Agriculture Reference
In-Depth Information
Table 17.7
Ingredients in premium and economy ice creams
Premium ice cream
Economy ice cream
Whole milk Reconstituted whey protein concentrate
Cream Reconstituted skimmed milk
Skimmed milk powder Glucose syrup
Sugar Oligofructose syrup
Mono- and di-glycerides of fatty acids Vegetable oil
Vanilla extract Whey solids
Locust bean gum Mono- and di-glycerides of fatty acids
Guar gum Vanilla extract
Carrageenan Locust bean gum
Annatto Guar gum
Sodium alginate
Annatto
In the production of, for example, vanilla dairy ice cream, the major ingredients
(whole milk, SMP, sugar, emulsifi ers, stabilisers, fl avouring and colour) are
combined as an ice cream mix, pasteurised at 82-87°C for 15-30 seconds,
homogenised at 70-80°C using two-stage homogenisation and aged at 0-5°C for
12-24 hours. Ageing allows the complete hydration of dry ingredients, fat
crystallisation and the destabilisation of the emulsion by the emulsifi er through
the desorption of protein (mainly casein micelles) from the surface of fat globules,
which improves air cell distribution during freezing and dryness, body, mouthfeel,
creaminess, and heat shock resistance after freezing. Freezing occurs in scraped-
surface heat exchangers when the mix is taken to -5 to -7°C, following which it
is packed and hardened in a blast freezer at minus 35-40°C. Scraped surface
freezing causes the rapid production of ice crystals <25 μm in size, which are too
small to be detected as sandiness on the palate.
The production of ice cream is dependent on the dairy ingredients used to
make it, principally the NFMS and the other major ingredients (e.g. fats and
sugars). Hard ice cream is sweetened with sucrose whereas soft serve ice cream is
sweetened with, for example, high-fructose corn syrup, dextrose and invert sugar,
all of which cause freezing point depression and increase the amount of unfrozen
water making the product softer.
Mono- and diglycerides of fatty acids (E471) are commonly used ice cream
emulsifi ers, though a variety of stabilisers are used including guar gum (E412),
locust bean gum (E410), sodium alginate (E401), carrageenan (E407) and tara
gum (E417). The function of stablisers is to control the movement of unfrozen
water in ice cream through hydrogen bonding, thereby preventing water migration
and the increase in ice crystal size as water freezes around ice crystals, which
would produce unacceptable mouthfeel. Some ice cream formulations also
include inulins, which are plant polysaccharides comprised mainly of fructose
and are classed as fructans. Their hydrocolloid function infl uences texture and
mouthfeel and can allow the reduction of sugar and fat - they contain less energy
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