Pectin formulations, products and methods having delayed-action acidulants

Pectin containing gelled products are provided such that their gelling is delayed for an enhanced length of time, adequate to permit the deposition or filling of the formulation into molds or containers before gelling proceeds. The products and method by which they are prepared more efficiently use pectin in a delayed gelation process by allowing setting at the optimum gelling pH in order to prepare final products of a desired gel strength with minimal quantities of pectin. A delayed-action or time-release acidulant is used in the method and is incorporated into the formulations and products of this invention, such acidulants including anhydrides, esters, lactones, and combinations thereof.

BACKGROUND OF THE INVENTION 
The present invention generally relates to gelling formulations and their 
use in preparing gelled products. More particularly, this invention is 
directed to formulations including delayed-action acidulants that provide 
improved open time attributes to the formulation whereby the formulation 
can be deposited in a pre-gelled state and subsequently gelled within a 
selected mold or container in order to prepare gelled products in a manner 
more suitable for use within mechanized filling operations which can take 
advantage of a delay between the time that the pre-gelled formulation is 
prepared and the time that the formulation begins to gel to a significant 
degree. Formulations making use of such delayed-action acidulants are also 
capable of preparing final products having desired gel strengths with 
optimum usage of pectin. 
Within the pectin gel food industry, it is well known that pectin gel 
formulations should include a source of solids, typically sugars or the 
like, a gel forming agent, usually pectin, and agents for controlling the 
pH of the formulation, typically a food grade acid in combination with a 
buffering agent, all within a aqueous system, which often can be 
characterized as a syrup. It is generally understood that the sugar solids 
and the acid combine to modify the pectin such that the modified pectin 
causes the aqueous system to gel, it being generally accepted that sugar 
is involved in the gelling mechanism by hydrogen bonding with the pectin, 
that water which is the medium in which the other ingredients are 
dissolved or suspended is also involved in the gelling mechanism, and that 
the gelling mechanism is triggered by the pH of the formulation. 
There are general interrelationships among these ingredients in the 
formulations; for example, when a formulation includes a relatively high 
solids content, gel setting will occur with relatively less pectin or with 
relatively less acid, and formulations containing relatively high pectin 
levels will gel set when such formulations contain relatively low 
quantities of solids or acid. 
Materials known as pectins are methoxylated esters of polyglacturonic acid 
and are hydrophilic colloids that hydrate slowly, although they dissolve 
in aqueous systems when mixed. Pectins are generally classified according 
to the number of methoxyl groups sybstituted on the ester backbone, this 
classification often being referred to as the degree of methylation (DM). 
A degree of methylation less than about 50 DM is generally understood in 
the art to refer to a "low methoxyl" pectin having an average of fewer 
than about 7 methoxyl groups on the pectin ester molecule, while a pectin 
classified as being at or greater than about 50 DM is understood in the 
art as being a "high methoxyl" pectin having an average of 7 or more 
methoxyl groups per pectin ester molecule. The "high methoxyl" pectins are 
usually further classified as either "slow set" pectins having an average 
of about 7 to 10 methoxyl groups, and "rapid set" pectins having an 
average of more than about 10 methoxyl groups on each molecule of pectin. 
While the present invention has been found to be suitable for either high 
or low methoxyl pectins, stronger gels typically will be formed when the 
so-called high methoxyl pectins are used. Actually, low methoxyl pectins 
gel by a mechanism different from that of high methoxyl pectin 
formulations and require the presence of a divalent ion, as described in 
Ross U.S. Pat. No. 3,185,576. 
It is generally recognized that a slow set pectin formulation will have an 
optimum gelation pH of between about 2.8 and 3.2, while that for a rapid 
set formulation is between about 3.4 and 3.8, meaning that hydrogen ion 
concentration needed for effecting gel setting of a rapid set formulation 
is lower than that needed for a slow set formulation. When the solids 
content of a formulation is relatively high, such as when it is desired to 
substantially reduce or completely elminate a drying operation after the 
formulation has been deposited into a mold or filled into a container, the 
solids content must be approximately the same as that needed for the 
finished product. However, when these higher solids formulations are used, 
they tend to set prematurely to the extent that, for example, for a slow 
set formulation, the formulation will set at a pH as high as 3.6, meaning 
that the formulation will not achieve its optimum pH between about 2.9 and 
3.2, whereat maximum gel strength is typically attained. Substantially the 
same problem is observed with regard to rapid set formulations, except 
that the pH for premature setting is on the order of about 4.0. 
When the pectin food product is in the nature of a confection, the targeted 
final solids content is usually between about 80 and 85 weight percent, 
based upon the total aqueous system, being roughly equivalent to a 
moisture content of between about 15 and 20 weight percent. A pectin gel 
formulation that is in the nature of a table spread will have a lower 
solids content and a correspondingly higher moisture content inasmuch as 
it is necessary that such products be spreadable, a typical solids content 
for a finished product being in the 68 to 72 weight percent range, the 
moisture level accordingly being between about 28 and 32 weight percent of 
the total final formulation. 
Advantages can be gained for pectin gel food formulations when they are 
prepared to contain relatively low quantities of pectin, both from the 
point of view of economy and from the point of view of reducing potential 
syneresis problems which are aggravated by the presence of pectin, 
especially when dealing with the higher moisture content products such as 
table spreads. Also, relatively high levels of pectin will tend to bring 
about the problem of premature gel formation whereby a product will not 
achieve its optimum gel strength, which is particularly important for 
confection gel products. 
It is also generally advantageous to prepare formulations that exhibit 
"open time", which is understood to refer to the amount of time that 
elapses between completion of the formulation and when the phenomena of 
irreversible gel setting is observed. The need to obtain some degree of 
open time is particularly critical in the pectin confectionery jellie 
industry, in which formulation batches are prepared, and small quantities 
thereof are each deposited into starch or rubber molds, the open time 
permitting deposition of a pre-gelled formulation which gels within the 
molds. While table spreads are generally deposited into larger containers, 
it can often be desired to prepare formulations exhibiting an open time 
adequate to avoid pre-gelling within the container filling machinery 
whereby the setting will occur within the filled container only, which can 
bring with it the advantageous effect of achieving a relatively high gel 
strength with a relatively low amount of pectin to reduce syneresis 
tendencies. 
In the past, open times of limited duration have been achieved by one or 
more avenues, some of which are discussed in Gallager, L. C. "Pectin 
Confectionery Jellies", Sunkist Growers, Ontario, California. They 
includes maintaining the formulation at temperatures as elevated as 
possible which has some effect in prolonging open time, although not to an 
extent sufficient to prevent premature gelation in most cases. Another 
approach is to deposit the formulation at a solids content lower than that 
desired for the final product and thereafter dry the deposited product in 
order to raise the solids content and thus enhance gelation, although such 
a drying procedure is expensive and can damage the final product. Another 
avenue is to adjust the active acidity or hydrogen ion concentration of 
the batch with a combination of a food grade acid, such as citric acid or 
malic acid, and a buffer, such as sodium citrate or sodium acetate. 
Typically, only part of the food grade acid will be initially added to the 
batch, while the remainder thereof will be added to the batch just before 
transferring it to the depositor apparatus in order to drop the pH within 
the setting range. Even with this last approach, premature gelling will 
occur unless deposition takes place within just a few minutes. If gelation 
progresses to a significant extent within the depositor, a weakly gelled 
final product will be prepared, it will be difficult to obtain a uniform 
count within a commercial, mechanized operation, and the formed confection 
jellie pieces will tend to be mishapened. 
By the present invention, it has been discovered that the problem of 
providing adequate open time to substantially eliminate premature setting, 
the advantage of being able to utilize relatively low amounts of pectin, 
and the feature of being able to provide finished products having good gel 
strengths are all attained by replacing some or all of the food grade acid 
within pectin gelling formulations with a delayed-action or time-release 
acidulant having a hydrolysis rate such that the hydrogen ion 
concentration within the total system remains above that at which 
significant gelling will proceed, such hydrogen ion concentration 
increasing to gelation levels after a preselected open time has elapsed. 
Delayed-action acidulants can include anhydrides, esters, lactones, 
combinations thereof, and combinations thereof with rapidly hydrolyzing 
food grade acids, provided the overall formulation is an edible one. 
It is therefore a general object of the present invention to provide 
improved pectin gel formulations, methods, and products. 
Another object of this invention is an improved method for extending the 
open time of pectin gel formulations, and products produced thereby. 
Another object of this invention is to provide pectin gel formulations 
which efficiently use the particular pectin therin by permitting gelation 
to take place at a pH level that is optimum for bringing about gelation 
within the formulation. 
Another object of the present invention is an improved method and products 
produced thereby, wherein products of desired gel strengths are maintained 
with formulations having a relatively low level of pectin. 
Another object of this invention is an improved method of preparing pectin 
confectionery jellies while avoiding pre-gelling problems, and gelled 
products produced thereby. 
Another object of the present invention is to provide an improved method, 
formulation and product produced thereby for in-situ preparation of gelled 
products within molds or containers. 
Another object of this invention is an improved method and formulation 
utilizing relatively high solids levels in order to substantially lessen 
or eliminate the need to reduce the moisture content of, or dry, the 
formulation after deposition into a mold or a container. 
Another object of this invention is to provide an improved pectin gel 
product that resists syneresis, especially when stored in contact with a 
low moisture product such as peanut butter. 
These and other objects of this invention will be apparent from the 
following further detailed description thereof. 
Delayed-action or time-release formulations prepared according to this 
invention are aqueous, sugar-containing systems that include pectin and an 
acidulant that works with the sugar to cause the pectin to gel the 
formulation after a predetermined open time during which gelling does not 
take place. The acidulant has a relatively slow rate of hydrolysis such 
that, during the open time, the hydrogen ion concentration within the 
formulation will be kept below levels that initiate significant gelation. 
More particularly, sugar within the formulation can be provided by one or 
more of sucrose from cane or beet sugar, usually as a mixture with other 
poly-saccharide or mono-saccharide sweeteners such as corn syrup, 
sorbitol, xylitol, mannitol, or the like, from natural fruit pulps, 
extracts, or juices, all within an aqueous environment, which sugar 
sources provide a major portion of the solids content of the formulation 
adequate to prepare a final product have a desired moisture content. When 
a pectin confectionery jellie is being prepared, the typical final product 
solids content will be between about 76 and 85 weight percent, based upon 
the total weight of the product, although the solids content can vary 
according to the texture desired in the final product. A table spread 
would typically desirably have a lower solids content so that it remains 
spreadable after it is gelled, typical solids content being between about 
65 and 72 weight percent, based upon the total weight of the table spread. 
In all cases, the solids content can vary somewhat depending upon the 
mouth feel, spreadability, and physical appearance desired. Generally 
speaking, formulations according to this invention should have a moisture 
level or solids content such that the solids content of the finally 
prepared gelled product is at or above 60 weight percent and below about 
90 weight percent, based upon the total weight of the finally prepared 
product. 
Usually, commercially prepared gel formulations contain fruit sources that 
are not adequate to provide pectin at levels high enough to promote 
adequate gelling. Accordingly, most formulations will have a supply of 
pectin added thereto. Most formulations would add a pectin of the high 
methoxy type, having a degree of methylation equal to or greater than 
about 45 DM, meaning that an average of about 7 or more of the 14 
available acid groups thereof are methoxylated. While low methoxyl pectins 
can be included in the present formulations, the high methoxyl pectins are 
preferred. Of the high methoxyl pectins, it is further preferred to 
utilize "slow set" pectins having an average of about 7 to 10 methoxyl 
groups per pectin molecule, primarily because high methoxyl pectins of the 
"slow set" variety are more economical than those of the "rapid set" type 
having an average of more than about 10 methoxyl groups per pectin 
molecule. 
Total pectin levels within the formulation, whether provided as a separate 
additive or whether provided from fruit sources within the formulation, 
need not be as high as those of commercial formulations not in accordance 
with this invention. Pectin levels in confectionery jellie formulations 
can be as low as about one weight percent, based upon the weight of the 
sugar formulation, which is usually roughly also about one weight percent 
of the total solids within the formulation and within the final product. 
In standard formulations, the amount of pectin can be as high as three 
weight percent, which is also a practical, economical upper limit for 
formulations according to this invention. When preparing formulations for 
table spreads, the amount of pectin desired will usually be lower than 
these pectin confectionery jellie formulation levels, typically between 
about 0.5 and about 1.5 weight percent, although these percentages can 
vary depending upon the formulation requirements. 
The delayed-action or time-release acidulant is one exhibiting a hydrolysis 
rate such that the total formulation will be provided with hydrogen ions 
sufficient to initiate gelling after the desired open time has passed. 
Inasmuch as they are incorporated within food formulations they should, of 
course, also be edible in the levels at which they are used. Certain 
delayed-action acidulants, although when they are used alone might not 
provide the desired hydrolysis rate, can be combined with other, faster 
hydrolyzing acidulants in order to achieve the desired open time for the 
total formulation. By the same token, certain delayed-action acidulants 
according to the invention can exhibit hydrolysis rates that are too fast 
for achieving a desired open time, and these can be combined with 
slower-hydrolyzing acidulants as desired. 
Delayed-action acidulants include anhydrides and esters, including internal 
esters such as lactones. The acidulant will be released to its acid form 
upon hydrolysis of an anhydride or an ester linkage when exposed to water. 
Examples are the anhydride of any edible acid, such as acetic anhydride, 
heptanoic anhydride, succinic anhydride, and glutaric anhydride; esters 
which are combinations of any edible acid and any edible alcohol, for 
example ethyl acetate, triacetin (glycerol triacetate), and other esters 
of glycerin, sugars, sorbitol, mannitol, or any of the other edible 
polyhydroxyl compounds; and lactones such as gluconodelta-lactone, 
glucuronolactone, propiolactone, butyrolactone, and isovalerolactone. 
Preferred for use as the delayed-action acidulant is glucono-delta-lactone. 
A discussion of the properties of this lactone can be found in "Food 
Acidulants", Chemicals Division of Pfizer, Inc., Technical Information 
Bulletin, 1977. 
The quantity of delayed-action acidulant to be used in formulations 
according to this invention will vary widely depending upon the particular 
acidulent used, the most important variable in this regard being the 
strength of the acid formed when the acidulant is hydrolyzed. For example, 
for the preferred delayed-action acidulant, the amount thereof can 
generally be said to range between about one and about five weight 
percent, based upon the weight of the sugar solution, which is roughly the 
same percentage based upon the weight of the solids within the formulation 
or the final product. Delayed-action acidulants which are stronger acids 
will have correspondingly lower weight percent ranges, while those that 
hydrolyze into weaker acids will be incorporated into formulations 
according to this invention at correspondingly higher weight percent 
ranges. 
Other ingredients can be incorporated into formulations according to this 
invention, particularly those ingredients that are incorporated in 
standard gel formulations. Included are food grade acids to bring about an 
initial lowering of the pH to one that is particularly desirable for the 
formulation prior to addition of the delayed-action acidulant. Typical of 
such initial pH values are between about 3.9 and 5.5, depending upon the 
optimum gelling pH of the pectin within the formulation. Suitable food 
grade acids include malic acid and citric acid. Usually such food grade 
acids will be used in combination with a buffer in order to closely 
control the pH and, when desired, permit enhanced tartness of the 
formulation by allowing the incorporation of additional food grade acid 
without significantly further lowering the pH to undesired intial, 
pre-gelation levels. For example, up to about one weight percent of a 
buffer such as sodium citrate could be added, as could about one weight 
percent of a food-grade acid such as malic adid. Quantities of other 
ingredients will typically be relatively minor and will be generally on 
the order of the amounts that they are used in traditional formulations. 
Miscellaneous other typical ingredients include flavoring compounds, 
coloring agents, and the like. 
When proceeding with the method according to this invention, an important 
aspect thereof is the incorporation of a delayed-action or time-release 
acidulant within a pectin gel formulation having an initial pH 
significantly higher than that of the optimum gelation pH of the pectin 
contained within the formulation. By this method, it is possible to 
achieve a significant open time to permit deposition into molds or 
containers and thereafter have the hydrogen ion concentration within the 
deposited formulation increase to achieve such optimum pH level of the 
pectin, with the result that relatively less pectin is needed in order to 
achieve a desired high gel strength. 
More particularly, the method includes preparing a pectin aqueous 
formulation including a sugar-containing syrup and a pectin. Depending 
upon the particular formulation, it is then typically necessary to lower 
the pH of the formulation in order to provide it with an initial pH that 
is significantly higher than the optimum gelling pH for the particular 
pectin incorporated into the formulation. Generally, these various 
ingredients are simply blended together, cold tap water or the like being 
added as necessary, accompanied by agitation in order to provide a 
relatively homogeneous blend for the purpose of preparing a generally 
consistent final product. The blend is then boiled or cooked at a 
temperature in excess of 100.degree. C. (212.degree. F.), usually between 
about 222.degree. and 235.degree. F., the temperature at ambient pressure 
being controlled as desired in order to achieve a formulation have a 
pre-selected solids or moisture content, the cooking generally preparing a 
colloidal solution of pectin. 
After cooking has been completed, the delayed-action acidulant is added and 
blended into the cooked formulation or colloidal solution formulation, 
which results in the step of providing a predetermined open time during 
which hydrolysis of the delayed-action acidulant within the formulation 
will proceed slowly enough in order to delay gelling or setting of the 
formulation until after the preselected open time has elapsed. 
The length of the open time is almost exclusively a matter of choice. 
Usually, in order to facilitate deposition within commercial filling or 
depositing machinery, an open time in excess of five minutes, usually ten 
minutes or longer, such as thirty to sixty minutes, will be desired. Open 
times of in excess of hundreds of hours can be provided, should this be 
desired, although in most commercial operations, this would add a 
processing time feature that would be economically undesirable. Sometimes, 
an especially long open time can be advantageous when it is desired to 
continue to develop the set or the tartness of a product while in storage. 
Typical desired open times will be between 6 and 20 minutes. 
Next, the formulation to which the delayed-action acidulant had been added 
will be filled into an appropriate container, such as a starch mold, a 
rubber mold, a glass jar, a sealable can, or a pouch. While therewithin, 
an in-situ gelling or setting step will take place in order to provide a 
final product having a predetermined gel strength. After the jellies are 
removed from their molds, they typically are "sanded" with granular sugar 
to provide a non-sticky product. 
When coloring ingredients or flavoring agents are to be incorporated into 
the formulation, it is generally preferred that they be added after the 
cooking step so as to minimize flash off of flavor essences and 
deterioration of colors. 
The initial pH of the formulation will be between about 4 and about 5.5. 
After in-situ hydrolysis and acidulation, the pH will be lowered to the 
optimum gelation pH for the particular pectin used. For example, a typical 
optimum gelation pH for a slow set, high methoxyl pectin will be between 
about 2.9 and about 3.2 or 3.3, while that for a rapid set, high methoxyl 
pectin will be between about 3.2 or 3.3 and about 3.6 or 3.7. Optimum 
gelation pH levels will also vary with the "grade" of the pectin, the 
values given herein generally being applicable for a 150 grade pectin. 
Usually during such hydrolysis, a relatively low quantity of water within 
the formulation will be used up, which is of assistance in reducing the 
amount of water that is found in the final product or that has to be dried 
out of the deposited or filled product. For example, the amount of water 
used by 2.5 weight percent of glucono-delta-lactone in an 82 weight 
percent solids batch will increase the solids content thereof between 
about 0.05 and 0.1 weight percent. This is another aspect of the invention 
which can be useful in preparing formulations of predetermined solids 
content while reducing the amount of drying needed to form a final product 
having such solids level. 
Products according to this invention are products that have been set from 
pectin gel formulations. The products include a gel network or matrix of 
sugar-type solids, the gel including pectin, acidulants, and other 
conventional ingredients such as flavorings, colorings, tartness 
enhancers, buffers, and the like. The gel will have a moisture level 
between about 28 and 35 weight percent, based upon the total weight of the 
formulation, when the product is of the table spread type, such as a jam, 
a jelly, a conserve, or a marmalade. When the products are pectin 
confectionery jellies, the moisture content will be somewhat lower, 
usually between about 15 and 24 weight percent, based upon the total 
weight of the product. 
Table spread products prepared according to this invention are 
characterized by particularly effective utilization of pectin within the 
formulation. Poor pectin utilization can result in a soft, runny gel, or 
syneresis may be evident by the presence of fluid apart from the gel 
structure, which is most noticeable when the product has been disturbed, 
such as when it is spooned or spread on bread. These types of problems are 
particularly evident in products not according to this invention in which 
premature gelling has begun before the product is filled into its 
container, resulting in a disturbance of the gel structure. Syneresis of 
table spread formulations tends to become an increasing problem for the 
portions of formulation batches that are filled from the "bottom" of the 
batch, while those filled from a freshly prepared batch tend to exhibit 
fewer syneresis problems. 
Products according to this invention, since they have been substantially 
completely gelled only in-situ, the gel structure, once formed, is not 
subsequently disturbed until it is consumed. In formulations not according 
to this invention, extra pectin is typically included within such products 
in order to increase gelling within the container so as to mask gel 
disturbance and attempt to reduce syneresis. Such additional pectin is not 
needed for formulations according to this invention. 
Table spread products according to this invention can be prepared such that 
they are filled into containers with the product moisture level being 
relatively low while avoiding premature gelling prior to filling. Such 
relatively low moisture levels are particularly suitable for products that 
are prepackaged layers of the low moisture table spread with another 
spread of traditionally very low moisture content, such as peanut butter, 
with the result that the gelled table spread moisture level is much 
closer, or equal to, the moisture level of the other spread to thereby 
retard undesirable moisture transfer between the layers of the different 
spreads. 
Pectin confectionery gel products according to this invention can be in 
either cast or slab form. The amount of solids in cast jellie products is 
usually between about 72 and 78 weight percent, although a higher solids 
content can be desirable to reduce or eliminate drying, and in a preferred 
embodiment of this invention, the formed and cast jellie product will have 
the solids content of a particularly desirable finished product, typically 
between about 80 and 85 weight percent. Although such higher solids 
content cast jellies require more fluidity to conform to the shape of the 
mold and prevent stringing, and require greater open time because of 
slower depositing times, these problems are generally substantially 
eliminated by products in accordance with this invention. Slab jellies of 
conventional formulations may show some gelation before the batch is 
leveled off, and this problem of lost gelling power is traditionally 
compensated for by adding pectin at levels higher than otherwise 
necessary, which compensation adjustment is not necessary in products of 
this invention. 
When the product prepared according to this invention is to have a high 
tartness level, such as that characteristic of a citric acid fruit, the 
product can include additional amounts of food grade acids. The amount of 
tartness achieved is a function of the equivalent weight and the amount of 
the acid used, such acids being weak organic acids, for example citric 
acid, malic acid, tartaric acid, fumaric acid, acidic acid, succinic acid, 
lactic acid, and adipic acid. When a particularly high tartness level is 
needed which would lower the pH to below the desired initial pH level, the 
pH of the total formulation can be maintained by a suitable buffer, such 
as an alkali metal salt of any of the just-listed organic acids. Also, 
sugars within the system can impart a slight degree of buffering activity 
to the formulation. 
Fruit gel products should have a relatively high titratable acidity, 
usually between about 8 to 15 meq/100 g, while products having spice or 
mint flavors or the like would typically have no organic acid added 
thereto. Within limits of food grade use, small quantities of mineral 
acids can be used to lower pH without achieving any significant titratable 
acidity. Titratable acidity can be arrived at by dissolving a sample of 
about 10 grams in warm water with agitation, after which it is then 
titrated to a phenothaelin endpoint with 0.1 N sodium hydroxide. The 
titratable acidity is expressed in meq/100 g of sample, which is 
equivalent to ten times the volume of sodium hydroxide titrated (ml) 
divided by the weight of the sample (grams). 
Confectionery jellie products prepared according to this invention make use 
of the basic requirement that the hydrolysis of the delayed-action 
acidulant proceed slow enough to allow enough open time to fill 
receptacles, molds, or slabs, but fast enough to lower the pH to a 
suitable place to get a firm enough piece for handling in the desired 
time. This can be referred to as the handling pH, which does not have to 
be as low as the optimum gelation pH for the particular pectin used, which 
optimum pH can be reached at a later time during the process or while the 
final product is in its container. The hydrolysis should be such that the 
half life of the reaction is 2 minutes to 2 hours under the conditions of 
preparation, a preferable half life range being on the order of between 3 
to 15 minutes. 
The smaller the batch of a formulation and the faster the rate of fill, the 
less open time will be required. For instance, a typical table spread 
batch will be more advantageously prepared with a longer open time than 
that for a pectin confectionery jellie formulation being deposited into 
small starch or rubber molds. 
Open time can conveniently be measured by means of a GT-4 gelation timer 
(Techne Corporation) which instrument has a plunger or disc that 
oscillates up and down at ten strokes per minute and is recorded on a 
digital readout counter, the machine generally being insensitive to 
viscosity changes. When this plunger is submerged in a sample of a 
just-prepared formulation, it will continue to oscillate until 
cross-linkage or gelation occurs, at which point it shuts off and thereby 
records the time to gelation. "Open times" provided herein were measured 
by such an instrument. 
It is possible to determine gel strengths for table spread products by the 
IFT "Sag" method ("Pectin Standardization", Food Technology, Vol. XIII, 
No. 9, pages 496-500, 1959). The gel strength is expressed in pounds of 
sugar gelled by one pound of pectin in order to give a gelled product 
"sag" of 23.5 percent under the standard conditions of the IFT test. 
In measuring the gel strength of pectin confectionery jellie products, the 
following procedure can be used, and was the one used in arriving at the 
gel strength values reported herein. Muffin cups, 11/8 inch deep and 
having a rim diameter of 23/4 inches were filled to the top with the 
particular sample, after which they were sealed with aluminum foil to 
prevent water evaporation and skin development. They were then allowed to 
set over night to develop a full gel strength, after which the samples 
were placed on a top loading balance and tared to zero. A 5/16 inch 
diameter rod was suspended in a guide tube vertically over the sample, the 
rod fitting loosely in the tube to allow free fall. The rod was rapidly 
depressed at an even rate until the gel was ruptured, and a reading in 
grams on the scale was recorded. Ten readings were taken on each sample 
and averaged. It was determined that, with such a test, a difference in 
the averaged readings of about 50 grams would be a significant difference 
at a 95% confidence level. A value of about 400 grams was determined to be 
a good average gel strength for a pectin confectionery jellie, with about 
250 to 300 grams being a minimum acceptable value.

The following specific examples will more precisely illustrate the 
invention and the scope thereof and teach the procedures presently 
preferred for practicing the same, as well as illustrate improvements and 
advantages thereof. 
EXAMPLE 1 
This example illustrates the preparation of pectin confectionery jellies 
and some of the physical properties of such gelled products. 
A pectin dry blend was prepared by mixing 30 grams of sucrose with between 
2 and 6 grams of "slow set" high methoxyl pectin (62 to 65 DM), between 0 
and 1.0 grams of sodium citrate, and between 0 and 0.75 grams of malic 
acid after which each prepared sample of pectin dry blend was wetted with 
from 25 to 50 cc of cold tap water, the larger volumes of water being 
needed for the larger amounts of pectin in the blend. Each solution thus 
prepared was allowed to stand for at least 30 minutes. A sugar solution 
was made by blending 120 grams of sucrose and 100 grams of regular 
conversion corn syrup (80 weight percent solids) with about 50 cc of water 
to wet out the sucrose. This was heated to 180.degree. F. to dissolve the 
sucrose at which point the wetted pectin solution was added. This 
buffered, pectin sugar solution was boiled to a temperature between 
220.degree. and 232.degree. F. depending on the solids desired. Then it 
was cooled to between about 200.degree. and 210.degree. F. at which point 
a second quantity of acidulant was added. Malic acid was used in some of 
the samples while glucono-delta-lactone (GDL) was added to others. As soon 
as the chosen acidulant was well blended in with vigorous agitation, a 
portion of each sample was transferred to a muffin tin for gel strength 
determination. The rest of each sample was placed under the plunger of a 
GT-4 Techne gel timer for a mechanical reading of the open time, and the 
pH was read after the tests had been completed. The data are set out in 
Table I. 
TABLE I 
__________________________________________________________________________ 
Sample A B C D E F G H I J 
__________________________________________________________________________ 
Pectin: 
(grams) 2.0 3.0 3.0 4.0 5.0 4.0 6.0 3.0 3.0 5.0 
(% of Sugars) 
.87 1.30 
1.30 
1.74 
2.17 
1.74 
2.61 
1.30 
1.30 
2.17 
Sodium Citrate 
(grams) 0.4 1.0 0.4 0.4 0.4 1.0 1.0 0 0 0.4 
Malic Acid 
(grams) 0.3 .75 0.3 0.3 0.3 .75 .75 0 0 0.3 
Boiling Point 
(.degree.F.) 
230 230 228 230 230 225 230 230 230 230 
Solids 
(wt. %) 82 81 82 83 81 76 77 82 83 82 
pH of Final 
syrup 3.3 3.3 3.1 3.3 3.1 3.4 2.9 3.3 3.0 3.1 
Second 
Acidulant 
Malic 
Malic 
Malic 
Malic 
Malic 
Malic 
Malic 
GDL GDL GDL 
(grams) 1.5 2.5 2.7 1.8 2.7 3.0 6.0 2.0 4.0 5.5 
Gel Strength 
(grams) 229 464 439 654 560 269 400 426 501 876 
Open Time 
(minutes) 
0.9 3.7 0 0.4 0 10.8 
0.2 12.2 
6.5 10.8 
__________________________________________________________________________ 
Samples F and G had a significantly lower solids than did the other 
samples. There is a noted reduction in the strength of the gel as can be 
seen by comparing these results with samples D and E. All of the samples 
show that an increased pectin content provided a stronger gel. The effect 
of these two variables on the gel strength is shown in FIG. 1. 
All of these samples, except perhaps Sample F, were in a pH range where the 
optimum gel strength for the pectin used is obtained. However, this pH is 
difficult if not impossible to use in the commercial production of such 
confections when accompanied by the very short open time of the malic acid 
runs at the optimum pH. There has to be sufficient open time to deposit 
the batch into molds or pour it on a slab. Times of 10 minutes or greater 
are preferred although an exceptionally well operated plant could operate 
with some success at times down to 2 to 3 minutes. Samples B and F are the 
only two samples prepared entirely with malic acid that had any 
significant open time. This is attributed to the fact that they were in 
the upper part of the acceptable pH range. Furthermore, sample F has lower 
solids which also delays the gel time. All the GDL samples had ample open 
time. 
EXAMPLE 2 
Illustrated in this example is an important relationship between pH and 
open time, the data of this example being plotted in FIG. 2. These data 
are grouped onto two curves, one of high solids formulations (about 82 
weight percent), and the other of medium to low solids formations (about 
75 weight percent), the curves indicating that in order to achieve a 
desired minimum open time of about ten minutes for these formulations, a 
pH not lower than about 3.4 should be sought for solids formulations of 
about 75 weight percent, while a pH not lower than about 3.65 should be 
the target for solids formulations of about 82 weight percent. When a high 
solids sample was formulated to have a pH below about 3.5, gelling was 
generally observed before stirring could be completed, indicating that 
substantially no open time was provided. 
These data show that, for example, if it is desired to substantially 
eliminate drying of a confectionery pectin jellie by formulating the 
batches to be deposited so they have the solids content of a finished 
confectionery piece, between about 80 and 85 weight percent, it is 
necessary to maintain the pH of the batch formulation at or above 3.6 in 
order to provide adequate open time for commercial depositing. Because of 
variations in the formula of each sample, including the type of pectin, 
the amount of pectin, and differences in the preparation procedures and 
techniques of properties measurement, the data shown in FIG. 2 are 
somewhat varied. 
EXAMPLE 3 
Additional tests were run to compare the open time and the gel strength 
obtained when using delayed-action or time-release acidulant in accordance 
with this invention when compared with that obtained with a traditional 
procedure. A typical procedure is to boil the batch to a lower temperature 
resulting in a lower solids level. Furthermore, the recommended pH after 
the addition of the second acidulant is 3.5.+-.0.1. Four samples were 
prepared according to the procedure in Example 1. Slow set pectin was used 
in all these samples. The sample parameters and results are given in Table 
II. 
TABLE II 
______________________________________ 
Sample L M N O 
______________________________________ 
Pectin: 
(grams) 4.0 4.0 3.0 3.0 
(% of sugars) 
1.74 1.74 1.30 1.30 
Sodium Citrate 
(grams) 1.0 1.0 1.0 0 
Malic Acid 
(grams) .75 .75 .75 0 
Boiling Point 
(.degree.F.) 
225 225 230 230 
Solids 
(wt. %) 76 76 82 83 
Post Boiling 
Acidulant Malic Malic GDL GDL 
(grams) 3.0 3.0 5.0 4.0 
pH of Final 
syrup 3.6 3.4 3.2 3.0 
Open Time 
(minutes) 44.5 10.8 35.5 6.5 
Gel Strength 
(grams) 237 269 -- 501 
______________________________________ 
Samples L and M were prepared according to traditional procedures by 
keeping the solids low and the pH high, the target pH value being 3.5, to 
achieve an acceptable open time, the pH being greater than the optimum pH 
for gel strength by this pectin, which is reflected in the very low gel 
strength values. Such formulas could be spread on a slab, allowed to set, 
cut and sanded with sugar in which case the final solids would be close to 
that of the syrup. However, such products are prone to sweating. Another 
method would be to cast such confections into starch molds and dry at 
140.degree. to 160.degree. F. for 8 to 24 hours to bring the solids up to 
82 to 85%. 
Samples N and O were prepared according to the invention. The open time was 
comparable to the traditional methods even though the pH values were 
significantly lower and near the optimum gelation pH for the pectin used 
in the formulation. The lower pH allowed better utilization of the pectin 
so that 25% less could be used. Still, the gel strength of the finished 
product was well in excess of the traditional procedure. Further, this 
method eliminated the need for drying and the product could be sanded 
immediately after it had set. 
EXAMPLE 4 
Five batches of sugar syrup were prepared with levels of sodium citrate, 
malic acid, and GDL to illustrate the relationship between the buffer and 
acids to the tartness levels, finished pH and time release. A 73% sugar 
solution the solids of which consisted of 40% regular corn syrup and 60% 
sucrose, was prepared to which various levels of sodium citrate and malic 
acid were added to give initial pHs of 4.0 and 4.5. Then enough GDL was 
added to give a final pH of 3.3 after hydrolysis. The variables and 
results are shown in Table III. 
TABLE III 
______________________________________ 
Sample Q R S T U 
______________________________________ 
Sodium Citrate 
(wt. %) .077 .163 .227 .242 .593 
Malic Acid 
(wt. %) .135 .133 .398 .264 .648 
GDL (wt. %) 1.43 2.13 2.12 2.80 3.44 
Initial pH 4.0 4.5 3.8 4.1 4.0 
pH at equilibrium 
3.2 3.4 3.3 3.3 3.3 
Titratable Acidity 
(meg/100g) 
(calculated) 
8.0 10.9 14.9 15.7 24.2 
Titratable Acidity 
(meg/1-0g) 
(measured) 5.8 12.5 15.3 15.5 22.5 
Tartness Score 
1.3 1.8 3.5 4.3 4.3 
______________________________________ 
The titratable acidity was measured by titration. Since only 75% of the GDL 
is hydrolyzed at equilibrium, the phenothaelin end point fades as more of 
the lactone hydrolyzed. Therefore, the end point was taken as the value 
when the color persisted for 15 seconds. Only 75% of the amount of the GDL 
was used in the calculation of the titratable acidity for this same 
reason, and the values agree fairly well. These samples were ranked in 
order of tartness by experienced panel with the smallest numerical value 
representing the least tart. Samples Q and R were significantly less tart 
than the other three at a 95% confidence level. On the whole, the ranking 
does indicate that the titratable acidity is a good measure of tartness. 
The hydrolysis rates of these samples was followed by observing the pH. The 
values are shown in FIG. 3, its curves demonstrating that pH lowering to 
below about 3.4 to 3.6 takes longer for the formulation having an initial 
pH of 4.5 than for those formulations having a lower initial pH, and the 
plots of the curves indicate that the overall hydrolysis rates for these 
samples are generally the same. 
EXAMPLE 5 
The amounts of sodium citrate and malic acid to obtain a given initial pH 
in a buffered pectin sugar solution and the amount of GDL to add to obtain 
a final pH of 3.0 can be calculated using the mass action equilibrium 
relationships. Several such calculations can be made and plotted to show 
the relationship of acid and buffer to the titratable acidity. This is 
shown in FIGS. 4 and 5 for two initial pH values, namely 4.5 and 5.5. The 
ratio of sodium citrate to malic acid for the higher pH is greater than 
for the lower pH, thus, more GDL has to be used to reduce the pH to 3.0 in 
order to obtain the same titratable acidity in the former case. The levels 
of buffer and acids from sample R in Example 4 demonstrates the 
application of FIG. 5. 
In further illustration, differing titrable acidities of jelly formulations 
in accordance with this invention can be prepared by varying the amounts 
of sodium citrate, citric acid, and GDL used. A formulation having a 0.1 M 
solution of sodium citrate (0.46 weight percent), 0.058 weight percent 
citric acid, and 5.3 weight percent GDL has a calculated total titratable 
acidity of 23.4 meq/100 g, a relatively high acidity value. A relatively 
low acidity value of 10.9 meq/100 g is calculated from a system having 
0.05 M (0.23 weight percent) sodium citrate, 0.029 weight percent citric 
acid, and 2.49 weight percent GDL. A moderate and generally more desirable 
calculated titratable acidity value of 16.4 meq/100 g is arrived at using 
0.33 weight percent sodium citrate, 0.04 weight percent citric acid, and 
3.74 weight percent GDL. Any one of these formulations would be expected 
to achieve a pH of about 3.0 after deposition, using a "slow set" high 
methoxy pectin. 
EXAMPLE 6 
When it is desired to prepare formulations for non-acidic flavors, the 
titratable acidity should be as low as possible, and this can be 
accomplished by omitting the acid and the buffer. A formulation of this 
type, having properties similar to those of Example 5, has a calculated 
titratable acidity of 0.09 meq/100 g with a total GDL content of 0.02 
weight percent. Actually slightly more GDL is needed since when the 
formulation has sugars that have a buffering capacity, that needs to be 
adjusted for by the acidulant. This buffering capacity is insignificant 
when a buffer such as sodium citrate is present at a level at or above 
0.03 M. 
EXAMPLE 7 
In this Example, a formulation similar to those in Examples 5 and 6, can be 
prepared by using a combination of GDL and of triacetin (glycerol 
triacetate) as the delayed-action acidulant. A titratable acidity of about 
18 meq/100 g is arrived at on the basis of 0.18 weight percent sodium 
citrate, 0.02 weight percent citric acid, 2.00 weight percent GDL, and 
0.50 weight percent triacetin, the formulation having an initial pH of 
5.5, and a finished product pH of 3.0, the pH dropping to about 3.1 within 
30 to 60 minutes, and then to about 3.0 after three or four days, the 
tartness level increasing during that time period until the slowly 
hydrolyzing triacetin is fully hydrolyzed. 
EXAMPLE 8 
A variety of formulations were prepared, and the open time and gel strength 
developed for each sample was measured, the data being reported in Table 
IV, all percentages being weight percent based on the sugar solution. 
In each case, the post-boiling acidulant was added after the sugar solution 
had been boiled and allowed to cool to below the boiling point. All 
samples were prepared using slow set pectin level. For samples W, W', X 
and X', the amount of pectin was cut to about 60% of the level used in 
most commercial pectin gel formulations, which lower amount was found to 
effect both the gel strength and the rate of set. Open time achieved using 
GDL was greater than that when using malic acid while maintaining the same 
pH, the same pectin levels, and substantially the same solids percentages, 
and the gel strength of the GDL formulations was substantially equal to or 
better than that using malic acid. It will also be noted that Sample Y', 
having the customary amount of pectin in the formulation, achieved a very 
high gel strength. 
TABLE IV 
______________________________________ 
Sample W W' X X' Y Y' 
______________________________________ 
Pectin 
(grams) 3 3 3 3 5 5 
(% of Sugars) 
1.30 1.30 1.30 1.30 2.17 2.17 
Sodium 
Citrate 
(grams) 1.0 1.0 0 0 .4 .4 
Malic Acid 
(grams) .75 .75 0 0 .3 .3 
Solids (wt.%) 
81 82 84 83 81 82 
Post-boiling 
Acidulant 
Malic GDL Malic GDL Malic GDL 
(grams) 2.5 5.0 1.0 2.0 2.7 5.5 
pH 3.2 3.2 3.3 3.3 3.1 3.1 
Open Time 
(minutes) 
3.7 35.5 1.7 12.2 0 10.8 
Gel Strength 
(grams) 464 -- 433 426 560 876 
______________________________________ 
EXAMPLE 9 
Delayed-action or timed-release acidulants according to this invention 
which are lactones similar to GDL (hydrolysis rate of 2.3.times.10.sup.-5 
/second) include beta-propriolactone (5.6.times.10.sup.-5 /second), and 
beta-butyro-lactone (1.4.times.10.sup.-5 /second) either of these two 
being similar to GDL in delayed-action acidulation. Another lactone, 
beta-isovalerolactone has a hydrolysis rate of 1.35.times.10.sup.-3 
/second, which is somewhat faster than the GDL rate. 
These hydrolysis rates are in water, and generally indicate expected 
variation of pH over time when added to water. A hydrolysis rate for a 
delayed-action acidulant within the types of sugar solutions utilized 
according to this invention is similar to the hydrolysis rate for that 
acidulant in water. Data in this regard are provided in FIG. 6. Curve AA 
is that of a one weight percent solution of GDL in water (Food Acidulants 
Technical Information, Pfizer, 1977), and curve BB is that of a 5 weight 
percent GDL solution in water (ibid), while curve CC, which approaches 
curve BB, is that of a sugar solution that had been prepared to have a 
solids content of about 60% sucrose and 40% regular conversion corn syrup, 
the sugar solution having been boiled to 230.degree. F. to provide a 
solids content of 82 weight percent, after which it cooled to about 
200.degree. F., 4 grams of GDL were added for each 100 grams of water 
(0.225 M), and while the temperature was maintained between 170 and 
200.degree. F., pH measurements were taken periodically for 80 minutes, 
the generated data being shown on curve CC. 
EXAMPLE 10 
Hydrolysis rates for delayed-action or timed-release acidulants having 
properties illustrating their usefulness either alone or with other 
acidulants are depicted by plots of pH drop over time, shown in FIG. 7. 
Curve FF plots pH vs. time for glucurono-lactone, the pH reaching 3.28 
after 1,145 minutes, indicating a very slow hydrolysis rate and a 
suitability for use in combination with quickly hydrolyzing acidulants in 
order to provide a delayed-action acidulant having a desirable open time. 
Curve GG is for triacetin within an unbuffered sugar solution; its 
hydrolysis rate was found to be slow, eventually reaching a pH of 2.80 
after 7080 minutes, indicating usefulness in combination with quickly 
hydrolyzing acidulants. Triacetin is especially suitable for use in sugar 
solutions since it is a liquid; it is a good carrier for powdered 
acidulants; it is useful as an agglomerating agent for powdered materials, 
particularly those that have a tendency to lump, to facilitate wetting out 
the dry acidulants as they are added to the sugar syrup; and it has a 
tendency to defoam the syrup. 
The timed pH drop for heptanoic anhydride is plotted on curve II, showing a 
rather favorable rate. This material exhibits defoaming properties, but it 
suffers from the disadvantage of not being particularly suitable for use 
in foods. Curves HH, JJ, and KK plot the pH drop rates for acetic 
anhydride, succinic anhydride, and citraconic anhydride. The acetic 
anhydride and succinic anhydride were tested in buffered sugar solutions 
starting at a pH of 5.3, while the citraconic anhydride was tested in 
water. Each of these three compounds has a tendency to hydrolyze rapidly, 
acetic anhydride and citraconic anhydride being generally too fast to be 
used alone as a delayed-action acidulant in accordance with this 
invention, but being useful in combination with a slowly hydrolyzing 
acidulant. Succinic anhydride, while also having a hydrolysis rate 
generally too fast for use alone as a delayed-action acidulant, its rate 
is somewhat slower, making it particularly suitable for achieving a 
desirable rate by blending with and using in combination with one or more 
of the slower acidulants. For example, having a half life of about 2 
minutes, it can be suspended in triacetin, having a half life of about 
3,600 minutes in accessible suspension ratios to prepare a formulation 
having an overall half life of about 10 minutes, half life being the time 
at which the pH is half way between the pH prior to addition and the pH of 
the product after sufficient time to reach hydrolysis equilibrium has been 
reached. 
EXAMPLE 11 
This example deals with the use of succinic anhydride as a delayed-action 
acidulant according to this invention. The data plotted in FIG. 8 were 
generated in the manner of the data illustrated in FIGS. 4 and 5. FIG. 8 
provides the relative quantities of succinic anhydride needed to prepare a 
product having a desired titratable acidity and tartness, the amounts of 
each of the anhydride, the buffer, and the acid being generally less than 
that needed when GDL is used as the delayed action acidulant, which is 
generally a reflection of the stronger acidic property of succinic acid 
compared to gluconic acid. 
EXAMPLE 12 
This example illustrates the use of the present invention in pectin table 
spreads normally known as preserves which include jams, jellies, 
conserves, marmalade, and the like. The gel structure of a spread is much 
softer than a confection, thus, less pectin is required. Another 
distinguishing feature is that it must contain fruit juice or fruit pulp 
to meet the regulatory agency standard of identity, which permits low 
solids so that typical preserves are in the 68 to 72% solids range. At 
this solids level, the gel formation is slow, and most preserves do not 
need the gel delay feature of this invention. However, there are special 
cases where a preserve of higher solids level is required. One situation 
where a delayed set would be helpful is in preparing jams using rapid set 
pectin. The higher viscosity of the rapid set pectin prevents fruit from 
floating. If the batch is to be filled over a length of time, gelation may 
start before it is all filled. 
Another application is the preparation of preserves to be used with peanut 
butter is copackaged products to reduce moisture migration from the higher 
moisture content table spread into the peanut butter. The best way of 
accomplishing this is by reducing the water in the preserve, which can be 
facilitated by using a delayed-action acidulant in the lower moisture 
formulation. The following formula is illustrative of a procedure which 
will produce such a preserve. 
Blend together: 
Grape puree concentrate (about 60% solids): 820 g 
Invert syrup or high fructose corn syrup (76%): 1315 g 
Pectin (slow set, 150 grade): 10 g 
Boil to 232.degree. F. to reach a solids of 83 to 85% based on the weight 
of the total formulation. 
While pumping the batch to the filling machine, GDL is metered in at the 
rate of 6 g/1000 g of preserve. The GDL must be kept dry so the metering 
must be done with a solids feeder or with a vibra screw at an open place 
or surge tank in the line. After this addition, the preserve is swirled in 
a fluid condition with the peanut butter while being filled into the 
receptical. The set will take place in the jar producing a clear preserve 
of desireable texture. 
EXAMPLE 13 
Rapid set pectins are traditionally not recommended for uses in pectin gel 
products discussed herein since their gels form too rapidly to give 
sufficient open time to process the batch. These gels also form at a 
higher pH than those of slow set pectins. These problems can be 
circumvented according to the present invention, as is illustrated by this 
example. Two samples were prepared with rapid set high methoxyl pectin (69 
to 73 DM) according to the procedure given in Example 1. The parameters of 
the samples and the results are given in Table V. 
TABLE V 
______________________________________ 
Sample Z Z' 
______________________________________ 
Pectin: (grams) 4.0 3.0 
(% of Sugar) 1.74 1.30 
Sodium Citrate (grams) 
.4 0 
Malic Acid (grams) 
.3 0 
Post-Boiling Acidulant 
Malic GDL 
(grams) 1.5 4.5 
pH 3.3 3.1 
Solids (wt. %) 83 84 
Open Time (Minutes) 
0 20.9 
Gel Strength 429 419 
______________________________________ 
These data indicate that the slow acid release method provides ample open 
time for processing. It also shows that the gel strengths are equivalent 
even though the slow release procedure had 25% less pectin than the 
traditional method. 
Another formulation according to this invention using "rapid set" high 
methoxyl pectin can be prepared from a buffered pectin sugar solution 
having an initial pH of 5.5, 0.89 weight percent (0.19 M) sodium citrate, 
and 0.15 weight percent (0.44 M) citric acid. To this can be added 2.97 
weight percent (0.94 M) GDL to achieve a final pH of 3.6, a calculated 
titratable acidity of 15 meq/100 g, and a finished moisture content of 
about 18 weight percent. It is noted that the amount of GDL used under 
these conditions is 20% less than found to be necessary for achieving a 
similar titratable acidity with the "slow set" formulations shown in 
Example 5. This example illustrates that it is possible to use a "rapid 
set" high methoxyl pectin in a pectin gel confectionary product, when one 
proceeds according to this invention, which avoids premature gelation due 
to the relatively high pH setting values of between about 3.0 and 3.8 
exhibited by the "rapid set" pectins. 
The preceding examples are offered to illustrate the present invention; 
these examples are not intended to limit the general scope of this 
invention in strict accordance therewith, but the invention is to be 
construed and limited only by the scope of the appended claims, including 
equivalents of the literal wording thereof.