Report of a research project funded by the National Honey Board and conducted
at the University of Wisconsin, Madison. Principal Investigator: Dr. R. Bradley.
ABSTRACT: Acceptance of ice cream sweetened with honey. C.J.
Painter and R.L. Bradley, Jr., Department of Food Science, University of Wisconsin,
Madison.
Objective of research was to develop formulations for honey sweetened ice
cream with optimum shelf stability. Mixes were prepared in 22.7 kg lots, pasteurized
at 71°C for 30 minutes, homogenized at 175 kg/cm2 , cooled to 7°C
on a surface cooler and held at 5°C for 24 hours. Each mix was flavored
with category I vanilla, frozen in a batch freezer, and hardened for 48 hours
at -25°C before evaluation. Mixes containing 13% milkfat, 11% MSFN, 10%
honey, 7% sucrose and .2% gelatin were most acceptable. Subsequently, ice
creams were prepared with and without honey to compare several flavor combinations.
Ice creams without honey contained 16% sucrose. All other components were
as given above. Descriptive sensory panels were used to assess the attributes
of the finished products. Statistical analysis of data showed all flavored
ice creams made with honey were preferred equally or more than the sucrose
control. Storage trials for 60 days at -23°C showed similar texture between
control and honey sweetened ice creams.
Research into the use of honey in frozen desserts was comprised of three
major objectives. The first goal of the project was to develop a honey-based
ice cream that was more stable during the freeze-thaw cycle. Most ice
creams that contain honey require a lower freezing temperature than other
ice creams,
and often crystallize rapidly. Second, researchers set out to develop
a honey-based ice cream that had high consumer taste appeal. Simply developing
an ice cream that won’t melt is not enough; the product must also
taste good. Lastly, researchers determined if honey-frozen yogurt was acceptable
to consumers and could enhance the fruit flavors often used in these types
of products.
The first objective of the research was to develop a honey-based ice cream formulation which has controlled freeze-thaw stability. One of the main considerations was that honey be the primary sweetener in the ice cream formulation. Using a blended honey, ice creams were made to contain 13% milkfat, 11% gelatin and the following levels of honey: 6, 7,8 and 9% with 9, 8, 7, and 6% sucrose, respectively. The two lower levels of honey were weak in flavor and did not fulfill the requirements of being the primary source of sweetener. The level of 8% honey as honey solids was selected as optimum from our trained frozen dessert panel. Finally, the 9% level was too sweet and was evaluated as too strong in honey flavor.
Trained frozen dessert evaluators were used to select the appropriate
level of honey in a premium formulation that would meet this objective.
The following formulation was selected as the most successful option:
The 8% honey formulation is in the premium range for fat content. It is
generally regarded that a fat level above 12% is premium. When this is
coupled with a reasonable overrun in the 80 to 85% range, a very excellent
product resulted. This formulation fulfilled the need for the ingredient
declaration to show honey as the primary sweetening ingredient.
Mixes were prepared according to the formula below. They were batch pasteurized at 160°ºF, held at that temperature for 30 minutes, then homogenized in two-stages at 2000 + 500 psi in a Manton-Gaulin unit. Mixes were cooled over a surface cooler to 40°ºF and stored for 24 hours to fully hydrate the gelatin stabilizer.
Product was frozen in an Emery Thompson 5-gallon batch freezer to the draw temperature of 23º°F, and 80% overrun. Product was packaged in 1/2 gallon containers stored in a hardening room at -15°ºF until ready for evaluation. All additives were added by weight.
Control ice cream had only cane or beet sugar at the 16% level. All other ingredients were at the same level as in the honey ice cream.
Storage trials were conducted with 1/2 gallons of honey-based and control ice creams. Containers of ice cream were placed in a cabinet at -10º°F and evaluated at 15 day intervals for 60 days. Judges trained in the evaluation of ice cream evaluated both ice creams as similar in texture after 60 days.
The graph on this page shows the amount of water that was frozen at a particular temperature for the two ice creams. Initial freezing points were 27.1°ºF for the control ice cream and 25.8°ºF for the honey-based ice creams. These formulations are 1.3°ºF apart at their initial freezing points. In fact, the honey ice cream is similar to a product with 5% fructose as a carbohydrate among other sweeteners present. At draw temperature from the continuous freezer (22º°F) the honey ice cream has 34% water frozen, while the control ice cream has 47% water frozen. It is desirable to have as much water frozen as possible in the continuous freezer since this is the only place that ice crystals are made. At all other storage temperatures ice crystals grow progressively until they are detectable organoleptically. In spite of this distinct difference, storage of products at -10º°F and evaluation for 60 days showed no difference between products.
Both were criticized at 30 days for a slight coarse texture and at 60 days for a course texture. It is obvious that the shorter the product storage, the better the ice cream will be at the consumer level.
Users of the 8% honey formula may wish to consider using the marketing strategies of some of the best ice creams available. Pack it in pint and no more than quart sized containers to minimize the time between sale and consumption. Further, the home freezer is not an adequate unit for this purpose. The nightly freeze and thaw creates a “torture chamber” for all frozen foods. Unfortunately, ice cream is not further processed before use.
Thus, its coarse, icy texture will be strikingly evident. The critical range of 10º°F to 0°ºF is where the Heat Shock Index is located. The smaller the value, the better the storage stability of the ice cream. The control ice cream has a value of 9% which indicates that over the 10º°F range the amount of water or ice that changes state. The honey-based ice cream has a value of 12%. Again, this is strikingly similar to 5% fructose ice cream.
The second objective was to develop a honey-based ice cream that ranks high on consumer scoring by use of taste panels.
The control and honey-based products that were manufactured and hardened in Objective 1 were subjected to descriptive sensory analysis. Panelists for this sensory analysis were experienced in the systematic evaluation of foods, but not specifically trained in evaluating these products.
Panelists were seated in individual booths when evaluating products and
were given approximately 4 oz. (.113 kg) of each sample in a plastic bowl.
Each product variation was coded with a different three-digit number. Prepared
ballots listed six selected attributes for evaluation on quantitative descriptive
analysis scales. Following analysis, markedballots were coded with appropriate
numerical values and then analyzed by computer with a program for analysis
of variance appropriate for a randomized complete block design. Individual
statistical analyses were done for the data sets obtained. Mean scores
for sample attributes, F-values, and least significant differences at 5%
were computed for each set of samples when F-values were significant.
The data in Table 1 show no difference in preference for the honey sweetened ice cream. Data shown in Table 2, which is an average of the analysis of the almond, banana and fudge swirl ice creams, show no statistical difference for the preference of ice creams sweetened with honey or all sucrose. Depending on what flavor is used, there tends to be some masking effect from the honey flavor. This should be anticipated and desired. The honey flavor is combined with many other flavors to give a total impression. Data in Table 3 suggest that the preference for strawberry ice cream sweetened with honey is slightly lower than sucrose sweetened strawberry ice cream at the 95% confidence value. Results suggest that nut, chocolate and most fruit combinations with honey as the principal sweetener are acceptable to consumers. It is the individual preference that drives purchases and would direct one flavor purchase over another.
The third objective was to determine if frozen yogurt, soft and hardened, has consumer acceptance as well as enhancement of fruit flavors.
Frozen yogurt was prepared with the formulation to the right. Mixes for soft-serve were prepared with the control containing cane or beet sugar as a substitute for honey. Thus control mixes contained 11.5% cane sugar and 6% corn sweetener. For each mix, pasteurization was at 160º°F for 30 minutes with homogenization two-stage at 500 + 2000 psi followed by cooling to 40°ºF on a surface cooler. Each mix was then diluted with a cultured 4% milk to a pH of 5.8. The milk was pasteurized in the University of Wisconsin dairy plant, then armed to 110°ºF inoculated with a culture of Lactobacillus delbruckii ssp. Bulgaricus, Lactobacillus acidophilis, and Streptococcus thermophilus (1:1:2), held at 110º°F in a warm room until the pH decreased to 4.6. The milk product was cooled. After 24 hours of cooling, the ice milk mixes were blended with enough cultured milk to give the desired pH of 5.8. Manufacturer will have their own pH minimums. This is probably based on a historical perspective. Compared to liquid yogurt, most frozen yogurts today are hardly acidified.
In the evaluation of the desirable level of acidity for a frozen yogurt,
several levels were evaluated. Products after preparation were reduced
in acidity by increments of 0.2 pH units. Thus pH 6.4, 6.2, 6.0, 5.8,
5.6 and 5.4 were evaluated both as mix and as the frozen product. It
was the judgment of the experienced evaluators that pH 5.8 was as low
as one should reduce the pH for a satisfactory honey-sweetened product.
Some of this frozen yogurt was soft-serve while some was batch frozen
in the Emery Thompson freezer (conditions 23º°F draw and 70%
overrun). Flavors evaluated were strawberry, blackberry, cherry and vanilla.
Soft serve ice milks were frozen in a Stoetling Model 2131 freezer with
twin barrels. One flavor was frozen per trial with control in one barrel
and honey-based mix in the opposing barrel. Trained ice cream judges
evaluated these products from the freezer and hardened. Fruit flavors
were highly rated while vanilla was severely criticized for lacking true
vanilla flavor. Not unusual when considering the quality of vanilla and
level of addition to these products. Vanilla does not appear as the true
vanilla that we know in the presence of acidity.
Two factors were evaluated initially before any finished product was produced.
These factors included the compatibility of honey-based flavoring and fruit
mixtures. This was done by evaluating seven flavors of Mountain High yogurt
from the local supermarket. Basically, these flavors were all too acid
and either contained a fair to poor fruit mixture or the flavor was artificial
in character. This was not a success.
©2007 National Honey Board
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