Yummy Ice-cream Facts

• Ice-cream is the most popular of all frozen desserts— also with the highest fat content.
• Chemically, ice-cream is a colloid food foam consisting of frozen ice crystals, air bubbles surrounded with fat globules and coated with an emulsified protein layer, and an unfrozen liquid phase containing sugars and salts in solution.
• Most popular flavours of ice-cream are vanilla followed by chocolate.
• It is prepared by simultaneously stirring and freezing a pasteurized mix of dairy (milk, cream, butterfat, etc.) and non-dairy (sweeteners, stabilizers, emulsifiers, possibly egg, colours, and flavours.)
• By law ice-cream must contain at least 10 % milk fat and 20% milk solids-not-fat, and at least 14 % in premium ice-creams.
• “Premium” or “Super Premium” Ice-creams are denser, smoother, richer, and higher in kilocalories because they use heavier cream than normal ice-cream.
• Since milkfat is the most expensive ingredient, the more milkfat, the higher the cost of production.
• Reduced fat ice-cream: less than 7 grams of milkfat.
• Light or low-fat ice-cream: less than 3 grams of milkfat.
• Nonfat ice-cream: less than 0.5 gram of milkfat.

Commercial preparation of Ice-cream:

• Combine liquid ingredients in a mixing vat (container), add sugar and dry ingredients and then heat to 43°C, warm enough to dissolve all ingredients.
• Pasteurise and homogenise ice-cream mix to improve the overall texture.
• Age the mix from 3 to 24 hours at 4.4°C in vats, to give it a smooth texture, improved body, and resistance to melting.
• Freeze the mix in ice-cream freezer to –5°C, to create tiny ice-crystals, giving the ice-cream a smooth texture. This step freezes 33 to 67% of the water.
• Add rock salt to the crushed ice surrounding the ice-cream freezer to speed the melting of ice and to absorb heat away from the freezer.
• Fill the ice-creams into containers at –5°C. This step freezes an additional 23 to 57% of the water.
• Harden the ice-cream at –34°C.
  
  
  
• Ice-cream is best stored at temperatures of –18°C or below for one to two months, and is best protected as much as possible from vast changes in temperatures.
• A thin, plastic film or a sheet of wax paper found inside the carton between the ice-cream and the carton to prevent absorption of other food odors in the freezer as well as exposure to moisture buildup.
• Ice-cream quality is best when first purchased because numerous small crystals are present. Any increase in temperature causes the smallest crystals to melt. The extra water is taken up by the remaining crystals, making them larger and the ice-cream more grainy.

Source: Amy C. Brown, Understanding Food Principles and Preparation, U
USA, Wadsworth/Thomson Learning, 2000, pg 504—511.