Inhibition of Ice Crystal Growth in Ice Cream Mix by Gelatin Hydrolysate

Abstract

The inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate produced by papain action was studied. The ice crystal growth was monitored by thermal cycling between -14 and -12°C at a rate of one cycle per 3 min. It is shown that the hydrolysate fraction containing peptides in the molecular weight range of about 2000 -5000 Da exhibited the highest inhibitory activity on ice crystal growth in ice cream mix, whereas fractions containing peptides greater than 7000 Da did not inhibit ice crystal growth. The size distribution of gelatin peptides formed in the hydrolysate was influenced by the pH of hydrolysis. The optimum hydrolysis conditions for producing peptides with maximum ice crystal growth inhibitory activity was pH 7 at 37°C for 10 min at a papain to gelatin ratio of 1:100. However, this may depend on the type and source of gelatin. The possible mechanism of ice crystal growth inhibition by peptides from gelatin is discussed. Molecular modeling of model gelatin peptides revealed that they form an oxygen triad plane at the C-terminus with oxygen-oxygen distances similar to those found in ice nuclei. Binding of this oxygen triad plane to the prism face of ice nuclei via hydrogen bonding appears to be the mechanism by which gelatin hydrolysate might be inhibiting ice crystal growth in ice cream mix.

Ice structuring proteins from plants: Mechanism of action and food application

“…Gelatin hydrolysate (small peptides, 2000-5000 kDa) produced by papain action showed inhibitory activity on ice crystal growth in ice cream mix (Damodaran, 2007). More studies are required to explore the possibility of special processing (e.g., enzymatic reaction) on safety and nutritional capacity of convenient food products, such as milk and meat, as new sources of ISPs.…”

“…In this model, nonpolar side chains of amino acids (e.g., methyl groups) fit in regular spacing on the surface of ice, i.e., ice cages, grooves, or hexagonal rings, through favorable van der Waals and/or hydrophobic interactions (Jorov et al, 2004;Yang et al, 1998). Hydrogen bonds may support these contacts; i.e., Damodaran (2007) proposed that formation of hydrogen bonds between an ice crystal and gelatin hydrolysate is inhibiting ice crystal growth. However, hydrogen bonding is not necessarily essential for ice binding.…”

Ice Morphology: Fundamentals and Technological Applications in Foods

“…34 Similarly, novel ingredients are being suggested to help control ice recrystallization, among them are the antifreeze proteins that can be extracted from natural sources 36 and the use of gelatin hydrolyzates. 37 Recently, Hagiwara et al 38 indicated that the self-diffusion coefficient of water in a freezeconcentrated matrix is a useful parameter for predicting and controlling the recrystallization rate.…”

Innovative Ingredients and Emerging Technologies for Controlling Ice Recrystallization, Texture, and Structure Stability in Frozen Dairy Desserts: A Review

“…Furthermore, in a series of studies Damodaran investigated the potential of using gelatin hydrolysed derivatives as ice crystal growth controllers in ice cream systems. Gelatin hydrolysed derivatives with molecular weights of 2000 -5000 Da have shown outstanding ability to hinder ice recrystallisation in ice cream (Damodaran, 2007). The recrystallisation inhibitory activity of gelatin hydrolysates is not observed in larger fractions (> 7000 Da).…”

“…Damodaran attributed the antifreeze activity of gelatin hydrolysates to the formation of an oxygen triad plane at the C-terminal with oxygen-oxygen distances similar to those found in ice nuclei. The presence of this oxygen triad plane facilitates the binding via hydrogen bonds with the prism face of ice nuclei hindering the ice crystal growth in the ice cream mix (Damodaran, 2007;Wang and Damodaran, 2009) reported that the use of cationic polypeptide fractions (700 -1400 Da) derived by papain gelatin hydrolysis at 30 -37 °C , pH = 7 in ice cream mixes subjected to a freeze-thaw protocol (between -10 and -12 °C) reduced the ice recrystallisation rate by a factor of ten.…”