Tapioca
Tapioca is a starch extracted from the tubers of the cassava plant, a species native to the North and Northeast regions of Brazil, but which is now found in West Africa, Southeast Asia, and elsewhere. It is a perennial shrub adapted to the hot conditions of tropical lowlands. Cassava copes better with poor soils than many other food plants.
Tapioca is a staple food for millions of people in tropical countries. It provides only carbohydrate food value, and is low in protein, vitamins, and minerals. In other countries, it is used as a thickening agent in various manufactured foods.
Etymology
Tapioca is derived from the word tipi'óka, its name in the Tupi language spoken by natives when the Portuguese first arrived in the Northeast Region of Brazil around 1500. This Tupi word is translated as 'sediment' or 'coagulant' and refers to the curd-like starch sediment that is obtained in the extraction process.Production
Establishment
The cassava plant is easily established by cutting, according to the NRCS "Propagate cassava by planting segments of the stem. Cut stems into 9-30 cm lengths; be sure to include at least one node. Segments can be buried vertically with 8-15 cm in the ground. The selection of healthy, pest-free cuttings is essential. Stem cuttings are sometimes referred to as 'stakes'. In areas where freezing temperatures are possible, plant cuttings as soon as the danger of frost has past. Cuttings can be planted by hand or by planting machines. Hand planting is done in one of three ways: vertical, flat below the soil surface or tilted. Under low rainfall conditions, vertical planting may result in the desiccation of the cuttings, while in areas of higher rainfall; flat-planted cuttings may rot. In general, flat planting 5-10 cm below the soil surface is recommended in dry climates and when mechanical planting is used. Germination seems to be higher; tubers tend to originate from a great number of points and grow closer to the surface of the soil, making better use of fertilizers applied on the surface and also making harvesting easier."The cassava plant can also be established from seed, although this is not advised as seed germination rate is usually less than 50 percent. Because of this, seedlings are normally only used for breeding.
Management
Cassava cuttings start growing roots within just a few days, and new shoots sprout from where the old leaves were attached to the stem. At first, growth is slow, so it’s important to keep weeds under control during the early months.Cassava grows best in light sandy loam or loamy sand soils that are deep, fertile, and retain moisture. It can also be cultivated successfully in a wide range of soils, from sandy to clayey textures, and in areas with relatively low soil fertility. Cassava is capable of producing economic yields on land that has been depleted by repeated cultivation and is unsuitable for most other crops. The crop generally performs well as long as the soil is friable enough to allow the tubers to expand properly.
When cassava is cultivated on newly cleared forest land, little preparation beyond clearing existing vegetation is required. When grown after other crops, cassava can often be planted immediately following harvest, although in some cases, the soil is plowed two or three times to remove grass and weeds.
Fertilization is generally unnecessary on newly cleared land or when sufficient land is available for rotational cultivation. However, cassava is a fast-growing crop that depletes soil nutrients rapidly. Continuous cultivation without nutrient replacement can result in declining soil fertility. Commercial producers often restore soil nutrients through the application of synthetic fertilizers, while smallholder farmers commonly use organic manures such as cattle dung, duck manure, or composted household waste to maintain soil productivity.
Harvest
Cassava does not have a clearly defined stage of maturity and can be harvested whenever the storage roots reach a desirable size for consumption or processing. For food use, harvesting generally occurs between 8 and 12 months after planting. In most tropical regions, cassava can be harvested about eight months after planting, though under less favorable conditions, such as cooler or drier climates, it may take 18 months or more to reach harvestable size. Cassava plants may remain unharvested for more than one growing season, allowing the roots to enlarge further; however, older roots often become fibrous and woody, reducing their edibility and starch content.Harvesting is usually performed manually by loosening the soil and pulling up the roots, although mechanical harvesting may be used in commercial operations. Under optimal conditions, yields of fresh roots can reach up to 90 tonnes per hectare, while global averages, largely from smallholder systems, are around 10 tonnes per hectare.
Preparation
The cassava plant has either red or green branches with blue spindles on them. The root of the green-branched variant requires treatment to remove linamarin, a cyanogenic glycoside occurring naturally in the plant, which otherwise may be converted into cyanide. Konzo is a paralytic disease associated with several weeks of almost exclusive consumption of insufficiently processed bitter cassava.In Brazil's north and northeast, traditional community-based tapioca production is a byproduct of manioc flour production from cassava roots. In this process, the manioc is ground to a pulp with a small hand- or diesel-powered mill. This masa is then squeezed to dry it out. The wet masa is placed in a long woven tube called a tipiti. The top of the tube is secured while a large branch or lever is inserted into a loop at the bottom and used to stretch the entire implement vertically, squeezing a starch-rich liquid out through the weave and ends. This liquid is collected, and the microscopic starch grains in it are allowed to settle into the bottom of the container. The supernatant liquid is then poured off, leaving behind a wet starch sediment that needs to be dried and results in the fine-grained tapioca starch powder similar in appearance to corn starch.
Commercially, the starch is processed into several forms: hot soluble powder, meal, pre-cooked fine or coarse flakes, rectangular sticks, and spherical "pearls." Pearls are the most widely available shape; sizes range from about 1 mm to 8 mm in diameter, with 2–3 mm being the most common.
Flakes, sticks, and pearls must be soaked well before cooking to rehydrate, absorbing water up to twice their volume. After rehydration, tapioca products become leathery and swollen. Processed tapioca is usually white, but sticks and pearls may be colored. Traditionally, the most common color applied to tapioca has been brown, but recently pastel colors have been available. Tapioca pearls are generally opaque when raw but become translucent when cooked in boiling water.
Brazil, Thailand, and Nigeria are the world's largest cassava producers. Currently, Thailand accounts for about 60 percent of worldwide exports.
Storage
When roots are sold to processing factories, they must be processed within 24 hours of harvest to ensure raw material freshness and prevent microflora growth. This would be observed as brown-black discolorations in a freshly broken root.All process water streams contain some amount of sulfur dioxide to control the growth of microbes. Dried starch provides a shelf-stable product. For example, uncooked, dried tapioca pearls have at least a 2-year shelf life stability, whereas freshly cooked pearls may last ten days in the refrigerator. This difference is accounted to the water activity difference between the dried and wet product, the latter introducing a much more favorable condition for microbes to grow.
Environmental issues
There is an issue with tapioca because a large amount of water is needed in order to produce it. One factory reports that it uses around 60 m3 for one ton of tapioca starch just in the first step of processing. With this much water being used, properly disposing of the wastewater is a priority. Cassava contains cyanide, and depending on whether the tapioca is made for human consumption or industrial purposes there will be less or more cyanide. The wastewater used to process the tapioca contains this cyanide and if the wastewater is leaked into bodies of water containing aquatic life, due to the contaminated water's low pH, there is a direct effect on fish and possibly other animals that live on the shores of the polluted water. Water pollution from tapioca manufacturing has been a problem in many countries in Southeast Asia.A typical Indonesian tapioca factory in 2011 produces wastewater with three times the allowed amount of cyanides. The bigger issues relative to regulatory limits are the total suspended solids, biochemical oxygen demand, chemical oxygen demand values. As a result, the main proposed treatment methods include anaerobic digestion, as fertilizer, and possible future reuse of the starch within. As of 2023, the technology to recycle the suspended starch granules in tapioca starch wastewater has become mature enough under the name of "liquid sugar". It is expected to create more money-value compared to biogas.
Uses
Nutrition
Dried tapioca pearls are 11% water and 89% carbohydrates, with no protein or fat. In a 100-gram reference amount, dried tapioca supplies 358 calories and no or only trace amounts of dietary minerals and vitamins.Flatbreads
A casabe is a thin flatbread made from bitter cassava root without leavening. It was originally produced by the indigenous Arawak and Carib peoples because these roots were a common plant of the rain forests where they lived. In eastern Venezuela, many indigenous groups still make casabe. It is their chief bread-like staple. Indigenous communities, such as the Ye-Kuana, Kari-Ña, Yanomami, Guarao or Warao descended from the Caribe or Arawac nations, still make casabe.To make casabe, the starchy root of bitter cassava is ground to a pulp, then squeezed to expel a milky, bitter liquid called yare. This carries the poisonous substances with it out of the pulp. Traditionally, this squeezing is done in a sebucan, an 8 to long, tube-shaped, pressure strainer, woven in a characteristic helical pattern from palm leaves. The sebucan usually is hung from a tree branch or ceiling pole, and it has a closed bottom with a loop that is attached to a fixed stick or lever, which is used to stretch the sebucan. When the lever is pushed down, stretching the sebucan, the helical weaving pattern causes the strainer to squeeze the pulp inside. This is similar to the action of a Chinese finger trap. The pulp is spread in thin, round cakes about in diameter on a budare to roast or toast.
Thin and crisp cakes of casabe are often broken apart and eaten like crackers. Like bread, casabe can be eaten alone or with other dishes. Thicker casabe usually are eaten slightly moistened. A sprinkle of a few drops of liquid is enough to transform a dry casabe into soft, smooth bread.