Authored by Niyonshima Alexandre*
Abstract
Rice (Oryza sativa) is among the seven crops of priorities in Rwanda that play a role in food security within household. Different varieties of rice both short and long are grown in Rwanda, among them Zong zeng, Yune Eritian and XY are grown and consumed in almost all parts of the country. The same for other crops, a huge amount of rice produced is lost during handling activities before reaching the consumer. The loss includes breakage, and loss of nutrients due to the removal of bran and husk. Different techniques are used for the reduction of such post-harvest losses of rice and rice parboiling is among the most useful techniques applied to reduce postharvest losses of rice and is now applied in different parts of the world. However, this technique has not yet been adopted by Rwandans for prevention of loss of rice after harvesting. Therefore, the objective of the present study was to assess the effects of parboiling technique on physico-chemical parameters of different rice varieties grown in Rwanda and to do its awareness for Rwandan population. Three new varieties: Zong Zeng, Yune Eritian, and XY were further prepared and analysed in comparing with the same rice varieties that is not parboiled. Paddy was weighed, cleaned 3 times, pre-steamed, soaked in water of 80 0C at ratio of 1: 2.5 in water bath set at 800C for 4 and 6 hours, and then the steaming was done for 10 min at 100 0C. Drying followed in order to reduce the moisture content using the dryer set at (20-25°C) and the the final moisture content was13%. Dried rice was then milled in a mortar by use of a pestle to remove husks. Nutritional analysis was done by measuring Ash, protein, fat and Vitamin B1. The findings of the present study show that parboiling resulted in increase of Fat, Vitamin B1, Protein and Ash content. 4 hours soaking time showed effect on the acceptability as the rice soaked for 4hours has been more accepted compared to the one soaked for 6 hours. 6 hours soaking time resulted in considerable increase of B1 compared to other used soaking times. Therefore, we can conclude that parboiling method is a good method for reduction of rice lost during rice processors and fighting against diseases such as beriberi caused by deficiency of Vitamin B1 due to its associated increase in B1.
Keywords: Zong Zeng; Yune Eritian; XY parboiling; Steaming; Vitamin B1.
Abbrevations: ANOVA: Analysis of Variance; CAVM: College of Agriculture, Animal Sciences and Veterinary Medicine; FAO: Food Agricultural Organization; G: Grams; MINAGRI: Ministry of Agriculture and Animal Resources; MINICOM: Ministry of Trade and Industry; MT: Metric Tones; NISR: National Institute of Statistics Rwanda; %: percentage; RCA: Rwanda Cooperative Agency; RDB: Rwanda Development Board; UR: University of Rwanda; YE: Yune Eritian; ZZ: Zong Zeng
Introduction
Background
Rwanda has a surface area of 26338km2 and the population in 2012 the total resident population was 10,515,973 inhabitants (NISR, 2014). Rwanda is a mountainous country with high land and flooded valley. As a result, the temperatures are generally low. An nual average temperatures range from 15 to 25 degree centigrade. Temperatures are much lower in lowlands producing areas. Rwanda has also about 165 000 ha of marshes of which 66 000 ha can be developed into rice fields, currently about 12 000 ha are irrigated. Rice is almost exclusively grown in marshlands at an altitude of 800 to 1200 m above the mean sea levels over two seasons; wet season (A) (March-August) and dry season (B) (September-January) (A Kathiresan, 2013).
Rice is a cereal crop from poaceae (graminiae) family with a scientific name of Oryza sativa, rice is categorized into two categories which Japonica (short and bold type) and Indica (long type). Rice was introduced in Rwanda in 1950s through various missions from China and Korea. After the initial success of growing rice in the valleys near Kigali and in the Southern province, a number of varieties became popular in 1960s. These varieties collectively referred to as Kigoli, are of short and bold type. In Bugarama, government introduced rice varieties from India such as Basmati 370 in 1980s (A Kathiresan, 2013). In 2012, the cultivation of rice covered 14,701 ha and results in the production of 81,908 MT of rice. It was expected that in 2018, the average productivity of 5.8 tons/Ha with a maximum of 7 tons/Ha, the cultivation area of 28,500 ha will be covered (RDB, 2017).
Due to the agricultural factors such as fertile soil, favorable weather, natural water resources, and efficient manpower make Rwanda highly suitable for rice cultivation. Furthermore, rice is preferred due to its long shelf-life, ease of cooking and transportation. Today, rice is selected as priority commodities according to MINAGRI in 2004 and has become a popular choice of food in schools, homes, restaurants, and public programs in Rwanda. For human being societies in different corners of the world. The rising incomes, growing urban population, and changing lifestyles have further aggravated the demand for rice. In response to this growing trend, the Government of Rwanda has identified rice as a priority crop since 2002. The national rice policy aimed at enhancing the productivity levels and raising the standard of post-harvest processing of rice was also developed. The vision was that Rwanda will attain self- sufficiency in rice production in the next 12 years and will be well- positioned to compete local and regional market with significant improvement in quality and value. The above policies were recommended aiming to attain the objective such as enhancing the quality of rice grains through improved management practices of harvesting, drying and storage of rice grain and raise the standard of milling operation and there by improve the quality and competitiveness of locally produced rice grains (A Kathiresan, 2010).
The postharvest activities are of great importance in terms of value addition and food losses, in spite of different strategies and programs for increasing of rice production and decrease of the rice postharvest losses is still high mainly due to inappropriate postharvest handling and storage techniques. In the rice value chain, there are several constraints which can decrease the yield during the process. Some of them start at the beginning during the preparation of field. Rice parboiling is a postharvest process carried out on paddy (unhusked) rice. Parboiling has a number of advantages, including the enhancement of the quality and yield of rice at milling and the preservation of nutritional values as parboiled rice has a longer shelf life (due to the deactivation of enzymes) and, because its grains are harder, it stores better and is more resistant to insect pests. The cooking quality of parboiled rice is better in several ways: its grains stay firm, they do not stick together, and it loses less starch during cooking [1]. So, the research will focus on the postharvest losses and how it can be treated by new technology which is parboiling. For human being societies in different corners of the world including Rwanda, rice is prepared in different ways such as boiling, where rice is soaked in 3-4 quart of water for 1 quart of rice, and boil for 15-20 minutes approximately.
In Rwanda, the parboiling technique is not applied, or it affects the nutritional content and other aspects that have been indicated by many researchers such as improvement of flavor that lead the consumer preference and unbreakable of rice grains, reduction of cooking time, etc. The aim of the present study is to apply the parboiling technique for rice preparation and determine its effects on different rice varieties grown in Rwanda.
Problem statement
Rice is a staple food which has a high demand of consumption compared to its production on market, as in 2012 rice consumption compared to other crop was 6.9% where 3.8% was produced (local) and 3.1% was imported, not only inside the country but also outside where in East Africa community the demand of rice is ≥ 2,088,000MT, according to RDB, 2017. Rice when milled is classified into 3types such as heady rice (long grain, medium grain, short grain), rice flour and broken rice grain; the breakage lead to post harvest loss and consumer do not prefer the quality of rice produced.
Different diseases such as beriberi and Wernicke-Korsakoff syndrome which are diseases caused by a deficiency of thiamine (vitamin B1) that affect the nervous system, cause visual impairment, lack of muscle coordination, mental decline, breathing, eye movement, heart function, alertness are caused by lack of vitamin B1 which is likely to be low in white rice as bran which is rich in Thiamine, riboflavin, niacin or nicotinic acid and mineral such as Calcium, Phosphorus, Potassium, Sodium has been removed by the milling and polishing; one of method to acquire all those nutrient is parboiling which refers to the hydrothermal treatment technique called parboiling and such rice will be a parboiled rice which will be rich in all those nutrients. The storage time or the shelf life of a product is so important, and parboiling is one of the ways of reducing the post-harvest losses of rice during storage that can be caused by rodents, insects, and other pests and increasing its storage time as the parboiled rice is very resistant to insect and rodent.
To read more about this article....Open access Journal of Nutrition & Food Science
To know more about our Journals....Iris Publishers
No comments:
Post a Comment