Nanotechnology research on buckwheat may open doors

Bruce Barker
November 16, 2010
By Bruce Barker

For Dr. Suresh Neethirajan, it is the little things that are important. And when looking at nanotechnology, little means very, very little. A nanometre (nm) is one-millionth of a millimetre. To put that into perspective, a strand of hair is about 100,000 nanometres. Yet Neethirajan has developed nanotechnology techniques to help improve the understanding and market potential of buckwheat.

For Dr. Suresh Neethirajan, it is the little things that are important. And when looking at nanotechnology, little means very, very little. A nanometre (nm) is one-millionth of a millimetre. To put that into perspective, a strand of hair is about 100,000 nanometres. Yet Neethirajan has developed nanotechnology techniques to help improve the understanding and market potential of buckwheat.

Neethirajan, an agricultural and biological engineer from Manitoba, is currently a Japan Society for the Promotion of Science Fellow working at the National Food Research Institute in Japan. Along with Japanese scientist Dr. Shigeru Sugiyama, Neethirajan is currently using nano-tools for studying and characterizing the morphology of chromosomes of buckwheat. Sugiyama is the chair of the Food Nanotechnology Project of the Ministry of Agriculture, Food and Fisheries of Japan, and the head of the Nanobiotechnology unit of the National Food Research Institute. Their findings have direct implications on buckwheat production and could offer new approaches for buckwheat breeding. They have used nanotechnology tools to characterize the DNA, chromosomes and starch of buckwheat.

The research is highly novel, informative and offers new potential for buckwheat growers on the Canadian Prairies, in Japan, and in other parts of the world. Neethirajan explains that the interesting part of their research is that other than nanotechnology tools, no other tools or techniques currently exist to measure or observe the genetic makeup and chromosome structures of buckwheat. “We measured chromosome volumes, and the results can be of indirect use in developing new varieties. Chromosomes are determinant of species. If you watch the CSI (Crime Scene Investigation) TV show, you might wonder how they trace the culprit or the murderer. The federal agents use fingerprints and look for hair or any tissue related markers of the involved persons. The tissue or blood samples have DNA or information about genes in them. By means of analysis of chromosomes, it is possible to tell whether the victim is a male or a female or has any particular physical traits,” explains Neethirajan. “We followed a similar approach, but developed our own technique in measuring the chromosome volumes and morphological parameters using nanotechnology tools. The results of our research provide new information such as which species is of primary evolution.”

Karyotype analysis and classification of buckwheat chromosomes were performed using atomic force microscopy (AFM). Karyotypes describe the number of chromosomes and their appearance. The researchers also obtained accurate topographic features specific to each chromosome. More specifically, they attempted the quantitative karyotyping of the chromosomes of F. tartaricum and F. esculentum buckwheat using volume measurement. Chromosomes were morphologically characterized by the size, volume, arm lengths and ratios. A cytogenetical analysis, the study of the structure and function of buckwheat chromosomes, had not been studied accurately before and the researchers are the first to report on it using AFM technology. “We propose that the chromosome volume is an accurate karyomorphological parameter for classification of chromosomes considering the inconsistencies in banding patterns, and in locating the centromere. The karyotype evolutionary trend indicates that F. esculentum is a more advanced evolutionary unit than the F. tartaricum,” explains Neethirajan. “The results of our study complement marker-assisted breeding through identification of genetic linkage maps and provide evidence for further study of molecular phyletic evolution.”

Using nanotechnology to produce bioproducts

Since buckwheat is an underutilized crop, the researchers also foresee the potential application of buckwheat nanocrystals, and possibly nanoparticles, to expand markets and encourage producers to expand their buckwheat acreage. Their research using atomic force imaging tools suggests that buckwheat starch could be used as a new biopolymer material in industries.

Buckwheat starches had never been studied on a nanoscale, but the researchers achieved new understanding of starch granule morphology and concentric growth rings using nanotechnology. Light scattering experiments showed that the starch granule sizes were in the range of three to 11 micrometres (micron; µm) and were round to polygonal in shape. Partially digested starch granules revealed a clear pattern of growth rings with the central core showing lamellar structure. Aqueous suspensions of starch nanocrystals prepared from A-type buckwheat starch using acid hydrolysis process produced starch nanocrystals with sizes between three to five nanometres. AFM analysis revealed the nanoscale sizes and differences in shape of the nanocrystals.

Neethirajan explains that a multi-scale structure with alternating amorphous and semi-crystalline growth rings and lamellae makes the buckwheat an attractive material for nano-composite applications. “Buckwheat starches are under-exploited and our research results indicate that buckwheat could be an excellent biopolymer and could possibly find new applications in industries,” says Neethirajan. “The results of our project prove the possibility of efficiently producing nanocrystals with applications focusing on drug delivery systems, packaging materials to achieve medium barriers, and as functional material for paper coating, specialty food product coating, and adhesives.  Biocompatibility and biodegradability of buckwheat nanocrystals looks very promising and so the possibility of producing bio-based packaging and nano-composites from buckwheat is huge.”

Buckwheat provides valuable nutritious and medicinal properties
The nutritious advantages of buckwheat make it a valuable crop. It is also important as a medicinal food for people who have been exposed to radiation, and for its health benefits such as reducing blood sugar and curing heart blood vessels. Buckwheat is an important pseudocereal in Canada and there is a strong connection between Canada and Japan, as Canada is the third largest exporter of buckwheat to Japan behind China and the US. In Canada, the Prairie Provinces grow more than 85 percent of buckwheat, and almost 90 percent is exported. As a result, Neethirajan’s research on nanotechnology may eventually provide additional benefits to Canadian buckwheat producers.

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