Evaluation of Thermal Degradation of Quality ...

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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