Key findings of a research project conducted for the National Honey Board
by the Center for Food
Safety and Quality Enhancement, College of Agricultural and Environmental
Sciences, University
of Georgia. Principal Investigator: R. Dixon Phillips, Professor.
Spreads are popular accompaniments to many food products, including bagels, breads and other baked goods and can be used as a filling in pastries. Honey spreads are a favorite in this category, particularly when the honey is blended with butter, margarine or peanut butter. Although these products are delicious, they contain notable amounts of fat (usually more than 60 percent), which can be a deterrent to consumers who are trying to reduce their fat intakes.
The goal of this research project was to develop low-fat and/or fat-free honey spreads with various flavor profiles that have the textural and sensory characteristics of higher-fat, honey-based spreads. Three primary objectives were developed:
Researchers prepared 16 honey spreads following procedures adapted from Miller1 and Dyce.2 Each spread contained varying amounts of 100 percent grade A honey, microcrystalline cellulose (thickening agent), oil, fat (vegetable shortening or reduced-calorie fat) and monoglyceride (emulsifier). Following are the steps used in spread preparation:
Researchers compared several reduced-fat honey spreads with a commercially available honey spread.
The commercial product contained 64 percent fat, 20 percent honey and 3 percent monoglyceride (Table 1). Other components of this spread included water, salt, diglycerides, soy lecithin, sodium-benzoate, citric acid and disodium EDTA (preservatives), artificial flavor, beta carotenes (for color) and vitamin A (palmitate).
The reduced-fat spreads used either vegetable shortening or a reduced-calorie fat as the fat source. The reducedcalorie fat, a structured triacylglycerol, functions like fat but contains approximately half the calories (5 kcal/g of fat compared to 9 kcal/g).
Texture measurements of the honey spreads were performed with an Instron Universal Testing Machine (Model 1122) fitted with a 25 mm flat-ended cylindrical plunger that was attached to a 50 kg compression load cell. Spread samples at 5°C were placed in an aluminum container with the plunger set to penetrate each sample for a distance of 4 mm at a speed of 5 mm/min. Then, the crosshead direction of travel was reversed and the plunger was withdrawn at the same speed.
Two base formulations of spreads were developed for consumer testing:
To determine the marketability of a reduced-fat spread, a panel of 50 consumers tested 13 spreads for overall acceptance, mouthfeel and spreadability.
A control and six pairs of spreads were developed using six different flavoring materials. Each spread in a pair was the same flavor but one contained shortening and the other a reduced-calorie fat.
After the evaluation, consumers answered questions relating to their willingness to purchase the spreads, how much they would be willing to pay for one pound of reduced-fat spread compared to the price of the commercial honey spread and how often they would purchase such spreads.
Researchers attained the greatest success with spreads containing 70 percent honey, 13.5 percent oil, 3 percent emulsifier and 13.5 percent vegetable shortening. Consumers preferred spreads prepared with the vegetable shortening over those made with reduced-calorie fat. Spreads made with shortening and flavored with butter extract earned significantly higher marks for mouthfeel, spreadability, and overall acceptance, compared to the commercial spread.
The optimal reduced-fat honey spread formulations were as follows (Table 1):
A. 70 percent honey, 13.5 percent oil, 13.5 percent vegetable shortening, 3 percent emulsifier.
B. 70 percent honey, 13.5 percent oil, 13.5 percent reduced-calorie fat, 3 percent emulsifier.
C. 70 percent honey, 27 percent reduced-calorie fat, 3 percent emulsifier.
Several spreads with varying honey:fat ratios were tested for texture quality. The measurements of the formulations that produced the optimal results appear in Table 2. Spreads containing 70 percent honey, 13.5 percent oil and 13.5 percent shortening exhibited textural qualities similar to those of the commercial spread. Spreads containing 70 percent honey and 30 percent fat had softer textures than the commercial honey spread and were not sticky. Spreads containing 13.5 percent reduced-calorie fat instead of shortening yielded textures that were significantly firmer than the commercial spread. Increasing the reducedcalorie fat content to 27 percent yielded an even firmer product.
More than 60 percent of the participants rated the flavored vegetable shortening honey spreads at 6.0 or higher, while only half did so for the commercial spread. Both the butter- and peanut-flavored vegetable shortening spreads earned the highest marks (mean 6.2 out of 9.0), which were significantly higher than the commercial spread’s mean score (5.3) (Table 3) Consumer preference Consumers preferred the flavored, reduced-fat honey spreads prepared with vegetable shortening over those prepared with reduced-calorie fat (Table 4).
More than half of the participants rated the mouthfeel of the butter-, chocolate-, lemon-, peach- and peanut-flavored shortening spreads and the commercial spread at 6.0 or higher. However, the differences among these ratings were not significant (Table 5).
Most of the participants rated the spreadability of the spreads at 6.0 or higher. The presence of fruit or chocolate affected the ratings (Table 6).
Spreads prepared with vegetable shortening had a glossy appearance not seen in the reducedcalorie fat spreads. This appearance may have influenced the consumers’ ratings for mouthfeel/texture and overall acceptance. Spreads flavored with butter or lemon extracts rated significantly higher than those with pieces of chocolate, peach, peanut or white chocolate mixed in. The presence of fruit or chocolate pieces alone, regardless of the fat source used in the spread, affected the mouthfeel/texture and spreadability ratings as well (Table 7). However, the presence of fruit or chocolate pieces did not affect the overall acceptance ratings of the spreads.
Eightyfour percent of the participants--Georgian residents surveyed in 1996- -were willing to buy reduced-fat honey spreads rather than the commercial honey spread (used in this study). More than half stated that they would be willing to purchase it occasionally, and 14 percent would buy it once a month. Approximately onethird for the consumers were willing to pay $0.50 more per pound of the reduced-fat honey spread compared to the commercial spread. Sixteen percent stated that they would pay up to $1.00 more per pound.
Researchers were able to produce reduced-fat honey spreads containing 70 percent honey, 13.5 percent oil, 13.5 percent shortening or reduced-calorie fat and 3 percent emulsifier successfully. These products were compared to a commercially available, higher-fat, honey spread product. Based on the results of the comparison, several conclusions may be made:
The objectives of the storage study were to determine:
The spreads were prepared as previously described using 70% honey, 13.5% oil, 13.5% solid fat (shortening or a reduced calorie fat), and 3% emulsifier. The spreads were packed into 10 U.S. ounce Rubbermaid containers and stored at refrigerator temperature (5°C) and room temperature (25°C) for up to three months.
Twenty grams of honey spread samples were weighed into 2 oz plastic cups, covered with lids. Freshly prepared samples and samples stored at 5°C were transferred to a refrigerator and samples stored at 25°C were left on the counter top overnight in the sensory lab until evaluation by the consumer panel.
Consumers evaluated a total of five samples in each of two sessions. Samples were identified with a threedigit random number. Evaluations were carried out in partitioned booths under red light to mask the color of the commercial and prepared samples.
The water activity of the commercial honey spread stored at 5°C decreased significantly with storage time while storing the samples at 25°C had no significant effect. Reducedfat spreads stored for two months at 5°C and 25°C experienced slight drops in water activity.
The viscosity of the commercial spread and the reduced-fat spread made with the reducedcalorie fat decreased with storage time at 5°C and was more pronounced at 25°C. Storage had no significant effect on the viscosity of the reduced-fat spread made with shortening.
The peroxide value was used to measure the degree of oxidation in the spreads. The PV of the commercial spread stored at 5°C and the reduced-fat spread prepared with the shortening stored at 25°C increased slightly with storage time. Data indicates that even at room temperature, the reducedcalorie spreads were stable to oxidation.
All samples held at 5°C for three months were not significantly different from their corresponding fresh samples. After storage at 25°C for three months, the commercial samples were significantly lower in spreadability (Table 8). Consumers preferred the product stored at 25°C over the freshly prepared spreads for its ease of spreadability.
The flavor of the spreads prepared with reduced-calorie fat or shortening were more stable compared to the commercial spread stored at 25°C (Table 9). When held for three months at 5°C, flavor scores for the commercial spreads decreased significantly (p<0.05). These decreases were not observed in the reduced-fat honey spreads.
The texture of the fresh spread prepared with reduced calorie fat and those held at 5°C for three months were not significantly different. The texture/mouthfeel of samples prepared with shortening remained unchanged, regardless of storage time or temperature (Table 10).
The overall acceptance ratings for the samples prepared with shortening and reduced-calorie fat scored significantly higher than the control when held at 5°C for three months (Table 11).
Shelf Study Conclusions
The objectives of the stability study were to determine the storage stability [by water activity (Aw), peroxide value (PV) and viscosity)] of the reduced-fat honey spreads compared to the commercial honey spread (fresh and stored at 5°C and 25°C for up to six months).
An AQUA LAB Model cx2 was used to determine water activity. Water activity for all spread samples was measured at 22-23°C.
The viscosity of the spreads was measured at room temperature (22°C) using a Brookfield Viscometer Model HA with ahelipath stand. A TBar (D) spindle was used at a speed of 10 rpm during the viscosity measurement. The helipath time was 106 seconds and data were collected during the last 60 seconds.
Peroxide value of the spreads was determined using a modified official A.O.A.C. Method (Cd 8-53). Fat was extracted with chloroform:water (1:2). Chloroform layer was separated, centrifuged and heated in a vacuum oven at 70°C overnight to evaporate the solvent. Five grams of the oil/fat was used to determine the peroxide value using the titration method.
Freshly prepared reduced-fat honey spreads had significantly lower Aw values (0.46 and 0.47) compared to the commercial honey spread (0.73) and this trend continued during the storage at both temperatures (Table 12).
The Aw of reduced-fat honey spread (shortening) remained unchanged for three months at both temperatures (5°C and 25°C), increased slightly for the fourth and fifth month, then decreased to the original value. The Aw of reduced-calorie fat spreads stored for two months at both temperatures (5°C and 25°C) decreased slightly, and increased significantly by the fifth month. The Aw of the commercial honey spread stored at 5°C decreased significantly with storage time up to the third month then increased to the original values while Aw of the spread stored at 25°C increased slightly up to the fourth month then decreased to the original value. Storage temperature had no significant effect on the Aw of the reduced-fat honey spreads. Commercial honey spreads stored at 25°C for three months had significantly higher Aw compared to the same spread stored at 5°C.
Table 13. Viscosity values (centi poise) of honey spreads stored at 5°C and 25°C for up to six months
Table 13 presents the means of the viscosity values of the honey spreads stored at 5°C and 25°C for up to six months. Freshly prepared reduced-fat honey spreads were more viscous (266,800- 345,150 cps) compared to the commercial honey spread (131,255 cps). Although the reduced-fat spreads had twice the viscosity value of the commercial spread, they both were spoonable and not sticky. The freshly prepared reduced-fat honey spread prepared with the reducedcalorie fat was more viscous (345,150 cps) compared to the spread prepared using the shortening (266,800 cps). The viscosity of the commercial spread and the reduced-fat spread prepared with reduced-calorie fat decreased with storage time at 5°C and the reduction was more pronounced at 25°C. Storage time had no significant effect on the viscosity of the reduced-fat spread prepared with the shortening at both temperatures. Storage temperature had no significant effect on the viscosity of the commercial honey spread or reduced-fat honey spreads prepared with shortening. Reduced-fat honey spreads prepared with reduced-calorie fat stored at 25°C for three or four months had significantly higher viscosity values compared to the same spread stored at 5°C.
Table 14 presents the means of the peroxide values (PV) of the honey spreads stored at 5°C and 25°C for up to six months. The peroxide value was used to measure the degree of oxidation in the spreads. The PV of the freshly prepared reduced-fat spreads ranged from 0.07 to 0.23 milli equivalent of peroxide per 1000 g oil. The PV of the reduced-fat spreads stored at 5°C increased slightly with the storage time to 0.32 (shortening spread) and to 0.60 (reduced-calorie fat spread) and increased to 1.61 (shortening spread) and 1.97 (reduced-calorie spread) when stored at 25°C for six months. The PV of the commercial spread increased with storage time to 2.22 (at 5°C) and to 8.27 (at 25°C) after six months. Storage temperature had significant effect on the PV of the spreads. Commercial honey spread stored at 25°C for two months had significantly higher PV compared to the same spread stored at 5°C, while the reduced-fat honey spreads stored for four months at 25°C had significantly higher PV compared to the same spread stored at 5°C. These data indicate that even at room temperature, the reduced-fat spreads were stable to oxidation and had lower PV values compared to commercial spreads stored at 5°C which may be due to the lower fat content of the reduced-fat spreads.
Reduced-fat honey spreads containing 70% honey, 13.5% oil, 13.5% fat (shortening or a reduced-calorie fat) and 3% emulsifier had very low water activity and peroxide values which indicate a very stable product. Reduced-fat honey spreads had twice the viscosity value of the commercial spread, but they were spoonable and not sticky. Reduced-fat honey spreads remained stable with regard to oxidation after storage for six months at 25°C compared to the commercial spread which had significant higher peroxide values even at 5°C. These results indicate a potential for commercialization of spreads containing very high levels of honey.
©2007 National Honey Board
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