Influence of formulation on the thermal behavior of ice cream mix and ice cream

Abstract

The influence of fat and emulsifier types on particle size and thermal behavior of aged mixes and the corresponding ice creams was investigated. Mixes and ice creams based on partially unsaturated monodiglycerides (MDG) were characterized by an increased percentage of agglomerated fat globules compared with saturated MDG-based systems. DSC thermograms obtained for refined coconut oil in mix showed a displacement of the main crystallization event toward lower crystallization temperatures compared with fat in the bulk phase. This supercooling effect was more or less pronounced for the three other fats used (hydrogenated coconut oil, refined palm oil, and anhydrous milk fat). In emulsified systems, an additional exotherm was observed that was interpreted in terms of MDG crystallization. The fact that this peak appeared at different temperatures ranging from 32 to 41°C as a function of the fat selection suggested that different fat-emulsifier interactions would occur. In the case of ice creams, although the water peak interfered with the fat peak, melting DSC curves allowed the discrimination between the fat types used in the formulation.Paper no. J10937 in JAOCS 82, 427-431 (June 2005). KEY WORDS:Fat, ice cream, ice cream mix, lipid emulsifier, thermal behavior.Ice cream is a complex polyphasic food system in which part of the dispersed phase consists of fat globules in a crystalline state. These globules are organized in a partially coalesced/agglomerated continuous 3-D network formed during the freezing and whipping steps of ice cream processing. This fat globule organization supports other microstructural elements in ice cream, such as air bubbles, and contributes greatly to the quality of the final product. The partial coalescence phenomenon and the extent of fat globule instability are greatly influenced by the amount of crystallized matter (1,2), the process (3), the size and shape of the fat crystals (2,4), the orientation of the crystals at the interface, and the surfactant type and concentration (5-8). Since each type of fat exhibits a specific polymorphism function of its TAG composition, the thermal behavior of fats during ice cream processing should influence the physicochemical properties of the intermediate and final products.In previous studies, we showed that the nature of the fat and the degree of unsaturation of the emulsifier led to different properties of the oil-in-water emulsions (9) and ice creams (10). Although particle size characterization was relevant to discriminate between emulsifiers, this method gave poor information regarding the influence of fat type in oil-in-water emulsions and ice creams. In contrast, determination of rheological parameters and melting times appeared to be two convenient methods to illustrate the influence of fat nature although melting times were related only to room temperature. In particular, a high linear correlation was found between the storage modulus measured at 20°C and the melting time (10). The aim of the present study was to investigate the effects of ...

Fat structures as affected by unsaturated or saturated monoglyceride and their effect on ice cream structure, texture and stability

“…Some oilsoluble emulsifiers, e.g., monoglycerides, interact with fat and, upon adsorption, alter droplet properties including size, surface and shape. For example, the size of aggregates in ice cream has been shown to be independent of the type of fat in the presence of saturated mono-di-glyceride, but not in the presence of unsaturated mono-di-glyceride (Granger, Schöppe, Leger, Barey, & Cansell, 2005). In the study by Granger et al (2005), the unsaturated monoglyceride exhibited a dependency on the degree of saturation of the fat for the resulting particle size, leading to larger diameters with refined or hydrogenated coconut oil than with anhydrous milkfat.…”

Enhancement of fat colloidal interactions for the preparation of ice cream high in unsaturated fat

“…Unsaturated monoglycerides have been shown to promote optimum aggregation among droplets. Some workers attributed this to greater protein displacement at increasing GMO concentrations (Davies, Dickinson, & Bee, 2000 while others put more emphasis on the interactions between unsaturated monoglycerides and hard vegetable fats for the formation of highly interacting droplets (Barfod, Schrader, & Buchheim, 2000;Granger, Leger, Barey, Langendorff, & Cansell, 2005a;Granger, Schöppe, Leger, Barey, & Cansell, 2005b). Adsorption of partially coalesced aggregates at the airewater interface imparts high air stability because localised fat clumps in the lamellae between air cells block water drainage during meltdown and so retard bubble coalescence (Chang & Hartel, 2002;Goff, 2001;Koxholt et al, 2001;Sofjan & Hartel, 2004).…”

Mapping of ice cream formulation using front-face fluorescence spectroscopy

“…Although studies on milk (Dufour & Riaublanc, 1997;Herbert et al, 1999;Lopez & Dufour, 2001) and cheeses Herbert et al, 2000) showed that fluorescence measurements could reveal different protein structures, to the best of our knowledge no study has been performed on ice creams. Rheological studies and thermal analysis (Granger, Scho¨ppe, Leger, Barey, & Cansell, 2005) showed that ice cream structure was dependent on the formulation, i.e., fat type, emulsifier and protein. On a molecular basis, fluorescence could also be a pertinent method to indicate the different interactions occurring in this type of dairy product.…”