Banca de DEFESA: LAÍS MARTINS FONTOURA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LAÍS MARTINS FONTOURA
DATE: 06/07/2023
TIME: 09:00
LOCAL: Remoto
TITLE:

Development and Physical-chemical Characterization of Extruded Flours of Rice and Colored Sorghum with Grape Peel. 

KEY WORDS:

By-product, Thermoplastic extrusion, Rice, Grape pomace, Sorghum

PAGES: 67
BIG AREA: Ciências Agrárias
AREA: Ciência e Tecnologia de Alimentos
SUBÁREA: Tecnologia de Alimentos
SPECIALTY: Tecnologia de Produtos de Origem Vegetal
SUMMARY:

The food processing industries, for the most part, generate a significant amount of by-products, many of which, by not having systems for their use, result in disposal into the environment, causing unwanted contamination in several areas, with consequences and damage to the population. Particularly, the grape production chain, in 2020 reached around 80 million tons in the world. Considering that on average around 20-25% corresponds to grape skin (GP), it will be around 15.6 million tons/year. In this sense, there is a need to implement policies that include ways to solve this problem and avoid its disposal into the environment. There is a large number of activities, whether agro-industrial, pharmaceutical, bioactive transformation, food processing, etc., which are taking advantage of the different properties, mainly nutritional and nutraceuticals, that this by-product has. In recent years, the number of works has grown, emphasizing the importance of using GP as a way to add value, reduce disposal in the environment and use this resource as a source for the extraction of many bioactive compounds and essential oils, among others. As a bioactive agent, several publications highlight the results of great benefits for human health, such as, for example, being rich in antioxidants, it can help fight free radicals in the body, help control chronic diseases, such as hypertension, high cholesterol, diabetes, promoting healthy aging. Scientific work has shown that it can act as an anticancer agent. With regard to the various forms of transformation of by-products, thermoplastic extrusion has proven to be an effective tool in obtaining various products, whether inputs or finished products ready for immediate consumption. This is because it offers significant advantages: low cost per part, flexibility of operation in hot extrusion, post-run changes are easy because the product is still heated, continuous operation, high production volumes, the use of many types of raw materials, good mixing (composition), finished products with good surface. There are certain foods, when processed by extrusion, – cereals, for example – that can be prepared with different degrees of cooking, allowing different functional properties. In this thesis work, with three chapters, the first is a review that deals with grape pomace and its use as a source of fiber and antioxidant and its relationship in industrial, economic and social activity. In the second chapter, an article already published, deals with the enrichment of rice flour with grape pomace, using thermoplastic extrusion technology. In the third chapter, an article already published, deals with the impact on the antioxidant activity, in the extrusion of colored mixtures of sorghum flour, with the addition of grape skin. A Brabender 19/20 DN single screw extruder was used for the experiments. The screw configuration was a compression ratio of 3:1; with a circular matrix of 3 mm in diameter. The screw speed, humidity and GP percentage were monitored according to the experimental design for each case, either using GP with rice flour or GP with sorghum flour. The extrudates were dried in a dryer with forced air recirculation. The extrudates were then used for physical and chemical characterizations to verify the effects of the parameters established in each experimental design. The results referring to the processing of formulations with GP/Rice flours (15/85, 20/80 and 25/75%, respectively), resulted in that higher percentages of GP in the formulation and screw speed create higher values in the longitudinal expansion index (LEI). This effect may be due to a reduction in viscosity and causing less starch conversion. By increasing screw speed, the water solubility index (WSI) was increased. Grape skin showed a negative effect on the extruded flour, by improving the starch-reduction interaction and consequently reducing solubility. Color is an important product parameter for consumers. The grape skin flour was darker and the control lighter due to the absence of grape skin. Thus, by increasing the grape skin content, the color of the extrudates became darker, indicating that the grape skin had a strong effect on the color of the extruded flours. The results obtained demonstrated that the incorporation of grape skin in rice is feasible. However, it is necessary to make some adjustments in the processing parameters to obtain a product.

COMMITTEE MEMBERS:
Presidente - ***.290.788-** - JOSÉ LUIS RAMIREZ ASCHERI - EMBRAPA
Interno - 2455049 - JOSE LUCENA BARBOSA JUNIOR
Externo à Instituição - REGINALDO FERREIRA DA SILVA - UFAC
Externo à Instituição - FELIPE MACHADO TROMBETE - UFSJ
Externo à Instituição - MANUEL SALVADOR VICENTE PLATA OVIEDO - UTFPR