Cooking and functional properties of parboiled milled local rice marketed in the south-east zone of Nigeria

Chinenye E. Azuka,Chinwendu R. Eze,Iro Nkama,Nahemiah Danbaba,Felix U. Asoiro

doi:10.7455/ijfs/9.2.2020.a5

Abstract

Imported rice is perceived to have better cooking properties than locally grown rice in Nigeria and it has increased its market share while reducing patronage for local rice. Rice in Nigeria has many applications, including consumption as whole cooked grain or dumpling or use as an adjunct in making beverages. Eighteen varieties of parboiled milled local rice and three imported rice varieties, coded Ip1, Ip2 and Ip3, were studied for their cooking and functional properties using standard methods. There was a significant (p<0.05) increase in the dimensions of all the rice varieties when cooked. There was a 25 g increase in the grain weight and an elongation ratio of more than 1.26 in all the rice varieties. Ghesua had the highest cooked grain weight (68.67 g) while Omor-Mas (6.00) and R-Bus (6.00) had the highest volume expansion ratio (VER). The VER was more than 3.00 for all the rice varieties. All the local rice varieties imbibed less water (17.67-25.33 ml) compared to the imported rice varieties (26.00-27.67ml) before they reached their optimum cooking time. The imported rice varieties were of soft gel consistency (89.67-73.50 mm) and intermediate amylose content (20.71-23.14 %) while the local rice varied in amylose and gel consistency. Abakiliki-Mas (27.00 mm) and R-8 (33.67 mm) were of hard gel-consistency, intermediate (21.11 %) and high amylose (27.21 %) content respectively and have not been exploited although they would be appropriate for making canned rice, dry mixes and rice-noodles.

Highlights

Rice is the staple food for over 3 billion people, constituting over half of the world’s population (Abiona, 2011; Anonymous, 2009; Danbaba et al, 2014; Imolehin & Wada, 2000; Muthayya, Sugimoto, Montgomery & Maberly, 2014; Oko & Ugwu, 2011; Sanusi, Akinoso & Danbaba, 2017) especially in India, China, other parts ofAsia, and Africa (Akaeze, 2010)
Amylose Content (AC) was determined according to the method of Juliano (1971). 100mg of rice flour was poured into a 100 ml volumetric flask. 1ml of 95% ethanol and 9 ml of 1 N NaOH was added to the rice flour and the mixture heated for 10 minutes in a boiling water bath
Amylose content of the samples was determined in reference to a standard curve and expressed on percent basis

Summary

Introduction

Rice is the staple food for over 3 billion people, constituting over half of the world’s population (Abiona, 2011; Anonymous, 2009; Danbaba et al, 2014; Imolehin & Wada, 2000; Muthayya, Sugimoto, Montgomery & Maberly, 2014; Oko & Ugwu, 2011; Sanusi, Akinoso & Danbaba, 2017) especially in India, China, other parts ofAsia, and Africa (Akaeze, 2010). Nigeria has been the largest rice producing country in West Africa since 1980 and the third largest in Africa, after Egypt and Madagascar (Imolehin & Wada, 2000). 2007 (Diagne, Bamba, Manful & Ajayi, 2011). This led to importation of rice from Thailand and USA as the quantity produced in Nigeria was not enough for the masses. Rice quality is partially determined by the genetic makeup of a variety but mainly by a variety of subjective and objective factors (Bida, 2013; Mutters & Thompson, 2009). Among the qualities determined objectively are the cooking and functional properties of the rice grain (Webb, 1972). Cooking properties’ evaluation is essential in order to know the way in which each rice vari-

Objectives

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Results

Conclusion