of the
refined cell wall to achieve disassembly of tertiary and secondary
structure. In practice a small fraction of the applied energy is
captured by structural expansion of the dispersed phase. The vast
majority of useful energy is lost into enthalpy of the continuous
phase and can complicate processing due to high temperature
excursions. As disassembly progresses and the structures become
smaller and selectively more internally ordered, disassembly rates
diminish rapidly and the process becomes self limiting.
[0015] Three general processes are known in the art of cellulose
manipulation to provide structurally expanded celluloses useful for
practice of this invention. The simplest is structural modification
from intense shear resulting from high velocity rotating surfaces
such as a disk refiner or specialized colloid mill as described in
U.S. Pat. No. 5,385,640. A second process is that associated with
high impact discharge such as that which occurs in high pressure
homogenization devices such as the Gaulin homogenizer described in
U.S. Pat. No. 4,374,702. The third process is that of high speed,
wet micromilling whereby--intense shear is generated at the
collision interface between translationally accelerated particles
as described in U.S. Pat. No. 4,761,203. It would be expected that
anyone skilled in the art could apply one or combinations of the
above processes to achieve structurally expanded forms of cellulose
useful in the practice of this invention. The complete disclosures
of each of U.S. Pat. Nos. 5,385,640, 4,374,702 and 4,761,203 are
incorporated by reference in the present specification as if set
forth herein in full.
[0016] Two other commercial modifications are commonly employed at
this structural level and are mentioned to distinguish the
resulting product from SECs. The first involves indiscriminate
fragmentation by various dry grinding methods to produce powdered
celluloses and is widely practiced. Such processes typically result
in production of multimicron dimensional particles as intraparticle
fragmentation and interparticle fusion rates become competitive in
the low micron powder particle size region. Typical powdered
celluloses contain particle size distributions ranging from 5 to
500 microns in major dimension and may be highly asymmetric in
shape. These products are employed as anticaking or flow
improvement additives for ground and comminuted forms of cheese.
The second process involves strong acid hydrolysis followed by
moderate dispersive shear producing colloidal microcrystalline
cellulose (MCC). It is believed that certain less ordered regions
comprising tertiary structure are more susceptible to hydrolytic
depolymerization than highly ordered domains resulting in shear
susceptible fracture planes. Dispersed forms of MCC are needlelike
structures roughly three orders of magnitude smaller than powdered
celluloses and typically measure about 5 nanometers in width and
about 500 nanometers in longitudinal dimension, respectively. On
spray drying MCC aggregates to form hard irregular clusters of
microcrystals whose particle dimensions range from 1 to 100
microns. The resulting MCC clusters can serve as a precursor for a
unique SEC best described as a microscopic "puff ball" reported in
U.S. Pat. No. 5,011,701 and is reported to be a fat mimetic. MCC
also finds application as a rheology control agent in processed
cheese products. The complete disclosure of U.S. Pat. No. 5,011,701
is incorporated by reference in the present specification as if set
forth herein in full.
[0017] Finally, the quaternary or final structural level of
cellulose is that of the cellular aggregate and is mentioned only
for completeness. These substances may be highly lignified such as
woody tissue or relatively nonlignified such as those derived from
the structural stalks and seed hulls of cereal grain plants.
Commercial types of these materials are basically dried forms of
nonvegetative plant tissue. These moderately elastic substances
respond to mechanical processing by deformation and ultimate
fracture along the principal deformation vector. Consequently,
these materials readily undergo macroscopic and microscopic size
reduction and are reduced to flowable powders by conventional
cutting, grinding or debridement equipment. Because of the cohesive
strength of the molecular ensemble comprising quaternary structure,
these materials are not candidates for systematic structural
expansion at the submicron level without chemical intervention.
[0018] The expression "structural expansion", as used herein refers
to a process practiced on refined celluloses involving mechanical
manipulation to disassemble secondary and tertiary cellulose
structure. The ultimate level of expansion would be to unravel the
cell wall into individual microfibrils. Although plant specific, a
typical microfibril is best described as a parallel array of 25 to
100 B 1,4 glucan chains with diameter in the 50 nanometer range and
variable length ranging from submicron to micron multiples. In
practice generation of a dispersed microfibril population is not a
realistic objective and only of academic interest. What is usually
achieved because of the relatively indiscriminate application of
mechanical energy is a highly heterogeneous population of miniature
fibrils, ribbon like and slab like structures. These structures
display irregular distention of individual microfibrils and
aggregates of microfibrils from their surfaces and at internal and
external discontinuities. The ensuing collage consists of an
entangled and entwined network of cell wall detritus to form a
particle gel. Some of the larger structural features with
dimensions in the micron range are discernable with the light
microscope; however, higher resolution techniques such as scanning
transmission electron microscopy are necessary for detailed
observation of submicron features. This particle gel network
exhibits a vast increase in surface area associated with the
volumetric expansion and projection of cell wall structure into the
continuous phase medium. Lastly, structurally expanded celluloses
useful for purposes of this invention may further be characterized
by possessing a water retention value greater than 350 and a
settled volume of at least 50% for a 5% w/w dispersion of said SEC
in aqueous media.
[0019] Two methods for characterizing SEC are useful for purposes
of practicing this invention. The first is a simple settled volume
test. A powdered or prehydrated SEC is fully dispersed at a
specified mass into a specified volume of water. The apparatus
usually employed to measure settled volume is the graduated, glass
cylinder. The dispersed cellulose phase is allowed to gravity
settle to a constant bed volume (usually 24 hr) which to a first
approximation reflects the specific dispersed phase volume or
degree of structural expansion. SEC useful for practicing this
invention is characterized by gravity settled volumes of at least
50% for a 5% w/w aqueous suspension of cellulose. For example a 5%
w/w suspension of powdered celluloses characterized as 200 mesh
from cottonseed (BVF-200, International Filler Corporation, North
Tonawanda, N.Y.), refined wood pulp (BW-200, Fiber Sales &
Development Corporation, St. Louis, Mo.) and refined soy hulls
(FI-1, Fibred Inc., Cumberland, Md.) yield settled volumes of
31.2%, 23.2% and 22.4%, respectively in 24 hr. These forms of
cellulose while potential precursors for SEC are readily
distinguished from SEC by this test.
[0020] A second method of characterization involves viscometry. SEC
begins to form volumetrically sustainable, continuous particle gels
at concentrations in the vicinity of 0.5% w/w in the absence of
other dispersed substances. This critical concentration may be
significantly reduced in the presence of other dispersed colloidal
matter. For example fragile gels can be detected in milk at SEC
concentrations as low as 0.1% w/w on fluid milk. The onset of
formation of the particle gel and the gel strength are
characteristic of the type of SEC and the degree of structural
expansion. Typically, the particle gels exhibit well behaved,
reversible pseudoplastic behavior in the 1% to 3% w/w concentration
range. This behavior can be modeled by the power law using a
rotational viscometer, such as the Brookfield DVIII, a programmable
rheometer (Brookfield Engineering Laboratories, Inc., Stoughton,
Ma.). A log/log plot of the shear rate versus shear stress at a
specified concentration gives two characteristic system parameters:
the flow index and consistency index. The consistency index is
reflective of intrinsic gel strength (resting state extrapolation)
and the flow index which is indicative of the degree of
pseudoplasticity or dynamic particle/particle shear dependent
interactivity. SEC's useful for practice of this invention are
preferably characterized by displaying pseudoplastic behavior which
is modeled by the power law. In the range of 1-2% w/w at 20.degree.
C. the preferred SEC's display flow indexes less than unity and
typically in the range of 0.2 to 0.7 with the preferred consistency
indexes typically ranging from 500 to 10,000 cp.
[0021] Preferred nutritionally-diminished, lipid-like substance for
use in practicing this invention are sucrose polyesters of long
chain fatty acids such as Olestra.TM., which is described in U.S.
Pat. No. 3,600,186 and subsequent related patents. Other useful
lipid-like substances include dialkyl, malonates, e.g.,
dihexadecylmalonate, esterified propylated glycerol and a glycerol
or other polyol ester of mixed short/long chain fatty acids.
[0022] It is contemplated that certain soluble hydrocolloids may
also be useful in the practice of the invention. Dispersive
hydrocolloids such as carboxymethylcellulose, CMC, are believed to
bind to SECs through interaction of unsubstituted regions on the
glucan backbone with the SEC surface, perhaps on the distended
microfibril. The presence of carboxymethyl substituents generates
anionic polyelectrolyte character to the CMC backbone and hence on
its association with SEC imparts a stationary negative charge to
the SEC surface. This stationary charge is believed to help control
flocculative association of SEC and perhaps colloidal lipid and
casein micelles. Other associative hydrocolloids which bind to
cellulose such as glucomannans (for example guar) help to control
water mobility. Other colloids such as MCC and hydrocolloids such
as xanthan and gellan gums are SEC interactive and assist in fine
tuning gel structure for the colloidal-network including the
dispersed lipid-like substance. Also, colloidal polymeric gums such
as xanthan, guar, and arabic and oligosaccharides such as pentosans
are excellent steric stabilizers of colloidal dispersions acting at
the lipid/water--lipid/protein interface with SEC to reduce
interfacial tension and provide insulative barriers to colloidal
lipid coalescence.
[0023] The following examples are illustrative procedures for
practicing this invention by one normally skilled in the art and
are not intended to limit its scope.
EXAMPLE 1
[0024] A commercially available sucrose polyester (SPE) with a
degree of substitution (DS) between 7 & 8, an iodine value of
86.3 and containing five dominant fatty acids with the following
triglyceride distribution--palmitic, stearic, oleic, linoleic and
behenic as 18.2, 3.6, 31.8, 29.1, and 4.5%, respectively, was used
as an example of an unmetabolizable lipid. The above lipid is
sterically not accessible as a substrate for human pancreatic
lipases and hence not metabolically available due to its inability
to be hydrolyzed into constitutive fatty acids which are readily
transported across the intestinal mucosa. The lipid is
compositionally designed such that it exists largely in beta
crystalline form at human body temperature which assists
incorporation into fecal solids in the colonic region and hence
solid phase expression. Two nonionic surfactants also based on
sucrose ester structure but with a much lower DS than the above SPE
were obtained from commercial sources--DK-160 with an average DS of
1.23, average molecular weight (AMW) of 659 and a 15 hydrophobic
lipophilic balance (HLB) number and DK-50 with a DS of 1.69, an AMW
of 777 and a 6 HLB number, and combined as a lipophilic surfactant
mixture to assist in the creation of an SPE oil-in-water/milk
emulsion.
[0025] Two different plant sources of SEC were employed as
prehydrated pastes which had been coprocessed with the sodium salt
of carboxymethyl cellulose (CMC) as a processing aid (15% w/w on
cellulose solids)--6XCS was a cotton seed cellulose derived SEC at
6.6% w/w nonvolatile solids displaying a flow index (FI) of 0.39
and a consistency index (CI) of 5200 cp measured at 1.5% w/w
nonvolatile solids and 3XWF was a refined wheat fiber cellulose
derived SEC at 5.8% w/w nonvolatile solids with a FI of 0.37 and CI
of 4200 cp measured at 1.5% w/w nonvolatile solids. A commercially
available pasteurized skim milk was employed which had a
nonvolatile solids content of 8.5% w/w. A freeze dried lactic
culture R-707 (mesophilic homofermentative O-culture) manufactured
by Chr. Hansen Inc., Milwaukee, Wis. was employed as a direct vat
set starter culture. CHYM-MAXII, a bacterial derived chymosin
preparation at 50,000 MCU/ml, also manufactured by Chr. Hansen, was
used as a coagulant. A four experiment set was conducted with the
compositions as outlined in TABLE 1.
1 TABLE 1 EXPT1 EXPT2 EXPT3 EXPT4 water 172.2 g 172.2 g 0 22.0 g
DK-16 4.0 4.0 4.0 4.0 DK-50 4.0 4.0 4.0 4.0 Na Citrate 4.0 4.0 4.0
4.0 6XCS paste 0 0 0 150.0 3XWF paste 0 0 172.0 0 SPE 0 113.6 113.6
113.6 skim milk QS all to 4000 g total
[0026] Each test composition contained 0.1% w/w of each surfactant
and Na Citrate with variation in SPE (zero or 2.8% w/w) and SEC
(zero or 0.25% nonvolatile solids). The individual solutions were
prepared as follows. Surfactants, sequesterant, SEC prehydrated
paste, and SPE were QS to 1000 g with skim milk at 90.degree. F.
The mixture was homogenized for 3 minutes on an rotor/stator
dispersator model OMNI-MACRO manufactured by Omni International,
Inc., Gainesville, Va. using a 35 mm generator and operating at
6000 rpm. The homogenized mixture was combined with 3000 g skim
milk preheated to 90.degree. F. and rehomogenized for an additional
3 minutes on the same assembly at 8000 rpm in a 5 liter plastic
beaker. At two minutes into the final homogenization step the
starter culture was added. Prior to use in each experiment, 1.5 g
of the lyophilized starter culture was dispersed into 100 ml of the
preheated skim milk by means of a micro-dispersator model 1000 also
manufactured by Omni International, Inc. using a 10 mm generator
operating at 10,000 rpm. The make procedure employed was as
follows. After homogenization and addition of the starter culture,
each container was incubated in a circulated air oven at 90.degree.
F. to ripen. After 1 hour 0.7 ml of the coagulant was added, the
mixture well stirred and the each beaker allowed to set quiescent
at 90.degree. F. After 1 hour the milk mixture had coagulated and
the curd mass was cut in situ into 1/2 inch cubes and allowed to
heal for 15 minutes. At that time the cut curd was rapidly cooked
by means of a microwave oven to 100.degree. F. and held at that
temperature in a circulated air oven at the same temperature. After
1 hour of cooking the whey was drained from the settled curd mass
and the curd was cut into 1/2 inch strips. The strips were returned
to the empty vat for cheddering whereby they were incubated for two
hours at 100 deg F. during which time the pH dropped to 5.6. At the
end of the cheddering step the curds were drained, shredded and
salted (2% w/w based on fluid milk used for each experiment). The
salted curd was allowed to cure for 30 minutes at 100.degree. F.
prior to pressing. Pressing was achieved by means of four parallel,
pneumatically driven cylinders with a 2.5 inch diameter cylinder
bore driving a 4.5 inch diameter compression disk (delivered
pressure 1/3 of drive pressure at the cylinder bore). Each
recovered curd mass was weighed and carefully packed into a nylon
mesh cloth lined, perforated plastic cylinder with a 40 mesh screen
overlaying a removable, latticed base plate for drainage. The nylon
mesh cloth was then carefully folded over the packed curd mass and
the top press plate positioned. The pressing sequence used was 10
minutes at 10 psi on the bore cylinder chamber. The pressure was
relieved and the press cake inverted. The cake was then repressed
at 10 psi for 10 minutes. The pressure was again relieved and the
cake inverted one more time. The pressure was elevated to 40 psi at
the bore cylinder for the final step. The curd cake was pressed at
this pressure to approximately constant volume, typically requiring
12-14 hr. However, in this example the final press step was
continued 21 hr. It should be pointed out that this technique
represents the most conservative curd mass recovery as whey
expression proceeds until compressive equilibration occurs whereby
only mechanically inaccessible fluids are retained. In commercial
practice the extent of mechanical expression of whey from the curd
is volumetrically limited as the curd container compression is
restricted to a predetermined volume. Commercial cheddar or other
hard cheeses made with this invention, therefore, will contain
substantially greater amounts of moisture and hence even lower
caloric indexes than those reported here where exhaustive
expression of whey fluids has been practiced. The results are
summarized in TABLE 2.
2 TABLE 2 EXPT1 EXPT2 EXPT3 EXPT4 (con- 0% SPE 2.8% SPE 2.8% SPE
2.8% SPE trol) 0% 0% SEC 0.25% CS- 0.25% WF- SEC SEC curd 314.4 g
505.3 g 813.8 g 893.6 g wt. cheese 254.4 g 398.3 g 324.1 g 289.9 g
wt.
[0027] It should be pointed out that large curd yields are obtained
for the experiments containing both forms of SEC versus the skim
milk control (EXPT1) and the lipid only control (EXPT2). The
limiting equilibrium whey expression was designed to emphasize the
facile removal of the large amount of entrained fluids within the
initial recovered curd if such removal was desired. The recovered
cheese cakes were air dried at 65.degree. F. and approximately 50%
relative humidity for 48 hr. with top to bottom rotation every 12
hours. The final dried cheeses were wax coated and aged at
40.degree. F. At the time of this report the cheeses were 6 months
into the ageing period. At 8 months the cheeses will be
organoleptically evaluated and proximate analysis conducted to
determine water and lipid retention as well as compute the
nutritional index. It is interesting to note that the
SEC-containing curds express whey more readily and more extensively
than the lipid control (EXPT2). This is expected to have a profound
impact on the yield and organoleptic quality for commercial cheese
which is not as extensively pressure processed.
EXAMPLE 2
[0028] A second form of lipid substitute is that of a structured
triglyceride (STG). Here the polyol is glycerol common to all
natural triglycerides, but the fatty acid distribution is
distributed between short chain fatty acids having less than 6
carbon moieties and very long chain fatty acids having greater than
20 carbon moieties. The short chain fatty acids are metabolically
accessible while the very long chain fatty acids are not. Hence the
caloric density usually associated with a 16-18 carbon triglyceride
at 9 kcal/g is typically reduced to 5 kcal/g for this category of
structured lipid. By carefully manipulating the fatty acid chain
length and distribution, melting properties can be controlled to
mimic saturated fatty acid lipids which are dominantly crystalline
at 70.degree. F. or unsaturated fatty acid lipids which are liquid
at 70.degree. F. Hence proprietary blends and formulations can be
produced which largely reproduce the physical functional properties
of the commonly used natural lipid substances, yet are diminished
in nutritional function. One commercially available material is
known as salatrim and is a proprietary structured triglyceride. The
basic formulation employed for this example is outlined in TABLE
3.
3 TABLE 3 EXPT1 EXPT2 EXPT3 EXPT4 DK160 surfactant 0.25% 0.25%
0.25% 0.25% 6XCS SEC 0.0 0.10 0.10 0.10 STG 0.0 0.0 2.0 2.0 skim
milk QS to 4000 g
[0029] The basic protocol of example 1 was followed for preparation
of the emulsion and make procedure. The skim milk was a consumer
grade pasteurized product and assayed at 8.6% nonvolatile solids.
In contrast to EXAMPLE 1 the third and final stage of pressing at
40 psi was only 12 hours. The results are summarized in TABLE
4.
4 TABLE 4 EXPT1 EXPT2 EXPT3 EXPT4 (control) 0.0% STG 0.0% STG 2.0%
STG 2.0% STG 0.0 SEC 0.1% SEC 0.1% SEC 0.1% SEC curd 322.4 g 420.4
g 403.3 g 502.8 g weight cheese 244.5 g 283.8 g 339.3 g 323.2 g
weight
[0030] Again a significant dewatering or whey expression associated
with the incorporation of SEC is seen when the limiting equilibrium
condition for mechanical pressing is applied. These cheese cakes
are only one month into the aging process and will be
organoleptically and analytically evaluated after 8 months.
[0031] Although the present invention has been described and
exemplified in terms of certain preferred embodiments, other
embodiments will be apparent to those skilled in the art. The
invention is, therefore, not limited to the particular embodiments
described and exemplified, but is capable of modification or
variation without departing from the spirit of the invention, the
full scope of which is delineated by the appended claims.
* * * * *