Transcript Diapositiva 1 - Feeding Knowledge

Ist International Symposium on Functional Drinks & Smart
Waters: solutions for a new revolution
Effect of High Pressure Supercritical CO2
Treatment on Antioxidant Components of
Blood Orange Juice
S. Fabroni 1, E. Maccarone 2, P. Rapisarda
1
1
C.R.A. Centro di Ricerca per l’Agrumicoltura e le Colture Mediterranee, Acireale (CT), Italy
2
Department of Horticulture, Floriculture, Arboriculture and Agrofood Technology (DOFATA), University of Catania, Italy
Malta polyphenols 2007 - November 14 & 16, 2007
Orange fruit production in Italy
PIGMENTED varieties: 70%
 Tarocco
40%
 Moro
 Sanguinello
BLOND varieties: 30%
 Navel group
 Valencia
 Biondo Comune
TAROCCO ORANGE
MORO ORANGE
SANGUINELLO ORANGE
Blood Orange Characteristics
With Respect To Blond Ones
 unique flesh and rind color due to red pigments belonging to the
anthocyanin class
 intense and characteristic aroma
 balanced sugar-acid ratio
 higher concentrations of vitamin C
 higher concentration of hydroxycinnamic acids and flavanones
 important biological role owing to their antioxidant activity
Approximately 50% of the production of these varieties is sent
to firms for juice processing
Fresh Unpasteurized Juice
 Minimal treatment after extraction
before packaging and distribution
 Must be stored at 4 °C
 Excellent flavor, but shelf life < 3 days
Preservation Techniques in Orange Juice
Processing
Required to:
 Destroy microbial contaminants
 Inactivate enzymes
(e.g.: PME to stabililize cloud)
Extend shelf-life
Traditional thermal methods
Emerging non-thermal methods
Orange Juice Thermal Pasteurization
88÷91°C in tubular or plate heat exchangers for 30 sec
Cold-pasteurization by Supercritical CO2
Conditions:
Pressure: 350-380 bar
Temperature: 33°C
Flow rate: 900 L/h (CO2 10%)
Residence time: 14,4 min
Changes of Physicochemical parameters
Untreated Juice
(UJ)
Treated juice
(TJ)
TSS (°Brix)
11,98
12,38
pH
3,44
3,43
TA (% citric Acid)
1,43
1,38
L*
27,99 B
32,94 A
a*
29,09 A
27,66 B
b*
21,44 B
26,34 A
Cloud (λ=650)
0,28 B
1,44 A
1261,04 A
929,11 B
Physicochemical parametersa
PE activity/g of pulp
aMeans,
n=3 represents the trends seen in three additional trials
Average
Cloud increase:
407,95%
Average
PE decrease:
26,32%
Changes of Antioxidant components
Untreated Juice
(UJ)
Treated juice
(TJ)
73,22 a
69,94 b
Total anthocyanins (mg/L)
127,82 A
122,31 B
Total Flavanones (mg/L)
68,90 B
91,37 A
Total Carotenoids (mg/L)
10,71 b
11,36 a
976,99 b
996,93 a
Caffeic acid (mg/L)
1,87 b
2,41 a
P-Coumaric
9,69 B
13,43 A
Ferulic acid (mg/L)
16,81 b
21,61 a
Sinapic acid (mg/L)
3,03 ns
3,63 ns
Antioxidant componentsa
Vitamin C (mg/100 ml)
Total Phenolics (mg/L)
aMeans,
acid (mg/L)
n=3 represents the trends seen in three additional trials
ORAC (µmol trolox equiv/100 ml)
2156 b
2472,92 a
Conclusions
 No relevant alteration of the quality characteristics of the juice
 Enhanced cloud in spite of still active PE
 average increased values for flavanones, phenolic acids, carotenoids and
total phenolics
 Evident increase of ORAC units
Potential
use
of
pressurized
supercritical
CO2
treatment
to
stabilize orange juice while improving the ‘functionality’ of freshly
squeezed blood orange juice
Thanks for your attention