Effect of Double Homogenization and Whey Protein Concentrate on the Texture of Ice Cream

<p>Ice cream was made with a mix composition of 11 % milk fat, 11 % milk solids-not-fat, 13% sucrose, 3% com syrup solids (36 dextrose equivalent), 0.28% stabilizer blend or 0 .10% emulsifier and vanilla extract. Mixes were high temperature short time pasteurized at 80°C for 25 sec, homogenized at 141 kg/cm² pressure on the first stage and 35 kg/cm² pressure on the second, and cooled to 3°C. Six treatments were prepared from 4 batches of mix. Mix from batch one contained 0.10% emulsifier. Half of this batch, treatment 1 (Tl), was subsequently frozen and the other half, upon exiting the pasteurizer was heated to 60°C, rehomogenized at 141 kg/cm2 pressure on the first stage and 35 kg/cm2 pressure on the second (T2), and cooled to 3°C. Mix from batch two contained 0.28% stabilizer blend. Half of this batch was used as the control (T3), the other half, upon exiting the pasteurizer was heated to 60°C, rehomogenized at 141 kg/cm2 pressure on the first stage and 35 kg/cm2 pressure on the second (T4) and cooled to 3°C. Batch three, contained 0.10% emulsifier and 1 % whey protein concentrate (WPC) substituted for 1 % nonfat dry milk (NDM), upon exiting the pasteurizer was heated to 60°C, rehomogenized at 141 kg/cm2 pressure on the first stage and 35 kg/cm² pressure on the second (T5), and cooled to 3°C. Batch four, contained 0.28% stabilizer blend and 1 % WPC substituted for 1 % NDM, upon exiting the pasteurizer was heated to 60°C, rehomogenized at 141 kg/cm² pressure on the first stage and 35 kg/cm² pressure on the second (T6), and cooled to 3°C. Fat and total solids of all treatment mixes were similar (P > 0.05). Results showed that T4 had a lower mean ice crystal size (P < 0.05) at 10 days post-manufacture compared to T3, however overall texture acceptability between T3 and T4 were similar (P > 0.05). Mean ice crystal size of T6 was less (P < 0.05) at 18 weeks post-manufacture compared to T3 however overall texture acceptability between T3, T4, and T6 was similar (P > 0.05). Mean ice crystal sizes of Tl, T2, and T5 were greater (P < 0.05) at 10 days and 18 weeks compared to T3. Sensory evaluation proved that T3, T4, and T6 had higher mean scores (P < 0.05) for coarse and icy, coldness intensity, and creaminess than Tl, T2, and T5 at 10 days and 18 weeks post-manufacture. The viscosity of T3 was greater (P < 0.05) than all treatments and the viscosity of T4 and T6 were greater (P < 0.05) than Tl, T2, and T5. Viscosity was increased (P < 0.05) in ice cream mix by the addition of stabilizer. Double homogenization lowered (P < 0.05) ice cream mix viscosity in the presence of stabilizer, but no difference (P > 0.05) in viscosity was observed without stabilizer addition. Whey protein concentrate added to ice cream mix at a rate of 1 % had no affect (P > 0.05) on mix viscosity.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - University Access Only

Discipline thesis:degree_discipline

Dairy Science

Year dc:date.available

2001

Author dc:creator

• Ruger, Paul

Contributors dc:contributor

• Robert J. Baer

• Dairy Science

Statement dc:rights

• <p>In Copyright - Non-Commercial Use Permitted<br /><a href="http://rightsstatements.org/vocab/InC-NC/1.0/">http://rightsstatements.org/vocab/InC-NC/1.0/</a></p>

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/1509

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-2511