Banca de DEFESA: CRISTINA BARBOSA PEREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : CRISTINA BARBOSA PEREIRA
DATE: 09/02/2021
TIME: 10:00
LOCAL: Skype
TITLE:

Bioconservation by Lactobacillus casei of the cold pressed apple juice

KEY WORDS:

cold-pressed apple juice; bioconservation; Lactobacillus casei; sensory shelf life; Napping.

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 production of cold pressed juices has grown continuously. To maintain its quality, the processing of the cold-pressed juice does not include the use of heat and additives chemical as preservation method, resulting in a product with better nutritional and sensory characteristics. However, have short shelf life. In this sense, bioconservation because it is a natural method, without nutritional losses and easy implementation, emerges as an alternative to thermal and chemical conservation methods in food. Although bioconservation has proved to be a viable strategy, it is known that the process can influence the sensory profile of the product throughout the production chain. Thus, the present work aimed to use Lactobacillus casei as a bioconservative agent, extending the shelf life of the product, besides evaluating the influence of storage temperature of bioconserved cold pressed apple juice, under different sensory aspects. Thus, through the bioconservation process associated with refrigerated storage it was possible to guarantee the microbiological safety of the product during the shelf life of the juice ensuring a period 3 times longer (15 days) than currently offered by most companies (3- 5 days). During the 6 h of exposure of cold pressed apple juice added from Lactobacillus casei at 37 °C it was possible to identify through physical, chemical, and microbiological analyses that there were no significant changes that justified the occurrence of fermentation. However, during cold storage, increased pH levels and reduced acidity indicate the occurrence of malolactic fermentation. According to the viability of Lactobacillus casei, storage at 10 °C proved to be the best condition, providing an increase in viable cells in 1 logarithmic cycle after 7 days of storage. This result is related to higher pH and lower acidity, negatively influencing consumer acceptance. Product acceptance was obtained by 55 consumers who evaluated 8 samples of bioconserved cold pressed apple juice, stored for 15 days under different temperatures (4°C, 8°C, 10°C). Most of the samples received positive scores, evidencing good acceptability, provided that the time and storage temperature of the product were adjusted. Through a Weibull distribution, the sensory useful life was estimated and all samples, even those with higher rejection scores, presented useful life above that offered by most industries in the category. Through Napping® associated with the ultra-flash profile, it was possible to identify that consumers noticed differences between samples, arising from storage time and temperature. storage at 8 °C proved to be a viable alternative for the commercialization of the product, because it presented extended sensory service life, meets the difficulty of the industry in maintaining the cold chain (4 °C), besides ensuring the microbiological stability of the product. About the application of bioconserved apple juice as a basis for fruit and vegetable blends, although not all blends have obtained good acceptance, the strategy may be feasible since less than 28% of consumers identified characteristics of the fermentation process.

BANKING MEMBERS:
Presidente - 1806986 - ELISA HELENA DA ROCHA FERREIRA
Interna - 024.950.088-44 - ROSIRES DELIZA - EMBRAPA
Externo à Instituição - ANDRE FIORAVANTE GUERRA - CEFET/RJ