Em um sistema biotecnológico, a identificação precisa das espécies é de suma importância para um processo eficiente. Em condições industriais, a fermentação é conduzida sem assepsiar e, consequentemente, o processo está sujeito a constante contaminação por cepas de bactérias e leveduras, incluindo espécies silvestres de Saccharomyces cerevisiae. A caracterização e identificação de espécies de leveduras tem sido baseada na morfologia e em características fisiológicas. No entanto, estas técnicas laboriosas muitas vezes deixam margem para dúvidas. Atualmente, a utilização de técnicas de biologia molecular permite a rápida identificação das espécies de leveduras envolvidas no processo fermentativo de forma eficiente e econômica. A bioprospecção de leveduras mais resistentes a condições de estresse poderá revelar cepas com bom potencial de utilização. Contudo, é necessária uma correta caracterização molecular e morfológica do isolado. O objetivo do presente estudo foi caracterizar cinco leveduras isoladas de extratos de frutos do cerrado brasileiro em nível morfológico e molecular. A análise morfológica das leveduras L32, L34, L36, L38 e B32 levou em consideração fatores como tamanho das colônias, cor, superfície e bordas. Esta caracterização foi complementada com identificação molecular realizada por PCR e PCR/RFLP. Os resultados mostram colônias predominantemente lisas e brilhantes. A análise da amplificação dos fragmentos de DNA ribossômico, após digestão com as enzimas Hae III e Hinf I, resultou em bandas correspondentes ao perfil de S. cerevisiae. Com estes resultados foi possível concluir que o método de isolamento de leveduras por pressão de estresses simultâneos permite selecionar as leveduras S. cerevisiae. Palavras-chave: Isolamento Seletivo. PCR. PCR/RFLP. DNA ribossômico. Colônias.

This chapter describes noodles that are produced and consumed in Asian countries as part of the local culture. These noodles are made from starch and can look similar to noodles made from wheat flour or other cereals. In China, noodles use wheat flour but also starches from plants native to South America such as canna, arrowroot, and sweet potato. Starch-based pasta is also consumed in Western countries. Still expanding markets for gluten-free foods and those for consumers with food intolerance syndrome may also value these products, in addition to traditional consumption. For this reason, this chapter also highlights baking with the use of sour cassava starch, that is, cassava starch subjected to lactic fermentation and UV radiation exposition. This special modified starch is traditionally consumed in almost all South American countries, under typical names such as "almidón agrio" and "polvilho azedo." It presents expansion without the use of leavening agents, besides being a gluten-free product.

It is possible to find small industries capable of extracting starch as alternative regional production. Other starchy raw materials are rice, sweet potato (Ipomea batatas), arrowroot (Maranta arundinacea), and canna (Canna indica). Most of these starches are extracted in small units with different processes and equipment. Similar solutions can also be found in the production of sour cassava starch, a traditional product found mainly in Brazil, Paraguay, Colombia, and Venezuela. The processing methods in small starch processing units are different from the big industries and are described in this chapter. The process of starch production from roots and tubers, irrespective of the degree of technology employed, comprises the steps of washing, cell disintegration and release of starch granules, separation of fibers and soluble material, starch concentration, and finally drying. Peeling is optional and may influence the starch purification process. The technologies adopted in small production units for the extraction of starch from canna, arrowroot, sweet potato, or cassava are very similar, despite the great distances between the producing regions. However, there are some regional differences, such as the use of small washing and peeling drums and centrifugal or vertical extraction sieves, in some of them. An obstacle for the development of sweet potato starch extraction, as for canna, is the high content of phenols, which impairs the final quality of the product, especially color. In this case, a settling tank for the purification of the starch, which allows for several washes to remove part of the phenolics compounds, allows for a brighter color of starch. This process is difficult for large-scale production.

An adhesive is a material capable of holding substrates together by surface interaction, while resisting separation. Adhesives and glues are universally used for both domestic and industrial purposes. Among the industrial uses, the textile, paper, and wood-based artifact industries stand out. The paper and cardboard industries use them mainly to obtain corrugated cardboard. Although in a smaller proportion, adhesives are also used in agriculture, as fixers for pesticides and foliar fertilizers. Despite the varied uses, the literature on adhesives is scarce, and in general, it deals with technical aspects and formulations made available by the producing companies. Starch is present in most formulations, because it has adhesive properties, but also because it is cheap and widely available. The formulations also mention manufacturing processes from modified starches because they have technical and quality advantages over their respective native starches. The most used are those obtained by heat treatment (pyrodextrins), followed by chemically modified starches (oxidized and acid-modified). The use of etherified and esterified starches is less common. Pyrodextrins and dextrins obtained by enzymes are little covered, although widely used. In addition, formulations are often based on corn starch because of its greater global availability and lower price. This chapter introduces the concept of adhesives and additives, presents the information available in the literature, describes the manufacturing processes and the official methods used to evaluate the adhesives produced.

Sour starch is a cassava starch derivative traditionally produced in Brazil, Paraguay, Bolivia, Colombia, and Venezuela; therefore, many of the documents cited in this chapter are in Portuguese or Spanish. Its origin has not been clearly established, but the fermentation process is a common habit of the Tupi Guarani Indians. The starch decanted in water is left to ferment naturally and then removed and dried in the sun. After drying, it shows its unique and persistent property of expanding in the oven without the addition of raising agents or extrusion. This differential promotes traditional food products but also allows it to be used in the gluten-allergic consumers' market. The sour cassava starch is on the rise consumption as a fast food, but sour starch is still a handmade product. This encourages its fraudulent replacement by chemically modified starches. In natural fermentation, lactic acid predominates and is technically linked to expansion, which can reach 14 cm3/g. Since native cassava starch does not present expansion, one must admit that sour starch is a modified starch. Research shows that it is possible to combine mechanized starch extraction with natural fermentation and sun drying, although a continuous process with the addition of lactic acid and the use of UV-C lamps is required. Recent results indicate that sour starch is a starch ether, resulting from grafting with lactic acid by UV-radiation energy.

This chapter describes the production processes of four food products derived from partial gelatinization of cassava starch. All can be made from humidified starch or from gum, a humid starch produced essentially in small units. The main partially gelatinized cassava starch products are: Brazilian tapioca (tapioquinha), tapioca pearl (sagu), broken tapioca pearls (tapioca), and popped tapioca pearls (farinha de tapioca), which will be described in this chapter. The production and equipment are described. Depending on the product, the production occurs in small units, with an installed capacity of less than 5 tons of cassava roots per day, or in large units, with an installed capacity of more than 200 tons. The market of Brazilian tapioca (tapioquinha) has grown a lot in Brazil in the last years, and this product has become one of the main cassava starch derivatives. Despite being in a growing market, popped tapioca pearls (tapioca flour) have a consumption limited essentially to the state of Pará, besides being exported to the Guianas. These products have a great market potential and can be consumed as fast food, with sweet or savory fillings, replacing cereals at breakfast, as energy bars, accompanying ice cream and in various types of desserts.

The chapter presents the design and evaluation of an equipment for disintegration and starch extraction of underground starchy crops from the viewpoint of process engineering. South America does not stand out in the engineering sector for large industrial equipment but has a tradition in small processing units. Many companies have specialized in copying equipment developed in industries from developed countries and, in case they are not adapted to local conditions and raw materials, making the necessary adjustments. This is the case for cassava starch production equipment, which often was initially developed for corn or potato starches. The starch release from raw materials, by grinding or grating, and the starch extraction are the two main processing steps and are the operations that we are focusing on to develop a suitable equipment for small units that can be used for several underground starchy crops, such as cassava, arrowroot, sweet potato, and canna. After presenting the requirements for the machine development, we present the main technologies already existing for raw material starch release and extraction from roots and tubers. Finally, the developed equipment is described, with the results of energy and water consumption and extraction tests from arrowroot and cassava. Although successful, the tests highlight the need to increase the length of the sieve. Extraction tests with faster sieve rotation could also reduce water consumption.

This chapter describes the topics covered in the third volume of the series "Underground Starchy Crops of South American Origin: Production, Processing, Utilization, and Economic Perspectives." The first part describes the processes of extraction and modification of starches from underground starchy crops, as well as starch food products, such as tapioca pearls, sour starch, and starch noodles. Although the starch industry is present worldwide and occupied by large modern companies, this volume also addresses the processes used by small traditional units. Then, the second part focuses on little-known markets that offer good development prospects, such as the pharmacology and cosmetology, the glue, carrier and encapsulation products, and the film and bioplastics industries. In addition to these starch markets, new ones are being developed and are mentioned in this chapter, such as those of superabsorbent, encapsulation and porous starch, purification and separation of material, battery production, and 3D printers, and their uses in human medicine are also discussed. Finally, this chapter addresses the problem of the market being concentrated on a few starch raw materials, valuing mainly availability and price. In many uses, the different characteristics of starch are little considered, which hinders the use of starches from other sources, such as the underground starchy crops from Latin America that are the subject of this series.

In Latin America, underground starchy crops are considered as very important in the fixation of humans through agriculture. As they are stored in the soil, they are less susceptible to attacks by pests and diseases than cereals. In addition to being used fresh as food and animal feeds, these crops can be processed and have extended storage. In this collection namely "Underground starchy crops of South American origin: Production, Processing, Utilization, and Economic Perspectives," we focus on the production and use of starch, an international as well as versatile product. Cassava and potatoes, native of the Amazon and the Andean highlands regions, are widely used for starch extraction, but these also have other under-exploited potentials. This chapter presents some main crops and emphasizes the lack of knowledge about these crops, except for potato and cassava(the main crops), with few scientific publications in English.