IMPACT OF ULTRASOUND APPLICATION ON QUALITY PARAMETERS IN MIXED ORANGE AND CARROT JUICE WITH ADDED PREBIOTIC
Name: BRUNA GASPARINI MACHADO
Publication date: 28/09/2021
Advisor:
Name |
Role |
|---|---|
| JACKLINE FREITAS BRILHANTE DE SÃO JOSÉ | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ÉRICA AGUIAR MORAES | Internal Examiner * |
| ERIKA MADEIRA MOREIRA DA SILVA | Internal Alternate * |
| JACKLINE FREITAS BRILHANTE DE SÃO JOSÉ | Advisor * |
Summary: Non-thermal food preservation methods such as ultrasound are alternatives to
traditional methods, providing nutritional benefits with an innovative
characteristic. The modern consumer`s interest in beverages such as fruit and
vegetable juices is a reflection of the global trend of consumption of
health-promoting foods, with blended juices being an alternative to
ultra-processed beverages. An incorporation of prebiotic substances, such as
fructooligosaccharide (FOS), into the primary mixed juice or as beneficial
health characteristics. For this, the ultrasound was researched in mixed
orange and carrot juice with the addition of FOS, which is a product with
high added value compared to conventional juices. In this context, the
objective of the present work was to evaluate the impact of treatments with
ultrasound (110W, 40 kHz, 5 minutes) combined with temperature (40°C, 50°C
and 60°C) on microbiological, physicochemical and compound aspects
bioactives and physical characteristics of the juice during storage (25 days,
6°C). Untreated juice was considered a control, and untreated juice added
with prebiotic and pasteurized juice was also evaluated. The juice was
prepared in an industrial blender with a 7:3 ratio of orange and carrot with
the addition of 3.2% of FOS, without the addition of water or preservatives.
Microbiological assays were performed by plating with PCA medium, PDA and
petrifilm plates for aerobic mesophilic, filament fungi and yeast and
coliform assays at 35 °C, respectively. Total titratable acidity was
performed by titration with a 0.1 N NaOH solution, pH by the potentiometric
method and total soluble solids with an analog refractometer. Instrumental
color analysis was performed in colorimeter, carotenoids and ascorbic acid by
high performance chromatography and by RP-18 column, respectively, and the
phenolic compounds and antioxidants were quantified using the Folin-Ciocalteu
reagent and DPPH radical test, respectively. Turbidity was calculated using a
spectrophotometer, sedimentation was calculated based on the sedimentation
index and microscopy using an optical microscope. Microbiological analyzes of
aerobic mesophiles, filamentous fungi and yeasts and coliforms at 35 °C did
not identify significant changes between treatments and times. The treatments
did not affect the values of total titratable acidity, pH, color,
carotenoids, ascorbic acid, phenolic compounds, antioxidant compounds and
turbidity. Total soluble solids showed a significant difference between the
control juice and the other treatments studied. Time affected turbidity,
ascorbic acid and antioxidant compounds values over the 25-day storage time.
Ultrasound treatments at 40°C/5 minutes and 60°C/5 minutes delayed the
sedimentation process. Microscopic analysis identified changes in cell
structure and extravasation of intracellular fluid, which may confer
desirable characteristics on juices treated with ultrasound. The weather
affected the values of turbidity, ascorbic acid and antioxidant compounds.
However, the ultrasound treatment preserved the characteristics of fresh
orange and carrot juice with the addition of prebiotic, with no significant
impacts on microbiological and physicochemical characteristics, as well as on
bioactive compounds, which can be justified by the low-severe process
parameters in the technology of barriers applied in this research.
