MadSci Network: Agricultural Sciences |
Aloha,
This is a very interesting question. Since I am a nutritionist, not a food scientist I had to check this out for myself in an introductory foods book. I used Introductory Foods, 10th ed., 1995, by Marion Bennion.
It turns out that ice cream, and other frozen desserts, such as sherbet are made by the same process. The difference is in the starting materials that go into the product.
First, for sherbet, the food production person begins with a mixture of fruits, fruit juices, or other flavoring materials, a small amount of gelatin, vegetable gum, or other stabilizer, and some milk or cream. Then the ingredients are weighed or metered and mixed. The mix is then pasteurized to destroy disease-causing microorganisms. Pasteurization (heating at a high heat for a short time) also helps the flavor development and keeping quality of the final product. The mix is homogenized by forcing it through a small hole to make the product more uniform. The mix is then cooled and usually aged for a few hours before freeezing.
Next, the product is frozen, usually in two stages. The mix is frozen rapidly while it is being mixed. This keeps the ice crystals small. When the mixture is partially frozen, it is placed into packages and transferred to cold storage rooms. The freezing and hardening process is finished without agitation.
Many of the parts of the process are now fully mechanized. You might want to see if there is a dairy nearby your home and ask if they offer tours. You might be able to see the sherbet being made, just as described above.
Since I am a nutritionist, I have to mention that sherbet is a source of energy, carbohydrates, and some fat and protein. If you want to get more calcium from eating frozen desserts, perhaps ice cream or some of the new lower-fat versions of ice cream would be a more appropriate choice.
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