Brown rice

About: Brown rice is a research topic. Over the lifetime, 8180 publications have been published within this topic receiving 81079 citations.

Effect of Soaking Temperature on Physical, Chemical and Cooking Properties of Parboiled Fragrant Rice

Abstract: KDML 105 is the most popular fragrant rice for export and consumption in Thailand but it has poor milling yield. To solve this problem, parboiling has been used for improving milling quality of damaged rice. Our present study investigated the effect of soaking temperature on physical, chemical and cooking properties of parboiled rice. The 12-month stored KDML 105 paddy samples were soaked at 40, 50 and 60°C for 3 h, then autoclaved with steam at 121°C 15 min and dried by cabinet tray dryer at 60°C to reach the moisture content of 23 g/100 g dry matter. Head milling yield was significantly increased from 51% in brown rice to 60-80% in parboiled rice. The results also showed that parboiling process significantly (p<0.05) increased protein, lipid and ash contents. Overall, soaking at 50°C for 3 h prior to steaming and drying was found to provide the most desirable quality of parboiled rice in our study in terms of nutritional quality and sensory properties.

Updated profile of aflatoxin and Aspergillus section Flavi contamination in rice and its byproducts from the Philippines.

Abstract: Our goal was to develop an updated profile of aflatoxin (AF) and AF-producing fungi contamination in rice and its byproducts from the Philippines. The total AF levels in 78 samples of polished and brown rice, determined by an immunoaffinity column clean-up method coupled with HPLC (detection limit: 25 ng/kg), ranged from <0.025-2.7 microg/kg (mean of positive samples: 0.37 microg/kg) and 0.03-8.7 microg/kg (mean of positive samples: 2.7 microg/kg), respectively. The incidence (% of positive samples) of AF in polished and brown rice were 94% and 100%, respectively. The AF levels in polished rice imported from Thailand and Vietnam were approximately 20% of the levels found in locally produced polished rice. AF levels decreased as the rice progressed through the various stages in milling. Fungi recovered include toxigenic Aspergillus flavus and A. parasiticus with an incidence ranging from 14% in rice bran to 78% in rough rice and producing <0.025-6200 microg/kg total AF in in vitro cultures on rice. All samples of rice bran and rice hull contained AF at levels ranging from 0.27-11 microg/kg. The estimated potential daily intake of AFB(1) from rice is between 0.1 and 7.5 ng/kg of body weight/day, the mean of which is 1.0 ng representing 9.1-5.3 times the estimated tolerable daily intake for AFB(1) reported to date for Asia. Thus, Filipinos have a potentially high risk of exposure to AF that can be easily controlled through proper post-harvest handling and storage of rice and its byproducts.

A systematic review of the influence of rice characteristics and processing methods on postprandial glycaemic and insulinaemic responses

Abstract: Rice is an important staple food for more than half of the world's population. Especially in Asian countries, rice is a major contributor to dietary glycaemic load (GL). Sustained consumption of higher-GL diets has been implicated in the development of chronic diseases such as type 2 diabetes mellitus. Given that a reduction in postprandial glycaemic and insulinaemic responses is generally seen as a beneficial dietary change, it is useful to determine the variation in the range of postprandial glucose (PPG) and insulin (PPI) responses to rice and the primary intrinsic and processing factors known to affect such responses. Therefore, we identified relevant original research articles on glycaemic response to rice through a systematic search of the literature in Scopus, Medline and SciFinder databases up to July 2014. Based on a glucose reference value of 100, the observed glycaemic index values for rice varieties ranged from 48 to 93, while the insulinaemic index ranged from 39 to 95. There are three main factors that appear to explain most of the variation in glycaemic and insulinaemic responses to rice: (1) inherent starch characteristics (amylose:amylopectin ratio and rice cultivar); (2) post-harvest processing (particularly parboiling); (3) consumer processing (cooking, storage and reheating). The milling process shows a clear effect when compared at identical cooking times, with brown rice always producing a lower PPG and PPI response than white rice. However, at longer cooking times normally used for the preparation of brown rice, smaller and inconsistent differences are observed between brown and white rice.

Simplified Determination of Amylose in Milled Rice

Abstract: Previous defatting is essential for correct colorimetric detn. of amylose content in rice (I2 method). Since no simplified method of defatting flour is satisfactory, a simple method of defatting in liquid phase was developed. The flour is dispersed in dilute alkali and the dispersion shaken successively with petroleum ether and CCl4. The aqueous supernatant is pipetted off for colour development and detn. at pH 7.5 and 630 nm. Results were essentially identical to those obtained from defatted flour. The method could also be applied to undermilled and brown rice.