By microencapsulating the protein hydrolysates in a mixture of gelatin and soy protein isolate significant reduced the bitterness of the resulting ingredient.
“[This] has the advantage of being a simple, low cost process, widely explored in the food industry,” explained the researchers from the University of Sao Paolo in the journal Food Hydrocolloids. “Moreover, the product is water and oil compatible, allowing a large number of applications.
“Also, soy protein has a high nutritional value, and both proteins used in this study are relatively inexpensive because they are abundantly produced by several countries,” they added.
The researchers used Solae’s Supro soy protein isolate (SPI) and Gelita’s bovine gelatine type B to encapsulate Kerry’s Hyprol casein hydrolysate. The casein ingredient is intended for use as a protein-source in infant products, and for enricing the protein content of food and beverages.
With the fear of commodification continuously looming, food manufacturers are turning to microencapsulation technologies as a way of achieving much-needed differentiation and enhancing product value. Many scientific studies have reported promising results for pectin to encapsulate a range of different ingredients.
The researchers tested different SPI to gelatin ratios, including 50:50, 60:40, and 40:60, to encapsulated the casein hydrolysate. The overall mix was either 20 or 30 per cent casein, with 80 or 70 per cent of the various gelatin- SPI mixtures.
All the formulations formed microcapsules, said the researchers, and all “reduced the bitter taste, the hygroscopicity and allowed controlled release properties of the casein hydrolysate”, they added.
The capsule with the lowest casein content was considered most adequate, they said, because of its higher encapsulation efficiency (over 90 per cent) and lower ability to absorb water (hygroscopicity).
“All the formulations lead to microspheres with similar morphologies, indicating that the concentrations of the hydrolysate and of the carrier did not influence morphology,” wrote the researchers. The particle ranged in size from 10.26 to 17.72 micrometres.
When tested by a panel of 20 trained tasters, all of the microencapsulated samples were rated as less bitter than the free casein hydrolysate, said the researchers.
The researchers considered this an interesting approach for the bitter taste masking of a value-adding ingredient. “These results indicated that spray drying of casein hydrolysate with mixtures of gelatin and SPI was successful to attenuate the bitterness of casein hydrolysate,” they said.
The study follows on from a similar study, published by the same group earlier this year in Food Research International (Vol. 42, pp. 1099-1104).
Source: Food Hydrocolloids
Published online ahead of print, doi: 10.1016/j.foodhyd.2009.10.012
“The Use Of Spray Drying Technology To Reduce Bitter Taste Of Casein Hydrolysate”
Authors: C.S. Favaro-Trindade, A.S. Santana, E.S Monterrey-Quintero, M.A. Trindade, F.M. Netto