Effect of Processing Conditions During the Partial Germination of
Whole Yellow Peas on the Quality of Spaghetti and Extruded Snacks
P. Frohlich1, G. Boux1, L. Malcolmson²
1Canadian International Grains Institute (Cigi), Winnipeg, Manitoba, Canada
2LM Food Solutions, Winnipeg, Manitoba, Canada
»» Similar Minolta colour values were observed for Pargem and untreated
spaghetti samples (Table 3).
»» All samples had similar crispiness values. Significantly higher fracturability
values were observed for both Pargem I and II samples when compared to
the untreated sample (Table 4).
Table 1. Effect of short germination time/high drying temperature (Pargem I) and long
germination time/low drying temperature (Pargem II) on the cooking time of spaghetti
Cooking Time (min)
11.0
1
ll
l
m
m
ge
b
3.4
3.3
3.2
Values with the same letters are not significantly different (p<0.05)
ll
3.1
em
rg
10.0 ± 0.0a
b
Pa
Pargem l
3.5
l
10.3 ± 0.4a
3.6
ed
Pargem l
3.7
at
11.0 ± 0.7a¹
3.8
re
Untreated
ge
a1
em
100% Durum Semolina Reference
Extruded Snack Sample
695.4 ± 59.4a¹
658.9 ± 67.88a
562.3 ± 84.14a
Pargem I
624.8 ± 26.2a
542.1 ± 12.73a
483.4 ± 9.19a
Pargem II
571.3 ± 84.9a
477.5 ± 71.42a
422.5 ± 24.75a
Values with the same letters are not significantly different (p<0.05)
l*
a*
b*
61.1
4.3
46.4
Untreated
49.2 ± 0.4a¹
14.9 ± 0.3a
36.12 ± 0.1a
Pargem I
48.6 ± 0.3a
14.2 ± 0.3a
34.37 ± 0.5a
Pargem II
48.2 ± 0.9a
13.7 ± 0.6a
33.91 ± 1.0a
100% Durum Semolina Reference
1 Values
within a column with the same letter are not significantly different (p<0.05)
Table 4: Effect of short germination time/high drying temperature (Pargem I)
and long germination time/low drying temperature (Pargem II) on the texture
(crispiness and fracturability) of extruded snacks
Extruded Snack Sample
Crispiness2
Fracturability3
Untreated
362 ± 3a¹
1543.0 ± 81.1a
Pargem I
414 ± 1a
2075.1 ± 128.0b
Pargem II
387 ± 1a
2222.4 ± 56.0b
Values with the same letters are not significantly different (p<0.05)
2 Determined using a TA.HD Plus Texture Analyzer expressed as the number of peaks during compression
3 Determined using a TA.HD Plus Texture Analyzer expressed as the linear distance between two points
on the compression curve
1
b
b
0.07
0.06
a1
0.05
0.04
0.03
0.02
0.01
ll
Untreated
0.08
em
449.0
rg
473.0
100% Durum Semolina Reference
Pa
532.0
Spaghetti Sample
l
Force at
12 min.
m
Force at
10 min.
Figure 3.
Effect of short germination time/high drying temperature (Pargem I) and long germination
time/low drying temperature (Pargem II) on the bulk density of extruded snacks
rg
e
Force at
8 min.
¹Values with the same letter are not significantly different (p<0.05)
Pa
Table 2: Effect of short germination time/high drying temperature (Pargem I) and long
germination time/low drying temperature (Pargem II) on the cooked spaghetti texture
measured at 8, 10 and 12 min.
Spaghetti Sample
cigi.ca
4.0
rg
Spaghetti Sample
Spaghetti Sample
Figure 2.
Effect of short germination time/high drying temperature (Pargem I) and long germination
time/low drying temperature (Pargem II) on the expansion ration of extruded snacks
3.9
Table 3. Effect of short germination time/high drying temperature (Pargem I) and
long germination time/low drying temperature (Pargem II) on the Minolta colour values
(l*, a*, b*) of dried spaghetti
@CigiWinnipeg
0.0
¹Values with the same letters are not significantly different (p<0.05)
»» Both Pargem samples had significantly higher bulk density values than the
untreated extruded snack samples (Figure 3).
1
Cigi
1.0
ed
Pargem and untreated pea flours were blended with corn meal at a ratio of 50:50
and extruded into a directly expanded extruded snack using a pilot scale twin screw
cooking extruder (EV-25 Clextral, France). The quality of the extruded snacks was
assessed by measuring the expansion ratio bulk density and texture (crispiness
and fracturability). Texture of the snacks was measured using a TA.HD Plus texture
analyzer equipped with a Kramer shear cell.
2.0
at
Extruded Snacks
3.0
nt
re
Colour (l*, a*, b*) of the dried spaghetti was determined using a Minolta CR-310
colorimeter. Cooking time, cooking loss and cooked spaghetti firmness were
determined according to AACC Method 66-50 Pasta and Noodle Cooking Quality
– Firmness. A 100% durum semolina sample was used as a reference.
4.0
nt
Pargem and untreated pea flours were blended with durum semolina at a ratio
of 30:70 and extruded into spaghetti using a Namad lab scale extruder (Model
number: Press 30C Rome, Italy). Following processing, the spaghetti was dried in
a Buhler batch dryer (CH-9240TDEL, Switzerland).
5.0
U
Spaghetti
6.0
U
Pargem peas were milled into flour using a Condux Universal Mill (Model GM280/
S-D, Germany) set to 9,000 rpm to produce a flour of a similar particle size distribution
as the commercially pin milled untreated flour used as a control. The flours were
then processed into spaghetti and a directly expanded extruded snacks.
a1
Pa
r
Flour Milling
»» Expansion ratios of snacks made with both Pargem samples were
significantly lower than those made from untreated peas (Figure 2).
7.0
Pa
r
Extruded Snacks
ab
1
Se 00%
R m D
ef ol u
er in ru
en a m
ce
The Pargem process was developed by Buhler AG in Switzerland. The process
consists of soaking, partial germination and kilning of peas. In this study, whole
Canadian yellow peas were partially germinated using two different germination
conditions: short germination time/high drying temperature (Pargem I) or long
germination time/low drying temperature (Pargem II).
b
8.0
Cooking Loss (%)
»» ThePargem I spaghetti sample exhibited higher cooked texture values when
compared to the Pargem II sample, however the values were not statistically
significant (Table 2).
9.0
Expansion Ratio
Partial Germination (Pargem)
»» Both Pargem samples showed higher cooking loss values compared to the
untreated yellow pea spaghetti. Cooking loss was significantly higher in the
Pargem ll sample compared to the untreated spaghetti treatment (Figure 1).
10.0
Bulk Density mg/cm3
Materials and Methods
»» Similar cooking times were observed for Pargem I, II and untreated spaghetti
samples (Table 1).
Pa
Spaghetti
at
ed
Developing processed foods with whole yellow pea flour results in products
exhibiting improved nutritional characteristics. It has been suggested that a
controlled partial germination process of whole yellow peas prior to flour milling can
improve the nutritional and flavour characteristics of these ingredients. Research
indicates that processed foods that include flour milled from partially germinated
peas exhibit some differences in end-product quality. It is not known, however,
if the processing conditions during partial germination (germination time and
drying temperature) will have an effect on end-product quality of products such
as spaghetti and directly expanded extruded snacks.
Figure 1.
Effect of short germination time/high drying temperature (Pargem I) and long
germination time/low drying temperature (Pargem II) on the cooking loss of spaghetti
nt
re
Results and Discussion
U
Objectives
Extruded Snack Sample
¹Values with the same letter are not significantly different (p<0.05)
Conclusions
»» Overall, differences in end-product quality were observed in spaghetti and
extruded snacks made with partially germinated and untreated peas.
»» Yellow peas subjected to a long germination and a low drying temperature
resulted in spaghetti with a higher cooking loss and lower texture value.
»» Altering processing conditions during germination resulted in a small effect
on the quality of extruded snacks. However, extruded snacks made using
germinated pea flour showed significant differences in end-product quality
when compared to snacks made using untreated pea flour.
Acknowledgements
Funding for this project was provided Alberta Innovates – Bio Solutions, Alberta Crop Industry Development
Fund and the Alberta Pulse Growers Commission. Special thanks to collaborating organizations that include
Buhler AG, Leduc Food Processing Development Centre, University of Manitoba, Agriculture and Agri-Food
Canada and Pulse Canada. The assistance of Cigi technical and communications staff is greatly appreciated.