In agriculture, seed quality depends on the use of grains. In the production of ethanol, the chemical composition of grains such as starch content is important, in the manufacture of food and feed, properties such as proteins, oils and sugars are significant, in the health of the milling industry is the most important factor to consider and for seed producers, the percentage of germination high (seed viability) and seed dormancy are important features to consider, for consumers properties such as color and taste will be important.
Video Grain quality
Grain quality properties
Overall grain quality is influenced by several factors including, growing practices, timing and type of harvest, postharvest handling, storage management and transport practices. Grain quality characteristics can be summarized into ten major factors (i) Uniform water content, (ii) high test weight, (iii) No foreign matter, (iv) Low percentage of damaged, damaged and damaged fruit (vi) high protein content, (viii) high viability, (ix) No afaltoxin (mycotoxin), and (x) absence of insects and molds.
Maps Grain quality
Characteristics of grain quality
Grain quality is characterized by two main factors (i) intrinsic factors, and (ii) extrinsic factors. The intrinsic factors of grain include, color, composition, bulk density, odor, aroma, size and shape.
Color is an important factor important for characterization and alignment, trade, and grain processing. This is a general criterion used in the trade of wheat.
The main ingredients of grains are carbohydrates (energy), proteins, lipids, minerals, fiber, phytic acid, and tannins. This varies depending on the type of grain, genetics, varieties, farming practices, and grain handling. Wheat composition plays an important role in grain valuation and marketing.
Bulk density is defined as the mass ratio for a given volume of a grain sample including interstitial cavities between particles.
Size and shape are important factors in grain quality and gradation; it varies between grains with grains and between varieties of the same species. It is commonly used in rice gradation and a key factor in the milling industry.
Extrinsic factors include: age, broken grains, immature grains, foreign bodies, infected grains and moisture content.
Grade class and specifications
Grain Grading and system specifications ensure that many grains meet customer-defined standards. In many countries, the grain content depends on four main properties; (i) bushel (test) weight (ii) moisture content (iii) broken foreign material or percentage of fragments of examples of broken corn raw materials (iv) damaged seed (ie total and heat damage).
Test weight
The heavy (bushel) test also known as volumetric weight is one of the simplest and most traditional criteria used to determine grain quality and grain mass density. This is an indicator of the general grain quality and specificity of primary grains, usually the higher the test weight the higher the quality, and the lower the test weight the lower the quality, and the quality of the grain decreases dramatically as the grain quality decreases. The seed weight test is influenced by many factors including moisture content (beginning and end), frost damage, and maturity, growth and harvest conditions, drying conditions, fine materials, and kernel damage rates, and variations.
Contents of moisture
Water content is an important factor in grain quality. This shows as the water quality per unit of grain mass and expressed as a percentage (ie wet or dry basis). Water content does not directly affect the quality of the seeds but may indirectly affect the quality because the granules will damage the contents of the above recommended moisture for storage
Foreign Materials (FM)
Damaged foreign material is an important factor in the assessment and classification of grains. It is described as a foreign object other than grains such as sand, pieces of stone, plastic particles, metal and glass pieces, contaminating many specific grains. In grain trading the presence of more than a certain percentage of FM results is either low value, price discount or much rejection, as the higher the FM the more the cost to clean before use.
Damaged kernel (DK)
Damaged kernel is an important valuation factor. DK are considered people who have visually obviously damaged and negatively affect their value of grain. Usually quantified by removing the damaged seed by hand from a potion free mixture. Grain levels contain limit kernel damage for each class, for example for wheat for first class must contain no more than 0.4% of the total weight. The main types of damaged are due to insects, heat, mold, and weathering, growing, frost, disease, uniform maturity and lack/partial filling of grains.
In the scoring system or defective specification, the kernel is divided into two main parts (i) the heat is broken and (ii) the total is damaged.
Non-grain standard properties
Important non-grain standards in US wheat standards include (i) damage susceptibility, (ii) grinding quality (iii) seed viability, (iv) nutritional value, (v) number of fungi and carcinogenic contents, and (vi) insect infestations and damage
The best examples of grain quality can be described as two general grains (wheat and rice).
Wheat
Wheat (Triticum aestivum L.) is the world's leading source of energy, protein and agricultural fiber; it belongs to the family of Graminaea and the genus Triticum and can be categorized into three main classes - hard, soft and durum. The quality of wheat can be well described in terms of end-user quality, nutritional quality, grinding, and roasting and rheological quality. In general, wheat should be healthy, clean, cooked, free of foreign material and damaged.
Quality of wheat
In general the quality of wheat can be divided into three main groups (i) botany (species and varieties), (ii) physical (iii) and chemical characteristics.
Botanical Criteria of Quality In terms of botany, the quality of buckwheat can be described as falling into the following two main criteria (i) species and (ii) varieties.
Physical criteria
Physical characteristics of wheat quality include, grain weight, hardness, grain size and shape, vitreousness and color.
The physical properties of grains such as wheat play a very important role in the quality of grains, and in end products such as flour. The main physical properties affecting wheat quality are weight, hardness, grain size and shape, vitreousness and color test.
Test weight
Wheat weight testing is considered the most common and easiest way to measure wheat. This is an important quality factor in wheat assessment because it gives a rough estimate of flour yields. The basic factors affecting the weight of the wheat test are the size and shape of the kernel, the kernel density, the maturity of the wheat, the anseases and the actual wheat varieties.
Violence
Hardness of wheat endosperm is very important in determining the suitability of wheat for various end products and affects the process and milling of wheat. This is a common characteristic used by manufacturers and traders to classify grain. In the case of violent wheat can be classified as hard or soft.
Color
In terms of color, wheat is classified into two classes (ie, red wheat and white wheat), hard red winter wheat is considered superior and commonly used for bread production, whilst white wheat is usually used for cakes, chapattis, and pasta (macaroni). ), each type of wheat has different properties such as flavor, cake quality and grinding results.
Vitreousness
Wheat vitreousness is an optical property used by many countries to assess or measure durum wheat. Based on vitreouness, wheat can be classified into three main classes: vitreous, mealy and piebald. Wheat vitreousness is different for non-vitreouness by kernel appearance (flour and opaque), wheat vitreouness is considered to be of better quality than non-vitreousness kernels, due to higher semolina protein quality, good color and uniform rough granulation.
Chemical properties (quality) of wheat
The chemical properties of the grain include moisture content, protein content (gluten), amylase content and fiber content.
Contents of moisture
Wheat wheat is normally harvested at 10-12% moisture content. In most countries, moisture content is not part of the scoring system, but it is the most important factor affecting the quality of grain, it is inversely proportional to the loss of dry matter. The water content has two important meanings in the quality of wheat (i) too low (too dry) resulting in flour rupture during storage and handling operations and (ii) too high will facilitate mold growth causing damage.
protein content
Protein is not part of wheat as a valuation factor, but its quantity and quality is the most important property in the grain business. Most buyers and mills need to know the amount of wheat protein content before buying it. Wheat contains five different protein classes; (Ii) glycol (dissolved in 70% ethanol aqueous) (iv) proteosa and (v) glutenin (soluble in dilute or alkaline acids).
Another important quality of wheat is the quality of milling and roasting
Grinding quality
Most of the wheat is sold commercially as ground flour or semolina, so the quality of milling is an important factor in the trade of wheat. Milling depends on three main factors (i) the size and evenness of the kernel - there is a close correlation with the weight of the grain, determined by the weight of the thousand-kernel, (ii) endosperm texture-characterized by glassiness or pearling and hardness index. They affect the utilization of energy required for grinding and the amount of semolina obtained, and (iii) the percentage ratio of the coats - the larger the kernel the lower the seed-layer ratio, and if the coating is not thicker, the percentage of the coats will decrease as well, and color of endosperm and coats.
Quality cake
Roasting quality is another criterion used to determine the quality and suitability of wheat; the quality of the cake depends on the type of wheat use and processing conditions, eg strong wheat (hard) is considered to have a higher quality and is suitable for baking, where most of the cake is made from soft wheat flour. The quality of the cake is determined by the rheological properties of wheat flour. The rheological nature of wheat flour is important because it determines other physical characteristics such as the volume of dough (bread) and sensory attributes.
Grading and grain quality classification
Wheat like other cereals is judged on certain criteria such as, test weight, purity, maximum percentage of defective and foreign material. In the United States, wheat is grouped into classes and subclasses, in wheat classes into eight different groups; hard red springs, harsh red winter, mild red winter, durum, hard white, soft white, mixed and unclassified wheat. Except for unclassified wheat classes, the next classes are subclasses into five classes (AS No.1-5).
Rice
Rice belongs to the Oryza genus of the Oryzinea sub-tribe in the Gramineae family. The three main categories of rice are, (i) long-term rice species - relatively long and thick, known as Carolina rice; (ii) medium, thin, cylindrical fiber, known as Patna, and (iii) short grains. short, fat, known as Spanish-Japanese.
Grain quality of rice
There is no precise definition or description of the quality of rice, because as the definition of quality depends on several factors such as the practice of cooking and the area and the use of for example rice milling he describes the quality of rice in terms of total recovery and or the head and kernel of damaged rice while the food processing will determine the concept of rice quality in terms of grain size, aroma, appearance and cooking ability.
In general, many countries count rice into four main categories (i) quality of milling (ii) cooking, eating and processing quality, (iii) nutritional quality and (iv) special standards for hygiene, health and purity. In the United States three more factors have been added (i) stomach and pericarp (ii) color of grain size, shape, weight, uniformity and general appearance and (iii) kernel chalkiness, translucency and color
Physical properties of rice
The common physical properties of rice are size, shape, color, uniformity, and general appearance. Other factors contributing to the general appearance of rice are hygiene, free from other seeds, vitreousness, translucency, chalkiness, color, damage and imperfect kernels.
For grain size, the grain can be grouped into three main groups (i) long (ii) shape and (iii) weight, the length is the size of coarse, brown, or milled rice in its highest dimension, while the shape is the ratio of length, width, and thickness, and for severe cases determined using 1,000-kernel weights.
The long, form and weight examples used in the US appraisal system for the red rice kernel are shown below.
Test weight
Test weight is an important factor of rice valuation, it is related to bulk density, and is used to measure the relative amount of foreign material or immature kernel, this is a useful index in milling machines. The average test weight per bushel of US crude rice is  £ 45.
Dirt and broken rice
Dirt and damaged rice are considered the single most important factors of rice quality as they directly relate to the value of the lot economy, for example the presence of sand and stones will increase the weight of the grain and damage the rubber when it is delivered to the plant. Dirt and damaged rice contains impurities, damaged seeds, calcareous grains, brown rice, damaged seeds or seeds and odors.
Quality of milling or recording
The main purpose of rice milling is to remove the outer layer (stomach), bran and germ with minimal damage of endosperm. The quality of rice milling is an important criterion used in marketing, assessment and classification of rice, as well as treatments such as conditioning, drying and parboiling, usually estimated by using grinding results. Milling results vary depending on several factors such as grain type, variety, chalkiness, drying and storage conditions, other including environmental conditions and moisture content at harvest
The quality of the milling can be determined by two general parameters (i) the total yield and (ii) the head results, as well as other parameters such as grinding rate and broken rice used to estimate grinding qualities expressed in percentages According to the definition of grinding quality is the ability of grain seed to stand grinding and or polishing without breaking, and to generate higher recovery amounts.
Nutrition and cooking qualities
The nutritional component of rice is one of the most important quality indicators; rice is a starchy food although it also contributes a number of proteins and vitamins, minerals, pentos and beneficial fibers. The chemical composition (nutrients) of the grain varies depending on factors such as the plant variety (breed), environmental conditions (ie location and season where it grows), fertilizer treatment, grinding rate, and storage conditions. The level of grinding and cooking methods lost a large amount of nutrients, so most of the vitamins and minerals are in the surface layer.
Cooking quality is another important criterion as far as the quality of rice is concerned, it is influenced by many factors such as cooking methods and time, bulk density, storage conditions, varieties and cultivation methods.
The two most important physiochemical properties of rice cooking qualities are the amylose content and the temperature of gelatinization.
Amylose content
This is another important factor in the quality of rice, like other cereal rice is a good source of starch, especially amylose. It comprises more than 80% starch and at a molecular-grade starch containing amylose (linear chain of glucose from (1-4) linkage) and amylopectin (glucose branched chain with (1-6) linkage In the case of amylose rice can be classified as a candle 0-2%, very low 2-10%, low 10-20%, intermediate20-25% and high 25-32% (dry rice).The starch content (amylose) from rice is a very important factor in the grain yield , processing and palatability.
Gelatinization temperature
The temperature of gelatinization is associated with many factors such as cooking time, granular size, molecular size of starch fraction; it is also used as a criterion of rice classified in several countries. Like other factors are also influenced by the environment such as maturation temperature, genetic varieties and rice and cooking time. The temperature of gelatinization is directly related to the contents of amylose; the higher the amylose the higher the temperature of gelatinization, the higher waxy rice has a higher gelatinization temperature than waxy or very little rice.
Classification and grading of rice
The main criteria used by many countries and factories to assess rice are milling, appearance (color), broken (broken) and calcareous kernel percentage. In the United States, rice is marketed according to three sizes, colors and major conditions (kernel damage), this property is directly related to quality, grinding percentage and other processing conditions. All the important properties in grading for example, kernel with chalky is not desirable as it gives lower grinding results after being processed and breaks easily during handling.
The color and grinding rate are other criteria that are mostly used to assess rice. Using these criteria, rice can be rated into four main classes, ground, lightly ground, finely ground and finely ground. Other factors also considered in rice assessment are the weight of the test has been associated with the percentage of grinding, empty grains, unripe grains and higher dock quantities. The average kernel weight test for rice was 56 kg/h for length, 58.5 kg/h for medium and 60 kg/h for short rice. Rice values ​​and requirements in the US
References
Source of the article : Wikipedia
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