Banca de DEFESA: NEWTON CARLOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : NEWTON CARLOS SANTOS
DATE: 20/10/2023
TIME: 08:30
LOCAL: MODO REMOTO: Google meet
TITLE:

INFLUENCE OF PRE-TREATMENT WITH ETHANOL ON DRYING AVOCADO PULP IN A FOAM LAYER AND ITS APPLICATION IN BAKERY PRODUCTS

KEY WORDS:

Goat milk; Functional food; Convection drying; Mathematical models; Emerging technologies.

PAGES: 209
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Tecnologia Química
SPECIALTY: Alimentos
SUMMARY:

The use of pre-treatments to enhance food drying is effective, ensuring high-quality products and energy savings. Foam-mat drying is a versatile and cost-effective technique suitable for incorporating new materials into foam formation. These powders have broad applications in the development of new food formulations. In this context, this research aims to evaluate the influence of ethanol pre-treatment on the foam-mat drying of avocado pulp, with the aim of using the powder in bread making. For this purpose, avocado pulp foam was prepared using goat milk powder (10, 15, and 20%), Emustab^® (4, 6, and 8%) with different agitation times (15, 20, and 25 min). The foam that exhibited the most suitable physical properties was subjected to the drying process (50, 60, and 70 °C), with or without ethanol pre-treatment (99.5%). Empirical and diffusive models were used to describe the drying kinetics and determine the activation energy of the process and thermodynamic properties. The final products were characterized in terms of physicochemical, nutritional, bioactive, antioxidant, morphological, structural, and thermal aspects. Additionally, the stability of carotenoids was assessed, and water adsorption isotherms were determined. Finally, sliced bread was prepared using different concentrations of avocado pulp powder (0, 5, 10, 15, 20, and 25%) as a substitute for hydrogenated vegetable fats. In this study, the optimized conditions for avocado pulp foam production were with 8% Emustab®, 20% goat milk powder, and 15 minutes of agitation. Foam drying was best represented by the Lewis model, especially when combined with ethanol pre-treatment and higher temperatures (70 °C). These conditions also improved various characteristics of the final product, including reduced water content, water activity, increased ash and carbohydrate content, as well as the content of phenolic compounds and antioxidant activity. Morphological, structural, and thermal analyses revealed irregular, amorphous particles with no formation of new functional groups and heat stability. However, the thermal stability of carotenoids decreased during storage, and water adsorption isotherms showed a Type III curve, with satisfactory estimates by the GAB model. Levels of up to 25% proved suitable for replacing hydrogenated fats, resulting in products with lower lipid and carbohydrate content, higher nutritional value, antioxidant activity, and changes in the structure and color of the bread. In conclusion, this study demonstrated that ethanol pre-treatment and foam-mat drying of avocado pulp are effective strategies for producing high-quality powder with broad applications in the development of food formulations.

COMMITTEE MEMBERS:
Externo à Instituição - ISANNA MENEZES FLORÊNCIO - UEPB
Externa à Instituição - ANASTACIA MARIA MIKAELLA CAMPOS NOBREGA ANDRE - UFCG
Presidente - 1517220 - MARCIA REGINA DA SILVA PEDRINI
Externa à Instituição - TAMIRES DOS SANTOS PEREIRA - IFPE
Externa ao Programa - 1052701 - THAYSE NAIANNE PIRES DANTAS - null