DOCSLIB.ORG

Water Minimization in the Tapioca Starch Production Industry: a Decision Support System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Water Minimization in the Tapioca Starch Production Industry: a Decision Support System The 3rd Conference on Starch Technology O-STARCH-03 Water Minimization in the Tapioca Starch Production Industry: A Decision Support System Natthakan Rungraeng1, Kanchana Saengchan1, Annop Nopharatana2 and Warinthorn Songkasiri3 1Department of Food Engineering, Faculty of Engineering, Food Engineering Practice School, King Mongkut’s University of Technology Thonburi, Ratchburana, Bangkok 10140, Thailand 2Pilot Plant Development and Training Institute (PDTI), King Mongkut’s University of Technology Thonburi, Bangkhuntien, Bangkok 10150, Thailand 3Biochemical Engineering and Pilot Plant Research and Development Unit (BEC), National Center for Genetic Engineering and Biotechnology (BIOTEC), 83 Moo 8 Thakham, Bangkhuntien, Bangkok, 10150, Thailand Abstract A typical tapioca starch manufacturing process consumes freshwater approximately 10 to 30 m3 per ton of starch produced. The amount of water consumption can be reduced considerably by the recycle of wastewater. This research utilizes a water pinch technology as a tool to minimize water consumption in the starch production process. The water pinch decision support system, called the W-Pinch program, was generated by the Starch Engineering and Process Optimization (SEPO) Program, King Mongkut’s University of Technology Thonburi (KMUTT). The W-Pinch modelling system includes 7 composition balances of water, starch, protein, pulp, sand, peel, and sulfur. Water composition is correlated to freshwater and wastewater calculations and the moisture content of the product. Starch and pulp compositions demonstrate the extractor efficiency. Peel, sand, protein, and sulfur compositions are the control parameters to monitor and control the final product quality after applying the water recycling patterns. Each composition stream was balanced for each unit in the starch production process, i.e., root receiver, washer/cutter, rasper/grinder, coarse extractor, fine extractor, separator I, separator II, separator III, centrifugal dewater unit, and flash dryer. A user inputs the removal efficiency of each component and the maximum allowable concentrations of each composition at that specific unit into the W-Pinch input file. Five recycling patterns were designed to evaluate the water minimization in the starch process. All the water streams do not require the water treatment before the reuse of water. In addition, the W-Pinch program allows a user customize his own recycling pattern. The W-Pinch model was validated with the data from one tapioca starch factory with a capacity of 200 tons starch per day. The W-Pinch simulations showed that, with a recycling water stream, the water consumption was reduced by 25 percent of that of the non-recycling system. Introduction Tapioca starch, one of the major export products of Thailand, is produced from the tuberous roots of the tapioca plant. The starch manufacturing process can be divided into the following stages: 1. Fresh roots are passed through the sand removing drum to separate out sands and dirts, then roots are washed, peeled, and rasped before the addition of water to become starch slurry. 2. Starch slurry is passed through extractors twice to extract starch from cassava pulps using centrifugal forces. Several extractors are interconnecting in series with different mesh sizes. 3. Freshwater is added to the starch milk in separator units to separate of the fruit water and its soluble contents, i.e. root protein. 4. Water is removed by draining, centrifuging and drying with pneumatic dryer. 5. Then, the starch is ready to pack. However, the starch producing processes consume freshwater approximately 10 to 30 m3 per ton of starch produced (Jirasaowapak, 1998). Thus, this research utilizes a water pinch technology as a tool to minimize water consumption in the starch production process by the reuse and recycle of water. The water pinch decision support system, called the W-Pinch program, was generated by the Starch Engineering and Process Optimization (SEPO) Program, King Mongkut’s University of Technology Thonburi (KMUTT). 97 Starch Update2005 Water pinch technology is a mass-exchange network involving the optimization of water- using operations in the production process (Srinophakun et al., 2000). The water pinch technology can be divided into three steps: (1) analysis Identifying, a priori, the minimum freshwater consumption and wastewater generation in water-using operations (2) synthesis Designing a water-using network that achieves the identified flow rate targets for freshwater and wastewater through water reuse, regeneration, and recycle (3) retrofit Modifying an existing water-using network to maximize water reuse and minimize wastewater generation through effective process changes. Jirasaowapak (1998) reported that the amount of water consumption can be reduced from 12 m3 per ton starch to around 5 m3 per ton starch by reusing the treated wastewater. Moreover, Prakotpol (2003) established a genetic toolbox for water pinch technology the program was written in MATLAB. The program can be used to minimize freshwater consumption for both single and multi contaminants according to user data inputs. 2. Methodology 2.1. The W-Pinch Model The W-Pinch program is written in FORTRAN language. The program consists of mass balance equations of each compostion around each production units as shown in the following equation. Flowouti, j Flowini, j u Efficiencyi, j ---(1) where i is the unit operation j is the compositions A user inputs the removal efficiency of each component and the maximum allowable concentrations of each composition at that specific unit into the W-Pinch input file. The compositions are 1. Water (W) 2. Starch (ST) 3. Protein (PR) 4. Pulp (PP) 5. Sand (SN) 6. Peel (PE) 7. Sulfur (SF) Water (W) composition is linked in the calculation of the flow rate of freshwater and wastewater and the moisture content of the starch product. Starch (ST) and pulp (PP) contents are the parameters used for the evaluation of the extraction efficiency. Peel (PE), sand (SN), protein (PR), and sulfur (SF) are the unwanted compositions for customers. They are included in this model to monitor and control the quality of the final product after applied water reused patterns. The units in the starch production process in the W-Pinch program are 1. Root receiving unit 2. Washing and cutting unit 3. Rasping and grinding unit 4. Coarse Extractor 5. Fine Extractor 6. Separator I 7. Separator II 8. Separator III 9. Centrifugal Dewatering unit 10. Flash Drying unit 98 The 3rd Conference on Starch Technology In addition, the pulp released from coarse and fine extractors are re-extracted in the pulp extractor. The wasted pulps are pressed to remove water and are sold as animal feeds. The amount of water, protein, pulp, sand, peel, and sulfur released from each unit depend on the machine efficiency specified by a user. 2.2. Reused Patterns Five recycling patterns were designed to evaluate the water minimization in the starch process. Note that all the water streams do not require the water treatment before the reuse of water. Pattern I (shown in Figure 1) - Water effluent from the pulp pressing and pulp extractor were reused in the washing and cutting unit - Water effluent from the separator I was reused in the rasping and grinding unit - Water effluent from the separator II was reused in the coarse extractor - Water effluent from the separator III was reused in the fine extractor Pattern II (shown in Figure 2) - Water released from the pulp pressing and pulp extractor were reused at the rasping and grinding unit - Water released from the separator I was reused at the washing and cutting unit - Water released from the separator II was reused at the coarse extractor - Water released from separator III was reused at fine extractor Figure 1 Water Reused Pattern I Figure 2 Water Reused Pattern II 99 Starch Update2005 Pattern III (shown in Figure 3) - Water released from the pulp extractor was reused at the rasping and grinding unit - Water released from the separator I and the pulp pressing unit were reused at the rasping and grinding unit - Water released from the separator II was reused at the fine extractor - Water released from the separator III was reused at the coarse extractor Pattern IV (shown in Figure 4) - Water released from the pulp extractor with the pulp pressing and the separator II were reused at the rasping and grinding unit - Water released from the separator I was reused at the coarse extractor unit - Water released from the separator III was reused at the fine extractor Pattern V (shown in Figure 5) - Water released from the pulp extractor and pulp pressing unit were reused at the rasping and grinding unit - Water released from the separator I was reused at the washing and cutting unit - Water released from the separator II was reused at the fine extractor - Water released from the separator III was reused at the coarse extractor. Figure 3 Water Reused Pattern III Figure 4. Water Reused Pattern IV 100 The 3rd Conference of Starch Technology Figure 5. Water Reused Pattern V 2.3 Model Calculations The amount of freshwater consumption without water reused network was calculated, and then the freshwater consumption of each reused pattern were calculated and shown in the table in the output file for the result comparison. 2.4 Model Validation This model was validated with the data from one of the tapioca starch factory in Thailand. After validation, the amount of freshwater consumption was approximately 23 m3 per ton of starch. 3. Results and discussion Table 1 shows the comparisons of water consumptions, amount of product, and starch compositions from each pattern of water reused. Water Consumption Water consumption of the no-recycle line is 22 m3 per one ton product and the amount of product is 96.4 tons daily. After apply 5 patterns for water recycle the water consumption are reduced to 17.97, 17.24, 17.02, 18.14, and 17.17 m3 per one ton product in pattern I to pattern V, respectively.
Load more

Recommended publications
  • Potato Wastewater Treatment
    6 Potato Wastewater Treatment Yung-Tse Hung and Howard H. Lo Cleveland State University, Cleveland, Ohio, U.S.A. Adel Awad and Hana Salman Tishreen University, Lattakia, Syria 6.1 INTRODUCTION In the past two decades, the potato industry has experienced rapid growth worldwide, accom- panied by a staggering increase in the amount of water produced. It is estimated that the US potato industry alone generates about 1.3 Â 109 kg of wastes each year [1]. Large volumes of wastewater and organic wastes are generated in potato processing as result of the water used in washing, peeling, and additional processing operations. The potato industry is well known for the vast quantities of organic wastes it generates. Treatment of industrial effluents to remove organic materials, however, often changes many other harmful waste characteristics. Proper treatment of potato processing wastewaters is neces- sary to minimize their undesirable impact on the environment. Currently, there is an increasing demand for quality improvement of water resources in parallel with the demand for better finished products. These requirements have obliged the potato industry to develop methods for providing effective removal of settleable and dissolved solids from potato processing wastewater, in order to meet national water quality limits. In addition, improvement and research have been devoted to the reduction of wastes and utilization of recovered wastes as byproducts. This chapter discusses (a) the various potato processing types and steps including their sources of wastewaters; (b) characteristics of these wastewaters; (c) treatment methods in detail with relevant case studies and some design examples; and (d) byproduct usage.
    [Show full text]
  • Identification of Valuable Corn Quality Traits for Starch Production
    Identification of Valuable Corn Quality Traits for Starch Production By: Lawrence A. Johnson Center for Crops Utilization Research Food Science and Human Nutrition C. Phillip Baumel Economics Connie L. Hardy Center for Crops Utilization Research Pamela J. White Food Science and Human Nutrition A project of the Iowa Grain Quality Initiative Traits Task Team Funded by the Iowa Corn Promotion Board 306 West Towers 1200 35th St. West Des Moines, IA 50266 October 1999 Center for Crops Utilization Research Iowa Agriculture & Home Economics Experiment Station Iowa State University, Ames, IA 2 Acknowledgment This report is intended to provoke discussion and debate that will lead to a vision among researchers in public institutions, seed companies, and the starch processing and food industries for modifying corn traits for starch (and other complex carbohydrates) production to enhance utilization and profitability of growing corn. The report attempts to provide direction to farmer organizations and to the corn industry about potential targets for investing research funds. One should recognize that some of the modifications considered required speculation about functional properties and potential applications. Additional research on the relationship between the structures of starch and other complex carbohydrates and functionality in food and industrial applications may refute some of that speculation. Also, this document is a consensus report taking into account the recommendations and reviews of the consultants and advisors identified below. Dr. Jay-lin Jane, Food Science and Human Nutrition, Iowa State University, Ames, IA Dr. Morton W. Rutenberg, Emmar Consultants, North Plainfield, NJ Dr. Henry Zobel, ABCV Starch, Darien, IL Dr. Robert Friedman, Cerestar USA, Inc., Hammond, IN Dr.
    [Show full text]
  • Wheat - a Challenging Substrate for Starch Production
    ŻYWNOŚĆ 2(23) Supl., 2000 W. BERGTHALLER, H.-J. KERSTING WHEAT - A CHALLENGING SUBSTRATE FOR STARCH PRODUCTION Abstract In contrast to the world-wide given situation for maize as the main substrate in starch isolation, wheat gains an advantageous position in the European starch industry although technical starch yield cannot compete fully material prices. Its remarkable position profits also from wheat gluten as valuable by­ product. Further indication for rising preference can be seen in the installation of new processing capaci­ ties in Europe. However, the economic situation of wheat starch production follows unavoidable fluctua­ tions of wheat gluten markets. Political decisions play an important role, too. The challenging situation connected with wheat as substrate for starch extraction is result of develop­ ments in equipment and remodelling of technology. The most important contribution consisted in an obvious shift of the relation of water to flour used for flour/water mixture preparation, starch and gluten extraction, and refining. This was initialised mainly by the introduction of separation techniques using centrifugal principles. With respect to limited availability of water and increasing costs for waste water treatment reduction of water supply is a steady target. In close connection to developments in separation technology wheat and wheat flour should gain ex­ tended attraction. Published standards are limited and reveal at most characteristics oriented to the, Martin process. With respect to recent developments in technology, alternative testing procedures have been proposed. Results demonstrate the suitability and specificity of the „Mixer method", a procedure adapted to flour/water relations in centrifugal separation. But, the time consuming procedure restricts general application.
    [Show full text]
  • Physicochemical and Functional Properties of Wheat Starch in Various Foods
    SPECIAL SECTION: Molecular Diversity and Health Benefits of Carbohydrates from Cereals and Pulses Understanding the Physicochemical and Functional Properties of Wheat Starch in Various Foods Clodualdo C. Maningat1 and Paul A. Seib2,3 ABSTRACT Cereal Chem. 87(4):305–314 This report highlights the structure and myriad properties of wheat eating quality, and texture of pasta and noodles, and its role is more than a starch in various food systems. Granule shape, size, and color, plus the filler in yeast-leavened bread products. Recent developments in the prop- proportion of A- and B-granules, amylose content, and molecular struc- erties and applications of commercially important wheat pyrodextrins and ture largely determine its functionality in food. The role of wheat starch is RS4-type resistant wheat starches are reported, along with their use to portrayed in three categories of flour-based foods that differ in water produce fiber-fortified foods. Gluten-free foods are also discussed. content. Wheat starch influences the appearance, cooking characteristics, Wheat (Triticum aestivum L.) is unique because of the proper- synthase I. Other embedded proteins with enzyme activities are ties of two principal macromolecular components, protein (gluten) soluble starch synthase, starch branching enzyme, and two poly- and starch. Wheat gluten is responsible for the dough-forming peptides that may have starch synthase activities (Rahman et al ability of wheat flour to make bread, which is unmatched by any 1995; Gao and Chibbar 2000). other proteins of plant, animal, or microbial origin (Gianibelli et The lipids consist of 0.7–1.4% that is interior-bound (Morrison al 2001; Wrigley et al 2006).
    [Show full text]
  • Starch and Starch Sugar Wastewater Treatment Technology Scheme and Operation Monitoring
    id27306828 pdfMachine by Broadgun Software - a great PDF writer! - a great PDF creator! - http://www.pdfmachine.com http://www.broadgun.com [Type text] ISSN : [0T9y7p4e -t e7x4t3] 5 Volume 1[0T Iyspseu ete 1x9t] BioTechnology 2014 An Indian Journal FULL PAPER BTAIJ, 10(19), 2014 [11286-11290] Starch and starch sugar wastewater treatment technology scheme and operation monitoring Chen Yong1*, Liu Shuaixia1, Xin Yinping2 1Henan Institute of Engineering，No.1 Xianhe Road, Longhu Xinzheng, Zhengzhou, Henan Province, 45119, (CHINA) 2Henan Zhengda environmental technology consulting engineering company limited, Wenhua Road No. 56, Zhengzhou City, Henan Province，450002, (CHINA) E-mail : [email protected] ABSTRACT This paper mainly through wastewater renovation project of a program of starch and starch sugar production enterprises and its actual operating results, the analysis of various treatment structures combined operation of the treatment plant treatment effect, the purpose is to understand the characteristics of each treatment structures in starch and starch sugar wastewater treatment process, for the follow-up design or improvement of starch and starch sugar the wastewater treatment technology has certain reference significance. KEYWORDS Starch and starch sugar; Wastewater treatment renovation; Monitoring results. © Trade Science Inc. BTAIJ, 10(19) 2014 Chen Yong 11287 INTRODUCTION Starch is polyhydroxylated natural high molecular compound, widely exists in plant roots, stems and fruits, food, medicine, chemical, papermaking, textile and other industrial sectors of the main raw material. The main raw material crop starch production is the corn, potato and wheat. Produce a lot of high concentrations of acidic organic wastewater in starch processing process, its content with the production fluctuation and change from time to time, which is mainly soluble starch and a small amount of protein, no general toxicity.
    [Show full text]
  • Aspects of Agricultural Use of Potato Starch Waste Water
    Reprint Neth. J. agric. Sei. 21(1973): 85-94 Aspects of agricultural use of potato starch waste water F. A. M. de Haan1, G. J. Hoogeveen2 and F. Riem Vis3 1 Laboratory of Soils and Fertilizers, Agricultural University, and Institute for Land and / Water Management Research, Wageningen, the Netherlands 2 Government Service for Land and Water Use, Utrecht, the Netherlands 3 Institute for Soil Fertility, Haren, the Netherlands Accepted: 24 January 1973 Summary Agricultural industries in the northeastern part of the Netherlands, with the potato starch industry as the most important one, produce a very large amount of waste water. Research work is now performed on possible solutions to the environmental problems resulting from discharge of this water on open canals. Land disposal offers such a possibility. Since the waste water contains the natural components of potatoes only it can be considered as a relatively innocent type of industrial waste water. Moreover, the main constituents are also the major elements for plant nutrition thus rendering an opportunity to recycle these components. Evaluation ofwast ewate r utilization for agricultural purposesmus t bebase d on a number of criteria of whichth emos t important onesare :purificatio n byth esoi lsystem , fertilization of agricultural crops, and economic effects for the farmer whose land is used for this kind of waste water treatment. In the economic evaluation with respect to other proposed solutions, cost of application is also to be taken into account. This article is confined to the three first-mentioned criteria. Experimental results and model calculations indicate that with mean yearly application rates in the range of 50 to 100 mm the relevant requirements can be met at a farmers profit of about 100 guilders per ha.
    [Show full text]
  • Status of Starch Sources in India, Their Processing and Utilization
    Status of Starch Sources in India, their Processing and Utilization Dharmesh Chandra Saxena Department of Food Engineering & Technology SANT LONGOWAL INSTITUTE OF ENGINEERING & TECHNOLOGY LONGOWAL (PUNJAB) INDIA 1 !! Starch,Starch, αα--DD glucanglucan polymerpolymer -- aa majormajor energyenergy sourcesource inin mostmost dietdiet !! VersatilityVersatility andand heterogeneityheterogeneity ofof applicationapplication inin thethe foodfood industryindustry !! TheThe useuse ofof starchstarch productsproducts asas aa foodfood ingredientingredient isis usuallyusually notnot basedbased onon theirtheir nutritionalnutritional valuevalue butbut onon theirtheir functionalfunctional value.value. !! AlmostAlmost allall majormajor industriesindustries (food(food andand nonnon--food)food) havehave foundfound somesome applicationsapplications forfor starch.starch. 2 StarchStarch isis widelywidely foundfound inin !! cerealcereal graingrain seedsseeds (e.g.(e.g. corn,corn, rice,rice, wheat),wheat), !! tuberstubers (e.g.(e.g. potato),potato), !! rootsroots (e.g.(e.g. sweetpotato,sweetpotato, cassava,cassava, arrowroot),arrowroot), !! legumelegume seedsseeds (e.g.(e.g. peas,peas, beans),beans), !! fruitsfruits (e.g.(e.g. greengreen bananas,bananas, unripeunripe apples),apples), andand !! leavesleaves (e.g.(e.g. tobacco).tobacco). 3 ! Starch can be simply manufactured by the combination of grinding the starch-rich crop followed by wet separation techniques. ! The starch granules will sediment in water due to their higher density. ! Three main classes of starch
    [Show full text]
  • Cassava As Animal Feed in Ghana: Past, Present and Future
    CASSAVA AS ANIMAL FEED IN GHANA: PAST, PRESENT AND FUTURE i CASSAVA AS ANIMAL FEED IN GHANA: PAST, PRESENT AND FUTURE Author Kwame Oppong-Apane - Chief Executive Officer, Oporhu Agricultural and Rural Development Consultancy Limited, P.O. Box CT 1738, Cantonments, Accra, Ghana Editors Berhanu Bedane Cheikh Ly Harinder P.S. Makkar Animal Production and Health Animal Production and Health Animal Production Officer, Officer, FAO Sub-regional Officer, FAO Regional Office Livestock Production Systems office for West Africa (SFW), for Africa (RAF), Accra, Ghana Branch (AGAS), FAO, Rome, Accra, Ghana Italy Food and Agriculture Organization of the United Nations Accra, 2013 i The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO in preference to others of a similar nature that are not mentioned. The views expressed in this information product are those of the author(s) and do not necessarily reflect the views or policies of FAO. ISBN 978-92-5-107687-3 (print) E-ISBN 978-92-5-107688-0 (PDF) © FAO 2013 FAO encourages the use, reproduction and dissemination of material in this information product. Except where otherwise indicated, material may be copied, downloaded and printed for private study, research and teaching purposes, or for use in non-commercial products or services, provided that appropriate acknowledgement of FAO as the source and copyright holder is given and that FAO’s endorsement of users’ views, products or services is not implied in any way.
    [Show full text]
  • Starch and Flour Extraction and Nutrient Composition of Tuber in Seven Cassava Accessions
    J. Bangladesh Agril. Univ. 10(2): 217–222, 2012 ISSN 1810-3030 Starch and flour extraction and nutrient composition of tuber in seven cassava accessions M. S. A. Fakir, M. Jannat, M.G. Mostafa and H. Seal1 Department of Crop Botany, 1Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh- 2202, Bangladesh, Email: [email protected] Abstract Cassava (Manihot esculenta Crantz) roots (tubers) are used as staple food. Starch extracted from tubers is widely utilized as raw materials in industries. Dry matter (DM) content, starch and flour extraction and proximate composition were investigated in seven cassava accessions (Coc-A1, Kh-A2, Cow-A3, Sa-A4, Me-A5, Va-A6 and Sy-A8.) in 2010- 2011. Leaf DM varied from 20.51% in Me-A5 to 29.01% in Sy-A8; that of stem from 27.24% in Va-A6 to 32.10% (average of Sy-A8, Me-A5 and Sa-A4); and that of tuber from 37.30% in Kh-A2 to 45.26% in Sy-A8. Starch was extracted by blending chopped tuber followed by decantation. Tubers were sliced, sun dried and milled into flour. Tuber starch content (fresh wt. basis) varied between 15.04% in Sy-A8 and 24.97% (average of Coc-A1 and Me-A5); that of peel from 4.54% in Va-A6 to 5.85% in Coc-A1. Crude protein varied from 1.80% (average of Kh-A2, Cow-A3 and Sy-A8) to 4.53% in Va-A6. Crude fiber content varied from 1.95% (average of Sa-A4 and Coc-A1) to 4.27% in Cow-A3.
    [Show full text]
  • 2.3.2. Genetic Modification of Plant Cell Walls for Enhanced Biomass
    Genetic Modification of Plant Cell Walls for Enhanced Biomass Production and Utilization Investigators Chris Somerville, Professor, Department of Biological Sciences, and Director, Carnegie Institution, Department of Plant Biology; Jennifer Milne, Postdoctoral Fellow, Department of Biological Sciences Introduction In 2002, The US Department of Energy released a document entitled “The Vision for Bioenergy and Biobased Products in the US” that envisioned 5% of energy, 20% of transportation fuel and 25% of chemicals being derived from biomass by 2030. A crucial factor in reaching these goals will be the net productivity of the plants used. It is generally accepted that the current practice of converting excess starch production to ethanol does not represent a significant long-term opportunity. By contrast harvesting the “cellulosic biomass” that comprises the body of plants represents an attractive target. A recent study by DOE and USDA estimated that there is approximately 1.4 billion dry tons per year of renewable excess biomass capacity in the US. This is roughly equivalent to the energy content of all imported petroleum. Plant biomass is primarily a mixture of six types of polysaccharides. These can be utilized for energy production in a variety of ways, including direct combustion, gasification, pyrolysis, and enzymatic conversion to ethanol or other organics. In order to maximize the energy efficiency of biomass production it is essential to minimize requirements for fixed nitrogen (~30 Gj/tonne), which is required primarily for protein and lignin synthesis. The polysaccharides that comprise the bulk of biomass do not contain any nitrogen. Thus, from a system engineering perspective, it is desirable to maximize polysaccharide accumulation while minimizing demand for nitrogen.
    [Show full text]
  • Physical And/Or Chemical Modifications of Starch by Thermoplastic Extrusion
    3 Physical and/or Chemical Modifications of Starch by Thermoplastic Extrusion Maria Teresa Pedrosa Silva Clerici Federal University of Alfenas-UNIFAL-MG Brazil 1. Introduction Starch makes up the nutritive reserves of many plants. Starch biosynthesis is a complex process, which may be summarized as during the growing season, the green leaves collect energy from the sun, this energy is transported as a sugar solution to the starch storage cells, and the sugar is converted into starch in the form of tiny granules occupying most of the cell interior. The conversion of sugar into starch takes place through enzymes (Corn Production Source, 2011; Tester et al., 2006). Starch granules are composed of two types of alpha-glucans, amylose and amylopectin, which represent approximately 98–99% of the dry weight. The ratio of the two polysaccharides varies according to the botanical origin of the starch and classifies starch as the ‘waxy’ starches contain less than 15% amylose, ‘normal’ 20–35% and ‘high’ amylose starches greater than about 40% (Tester et al., 2006; Wurzburg, 1989). Amylopectin is a much larger molecule than amylose with a molecular weight and a heavily branched structure built from about 95% ( 1- 4) and 5% ( 1- 6) linkages. Amylopectin unit chains are relatively short compared to amylose molecules with a broad distribution profile. They are typically, 18–25 units long on average (Tester et al., 2006; Wurzburg, 1989). Nutritionally, starch is consumed as an energy source, and it is the most abundant energy source in the human diet as it is present at high amounts in cereals, roots and tubers, which products range from breads, cookies, pastes to consumption as snacks, porridges, or as processed cooked grains (white rice, corn grain) or whole grains (whole grain of rice, wheat, popcorn, etc.).
    [Show full text]
  • Starch and Modified Starch in Bread Making: a Review
    Vol. 10(12) pp. 344-351, December 2016 DOI: 10.5897/AJFS2016.1481 Article Number: F11ADFD61432 ISSN 1996-0794 African Journal of Food Science Copyright © 2016 Author(s) retain the copyright of this article http://www.academicjournals.org/AJFS Review Starch and modified starch in bread making: A review Calvin Onyango Food Technology Division, Kenya Industrial Research and Development Institute, P. O. Box 30650-00100, Nairobi, Kenya. Received 30 June 2016, Accepted 27 September, 2016. Starch is an important source of energy in human nutrition. It is also widely used as a processing aid in several food and non-food industries. Starch in wheat flour contributes to the development of optimal bread crumb and crust texture. It is also responsible for physical deterioration of bread quality through staling. Starch is mainly extracted from starch-rich plants such as cereals, root and tuber crops and legume seeds. It can be modified using chemical, physical or enzymatic techniques to obtain modified starch. Traditional plant breeding or genetic modification can also be used to produce starches with modified functionalities. Modified starches are essential food processing aids because of their enhanced functional properties. The aim of this paper is to review the role of starch in bread making and subsequently elucidate the influence of modified starch on the quality of wheat bread. Key words: Bread, modified starch, starch, wheat. INTRODUCTION Bread is an important source of energy in the human diet used in bread making are first mixed into viscoelastic because of its high content of readily digestible starch (40 dough which is then fermented in two or several stages g/100 g) (Mckevith, 2004).
    [Show full text]