by Yoshito Matsumoto,Satake Corporation, China


This article explainshow rice millers can effectively take advantage of laboratory analysing equipment or apparatus,such as the Milling Meter MM1D, one of the most basic and important pieces of analysing equipment, which will be described in detail later.

Satake strongly believesthat smart application of analysing equipmentcan contribute to improving profit in the milling industry.Unfortunately, Satakehas seen too many rice mills whereinanalysing equipment were routinely operated incorrectly. Some rice milling facilities do noteven possess anyanalysing tools. In these rice mills, milling machine adjustment can only be done with operators" knowledge and skills acquired from experience.

Furthermore, milling datas including incoming raw materials and final products"conditionssareoften not captured quantitativelyas well. Satake would like to propose a potentially lucrativeprocedure,based on collecting pertinent data from analysingequipment,for competitive advantages.



First and foremost,rice millersneed to recognisethe benefits of using analysing equipment (see figure one). Laboratory equipment is not justtools to measure indices,provided on a QC checklist as routine work, it is directly connected to profit and could be considered a lucrativestrategy.Sharing this point of view among managers and operators is the first steptowards an effective implementation of analysing equipment. MM1D,for example, measures whiteness/milling degree, but also provides a tool to manage andhelp achieve a more profitable operation (see figure two).

MM1Dcan measure whiteness/milling degree simultaneously for both brown and white rice. The range of whiteness degree is 0-100,where 0 is jet-black and 100 is as white as oxidisedmagnesium powder. Itcan determine the ricedegree of whiteness.In Japan, whiteness degrees of brown andwhite rice are approximately20 and 40 respectively. Please note, whiteness degree fluctuates withrice varieties and grain conditions.

On the other hand, milling degree range is 0 for brown rice and 100 for white rice, with all bran layer and germ removed completely, but leavingstarch inside the grains untouched. The milling degree is derived from the measurement of both reflected light from rice and transparent light going through it.

Using a mathematical formula, a curve can be generated to show the relationshipbetween whiteness and milling.It also providesthe calculated milling degree thatindicates how well the rice is milled.

The following is a summary of what needs to be considered when usinga milling meter effectively. 1) Depending on varieties, there are high-low whiteness degree intrinsic tendencies.For example, the best whiteness degree for a certain variety A is 40,while for variety B it could be 38. Therefore, it is not appropriate to determine milling target in terms of whiteness degree,without considering the variety characteristics

2) After scratching(milling) the surface of brown rice, actual milling ratio can be measured,based on the weight of bran removed, directly proportional to whiteness degree. Oncescratch encroaches on starch, whiteness degree rate-of-increasedwindles

3)If a starch layer is removed, rice will absorb excessive water, resulting in gooey textureaffecting taste,because of starch diffusion into water during cooking

It is highly recommended to check (2)manually, if a friction type laboratory mill and a whiteness meterare accessible. First, prepare brown rice and put it gradually into the mill without any load. Measure periodicallyremovedbran weight and whiteness degree. Then, plot all points from test results (see figure three).The dots illustratea decrease in whiteness gradient when the whiteness degreeis equal or exceeds approximately40.

Once the dots are connected, you will realize that there will be two lines, with the first line starting from brown rice, which can be expressed in one straight line until a certain point,which shows that weight of rice is directly proportional to whiteness degree, and the second straight line with lower gradient once whiteness hits 40 (see figure four).

Apparently, the whiteness degree and actual milling degree have a linear relationship,in the early stage of milling. Oncethe milling process crosses over the border to the starch layer, the gradient starts to taper off. In other words, atthis point, which is also called the clipping point, when rice milling reaches the starch layer, the rate-of-increase in whiteness is lower compared to anearlier stage of the milling process.

The clipping point would be the target for rice milling, since this is the pointwhere maximum quantity of bran is removed and no starch is damaged. Ideally, if the clipping point is a known parameter, it would be the ultimate target for the milling process. By using the MM1Dreadings properly, we could avoid excess milling and produce consistent high-quality tasty rice, which will enhance the mill"s profitability.

For many rice millers in China and Korea, the priority in rice milling operation is the finished rice appearance because it attracts consumers" attention. They value whiter rice overtaste and quality. Many consumers are unknowingly purchasing potentially good rice but with inferior milled quality. Does it truly benefit the industry and the market?

As Japan experienced in the past, excessively polished and whiter rice will eventually be taken out by true quality rice with a superior taste. The market demand will eventually shift from whiter appearance to a more tasty and high-quality rice. Soon, current operation will no longer be effective, and profitability of the industry will suffer.

Only mills equipped with proper scientific milling operation management will be able to respond effectively to the market demand. The industry may also see additional benefits,such as easier milling operations and product quality control, to allow a more consistent production. Operation relying heavily on millers" experience can be significantly improved by scientific control and monitoring by using data from the laboratory equipment. The data will also show the variety and daily production lot differences, to help maintainthe quality of their product.

Satakemanufacturesnot only drying, milling, sorting and other post-harvest grain processing machines, but also pre-harvest analysing equipment and post milling machines,such asindustrial cooker systems. The analysing equipment made it possible to operate processing machines under various processing conditions and raw materials with different characteristics.

History shows that processing machines were always developed in conjunction with laboratory equipment. For example, in many countries,dryers are being manufactured to dry paddy, however, uneven and unstable drying was a common problem. A few decades ago, Satake, by using single kernel moisture meters, solved the problem and can now supply dryers with minimum moisture content deviations.

Reasons why Satake believes in the importance of the "pre" and "post" harvestprocesses of rice is because it is detrimental to the production of consistent tasty quality rice. We are aware that we need toconsider not only drying, husking and milling processes, but also all the other processes, from paddy seed to cooked rice.The following information shows important factors in each process and their influence on taste.


Indices for tasty rice production

The factors considered in various interactions can determine final taste (see figure five). One mis-handled step in a processmay degrade the latent taste of rice. Seeking the best efficiency in one section does not necessarily lead to the best in the overall process. For instance, if farmers, in order to achieve maximum profit,delay harvest to obtain larger crops, it would actuallyincrease the amount of cracked paddy and lead to potentially unsatisfactory and tasteless rice afterwards.

In order to achieve the best quality in both technical and commercial terms, the partiesinvolved in each individual process must know and understand the entire product flow from farmers toconsumers.


You might also like

Latest Videos

Leave A Comment

Don’t worry ! Your email address will not be published. Required fields are marked (*).





QR Code


" "