Digestibilidade in vitro de géis de gelana contendo extrato de jabuticaba

Author(s)

Tatiana Porto dos Santos

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2017-03-08

Examining board members

Rosiane Lopes da Cunha; Mário Roberto Maróstica Junior; Marisa Masumi Beppu

• Advisor: Rosiane Lopes da Cunha

Abstract

Gellan gels can be used with innumerous purposes according to its capacity to modify texture and to be used as wall material for encapsulation systems due its resistance for gastric pH. Anthocyanins, a phenolic compound that promotes a lot of benefits for human healthy are very susceptible to gastrointestinal tract conditions and to be absorbed in intestine, its encapsulation to control release seemed to be necessary. In order to contribute to the development of systems which contains gellan gum in its composition, gellan gels were formulated, characterized and subjected to digestion conditions in a gastrointestinal in vitro system. Furthermore, these gels were tested as a wall material for encapsulation systems of anthocyanins present in jabuticaba extract. Gels were composed by gellan gum and was obtained from different process (thermic and with different pH and ionic strength), originating structures with varied mechanical behaviors. Gels were initially characterized according to their mechanical properties (until rupture), water holding capacity, structure by scanning electron microscopy and in vitro digestion. In addition, model gels with jabuticaba extract addition were evaluated under in vitro digestion systems in order to verify their capability to retain and deliver anthocyanins. Simultaneously, this work aimed to develop gastrointestinal in vitro systems, and thus an in vitro dynamic prototype system was improved. Aiming to evaluate the performance of this prototype, studies with gellan gels were performed using this system and compared with static in vitro system. Gellan gels seemed to be affected by pH and ionic strength conditions, increasing its strength and hardness properties. On the other hand, the ions addition method demonstrated to be very important and affected mechanical properties and structures of gellan gels. A lower addition rate originated more organized gels and increased its strength and hardness. Besides, it was possible to notice how different structures were affected by digestion in vitro process. Stronger gels reduced its stress at rupture during digestion in vitro process, whereas weaker gels acted differently, thus they can be indicated to different applications according to their final characteristics. Gellan gels also showed different trends of jabuticaba extract retention and anthocyanins release during digestibility process. Gels containing only gellan gum and extract were the most effective and released values greater than 80% of anthocyanins during digestibility process, whereas the same gels added by calcium released at most 70%. Furthermore, it was noticeable that gellan gels had its characteristics and mechanical properties changed when the extract was added, while gels with an extra addition of calcium chloride did not present such differences. It was possible to verify that depending on the components added to gellan solution and the process of addition, different structures were formed, and this structures can be used in many applications as structural agent and wall material for encapsulations systems (AU)

• FAPESP's process: 15/21677-4 - In vitro digestibility of gellan gels: static and dynamic systems.
• Grantee: Tatiana Porto dos Santos
• Support Opportunities: Scholarships in Brazil - Master