Banca de QUALIFICAÇÃO: ROMAYANA MEDEIROS DE OLIVEIRA TAVARES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ROMAYANA MEDEIROS DE OLIVEIRA TAVARES
DATE: 30/09/2020
TIME: 14:30
LOCAL: Sessão pública realizada por videoconferência
TITLE:

EFFECT OF BLEACHING AND KINETIC STUDY FOR THE BENEFIT OF GREEN BEANS [Vigna unguiculata (L.) Walp.]

KEY WORDS:

Heat treatment; peroxidase; quality attributes; legume; Shelf Life; quality control.

PAGES: 92
BIG AREA: Ciências da Saúde
AREA: Nutrição
SUMMARY:

The green bean is a leguminous vegetable of the species Vigna unguiculata L. Walp., Which has an important role in the economy and nutrition of several populations, mainly in South America, Asia, Africa, Central America, and the Middle East. However, the high perishability of grains causes the marketing to be impaired and sometimes discontinued. Procedures such as blanching are a technological alternative for this type of grain, to benefit production and give greater durability to green beans. The study aims to investigate the effects of blanching, study the kinetic models of the reactions, and evaluate the shelf life of fresh and blanched green beans stored under refrigeration. Experiments were carried out in different time-temperature binomials with six times (1, 2, 4, 6, 8, and 10 minutes) and three different temperatures (70, 80, and 90 °C). The fresh and blanched grains were evaluated for enzymatic activity, firmness, color, mass gain, and the kinetic behavior of these parameters. The analysis of shelf life under refrigeration was carried out with the study of physical-chemical variations, microbiological patterns, enzyme activity, and photographic monitoring. The investigation of the blanching effect showed a significant decrease (p < 0.05) in the enzymatic activity after the application of the thermal shock, with relative activity ranging from 55.24 (2.09) to 1.25 (0.51) depending on the time-temperature binomial used. However, the application of high temperatures for a long period had a negative effect and compromised the firmness, causing softening of the beans of green beans, as well as, a greater percentage of the mass gain and decrease of the green shade in the grains. The dependence on decreased enzymatic activity, firmness, and color with temperature followed the first-order model. The values of the coefficient of determination (R2) indicated the satisfactory adaptation of the data to the model in all the response variables and investigated temperature ranges. The study of the effects and the kinetic model showed that the use of temperature and mild time (70 °C for 4 minutes), was favorable for the maintenance and/or improvement of the physical characteristics of the raw material. The analysis of the shelf life of the grains showed that blanching was beneficial for prolonging the shelf life. The pH and ATT remained unchanged during the storage period under refrigeration, presented a significant logarithmic reduction (p < 0.05) in the microbial load until the eighth day of analysis, and maintained the reduction of POD activity in bleached green beans, showing no significant difference (p > 0.05) until the eighth day of storage.

BANKING MEMBERS:
Interno - 3652554 - FRANCISCO CANINDE DE SOUSA JUNIOR
Presidente - 3211846 - KARLA SUZANNE FLORENTINO DA SILVA CHAVES DAMASCENO
Externo à Instituição - ROBERTO RODRIGUES CUNHA LIMA
Externo à Instituição - SAULO LUÍS CAPIM