Paper Number
VP78 

Session
Pre-recorded Flash Presentations (virtual)

Title
On the inverse quenching technique applied to gelatin solutions

Presentation Date and Time
All Week (Asynchronous) Any Time

Track / Room
Pre-recorded Presentation / Virtual

Authors (Click on name to view author profile)

1. Avallone, Pietro R. (University of Naples Federico II, Chemical, Materials and Industrial Production Engineering)
2. Pasquino, Rossana (University of Naples Federico II, Chemical, Materials and Industrial Production Engineering)
3. Costanzo, Salvatore (University of Naples Federico II, Chemical, Materials and Industrial Production Engineering)
4. Sarrica, Andrea (Perfetti Van Melle)
5. Delmonte, Marco (Perfetti Van Melle)
6. Greco, Francesco (University of Naples Federico II, Chemical, Materials and Industrial Production Engineering)
7. Grizzuti, Nino (University of Naples Federico II, Chemical, Materials and Industrial Production Engineering)

Author and Affiliation Lines (in printed abstract book)
Pietro R. Avallone¹, Rossana Pasquino¹, Salvatore Costanzo¹, Andrea Sarrica², Marco Delmonte², Francesco Greco¹ and Nino Grizzuti^1
1Chemical, Materials and Industrial Production Engineering, University of Naples Federico II, Naples 80125, Italy; ²Perfetti Van Melle, Milan, Italy

Speaker / Presenter 
Avallone, Pietro R.

Keywords
experimental methods; gels; rheology methods

Text of Abstract
Gelatin gels are known to be non-equilibrium systems, due to the continuous growth and shuffling of the junction zones throughout all accessible time scales. For this reason, performing rheological experiments on a distinct gel microstructure, characterized by a definite number of junctions, is a challenging task. Inspired by the inverse quenching technique applied in the past to semi-crystalline polymers, we here apply an unusual thermal history to an aqueous solution of gelatin in the semi-concentrated regime (6.67%w pig-skin gelatin), in order to freeze the system in a metastable condition for a time sufficiently long to perform a rheological characterization. The solution, initially kept in the sol-state at 60°C, is rapidly cooled below gelation temperature, and isothermal gelation is started at 10°C. After soaking at this low temperature for a given time, the sample is rapidly heated (inverse quenching) up to a value in the range 24-29°C, where kinetics are monitored. If the waiting time at low temperature and the inverse quenching temperature are suitably chosen, sample elasticity will remain stationary for a relatively large time window, and rheological experiments will then be reliably performed.