Biocomposites of passion fruit and buriti pulps: characterization and application in milk

Author(s)

Tais Fernanda Borgonovi

• Document type: Master's Dissertation
• Press: São José do Rio Preto. 2018-03-08.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto
• Defense date: 2018-02-28
• Advisor: Ana Lúcia Barretto Penna; Sabrina Neves Casarotti

Abstract

In recent years, there has been an increase in the world population demand for healthy foods, which include fermented dairy products. The most commonly used strains for the production of such fermented products are lactic acid bacteria (LAB), which modify the nutritional characteristics of the products, and additionally may provide desirable beneficial physiological effects to consumers. The addition of fruit pulp to fermented milk has also gained importance, since they confer valuable technological and sensorial characteristics to the products, besides increasing their nutritional value, due to the content of bioactive compounds. The present work was divided into three phases. In the phase 1, fruit pulps were obtained, prepared and characterized by means of chemical composition, fatty acid profile, total phenolic compounds, total flavonoids, total carotenoids and antioxidant activity. Passion fruit pulp presented higher moisture, total protein and ashes values when compared to buriti pulp. On the other hand, buriti pulp presented higher values of lipids (70% of unsaturated fatty acids), total phenolic compounds, yellow flavonoids and anthocyanins, β-carotene, lycopene and antioxidant activity. In phase 2, tests were carried out to evaluate the effect of phenolic compounds present in the pulps extracts on the viability of LAB strains. The addition of both passion fruit and buriti pulps stimulated the growth of LAB, demonstrating that these fruit pulps can be used as a source of energy for bacteria growth. Lactobacillus casei SJRP38 presented the highest growth in the presence of fruti pulps and was selected for the preparation of fermented and acidified milk. In phase 3, fermented and acidified milk with passion fruit and buriti pulps were produced. The kinetic parameters and the count of viable microorganisms during storage of fermented milk were determined. Both types of products (fermented and acidified milk) were characterized regarding their chemical composition, acidity, water holding capacity (WHC), syneresis, total phenolic compounds and antioxidant activity. Fermented milk with the addition of passion fruit pulp showed the shortest acidification time. Lactobacillus casei SJRP38 population remained stable throughout the storage period. The acidity of fermented milk increased, while the acidified milk reduced its acidity during the storage period. The WHC of all treatments increased during the storage period, on the other hand the syneresis of fermented milk remained stable. The addition of fruit pulps contributes to increase the phenolic content of both fermented and acidified milk, but there was a reduction of these compounds during the storage period in all treatments. Passion fruit and buriti pulps contain bioactive compounds and showed promising results when used simultaneously with L. casei SJRP38, without altering the strain viability during storage. The products (fermented or acidified milk) with the addition of buriti pulp were distinguished by their high antioxidant activity, with the potential to be added to functional foods and to provide beneficial health effects. (AU)

• FAPESP's process: 16/15967-2 - Biocompounds of buriti and passion fruit pulps: characterization and application in milk
• Grantee: Tais Fernanda Borgonovi
• Support Opportunities: Scholarships in Brazil - Master