Chemistry Reference
In-Depth Information
1982; Huse et al., 1984; El-Neshawy et al., 1988; Lindamood et al., 1989;
Morr and Barrantes, 1998; Matak et al., 2003). Lactose hydrolysis makes the
products digestible for those who are lactose-intolerant and also is a strategy
to reduce the potential for the development of lactose crystallization (sandi-
ness); however, hydrolyzed lactose causes twice the freezing point depression
of an equal concentration of lactose, so that softness at storage or retailing
temperatures and greater rates of ice recrystallization become the issues to
overcome if hydrolysis is to be considered. Levels of lactose hydrolysis can be
controlled easily from 25 to 100% based on source and activity of the
-
galactosidase preparation, concentration, time and temperature of treatment
(Lindamood et al., 1989; Matak et al., 2003). The sweetness of lactose-
hydrolyzed ice cream is increased compared to its unhydrolyzed control (El-
Neshawy et al., 1988; Lindamood et al., 1989), and this fact allows for some
reduction in sucrose or blending of alternative sweeteners, such as sugar
alcohols, to obtain the optimal formulation for sweetness and freezing
point depression.
It is possible to formulate a lactose-free (or reduced) or a sugar-free
product by selection of anhydrous milk fat or butter as the dairy fat source, or
vegetable fats as the non-dairy fat source, together with high-concentration
milk protein concentrates, either whole milk proteins or caseinates, as the
MSNF source (Parsons et al., 1985; Lee and White, 1991; Geilman and
Schmidt, 1992; Rossi et al., 1999; Alvarez et al., 2005; Whelan et al., 2008).
With such a formulation, the presence of lactose in the product can be
avoided. For lactose-free (or reduced) formulae, cream should not be used
to supply fat and milk should not be used to supply water for formulation
balancing, as these also contain lactose. The milk protein concentrate or
caseinate blend must supply all of the desired functionalities of the proteins,
including emulsification of the fat, aeration of the foam and water-holding
capacity in the unfrozen phase.
References
Alvarez, V.B., Wolters, C.L., Vodovotz, Y., Ji, T. 2005. Physical properties of ice cream contain-
ing milk protein concentrates. J. Dairy Sci. 88, 862-871.
Baer, R.J., Keating, K.R. 1987. Determination of ice cream mix freezing points: a comparison of
methods. J. Dairy Sci. 70, 555-558.
Berger, K.G. 1997. Ice cream. In Food Emulsions, 3rd edn. (S.E. Friberg, K. Larsson, eds.),
pp. 413-490, Marcel Dekker, New York.
Bradley, R.L. 1984. Plotting freezing curves for frozen desserts. Dairy Record 85(7), 86-87.
Bradley, R.L., Smith, K.E. 1983. Finding the freezing point of frozen desserts. Dairy Record
84(6), 114-115.
De Cindio, B., Correra, S., Hoff, V. 1995. Low temperature sugar-water equilibrium curve by a
rapid calorimetric method. J. Food Eng. 24, 405-415.
