1. Effects of Nondairy Milk on Ice Cream
By:
Megan McCarthy
Brittany Gleeson
Friday Lab, Section 2, Station 3
Effects of Nondairy Milk on Ice Cream

2. Clinical Condition Lactose Intolerance
A condition where some individuals suffer from gas and/or bloating due consumption of dairy products
Types
Lactase deficiency
Individual is lacking the enzyme, lactase, and can not digest lactose found in dairy products
Can lead to lactose malabsorption
Lactose malabsorption
Undigested lactose passes to the colon where bacteria break down the lactose which creates the gas and fluid which leads to diarrhea, gas & bloating

3. Our Project
Substituting dairy products in a common favorite dessert, ice cream, with nondairy products allows individuals with lactose intolerance to be able to consume ice cream without digestive symptoms
We substituted milk and whipping cream with:
Coconut milk
Lactaid milk
Almond milk
These items are dairy free and conveniently available to those who are lactose intolerant or lactose sensitive

4. Materials Food items: Equipment: Egg yolk Hand mixer Milk 4 loaf pans
Whipping cream
Coconut milk
Almond milk
Lactaid milk
Sugar
Salt
Vanilla
Equipment:
Hand mixer
4 loaf pans
1 quart sauce pan
Whisk
Spatula
Mixing bowls
Spoons
Thermometer

5. Methods and Procedures
Substituted regular milk and whipping cream with nondairy products
Lactaid milk, coconut milk, and almond milk
Procedures
1. Beat the egg yolk and blend with sugar, salt, and milk.
2. Pour into one-quart and heat slowly to 85°C, stirring occasionally
3. Add the vanilla and pour into metal loaf pan.
4. Place in the freezer for 30 minutes.
5. Beat the whipping cream until stiff.
6. Transfer freezing mixture from metal loaf pan to bowl and beat until smooth.
7. Fold in whipping cream, return to metal pan and put back in the freezer.
8. Stir thoroughly every 10 minutes in the first half hour. Then in 15 minute intervals  for the second half hour.  
9. Freeze for 2 more hours.  

6. Objective and Subjective Measurements
Percent Overrun
Melting Point
Subjective
Structure/ Stability
Color
Sweetness
Mouthfeel

7. Control Sample

8. Coconut Milk Sample

9. Almond Milk Sample

10. Lactaid Milk Sample

11. Results Objective Evaluation Results Table 1. Objective Evaluations
Product
Percent Overrun (cm)
Melting Point (℃)
Control (whole milk)
1.9
15.9
Lactaid Milk .9
15.2
Coconut Milk 1
15.1
Almont Milk
.75
7.9
Overall Average
1.1
13.5

12. Results: Structure/Stability
Subjective Evaluation
Figure 1. The mean ice cream scores ± 1 SD for variations in milk. N=6 for each sample group. P= .22 for coconut milk, p= .03 for almond milk, and p= .10 for Lactaid milk indicating only the almond milk produced statistically significant results. Structure and stability were rated on a scale of 1-5 where 1 represented too soupy and runny, 2 somewhat too soupy and watery, 3 just right, 4 somewhat too viscous and frozen, and 5 too frozen too scoop.

13. Results: Color Subjective Evaluation
Figure 2. The mean ice cream scores ± 1 SD for variations in milk. N=6 for each sample group. P= .001 for coconut milk, p= .08 for almond milk and p= .19 for Lactaid milk indicating only coconut milk produced statistically significant results. Color was evaluated on a scale of 1-5 where 1 identified as much too yellow, 2 somewhat too yellow, 3 just right, 4 somewhat too white and 5 much too white.

14. Results: Sweetness Subjective Evaluation
Figure 3. The mean ice cream scores ± 1 SD for variations in milk. N=6 for each sample group. P= .06 for coconut milk, p= .04 for almond milk and p = .11 for Lactaid milk indicating only the almond milk produced statistically significant results. Sweetness was evaluated on a scale of 1-5 where 1 identified as not at all sweet enough, 2 somewhat not sweet enough, 3 just right, 4 somewhat too sweet, and 5 much too sweet.

15. Results: Mouthfeel Subjective Evaluation
Figure 4. The mean ice cream scores ± 1 SD for variations in milk. N=6 for each sample group. P= for coconut milk, p= .10 for almond milk and p= .01 for Lactaid milk indicating coconut milk and Lactaid milk produced statistically significant results. Mouthfeel was evaluated on a scale of 1-5 where 1 identified as very gritty and abrasive, many crystals felt, 2 somewhat too gritty, smaller crystals felt, 3 just right, 4 some grittiness, mostly smooth, and 5 too smooth and moist.

16. Results: Overall Liking
Sensory Ballot Question 2:
Overall Liking of the product
Product
Average of Overall Liking (1-9)
Control (whole milk)
7.5
Lactaid Milk
5.5
Coconut Milk
5.7
Almond Milk
6.5
According to the average, the majority of people preferred the control sample. The following favorite was the almond milk, followed by the coconut milk, followed by the Lactaid milk.

17. Discussion Issues we came across:
While the whipping cream whipped into a perfect foam in our control sample, the almond milk, Lactaid milk, and coconut milk did not whip. In order to improve on the taste of the product, certain changes could be made to the recipe to promote whipping in the milk substitute samples.
Instead of using coconut milk sold in the carton, use canned coconut milk due to a higher fat content and add sugar to stabilize.
Addition of xanthan gum or pectin as an emulsifier and stabilizer
Increase fat content by adding an oil
Adding an acid, such as cream of tartar, compensates for a smaller fat content

18. Discussion Fat adds to a smoother texture
The outer member membranes of fat are removed when whipping begins  destabilization of fat globules
The experimental samples lack the network of solid fat spheres which hold the air bubbles in place, and prevents the foam in forming a definitive structure
Evidence:
“Decreasing the fat content in ice cream formulation will cause the loss of several important textural properties in the final product” (Mostafavi)
Our conclusion:
The experimental samples had a lower fat content therefore the products did not have as much volume and stiffness
Air adds to a lighter, smoother texture
The control had air incorporated, therefore the product was a lighter, smoother texture.
The experimental groups did not have these characteristics because the milks did not foam when whipped and air was not incorporated.

19. Discussion Freezing Time
A study comparing full fat to low fat ice cream products showed that removing the fat from ice cream made it more icy and more crumbly with fewer visible air holes, similar to our results.
Our conclusion:
Less time was needed for these samples to freeze

20. Discussion Percent Overrun Melting Point Our conclusion:
Ice cream with lower over runs had a harder texture when frozen, but melted more rapidly. (Sofjan)
Melting Point
As the fat content of the ice cream decreased, the sample was harder, and melted more quickly. (Roland)
Our conclusion:
The higher the percent overrun, the higher the melting point
The less fat the sample contained, the less air it contained, and therefore the lower the melting point.

21. References
McWilliams, M. Foods: Experimental Perspectives, 8th edition. Prentice Hall Print.
Mostafavi, F. )., Tehrani, M. )., & Mohebbi, M. ). (2016). Rheological and sensory properties of fat reduced vanilla ice creams containing milk protein concentrate (MPC). Journal Of Food Measurement And Characterization, 1-9.
Roland, A. M., Phillips, L. G., & Boor, K. J. (1999). Article: Effects of Fat Content on the Sensory Properties, Melting, Color, and Hardness of Ice Cream1. Journal Of Dairy Science, 
Sofjan, R. P., & Hartel, R. W. (2004). Effects of overrun on structural and physical characteristics of ice cream. International Dairy Journal, 
"The Science of Ice Cream." RSS. Web. 07 Dec
"Lactose Intolerance." National Institutes of Health. U.S. Department of Health and Human Services, Web. 07 Dec