This study evaluated the use of natural humectants (honey, molasses, maple syrup) in pie crusts compared to glycerol. Pie crust dough was prepared with 0.5-1.5% of each humectant replacing water. After baking, crusts with 1% maple syrup had the highest moisture content while molasses crusts had the lowest. Honey and 1.5% maple syrup crusts had similar moisture to glycerol crusts but lower water activity, indicating they provide similar water binding with greater antimicrobial effects. Therefore, honey and high concentration maple syrup can effectively replace glycerol as natural humectants in pie crusts.

1. Results
Baking Stability of Pie Crust Using Natural Humectants
Olivia Coroneos, Elizabeth Fitterer, Noelle Bartness, Sayali Bhadke, and *Dr. Eun Joo Lee
Department of Food and Nutrition, University of Wisconsin-Stout, Menomonie, WI 54751.
Introduction
 Humectants are common food additives used to bind the
water molecule in a system for maintaining the product
moist and texture, reducing water activity and microbial
activity, and enhancing baking stability.
 Sorbitol, glycerol and propylene glycol have been used as a
food humectants.
 However, due to the consumer demand for natural
ingredients and label friendly trend, bakery industry has
been seeking natural humectants, which have similar value
of water activity depressant (WAD) with sugars (8-10 range).
Objective
 The objective of this study was to determine the baking
stability of pie crust with different types and concentrations
of natural humectants included honey, molasses, and maple
syrup.
Methods and Materials
 Control dough sample was prepared with mixing flour
(49.5%), unsalted butter (35.0%), ice water (13.9%), salt
(0.8%), and sugar (0.8%).
 For natural humectant treatments, 0.5, 1.0, and 1.5% natural
humectants were added instead of the same amount of ice
water (Table 1).
 0.5% glycerol, the most common humectant in food
industry, was used as a control treatment.
 After storage of doughs covered by the plastic wrap for
overnight in the refrigerator, dough was rolled to a thickness
of 6.35 mm, cut into 2 square inch pieces, placed on a full
sheet tray lined with parchment paper, and baked for 15
minutes at 350 °F (Figure 1).
 Water activity (aw), moisture contents, and pH were
determined for baking stability and the surface texture of pie
crust was measured by scanning electron microscope (SEM).
Tube # % Humectant Ice Water (g) Humectant
1 0.0 22.5 (none)
2 0.5 21.7 0.82 g glycerol
3 0.5 21.7 0.82 g honey
4 1.0 20.9 1.06 g honey
5 1.5 20.1 1.42 g honey
6 0.5 21.7 0.82 g molasses
7 1.0 20.9 1.06 g molasses
8 1.5 20.1 1.42 g molasses
9 0.5 21.7 0.82 g maple syrup
10 1.0 20.9 1.06 g maple syrup
11 1.5 20.1 1.42 g maple syrup
Sample % Moisture pH Aw
Water 49.75 6.33 0.77
0.5% Glycerol 58.89 5.83 0.70
0.5% Honey 54.36 5.51 0.57
1.0% Honey 54.45 5.23 0.43
1.5% Honey 53.25 5.42 0.56
0.5% Molasses 55.43 5.37 0.79
1.0% Molasses 47.51 5.46 0.70
1.5% Molasses 47.71 5.49 0.76
0.5% Maple Syrup 54.93 5.39 0.76
1.0% Maple Syrup 62.32 5.43 0.61
1.5% Maple Syrup 53.24 5.46 0.42
P Value 0.866 0.00015 0.298
Discussion
 1.0% maple syrup treatment showed highest moisture
content (62.3%) while 1.0 and 1.5% molasses treatments
were lowest moisture content (47.5%) (Table 2).
 All natural humectant treatments had lower pH values
(5.23-5.51) than glycerol (5.83) and control (6.33) sample.
 All molasses treatment samples had high values of water
activity (0.70-0.79) similar with water (0.77) and glycerol
(0.70) sample.
 0.5, 1.0, and 1.5% Honey treatments showed the lowest
water activity (0.57, 0.43, and 0.56).
 Compared to 0.5% glycerol treatment, 1.5 % maple syrup
and all honey treatments were similar moisture contents
with low water activity values,
 It indicated that those treatments were similar water
holding capacity (humectant effect) and higher
antimicrobial effect than 0.5% glycerol.
 SEM photos showed the surface texture of the pie crusts,
but there are no differences between treatments (Figure
2-5).
Conclusion
 All honey samples and 1.5% maple syrup sample showed
similar moisture content with 0.5% glycerol.
 All honey samples and 1.5% maple syrup sample have
lower water activity.
 Therefore, honey and 1.5% maple syrup can be the most
comparable natural sugar humectant to glycerol.
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Acknowledgements
Erik Williams; Research Scientist (Cereals); Kerry and Vamshi Krishna Chintha; Teaching
Assistant; Food and Nutrition Department; University of Wisconsin – Stout.
Figure 2. SEM photos of control
(Left: Water; Right 0.5% Glycerol)
Figure 3. SEM photos of honey samples
(Left: 0.5%; Middle: 1.0%; Right: 1.5%)
Figure 4. SEM photo of molasses samples
(Left: 0.5%; Middle: 1.0%; Right: 1.5%)
Figure 5. SEM photo of Maple Syrup samples
(Left: 0.5%; Middle: 1.0%; Right: 1.5%)
Figure 1. Baked Pie Crust Samples
Table 1. Humectants and water additions for dough variations
Table 2. Baking stability of pie dough with various natural
humectants