Avallone, Pietro Renato (2022) Thermorheological behavior of edible hydrogels. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Resource language: English
Title: Thermorheological behavior of edible hydrogels
Creators:
CreatorsEmail
Avallone, Pietro Renatopietrorenato.avallone@unina.it
Date: 9 March 2022
Number of Pages: 161
Institution: Università degli Studi di Napoli Federico II
Department: Ingegneria Chimica, dei Materiali e della Produzione Industrialea
Dottorato: Ingegneria dei prodotti e dei processi industriali
Ciclo di dottorato: 34
Coordinatore del Corso di dottorato:
nomeemail
D'Anna, Andreaandrea.danna@unina.it
Tutor:
nomeemail
Pasquino, RossanaUNSPECIFIED
Grizzuti, NinoUNSPECIFIED
Date: 9 March 2022
Number of Pages: 161
Keywords: Rheology; Viscoelasticity; Gelation kinetics; Hydrocolloids; Gelatin, k-carrageenan; Jellies;
Settori scientifico-disciplinari del MIUR: Area 09 - Ingegneria industriale e dell'informazione > ING-IND/24 - Principi di ingegneria chimica
Date Deposited: 17 Mar 2022 12:39
Last Modified: 28 Feb 2024 10:24
URI: http://www.fedoa.unina.it/id/eprint/14490

Collection description

Hydrocolloids are a class of long chain polymers able to form gels or viscous solutions when dissolved in water. In recent years there is a growing interest in the study of hydrocolloids, due to their properties as stabilizers, thickeners and gelling agents. Different market survey, indeed, suggests that the global food hydrocolloid market will increase in value by minimum 50% within the next ten years. Hydrocolloids are widely used in food formulations, specially in confectionery products. Soft candies, such as jellies sweets, are a class of high-sugar confections based on hydrocolloids, in which the latter plays the role of gelling agent. The most used gelling agent in jellies recipe, which guarantees the typical chewy texture, is gelatin obtained from pig and/or bovine skin. For this reason, a detailed thermo-rheological characterization on gelatin gels is performed. We investigate the sol-gel transition of aqueous pig-skin gelatin solutions at different concentrations and temperatures. In particular, we characterize the isothermal gelation kinetics close to the critical melting temperature. The time evolution of the moduli is analyzed at a specific fixed frequency and at various temperatures and concentrations. The isothermal study allows to evaluate the gel time and to determine its dependence on concentration and temperature. Furthermore, the effects of co-solutes on aqueous gelatin solution is evaluated. Such a analysis allows to understand the key role that sugars play in the molecular architecture of gelatin gels. We demonstrate that co-solutes enhance the gelation phenomenon leading to both stronger gel elasticity and improved thermal stability. According to results obtained from gelatin gels, a hydrocolloidal mixture composed by k-carrageenan and xanthan gum is proposed as possible replace for gelatin in jellies. Moreover, the thermo-rheological behavior of aqueous solutions of k-carrageenan and xanthan is studied both in the presence and in the absence of co-solutes. From this analysis we can demonstrate that, also in this case, co-solutes exhibit a stabilizing effect, improving the mechanical properties of the resulting gel.

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