QUALITY ASSURANCE

  GRAIN QUALITY FACTS

For OATLAND, the promised quality is the outmost and that we sustain and keep what we have promised. We have here below summarized the characteristics of grain (applicable for all types of grain).   

Grain quality

Grain quality is a term that refers to the quality of grain. However, what constitutes quality depends on the use of the grain.  For instance in ethanol production, the chemical composition of grain such as starch contents is important, in food and feed manufacturing, properties such as protein, oil and sugar are significant, in milling industry soundness is the most important factor to consider and for seed producer, the high germination percentage (viability of seed) and seed dormancy is the important feature to consider, for consumers the properties like color and flavor will be important.  

Properties of grain quality

  Overall quality of grain is affected by several factors includes, growing practices, time and type of harvesting, postharvest handling, storage management and transportation practices. The properties of grain quality can be summarized into ten main factors (i) Uniform moisture contents, (ii) High test weight, (iii) No foreign material, (iv) Low percentage of discolored, broken and damaged kernels, (v) Low breakability, (vi) High milling quality, (vii) High protein and oil content, (viii) High viability, (ix) No afaltoxin (mycotoxin), and (x) No presence of insects and molds.   Overall quality of grain is affected by several factors includes, growing practices, time and type of harvesting, postharvest handling, storage management and transportation practices. The properties of grain quality can be summarized into ten main factors (i) Uniform moisture contents, (ii) High test weight, (iii) No foreign material, (iv) Low percentage of discolored, broken and damaged kernels, (v) Low breakability, (vi) High milling quality, (vii) High protein and oil content, (viii) High viability, (ix) No afaltoxin (mycotoxin), and (x) No presence of insects and molds.      

Characteristics of grain quality

  Grain quality is characterized into two main factors (i) intrinsic factors, and (ii) extrinsic factors. The intrinsic factors of grain includes, color, composition, bulk density, odor, aroma, size and shape.   Color is an important primary factor for characterization and grading, trade, and processing of grain. It is a common criterion used in wheat trade.   The main compositions of grain are carbohydrates (energy), protein, lipids, mineral, fiber, phytic acid, and tannins. It varies significant depends on the type of grain, genetics, varieties, agricultural practice, and handling of the grain. Grain composition plays a significant role in grading and marketing of grains.   Bulk density is defined as the ratio of the mass to a given volume of a grain sample including the interstitial voids between the particles.   Size and shape are important factors in grain quality and grading; it varies between grain to grain and between varieties of the same species. It is commonly used in rice grading and key factors in milling industry.   The extrinsic factors include: age, broken grain, immature grain, foreign matter, infected grain and moisture content.  

Grain quality grade and specification

  Grain grading and specification system assures that a particular lot of grain meets the required set standards customer. In many countries grading of grain depends on four main properties; (i) bushel (test) weight (ii) moisture contents (iii) broken foreign material or the percentage fragments example broken corn foreign materials (iv) damaged kernels (i.e. total and heat damaged).  

Test weight

  Test (bushel) weight also known as volumetric weight is one of the simplest and traditional criteria used to determine quality of grain and measure of grain bulk density.  It is an indicator of general grain quality and primary grain specification, normally the higher the test weight the higher the quality, and the lower the test weight the lower the quality, and grain quality decreases dramatically as grain deteriorates. Test weight of grain is affected by many factors including moisture contents (initial and final), frost damage, and maturity, growing and harvesting conditions, drying conditions, fine material, and degree of kernel damaged, and variety.  

Moisture contents

  The moisture content is one among important factors in grains quality. It is denotes as the quality of water per unit mass of grain and expressed on a percentage basis (i.e. wet basis or dry basis). Moisture content does not directly affect grain quality but can indirectly affect quality since grain will spoil at moisture contents above that recommended for storage  

Foreign material (FM)

  Broken foreign material is an important factor in grading and classification of grains. It is described as foreign material other than grains such as sands, pieces of rocks, plastics particles, metals and pieces of glass, contaminating a particular lot of grain. In the grains trade presences of more than set percentage of FM results either low grades, price discount or lot rejection, because the higher the FM the more the cost to clean before uses.  

Damaged kernel (DK)

  Damaged kernels constitute an important grading factor. DK are considered those that have an evident visual damaged and negatively affect their value of the grains. It is usually quantified by removing damaged kernels by hand from potions free of impurities. Grain grades contain a limit of damage kernels for each grade, for instance for wheat to be grade one must contain no more than 0.4% of the total weight. Main types of damaged are due to insects, heat, molds, and weathering, sprouted, frost, diseases, and lack of grain filling. In the grading systems or specification damaged kernels is divided into two main parts (i) heat damaged and (ii) total damaged.