Natural ice modulator sourced from gelatin hydrolysate.
Concerns about product quality inevitably arise for such frozen products as ice cream when these types of products are stored in cold environments and ice crystals develop. There is a strong direct relationship between the size of ice crystals and the development of coarse texture.
Incorporating antifreeze proteins or peptides in ice cream in order to control recrystallization greatly enhances the ability to deliver smoother ice cream to consumers. However, how well gelatin hydrolysate can inhibit the growth of ice crystals in ice cream has not been extensively examined.
So, scientists at the University of Wisconsin investigated the extent that enzymatically hydrolyzed gelatin might inhibit ice crystal growth in an ice cream mix. They also characterized the active gelatin hydrolysate fractions in the product. The results of their research suggest that gelatin hydrolysate could be a natural ice modulator used during the cold storage of frozen products.
The scientists hydrolyzed gelatin from pork skin or beef hide (types 225A30, 225B40 and 100B40) with papain at 37 C for different intervals: 10, 15, 20, 30, 40 and 60 minutes; at a variety of pH: 5.0, 7.0 and 9.0; and in different enzyme-to-gelatin ratios: 1:10, 1:15, 1:25, 1:50 and 1:100. The gelatin hydrolysate was fractionated, and the fractions were pooled together and lyophilized. Then the researchers tested how each fraction would affect ice crystallization in an ice cream mix.
The samples were quickly frozen to -40 C. Their temperature was increased to -14 C at 1 C-per-minute intervals, and then cycled seven times between -14 C and -12 C at a rate of one cycle every three minutes. The gelatin hydrolysates obtained from gelatin types 225B40 and 100B40, which were processed at 37 C for 30 minutes, at pH 7.0, and in an enzyme-to-gelatin ratio of 1:15, inhibited ice crystal growth in the ice cream mix.
In addition, the hydrolysate fractions with an average molecular mass of less than 2,000 Da significantly retarded the ice recrystallization process, suggesting that the ability to inhibit ice crystallization was related to the molecular mass of gelatin hydrolysate peptides. Further information. Srinivasan Damodaran, Department of Food Science, University of Wisconsin-Madison, A103A Babcock Hall, 1605 Linden Dr., Madison, WI 53706; phone: 608-263-2012; fax: 608-262-6872; email: firstname.lastname@example.org.