8:30 am - 9:30 am
A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Course-Based Seminar by Xinying Wang. This seminar is open to the general public to attend.
Meeting ID: 973 2505 7893
Project Topic: Gelatin and Gelatin Hydrolysate as Cryoprotectant in Meat
MSc with Dr. Mirko Betti.
As one of the major techniques to preserve meat, frozen storage can inhibit rancidity caused by microorganisms and prolong its shelf-life. However, the temperature fluctuation and abuse in transportation cause the quality deterioration of meat, including flavors, texture, appearance and other functional properties loss due to the ice crystals induced cell dehydration, protein structure changes and lipid oxidation. Cryoprotectants has attracted more attention from the researchers due to its capacity to slow down the rate of the protein deterioration and improving the consumer acceptability of frozen meat.
Gelatin is a collagen-derived multifunctional biopolymer that has been utilized in food industry for a long time. Gelatin hydrolysate (GH) has a lower molecular weight, and obtained by heating and enzymatic hydrolysis of gelatin. Both gelatin and GH previously showed a potential to protect biological tissues from freezing damage and ice-induced quality deterioration.
The first study evaluated the effect of gelatin and GH on functional properties of beef burgers during freeze-thaw cycles. The changes in water-holding capacity, color, and tenderness of burgers, along with protein oxidation and denaturation, were evaluated. The results indicated that both gelatin and GH at 3% and 6% were able to perform as cryoprotectants by preventing the meat cells from dehydration during freeze-thaw cycles and immobilizing the structure and integrity of the protein matrix formed during cooking. In addition, the texture properties of meat were maintained in terms of hardness, cohesiveness, springiness and chewiness. Addition of 6% GH were shown to have the best performance in terms of protecting the meat from water loss caused by freeze-thaw cycles and cooking.
In the second study the sensory evaluation of beef burgers was conducted to establish an acceptable incorporation level of gelatin and GH. The overall acceptability, appearance, texture, flavor, aftertaste and other characteristic were evaluated in different treatments. By analyzing over 113 responses from panelists, addition of 3% or 6% GH showed greater hedonic scores as compared to the burgers with 3% or 6% gelatin in terms of overall acceptability, appearance, flavor, texture, and aftertaste of cooked burgers. The burgers with 6% gelatin were found as the most unacceptable product from the panelists’ perspective. Addition of GH provided a higher score in the investigation of the intent of future purchase compared to the burgers with gelatin inclusion.
In conclusion, GH exhibited greater potential than gelatin in textural parameter contribution, and good potential to be applied to the ground meat system as a cryoprotective agent without compromising palatability.