Impact of reciprocating agitation thermal processing. (RA-TP) on quality of canned vegetables was studied. For this, fresh vegetables (potato and radish) were.
Evaluation of Thermal Degradation of Quality Attributes for Potato & Radish Jia You, Anika Singh, Anubhav P Singh and Hosahalli S. Ramaswamy Food Science & Agricultural Chemistry, McGill University (Macdonald Campus), Sainte-Anne-de-Bellevue, Quebec, Canada – H9X 3V9
Visual analysis
Methodology
Abstract Thermal Kinetics
Canning of vegetables
Potato cubes (15 x 15 x 15 mm) & uniform size
For this, fresh vegetables (potato and radish) were
whole red globe radish (average radius: 15 mm)
processed in 307 X 409 cans with brine solution (1%
were
NaCl + 1% CaCl2) and subjected to RA-TP in a custom
80 ºC, 90 ºC and 95 ºC) for various instants of time.
modified steam retort at different retort temperatures
Samples were cooled to the room temperature for
(110, 120 and 130°C) and reciprocation frequencies (0,
Reciprocating retort (Fig. 1) was employed; Potato & radish in brine were processed in
subjected to different temperatures (70 ºC,
307X409 cans subjected to reciprocating agitation Operating temperatures: 110, 120 & 130°C;
quality analysis;
0.75, 1.5, and 3 Hz). Different quality attributes (visual
Reciprocation frequencies: 0.75, 1.5, & 3 Hz
Reciprocating Retort (Singh et al., 2015)
quality, color, texture, % residual solids in covering
Quality Analysis
liquid and antioxidant activity) were evaluated. In general, RA-TP resulted in better quality of processed
Hardness, chewiness & gumminess were obtained
vegetables due to shorter process times. Higher
with a 2 kg load cell and a cylindrical aluminum probe
temperatures and higher reciprocation frequencies
using Texture Exponent software;
resulted in better retention of color and antioxidant
Color: L, a, b value & total color loss were evaluated
Reciprocating Cage
activity. Although extreme high frequency agitation
by using a Minolta Tristimulus Colorimeter:
induced severe texture damages, particle breakage and
Total color change; ∆𝐸 =
nutrient leaching, these effects were minimized at
assay as detailed in Singh & Ramaswamy, (2014).
Thus, RA-TP under high temperatures was found to be
Introduction & Objective
of
reciprocating agitation thermal processing on quality of canned
potato
and
radish
with
the
purpose
of
identifying conditions that allow better retention of quality parameters
2 3 Temperature (ºC)
0
4
60
5
70
80
90
100
3000 2000 1000
0
3
2.5
y = -0.2406x + 2.7684 R² = 0.9668
2.5 1.5 L-value
1
△Evalue
0.5 0 0
y = -0.2798x + 2.1767 R² = 0.9258
2 4 Temperature (ºC)
y = -0.0322x + 4.3006 R² = 0.9957 y = -0.0467x + 5.5333 R² = 0.9943
2
2
1.5 Hardness
1
Gumminess
0.5 6
Fig 2: D vs T curves for potato & radish
y = -0.0294x + 3.8455 R² = 0.9754
Chewiness
0 60
70
80 90 Temperature (ºC)
90 60 30
0
Temperature (ºC)
100
Fig 3: D vs T curves for potato & radish
0.75
1.5
110 ºC
120 ºC
1500 1000 500
0
0.75
1.5
various temperatures and establish the kinetic Color for both vegetables followed 1st order reaction kinetics
2. To investigate the quality retention in canned potato
Rate of thermal softening of vegetables well fitted the 1st order at
& radish under the reciprocation agitation thermal
lower temperatures however, at higher temperatures softening rate
processing.
was described by two simultaneous pseudo first order reaction kinetics.
References
6 Total color change in potato (ΔE)
parameters.
110 ºC
150
It was observed that reciprocating agitation can be very effective for getting firm product with less effect to the color. The best quality of vegetables was obtained at 130 ºC in 3 Hz for potato and at 130 ºC in 1.5 Hz for radish. Excessive agitation during RA-TP can result in particle breakage
130 ºC
90 60 30
1.5
3
110 ºC
120 ºC
130 ºC
60
30
0
0
0.75
1.5
0 0.75 1.5 Reciprocation frequency (Hz)
3
Reciprocation frequency (Hz)
120 ºC
130 ºC
4 2 0 0
0.75
1.5
3
0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0
110 ºC
0
Reciprocation frequency (Hz) 35
Total color change in Radish ( ΔE)
for texture, 36-42 ºC for color & 61 ºC for antioxidant activity.
120 ºC
120
3
0.75
Reciprocation frequency (Hz)
0
110 ºC
For Potato, z values were 20-25 ºC for texture, 43-46 ºC for color & 39 ºC for antioxidant activity and for radish, z values were 21-34 ºC
Singh, A. P., Singh, A. & Ramaswamy, H. S. (2015). Modification of a static steam retort for evaluating heat transfer under reciprocation agitation thermal processing. Journal of Food Engineering. 153, 63-72. Rattan, N. S. & Ramaswamy, H. S. (2014). Comparison of free/bi-axial, fixed axial, end-over-end and static thermal processing effects on process lethality and quality changes in canned potatoes. LWT-Food Science and Technology, 58(1), 150-157.
0
3
3
Fig 5: Effect of RA-TP on texture of potato & radishes
Conclusions
kinetics of texture and color of potato and radish at
1.5
90
Reciprocation frequency (Hz)
1. To study and characterize the thermal destruction
0.75
180
0 0
100
Reciprocation frequency (Hz)
130 ºC
130 ºC
0
Reciprocation frequency (Hz) 2000
120 ºC
200
0
3
110 ºC
130 ºC
Gumminess (g Force)
Chewiness
4000
120 ºC
Chewiness (g Force)
effect
0.5
y = -0.2184x + 1.92 R² = 0.907
y = -0.0488x + 5.5753 R² = 0.9565
110 ºC
130 ºC
Antioxidant activity (% DPPH Inhibition =x*100%)
the
1
Gumminess
120 ºC
110 ºC
120 ºC
130 ºC
25 15 5 -5
0
0.75
1.5
120 ºC
130 ºC
0.75
1.5
3
Reciprocation frequency (Hz)
3
Reciprocation frequency (Hz)
Fig 6: Effect of RA-TP on total color change
Antioxidant activity (% DPPH Inhibition = x*100%)
0
log D
investigate
1
0
scientific studies on the quality of canned vegetables to
△E-value
Hardness
110 ºC
Chewiness (g Force)
0.5
objective in process design. However, there is lack of
order
L-value
1.5
120
Gumminess (g Force)
1.5
the quality loss during thermal process is an important
when subjected to reciprocation agitation processing.
Log D
2 1
y = -0.0458x + 5.5185 R² = 0.9865 y = -0.0399x + 4.8814 R² = 0.9765
2
Log D
are also susceptible to heat damage. Minimization of
2.5
log D
texture, color, antioxidant compounds, vitamins etc.
y = -0.234x + 3.0666 R² = 0.9814
300 5000
2.5
3
cause severe damage to the quality attributes of
Texture kinetics
Hardness (g Force)
foods are well documented. Thermal processing can
Quality of canned vegetable
Hardness (g Force)
Color kinetics
Fig 4: Vegetables treated under different Processing conditions
analysis
Kinetics
Effect of thermal processing on quality of canned
In
Analysis of Variance was employed for statistical
Fig 1: Reciprocating Slider-Crank Assembly Retort
most suitable to obtain best quality products.
Hence,
∆𝐿2 + ∆𝑎2 + ∆𝑏 2
The antioxidant activity was measured using DPPH
higher temperatures due to shorter agitation time.
processed vegetable as many quality attributes such as
Potato
(RA-TP) on quality of canned vegetables was studied.
Radish
Impact of reciprocating agitation thermal processing
0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0
110 ºC
0
0.75
120 ºC
130 ºC
1.5
3
Reciprocation frequency (Hz)
Fig 7: Effect of RA-TP on antioxidant activity