Endosperm floury

The floury endosperm is surrounded by the vitreous endosperm, being the innermost part of the kernel. The floury endosperm contains the same components found in the vitreous endosperm but the starch granules are bigger and less angular in shape, the association between the starch granules and the protein matrix is weaker, and the starch is less surrounded by protein bodies. Furthermore, compared to the vitreous endosperm, in the floury endosperm the cell walls are thinner and have less protein content (i.e., less compact structure). Minuscule air spaces give a floury or opaque-chalky appearance. 

The ratio of floury versus vitreous endosperm determines the hardness and density of the grain, thus affecting the food processing attributes. For instance, grain hardness affects the efficiency of decortication, dry and wet-milling processes, and optimum cooking times and conditions. 

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Endosperm constitutes the main part of the corn kernel and consists of 85 to 90% starch, 8 to 10% protein, and a small amount of oil and other compounds. Corn endosperm can be divided into two distinct parts floury and horny endosperm. In floury endosperm, starch particles are round and are dispersed loosely in the protein matrix. In the horny endosperm, the protein matrix is stronger and starch particles are held more firmly. Starch granules are encased in the continuous protein matrix. The tighter setting in horny endosperm gives starch particles a polygonal shape. On average, the amount of horny endosperm in the corn kernel is twice that of the floury endosperm. However, this ratio is a function of the corn kernel protein content (Wolf et al., 1952). 

Table 4.1.40A. Wheat middlings (IFN 4-05-205). Consists of the fine bran particles, germ and a small proportion of floury endosperm particles as separated in the usual processes of commercial flour milling (CFIA, 2007). It has to contain less than 95g/kg crude fibre.

Figure 6.2 Morphological evolution of maize starch granules in floury endosperms of normal maize (A76) and high-amylose maize (A62 and A36) during maturation from the fifteenth to the 72nd day after anthesis, as seen under polarized light. Note that the filamentous starch granules of the high-amylose maize show Maltese crosses only in some nucleations. Percentages are amylose contents during maturation.14...

Figure 9.1 Longitudinal 10-pm bisection ofa steeped dent com kernel (magnified X6, iodine stained). Note how starch has been lost from floury endosperm cells as a result of sulfur dioxide action.

The pericarp or hull of the corn kernel is a thin outer covering made up of two layers. Removal of this part of the corn kernel results in corn bran. The endosperm, which comprises up to 82% of the kernel s dry weight, is the source of energy for the germinating seed. In all field corn, the endosperm is comprised of two types of starch vitreous and floury. The proportion of these starches is controlled genetically. The floury endosperm is the softer starch, and as the kernel matures, this type of starch dries down to create the dent in the top of the kernel. The major chemical component of the maize... 

Most of the interior of the grain is taken up by the floury endosperm. The embryo occupies the small raised area at the base. The scutellum, a shield-like stractirre, separates the embryo from the endosperm. Attached to the base of the scutellirm are the five roots of the embryo, one primary and two pairs of secondary rootlets. The roots are enclosed by a sheath called the coleorhiza while the shoot is enclosed by the coleoptile. The position of the radicle and the pliunule can be seen in Fig. 1.7. The scutellirm can be regarded as the cotyledon of the seed. There is only one cotyledon present and so wheat is a monocotyledon. 

For years, plant scientists assayed the world s corn varieties one by one, looking for a strain with more nutritionally balanced protein. Finally, in 1963, a Purdue University team headed by biochemist Edwin T. Mertz analyzed an odd group of corns characterized by soft, floury endosperm inside an opaque, chalk-white kernel. The Purdue scientists found that the opaque characteristic of corn, which had been noted for years without exciting much scientific interest, is associated with a recessive gene that replaces some of the kernel s amino acid deficient zein with other protein higher in the needed lysine and tryptophan. The mutant— routinely labeled opaque-2, or O2 for short—had a lysine... 

Recent advances in color machine technology have provided sophisticated tools with extensive new applications for evaluating food quality. Shearer and Payne (1990) reported on sorting bell pq>pers based on color as characterized by the hue of light reflected from the pq>per surface. Shearer and Holmes (1990) proposed a color texture approach to identify seven common cultivars of nursery stock based on cooccurrence matrices. The addition of hue texture improved the classification accuracy from 81.7% to 90.9% over using intensity texture features alone. Liao et al. (1991) used color differences between vitreous and floury endosperm area of a corn kernel to classify corn hardness. Edan et al. (1994) used machine vision extracted appearance attributes such as size, shape and color for a multi-sensor based quality evaluation of tomatoes. These researches used color as an added dimension of information for classification, but made no attempt to quantify the colors of the food materials they were investigating. 

This is the most popular in the soft wheat category. It possesses a floury endosperm with low protein content (6.5%—10.0%) and produces weak gluten adequate for the fabrication of cookies, cakes, and products leavened with chemical agents. 

In order to understand the important changes that cereals undergo during processing, it is essential to comprehend the macro and micro structure, physiology, biochemistry, and composition of each anatomical part of the caryopsis. The structure and the appearance of cereals have been modified by breeding. Within each type of cereal, important variations exist in endosperm hardness due to the different proportions of vitreous and floury endosperm types, pericarp color and thickness, type of starch, and kernel size. 

What would happen to the chemical composition and yield of decorticated kernels of a high-tannin sorghum subjected to abrasive decortications to remove 25% of its weight Remember that most brown sorghums have a soft or floury endosperm texture. 

Pordesimo, L.O., Anantheswaran, R.C., and Mattem, PJ. 1991. Quantification of homy and floury endosperm in popcorn and their effects on popping performance in a microwave oven./. Cereal Sci. 14 189-198. 

Prehispanic dishes in which one of the main ingredients is whole nixtamal, generally prepared from Cacahuacintle (white and large kernels with floury endosperm) maize. Pozole is a spicy soup that generally contains peppers, shredded meats, and other spices. The lime or lye-cooked maize is mixed with beef stomach or shredded pork, peppers, spices, and onions to yield pozole. 

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