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Development of High-Protein Oat for the Feed and Food Industry

SUNILKUMAR, BINDU LU (2016)
Abstract
Oats are an excellent source of high-quality proteins, with a favourable amino acid composition. Oat proteins therefore have great
potential to complement existing animal and plant protein sources, especially if the protein content could be increased. In this thesis,
high-protein oat lines were identified and characterised. More than a thousand individual lines in a mutagenised oat population
(Targeting Induced Local Lesions in Genomes (TILLING) population) were screened for total protein using an elemental particle
analyser. This identified 230 lines with a seed protein content of 15% protein or higher. Belinda, the original variety from which the
mutagenised population was constructed, had approximately 12%, and the... (More)
Oats are an excellent source of high-quality proteins, with a favourable amino acid composition. Oat proteins therefore have great
potential to complement existing animal and plant protein sources, especially if the protein content could be increased. In this thesis,
high-protein oat lines were identified and characterised. More than a thousand individual lines in a mutagenised oat population
(Targeting Induced Local Lesions in Genomes (TILLING) population) were screened for total protein using an elemental particle
analyser. This identified 230 lines with a seed protein content of 15% protein or higher. Belinda, the original variety from which the
mutagenised population was constructed, had approximately 12%, and the most protein-rich line had 24%.The amino acid
compositions for 31 of the high-protein lines were determined by various methods, and the contents of essential amino acids (EAA)
were evaluated according to the FAO/WHO amino acid recommendations. This showed that several of the high-protein lines
contained sufficient levels of EAAs, although there was some variability in the amounts of nutritionally limiting amino acids. Several
lines had higher EAA levels than Belinda. Five of the high-protein oat lines were selected for asymmetric flow field-flow fractionation
(AF4) analysis. In all experiments the AF4 instrument was connected to an online multi-angle light scattering (MALS) and ultraviolet
(UV) detection system. Greater variation was found in the quantity of soluble proteins in the different high-protein lines than in Belinda,
and a few lines had clearly elevated levels of globular proteins. Sodium-dodecyl sulphate polyacrylamide gel electrophoresis (SDSPAGE)
also revealed that the increase in protein in the high-protein lines was mainly due to an increase in the globulin fraction. The
effect of heat treatment on the soluble protein content in oat groats was also evaluated, using the AF4 system and amino acid
analysis. The results showed that the total amount of soluble protein was reduced by 50%, mainly due to a reduction in amino acids
associated with albumin and water soluble prolamins. An attempt was made to increase protein content by nitrogen fertilisation, and
effects on grain quality were also analysed using avenin protein of Belinda oat cultivars grown or developed under various fields and
in the greenhouse as a reference. Results showed that excess nitrogen fertilisation (≥ 100 kg/ha) increased total protein percentage
in Belinda and high-protein oat lines. Furthermore, oat lines grown under field conditions showed differences in avenin proteins when
compared to the corresponding lines grown in the greenhouse, as analysed by SDS-PAGE gel electrophoreses. This may explain
the differences in protein levels in cultivars grown under different environmental conditions. Crosses were performed between the six
lines with the highest protein levels and the original non-mutated Belinda variety from which the mutagenised population was derived.
The F1 hybrid seeds were grown in a greenhouse, and self-pollinated and individual seeds from the F2 offspring were analysed. This
showed that the high-protein character was stably inherited. To test this further, the 15 high protein lines were amplified in several
different plots in the field and the protein content was again determined in seeds harvested at the end of the season. This confirmed
the stability of the high-protein character. Total dietary fibre (TDF), ß-glucan and lipid levels were also measured in the selected lines.
The analysis showed that the values for these components were normally distributed around the original level in Belinda, i.e. there
was no positive or negative correlation between fibre, ß-glucan, lipid and high protein content. In conclusion, the high-protein oat
lines, identified here from an oat mutagenised population, proved to be phenotypically stable in the field and produced high-quality
proteins. When developed further, the resulting cultivars will be very valuable for future use in the food and feed industry. Total dietary
fibre, especially soluble and insoluble fractions andβglucans, is high in these lines, which is another important benefit in the use of
high-protein oat lines for food applications. Since oats in general give good yields and quality, especially in the Nordic countries, the
lines presented here have potential to become a new source of vegetable proteins and will enable the development of novel food
products based on oat. (Less)
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author
supervisor
opponent
  • Professor Svanberg, Ulf, Chalmers University of Technology
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Oats, protein, mutation, segregation, dietary fibre,βglucan, lipids, electophoresis, amino acids, fractionation, avenin,, dietary fibre, amino acid, beta glucan, crossing, amplification, quality, quantity, high protein, fractionation
pages
91 pages
publisher
Lund University
defense location
KC, Kemicentrum, Naturvetarvägen 14, Lund University, Faculty of Engineering
defense date
2016-10-21 09:15
ISBN
978-91-7623-936-0
978-91-7623-937-7
language
English
LU publication?
yes
id
44667216-de9f-4475-a0f1-4e085bf44b27
date added to LUP
2016-09-20 15:56:11
date last changed
2016-09-28 14:39:03
@phdthesis{44667216-de9f-4475-a0f1-4e085bf44b27,
  abstract     = {Oats are an excellent source of high-quality proteins, with a favourable amino acid composition. Oat proteins therefore have great<br/>potential to complement existing animal and plant protein sources, especially if the protein content could be increased. In this thesis,<br/>high-protein oat lines were identified and characterised. More than a thousand individual lines in a mutagenised oat population<br/>(Targeting Induced Local Lesions in Genomes (TILLING) population) were screened for total protein using an elemental particle<br/>analyser. This identified 230 lines with a seed protein content of 15% protein or higher. Belinda, the original variety from which the<br/>mutagenised population was constructed, had approximately 12%, and the most protein-rich line had 24%.The amino acid<br/>compositions for 31 of the high-protein lines were determined by various methods, and the contents of essential amino acids (EAA)<br/>were evaluated according to the FAO/WHO amino acid recommendations. This showed that several of the high-protein lines<br/>contained sufficient levels of EAAs, although there was some variability in the amounts of nutritionally limiting amino acids. Several<br/>lines had higher EAA levels than Belinda. Five of the high-protein oat lines were selected for asymmetric flow field-flow fractionation<br/>(AF4) analysis. In all experiments the AF4 instrument was connected to an online multi-angle light scattering (MALS) and ultraviolet<br/>(UV) detection system. Greater variation was found in the quantity of soluble proteins in the different high-protein lines than in Belinda,<br/>and a few lines had clearly elevated levels of globular proteins. Sodium-dodecyl sulphate polyacrylamide gel electrophoresis (SDSPAGE)<br/>also revealed that the increase in protein in the high-protein lines was mainly due to an increase in the globulin fraction. The<br/>effect of heat treatment on the soluble protein content in oat groats was also evaluated, using the AF4 system and amino acid<br/>analysis. The results showed that the total amount of soluble protein was reduced by 50%, mainly due to a reduction in amino acids<br/>associated with albumin and water soluble prolamins. An attempt was made to increase protein content by nitrogen fertilisation, and<br/>effects on grain quality were also analysed using avenin protein of Belinda oat cultivars grown or developed under various fields and<br/>in the greenhouse as a reference. Results showed that excess nitrogen fertilisation (≥ 100 kg/ha) increased total protein percentage<br/>in Belinda and high-protein oat lines. Furthermore, oat lines grown under field conditions showed differences in avenin proteins when<br/>compared to the corresponding lines grown in the greenhouse, as analysed by SDS-PAGE gel electrophoreses. This may explain<br/>the differences in protein levels in cultivars grown under different environmental conditions. Crosses were performed between the six<br/>lines with the highest protein levels and the original non-mutated Belinda variety from which the mutagenised population was derived.<br/>The F1 hybrid seeds were grown in a greenhouse, and self-pollinated and individual seeds from the F2 offspring were analysed. This<br/>showed that the high-protein character was stably inherited. To test this further, the 15 high protein lines were amplified in several<br/>different plots in the field and the protein content was again determined in seeds harvested at the end of the season. This confirmed<br/>the stability of the high-protein character. Total dietary fibre (TDF), ß-glucan and lipid levels were also measured in the selected lines.<br/>The analysis showed that the values for these components were normally distributed around the original level in Belinda, i.e. there<br/>was no positive or negative correlation between fibre, ß-glucan, lipid and high protein content. In conclusion, the high-protein oat<br/>lines, identified here from an oat mutagenised population, proved to be phenotypically stable in the field and produced high-quality<br/>proteins. When developed further, the resulting cultivars will be very valuable for future use in the food and feed industry. Total dietary<br/>fibre, especially soluble and insoluble fractions andβglucans, is high in these lines, which is another important benefit in the use of<br/>high-protein oat lines for food applications. Since oats in general give good yields and quality, especially in the Nordic countries, the<br/>lines presented here have potential to become a new source of vegetable proteins and will enable the development of novel food<br/>products based on oat.},
  author       = {SUNILKUMAR, BINDU},
  isbn         = {978-91-7623-936-0},
  keyword      = {Oats, protein, mutation, segregation, dietary fibre,βglucan, lipids, electophoresis, amino acids, fractionation, avenin,,dietary fibre, amino acid, beta glucan, crossing, amplification, quality, quantity, high protein, fractionation},
  language     = {eng},
  pages        = {91},
  publisher    = {Lund University},
  school       = {Lund University},
  title        = {Development of High-Protein Oat for the Feed and Food Industry},
  year         = {2016},
}