(Pisum sativum L.) przeznaczonego do wysiewu. The content of

Zeszyty Problemowe Postępów Nauk Rolniczych
nr 577, 2014, 63–71
THE CONTENT OF ORGANIC COMPOUNDS IN PEA
(PISUMSATIVUM L.) SEEDS
Krzysztof K. Jadwisieńczak, Dariusz J. Choszcz,
Stanisław Konopka, Joanna Majkowska-Gadomska,
Katarzyna Głowacka
Uniwersytet Warmińsko-Mazurski w Olsztynie
Summary. The aim of this study was to determine the content of organic compounds in pea
(cv. ‘Kelvedon Wonder’) seeds intended for planting. Chemical analyses were performed to
determine density, the content of dry matter, total sugars, protein, fat, dietary fiber and ash
in eight seed fractions separated at different velocities of the air stream. Seed surface structure was analyzed by scanning electron microscopy. The levels of organic compounds were
found to be optimal for pea seeds. Seed fractions separated at the highest air stream velocity
were characterized by significantly higher density and a significantly higher protein and fat
content. They also tended to accumulate higher amounts of total sugars and therefore had
higher germination capacity. A microscopic analysis revealed no significant differences in
seed coat structure and the number of starch grains between dry and imbibed pea seeds.
Key words: seeds, pea, chemical composition, seed coat structure
INTRODUCTION
The pea (Pisumsativum L.) is one of the oldest cultivated vegetables in the world. Peas
are also a traditional crop in Poland – they have been widely grown in our country for
centuries and are included in many commonly-used proverbs in the Polish language. Peas
are also very important in human nutrition. Both green garden peas, immature and fresh,
and sugar pea pods are eaten. Dry seeds are less commonly consumed, but they are still
a valuable protein source for humans and animals [Wierzbicka 2007, Remiszewski et al.
2007, Klimek and Zając 2009].
Corresponding author – Adres do korespondencji: Krzysztof Konrad Jadwisieńczak, Uniwersytet
Warmińsko-Mazurski w Olsztynie, Wydział Nauk Technicznych, Katedra Maszyn Roboczych
i Metodologii Badań, ul. Michała Oczapowskiego 11, 10-719 Olsztyn, e-mail: krzychj@moskit.
uwm.edu.pl
64
K.K. Jadwisieńczak, D.J. Choszcz, S. Konopka i inni
Pea seeds can be smooth or wrinkled, depending on the variety. Usefulness of pea
varieties for cultivation and food processing is genetically determined [Kumar et al. 2013,
Sharma and Bora 2013].
Commercial pea cultivars intended for the processing industry should be characterized by uniformity of pod setting, filling and ripening, and high yield stability, including
under adverse weather conditions, with seed yield above 20% of total green matter; they
should also be well suited for mechanical harvesting. ‘Kelvedon Wonder’ is a popular
commercial pea cultivar, resistant to lodging, with plant height of 40÷80 cm, upright
stems and small delicate leaves [Stelling 1994].
Pea seeds can be planted directly in the field. In Poland, planting takes place in early
spring, when the soil is moist and cold. The rate of seed germination and seedling emergence is very slow, which increases the risk of infection and pathogen attack [Pięta and
Pastucha 2008]. Seed material should be characterized by specific purity of 99% and
minimum germination capacity of 80%. Adverse weather conditions during the growing
season, including too high or low temperatures and high relative air humidity, contribute
to uneven ripening and yield decrease, thus deteriorating seed quality. After harvest, the
planting value of seeds is significantly affected by drying rate and temperature [Gugała
and Zarzecka 2009, Klimek and Zając 2009].
The aim of this study was to determine the content of organic compounds in pea (cv.
‘Kelvedon Wonder’) seeds intended for planting, and to analyze their coat structure.
MATERIALS AND METHODS
The experimental materials comprised pea cv. ‘Kelvedon Wonder’ seeds supplied by
a farm located in Gronówko, Kujawy-Pomerania Province. The seeds were planted on
10 April 2010. The recommended cultivation practices for peas were applied. Due to adverse weather conditions (heavy rainfalls), harvest was preceded by desiccant application
(Reglone 200 SL). After seven days, on 8 July, peas were harvested using a conventional
combine harvester. Dry seeds (ca. 5 tons) were placed into 25 kg bags and transported to
Przedsiębiorstwo Nasiennictwa Ogrodniczego i Szkółkarstwa “TORSEED” S.A. (Horticultural Seed Production and Nursery Co., Ltd) in Toruń, to perform a laboratory analysis
which revealed low germination capacity of seeds, at ca. 37%. The seeds could not be
used as breeding material. Due to the high market value of seeds, an attempt was made
to increase their germination capacity by cleaning with the use of the Petkus K-541 seed
cleaner equipped with an upper screen measuring ≠ 5.5÷8.0 mm and a lower screen with
a mesh size of ø 3.75÷4.25 mm. Cleaned and sized seeds still had low germination capacity of 53%. Repeated grading did not improve seed germinability and led to considerable
loss of choice-quality seeds, which constituted a serious problem for the seed processing
plant.
An average seed sample (ca. 5 kg) collected at ‘TORSEED’ [PN-EN ISO 13690:2007]
was transported to the laboratory of the Department of Separation Processes, University
of Warmia and Mazury in Olsztyn, where preliminary analyses were performed. The seeds
were uniform in size, and their diameter ranged from 5.9 to 6.5 mm. The experimental
procedure was divided into several stages. At the first stage, pea seeds were separated
Zeszyty Problemowe Postępów Nauk Rolniczych
The Content of Organic Compounds in Pea (Pisumsativum L.) Seeds
65
into fractions [Choszcz et al. 2011]. Seed density ρ, defined as mass [m] of the material
per unit volume V
, was determined by the indirect method. At successive stages,
seed fractions separated at eight different velocities of the air steam were subjected to
chemical analyses and evaluated under a scanning electron microscope. Analytical samples were collected from each batch of seeds, according to Polish Standard [PN-EN ISO
13690:2007]. The first samples was used to determine the content of: dry matter – by
drying the collected plant material at 105°C to constant weight [PN-90/A-75101/03],
total sugars – by the Tillmans method modified by Pijanowski [PN-90A-75101/11], protein, fat, dietary fiber and ash – with the use of a MPA 0620 spectrometer. The second
sample was divided into two subsamples, to evaluate the coat structure of dry (Fig. 1)
and imbibed (Fig. 2) seeds. The surface of dry seeds was analyzed under a JSM-5310LV
scanning electron microscope (JEOL, Japan) at 15 kV. Prior to the analysis, specimens
had been sputter coated with gold in the presence of argon (Fine Coater, JCF-1200). Imbibed seeds, cut along the micropyle, were stained with iodine-potassium iodide solution
(v/v, 1/2) (Fig. 4 and 5) and were evaluated under a LEICA M205C stereo microscope
equipped with a DFC 425C digital camera. The first and second datasets were processed
using the NSS Version 3.0 (Thermo Fisher Scientific) program and the LAS V3.8 program, respectively.
Fig. 1.
Rys. 1.
Dry pea seeds (scale 5 mm)
Suche nasiona grochu (skala 5 mm)
nr 577, 2014
Fig. 2.
Rys. 2.
Imbibed pea seeds (scale 5 mm)
Spęczniałe nasiona grochu (skala 5 mm)
Longitudinal sections of imbibed seeds
showing the embryo; k.z. – radicle, m.k.
– root apical meristem, h – hypocotyl,
cz.p. – epicotyl, m.p. – shoot apical meristem, z.l. – leaf primordia; l – cotyledons (scale 1 mm)
Przekroje przez zarodki napęczniałych
nasion grochu; k.z. – korzeń zarodkowy,
m.k. – merystem wierzchołka wzrostu
korzenia, h – hipokotyl, cz.p. – część pędowa zarodka, m.p. – merystem wierzchołka wzrostu pędu, z.l. – zawiązki
liści, l – liścienie (podziałka 1 mm)
Fig. 3.
Rys. 3.
Fragment of a pea cotyledon stained
with I/KI solution (v/v, 1 : 2). Starch
grains violet-blue (scale 200 μm)
Fragment liścienia grochu wybarwionego I w KI (v/v, 1 : 2). Ziarna skrobi
wybarwione na kolor fioletowo-granatowy. Podziałka 200 μm
Fig. 4.
Rys. 4.
Pea seed surface observed under
a scanning electron microscope at
15 kV (scale 250 μm)
Powierzchnia nasion grochu obserwowana w mikroskopie elektronowym skaningowym przy napięciu
15 kV (podziałka 250 μm)
Fig. 5.
Rys. 5.
The Content of Organic Compounds in Pea (Pisumsativum L.) Seeds
67
The results were processed statistically by ANOVA followed by Duncan’s (post-hoc)
test to identify homogeneous subsets of means, with the use of Statistica PL v. 10 software. Table 1 shows significant differences in seed density and chemical composition
(dry matter, protein and fat content) resulting from an increase in the critical velocity of
the air stream. Homogeneous subsets were denoted by the same letters. The relationships
between the studied parameters were determined by correlation and regression analyses.
Total sugars – Cukier ogółem
[g·100 g–1]
Protein – Białko
[g·100 g–1]
Fat – Tłuszcz
[g·100 g–1]
Dietary fiber
Błonnik pokarmowy
[g·100 g–1]
Ash – Popiół
[g·100 g–1]
1.15a
93.6a
13
15.6
23.9a
2.1a
10.6
4.3
11.55
1.16a,b
93.5a
39
15.7
24.7b
2.1a
10.1
4.2
a,b,c
Dry matter – Sucha masa
[%]
11.00
Density – Gęstość
[g·cm–3]
Germination capacity
Zdolność kiełkowania
[%]
Air stream velocity
Prędkość strumienia powietrza
[m·s–1]
Table 1. Chemical composition of pea seeds from different fractions
Tabela 1. Skład chemiczny nasion grochu z różnych frakcji
b
bc
b
12.10
1.17
93.1
51
15.4
24.8
2.2
11.1
4.6
12.65
1.18a,b,c,d
92.5c
69
15.8
24.8c
2.3c
10.8
4.6
13.20
1.19b,c,d,e
92.3c,d,e
71
16.2
25.1d
2.4c.d
11.5
5.2
d
d
d,e,f
13.75
1.21
14.30
1.23f,g
g
14.85
1.25
Mean
1.19
92.2
d,e,f
77
16.0
25.1
2.5
10.1
4.4
92.1d,e,f
81
16.9
25.2d
2.6e
8.8
4.2
e
e
f
92.0
87
16.9
24.5
2.7
8.6
3.8
92.7
61
16.1
24.8
2.4
10.2
4.4
a, b, c, d, e
– average valuas in columns determined with the same letters do not differ statistically significantly
(uniform groups) / wartości średnie w kolumnach oznaczone tymi samymi literami nie różnią się statystycznie
istotnie (grupy jednorodne).
RESULTS AND DISCUSSION
In Poland, habitat conditions are conducive to growing peas [Baraniak and Niezabitowska 2004]. However, the seedling field emergence index does not always meet producers requirements. Seedling emergence is determined by many factors, including seed
quality which is affected by seed production technology, seed vigor viability, germinability and age, as well as air temperature and humidity, and cultivation practices [Bujak and
Frant 2010]. The germination capacity of seeds depends, among others, on their chemical
composition [Andrzejewska et al. 2002, Klimek and Zając 2009]. Loss of seed vigor
and viability may be caused by three functionally interrelated factors: damage to the
cell membrane, inactivation of multiple enzymes and genome damage [Kopcewicz and
nr 577, 2014
68
K.K. Jadwisieńczak, D.J. Choszcz, S. Konopka i inni
Lewak 2002]. During storage, the dissimilation process occurs in seeds which increases
acidity and soluble sugar content, and decreases protein content. As a result, reducing
sugars undergo the Maillard reaction with proteins [Górecki and Grzesiuk 2002].
The density of pea seeds varied significantly between fractions, and it was found to
increase with increasing velocity of the air stream, from 1.15 g·cm–3 to 1.25 g·cm–3 (Table 1).
Dry legume seeds are a rich source of organic compounds [Remiszewski et al. 2007].
An analysis of the chemical composition of pea cv. ‘Kelvedon Wonder’ showed that the
dry matter content of seeds ranged from 92.0% in the fraction separated at air stream
velocity v = 14.85 m·s–1 to 93.6% in the fraction separated at v = 11.00 m·s–1. The noted
differences were significant are similar to those reported by [Kunachowicz et al. 2006].
A comparison of the dry matter content and germinability of pea seeds [Choszcz et al.
2011] indicates that seeds with a lower dry matter content are characterized by higher
germination capacity. There were no significant differences in total sugar concentrations
between seed fractions. The nutritional value of legume seeds is determined by protein
content [Messina 1999]. Research results show that the protein content of dry pea seeds
ranges from 23.8 to 30.0 g·100 g–1 [Kulig et al. 1997, Kunachowicz et al. 2006, Sabanis
et al. 2006, Wójtowicz 2009].
In our study, the protein content of pea seeds was within the above range, but significant differences were observed between seed fractions. The lowest protein content was
noted in seeds separated at air stream velocity of 11.00 m·s–1, while seeds separated at
v = 13.20÷14.30 m·s–1 had the highest protein concentrations. A comparison of the present
results with previous findings [Choszcz et al. 2011] shows that pea seeds from the fractions separated at higher air stream velocities were characterized by higher germination
capacity. A similar trend was noted with respect to the fat content of seeds, which ranged
from 2.1 g·100 g–1 to 2.6 g·100 g–1, and increased with increasing velocity of the air
stream. The dietary fiber content of seeds decreased as air stream velocity was increased
in the separation process. According to [Kunachowicz et al. 2006], the dietary fiber content of dry pea seeds should oscillate around 15 g·100 g–1. The values noted in our study
were lower. The highest dietary fiber content was observed in seed fractions separated at
air stream velocities of 11.00 to 13.20 m·s–1, and the lowest – in the fractions separated
at v = 14.30 and 14.85 m·s–1. The ash content of pea seeds cv. ‘Kelvedon Wonder’ varied
from 3.8 g·100 g–1 to 5.2 g·100 g–1, with no significant differences between fractions.
Table 2 presents the coefficients of correlation between the air stream velocity, seed
density and germination capacity vs. the nutrient content of seeds.
Variables affecting germination capacity (organic compounds) were selected and
a regression equation was derived. Decision variables that had the most significant effect on the germination capacity of seeds were dry matter (r > 0.96) and protein content
(r > 0.72).
A microscopic analysis revealed no significant differences in seed coat structure between dry and imbibed seeds (Fig. 4 and 5). In all analyzed groups, seed embryos had
similar structure, with normally developed radicles, hypocotyls and epicotyls, shoot apical meristems and leaf primordia. Starch grains in the cotyledon cells of pea seeds stained
violet-blue with iodine-potassium iodide solution (Fig. 4). No significant differences in
the number of starch grains were observed between groups.
Zeszyty Problemowe Postępów Nauk Rolniczych
Air stream velocity
Prędkość strumienia powietrza
[m·s–1]
Density – Gęstość
[g·cm–3]
Germination capacity
Zdolność kiełkowania
[%]
Dry matter – Sucha masa
[%]
Total sugars – Cukier ogółem
[g·100g–1]
Protein – Białko
[g·100g–1]
Fat – Tłuszcz
[g·100g–1]
Dietary fiber – Sucha masa
[g·100g–1]
Ash – Popiół
[g·100g–1]
Table 2. Coefficients of correlation between the analyzed parameters and the results of regression
analysis
Tabela 2. Współczynniki korelacji między analizowanymi parametrami i wynikami analizy regresji
Air stream
velocity
Prędkość
strumienia
powietrza
[m·s–1]
1.0000
–
–
–
–
–
–
–
–
Density
Gęstość
[g·cm–3]
0.8655
1.0000
–
–
–
–
–
–
–
Germination
capacity
Zdolność
kiełkowania
[%]
0.8390
0.8784
1.0000
–
–
–
–
–
–
Dry matter
Sucha masa
[%]
–0.8424 –0.8972 –0.9631
1.0000
–
–
–
–
–
Total sugars
Cukier ogółem
[g·100g–1]
0.7983
0.9140
0.7361
–0.7894
1.0000
–
–
–
–
Protein
Białko
[g·100 g–1]
0.5021
0.4239
0.7242
–0.6328
0.3330
1.0000
–
–
–
Fat
Tłuszcz
[g·100 g–1]
0.9090
0.9850
0.8961
–0.9395
0.9050
0.4639
1.0000
–
–
Dietary fiber
Błonnik
pokarmowy
[g·100 g–1]
–0.5701 –0.7510 –0.4361
0.4292
–0.7779 –0.0228 –0.6667
1.0000
–
Ash
Popiół
[g·100 g–1]
–0.2275 –0.4022 –0.0391
0.0072
–0.3838
0.8611
1.0000
0.3765
–0.2877
Statistical analysis – Analiza statystyczna:
Significance level (α) / Poziom istotności (α)
0.05
Percentage of explained variation / Procent wyjaśnionej zmienności
94.96
Coefficient of multiple correlation / Współczynnik korelacji wielokrotnej 0.974
Calculated value of F statistic / Obliczona wartość statystyki F
56.5651
Probability level in p-test / Poziom prawdopodobieństwa testu
0.0001
Regression equation – Równanie regresji:
y = 2812.8599 – 32.7384 x1 + 11.3822 x2
x1 – Dry matter/Sucha masa [%]
x2 – Protein content/Zawartość białka [g·100 g–1]
y – Germination capacity/Zdolność kiełkowania [%]
70
K.K. Jadwisieńczak, D.J. Choszcz, S. Konopka i inni
CONCLUSIONS
1. The highest coefficients of correlation (exceeding 0.9) were noted between the fat
content of pea seeds vs. density, dry matter and total sugars. A high coefficient of correlation was observed between fat content and air stream velocity during the separation
process. A significant correlation was also found between the germination capacity of pea
seeds vs. the concentrations of dry matter and total sugars.
2. Among the analyzed organic compounds, the concentrations of dry matter and
protein had the most significant effect on the germination capacity of pea seeds, which
was further validated by a mathematical formula describing the relationships between
changes in the analyzed parameters. The suitability of the proposed equation for predicting the germination capacity of pea seeds was also confirmed by a high percentage
of explained variation (nearly 95%) and a high probability of exceeding the calculated
p-value (0.0001).
3. A microscopic analysis revealed no significant differences in seed coat structure
and the number of starch grains between dry and imbibed pea seeds.
LITERATURE
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siewnego (Pisum sativum L.) na glebach kompleksu żytniego bardzo dobrego. Acta Sci.
Pol., Agricultura 1 (1), 59–72.
Bujak K., Frant M., 2010. Plonowanie grochu siewnego w zależności od sposobu uprawy roli i poziomu nawożenia mineralnego. Ann. UMCS Lublin, sec. E65 (1), 18–25.
Choszcz D., Jadwisieńczak K., Konopka S., Majkowska-Gadomska J., 2011. Próba odseparowania
z materiału siewnego nasion grochu o niskiej zdolności kiełkowania. Inż. Roln. 5 (130),
39–45.
Górecki R., Grzesiuk S., 2002. Fizjologia plonowania roślin. Wyd. UWM, Olsztyn.
Gugała M., Zarzecka K., 2009. Wpływ gęstości siewu i sposobów pielęgnacji na plonowanie grochu siewnego (Pisum sativum L.). Fragm. Agron. 26 (2), 64–71.
Klimek A., Zając T., 2009. Produkcyjność grochu (Pisum sativum L.) na tle postępu hodowlanego.
Post. Nauk Roln. 1, 77–90.
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Kunachowicz H., Nadolna I., Iwanow K., Przygoda B., 2006. Wartość odżywcza wybranych produktów spożywczych i typowych potraw. Wyd. Lekarskie PZWL, Warszawa.
Kumar B., Kumar A., Singh A.K., Lavanya G.R., 2013. Selection strategy for seed yield and maturity in field pea (Pisum sativum L. arvense). Afric. J. Agric. Resear. 8 (44), 5411–5415,
DOI: 10.5897/AJAR2013.7332.
Kulig B., Pisulewska E., Ziołek W., Antoniewicz A., 1997. Wpływ sposobu zbioru na plonowanie
i jakość białka nasion dwóch odmian grochu siewnego. Zesz. Probl. Post. Nauk Rol. 446,
147–152.
Messina M.J., 1999. Legumes and soybeans: overview of their nutritional profiles and health effects. Am. J. Clin. Nutr., Suppl. 70, 439–450.
Pięta D., Pastucha A., 2008. Antagonistic bacteria and their post-culture liquids in the protection of
pea (Pisum sativum L.) from diseases. Acta Sci. Pol., Hortorum Cultus. 7 (4), 31–42.
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PN-EN ISO 13690:2007. Ziarno zbóż, roślin strączkowych i przetwory zbożowe – Pobieranie próbek z partii statycznych.
PN-90/A-75101/03. Oznaczanie zawartości suchej masy metodą wagową.
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aktywność przeciwutleniającą nasion wybranych roślin strączkowych. Żywność. Nauka.
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ZAWARTOŚĆ SKŁADNIKÓW ORGANICZNYCH W NASIONACH GROCHU
ŁUSKOWEGO (PISUM SATIVUM L.) PRZEZNACZONEGO DO WYSIEWU
Streszczenie. W pracy podjęto próbę określenia zawartości składników organicznych
w nasionach grochu łuskowego odmiany Cud Kelwedonu przeznaczonych do siewu. Przeprowadzono analizy chemiczne, w których oznaczono gęstość, suchą masę, cukry ogółem, białko oraz tłuszcz, błonnik pokarmowy i popiół dla 8 frakcji nasion wydzielonych
przy różnych prędkościach strumienia powietrza. Przebadano również ich strukturę, wykorzystując mikroskop skaningowy. Zawartość poszczególnych składników organicznych
kształtowała się na optymalnym poziomie dla nasion grochu. Frakcje nasion pozyskane
przy największej prędkości charakteryzowały się istotnie większą gęstością oraz zawartością białka i tłuszczu, jednocześnie wykazywały tendencję zwiększonego gromadzenia
cukrów ogółem, co miało odzwierciedlenie w zwiększeniu zdolności ich kiełkowania. Analiza mikroskopowa nie wykazała znaczących różnic w budowie okrywy nasiennej zarówno
na powierzchni suchych, jak i spęczniałych nasion grochu oraz nie zaobserwowano różnic
w występowaniu czy też liczbie ziaren skrobi.
Słowa kluczowe: nasiona, groch, skład chemiczny, struktura powierzchni
nr 577, 2014