Prospects of Maize in India as a Source of Edible Oil
Authors: Varun Kumar Badaya and Amit Dadheech
Department of Plant Breeding and Genetics, Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur-313 001, Rajasthan, India.
Email: varunbadaya67@gmail.com


Introduction

Maize is known as queen of cereals because of its high genetic yield potential and it can be grown in diverse seasons and ecologies. Maize assumes worldwide significance since it serves as staple food for billions of people in Africa, South America and Asia. It plays significant role in human nutrition too. It is primarily used for feed (60%) followed by human food (about 24 %), industrial (starch) products (14 %), beverages and seed (1% each) and oil (4.5%). It is one such crop which yields several useful products. Among several corn related products, corn oil is an emerging one. Corn oil is becoming popular among edible oils owing to its unique health related benefits (Dunford, 2005).

In India, corn oil is not very popular for domestic uses. Corn oil does not constitute a part of conventional food recipe in our country. High price of corn oil is a limiting factor in popularization of corn oil in the country. Moreover public awareness is also lacking in the country regarding the health benefit associated with corn oil. A great diversity of morphological, physiological and biochemical traits of maize, together with a very broad adaptability and genetic variability provide the development of types with various purposes in the process of selection (Pajic, 2007).

Properties of corn oil

Corn having oil content of more than 6% is called high oil corn. Corn oil is a pale yellow oil procured from the kernel of corn. The first commercial production of corn oil took place in 1889. Refined corn oil is tasteless and odorless oil. Corn oil is used as a cooking medium and for manufacturing hydrogenated oil.

From the standpoint of nutrition and quality, corn oil is rated superior to other edible oils as it is conducive to controlling cholesterol. The high Poly Unsaturated Fatty Acid (PUFA) content in corn oil meets the essential fatty acid requirements in human nutrition. In corn oil, the total percentage of PUFA constituted by linoleic acid (18:2) alone is about 60% and MUFA (oleic acid; 18:1) is about 24%. The percentage of fatty acids in common edible oils in total fat percent states that corn oil ranked fourth in PUFA content. India being the world’s largest importer and third largest consumer has commercial interest in corn oil by considering large planting under maize with high productivity.

Processing of corn oil

By knowing the important features of corn oil, refined corn oil is considered to be the best edible oil used internationally. Presently corn oil makes an inadequate proportion in the edible oil consumption. The corn oil also receives a high rating in terms of animal nutrition and corn germ cake is an important ingredient of high quality feeds. Processors carry out blending of oil such as corn oil with olive oil and rice bran oil etc. Blending with corn oil results in recommended ideal level of monounsaturated and polyunsaturated fatty acids. This ensures excellent flavor as well as the taste of food. Corn oil extraction also opens up new avenues of entrepreneurship to corn growers and processors. Research avenues states that the main criteria which can help to successfully implement the perspective plan of quality products for consumption and entrepreneurship of maize are the development of high oil corn.

Some basics about corn oil

Corn oil is an important value added product from left over embryo/germ in addition to starch extraction from endosperm of kernel. The commercial and economic value of discarded embryo is enhanced when corn oil is extracted from it. Hence, increasing the proportion of germ and oil content in germ will be the foremost objective of breeding for oil in corn. The main strategy for the development of high oil corn is the development of hybrids (single cross) with high oil content (> 6%). A high oil corn hybrid is the result of long term conventional selection and breeding for the trait. There exists a huge amount of genetic variability for oil content in maize populations (3-8 per cent). Literature illustrates influence of the male parent genotype through xenia effect where male genotype of high oil population has additive or dominant gene action causing the germ size of the normal oil hybrid to increase slightly and increase the concentration of oil in the germ with small change in grain yield.

Recently, there has been much interest in producing high oil corn from hybrids using top cross system where one type, representing 90 to 92% of the seed, is an elite hybrid taken as the “grain parent” (commercial hybrid detasselled during pollination) and other is elite high oil inbred. The pollen shed from these pollinator plants contain genes that cause a kernel to produce a much larger than average germ or embryo utilizing xenia effect. Contract production of high oil grain may offer corn growers higher profits through premiums.

Future prospects

In India, there is immense scope to increase the production of corn oil by improving the efficiency of oil extraction from corn germs. As the high oil material in maize is limited in India, hence emphasis should be given to develop new high oil inbred lines by importing new germplasm or by incorporating the high oil genes in the existing elite material. These lines may be used as pollinators with best existing single cross hybrids to increase the oil content in maize grain. This will solve the problem of not only quality edible oil but also save foreign currency in the country.

References:
1. Dunford, N. T. (2005). Germ Oils from Different Sources Bailey’s Industrial Oil and Fat Products, Sixth Edition, Six Volume Set. Edited by Fereidoon Shahidi. Copyright # 2005 John Wiley & Sons, Inc.
2. Pajic, Z. (2007). Breeding of maize types with specific traits at the Maize Research Institute, Zemun polje. Genetika 39(2): 169-180.


About Author / Additional Info:
I am currently pursuing Ph.D in Plant Breeding and Genetics from RCA, MPUA&T, Udaipur, Rajasthan (INDIA)