Tapioca starch processing

FIGURE 5.7 X-ray diffraction profiles of native (ungelatinized), partially gelatinized, and completely gelatinized (amorphous) tapioca starch. Reprinted from Carbohydrate Polymers, Vol. 67, Ratnayake and Jackson (2007), A new insight into the gelatinization process of native starches. Pages 511-529, 2007, with permission from Elsevier. 

The particle size distribution depends on the type of plant (see Table 5). The size of the potato starch granules is considerably higher than the size of com and tapioca starch granules. Also, the moisture absorption of potato starch is much higher than for com and tapioca starch. Thus, processing of tapioca starch in technical processes like compounding is similar to that of com starch [10]. 

Starch Liquefaction. Starch in its natural state is only degraded slowly by CC-amylases. To make the starch susceptible to enzymatic breakdown, it is necessary to gelatinize and liquefy a slurry with a 30—40% dry matter content. Gelatinization temperature depends on the type of starch (67) com is the most common source of industrial starches followed by wheat, tapioca, and potatoes. Liquefaction is achieved by adding a heat-stable a-amylase to the starch slurry. The equipment used for liquefaction may be stirred tank reactors, continuous stirred tank reactors (CSTR), or a jet cooker. Most starch processing plants liquefy the starch with a single enzyme dose in a process using a jet cooker (Fig. 9). 

Some creative approaches to try to match the regular demand of a tapioca production process with the irregular supply of feedstock have been taken. Meuser et al.27 demonstrated that starch could be recovered from either cassava chips or pellets, although the starch is obtained at some sacrifice of quality. Nauta28 has proposed large silos for the storage of tapioca starch, similar to those used in the potato processing industry. At present, the primary supply of tapioca starch remains fresh roots. 

As a native starch, lipids and protein residuals are significantly lower than they are in many other commercial starches. These properties of tapioca starch have been utilized in many industries and further enhanced by means of physical and/or chemical modifications which give close control of its properties to fit the needs of customers in process and product applications. However, tapioca starch is regarded as a specialty starch outside of its local production area. 

Dextrinization of tapioca starch is well-known. The difficulty in dextrinizing corn starch,64 and the relative ease of tapioca starch conversion,65 have been described. The near-absence of lipids, which interfere with the dextrinization process, has given tapioca dextrins an advantage in stability and color because of their ease of manufacture and control. However, the economics of base starch supply have resulted in a significant shift to waxy com starch as a base for industrial dextrins, even though... 

The effects of food ingredients on thermal transitions and physicochemical properties are of importance to the processing and properties of starch-based products, and can play major roles in the quality and storage stability of tapioca starch-containing products. For the food scientist, it remains vital to understand the role of ingredients and their properties, with the understanding that results can vary with the conditions of use. 

The past two decades have also seen a considerable enlargement and maturation of the cassava (tapioca) starch industry that is reflected in another larger chapter, which also compares the characteristics of tapioca/cassava starch with those of other starches. The chapter on potato starch has also been considerably updated, especially from a processing standpoint. The latter chapter contains a discussion of all-amylopectin potato starch. 

Nitric acid esters of starch are the oldest known starch derivatives and are the only starch esters commercially produced on a large scale. Like cellulose nitrates, the starch nitrates are excellent explosives. They are used extensively in blasting compositions, for quarrying and for certain types of mining. Tapioca starch was used mainly for commercial nitrations in the United States until the advent of World War II and the disruption of supplies made it necessary to nitrate com starch. This transition has been accomplished with little difficulty, although the exact process used is a trade secret. 

High-pressure processing was shown to induce the formation of tapioca starch gels with different physico-chemical properties from temperature-induced gels. These differences might result in a different performance in starch-containing food products. 

Dextrins may be produced from all of the commercial grain and tuber starches, but maize, potato, and tapioca starch are most commonly used. When conversions are carried out in the presence of an acid catalyst, hydrochloric acid is most often employed, because it is a strong acid, disperses uniformly through the starch, and tends to volatilize during the last stages of dextrinization, so that neutralization of the product may not be necessary. In the preparation of British Gums, an alkaline catalyst, such as sodium carbonate may sometimes be used. Details of the industrial processes have been described. ... 

The cassava root is long and tapered, with a firm homogeneous flesh (which is source of tapioca starch) encased in a detachable rind, about 1 mm thick, rough and brown on the outside. Two varieties of the cassava are of economic value the bitter, or poisonous and the sweet, or nonpoisonous (Table 4A.2). Farmers often prefer the bitter varieties because they deter pests, animals, and thieves. Because the volatile bitter constituents can be destroyed by heat in the process of preparation, both varieties yield a wholesome food. Cassava is harvested by hand by raising the lower part of the stem and pulling the roots out of the ground, then removing them from the base of the plant. The upper parts of the stems with the leaves are plucked off before harvest. The roots are then washed and the peel (skin and cortex) is removed to process only the central part of the root. 

Tapioca starch was dried at 80 °C in a vacuum oven for 24 h. It was first premixed with 35 wt% of glycerol using a kitchen blender (3000 rpm, 2 min) until a homogeneous mixture was obtained. Then, the mixture was stored overnight in a dry place. Later the mixture was processed using a heated two-roll mill at a temperature of 150 °C the mixing time was 10 min. 

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