REVIEW Recent trend in the physical and chemical modification of starches from different botanical sources: A review Adeleke Omodunbi Ashogbon 1 and Emmanuel Temitope Akintayo 2 1 Faculty of Science, Department of Chemistry and Industrial Chemistry, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria 2 Faculty of Science, Department of Chemistry, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria Starch is, after cellulose, the most abundant organic compound in nature. Modification of starch is carried out to enhance the positive attributes and to eliminate the shortcomings of the native starches. Various methods have been developed to produce a range of modified starches with a variety of characteristics and applications. Physically modified starches are simple and inexpensive because they can be produced without chemicals or even biological agents. In contrast, chemical modification is possible due to ubiquitous hydroxyl groups in starches that have been exploited for over a century, principally in the preparation of starch esters and ethers, but also in more subtle alterations, e.g., in order to tune the structure of starches for specific applications. All these techniques tend to alter the highly flexible starch polymer with changed physicochemical properties and modified structural attributes of high technological value for the food and non-food industries. Modification of starch is an ever evolving industry with numerous possibilities to generate novel starches which includes new functional and value added properties as demanded by the industry. This review aims to summarize the latest developments and recent knowledge regarding physically and chemically modified starches. This paper covers physical modification methods (pre-gelatinization, hydrothermal, and non-thermal processes), some chemical modifications and a combination of both. Received: April 30, 2013 Revised: July 10, 2013 Accepted: July 17, 2013 Keywords: Chemical / Physical / Properties / Starch Granules / Starch Modification 1 Introduction Starch is a naturally occurring, biodegradable, cheap, renewable, and abundantly available polysaccharide molecule. The different botanical sources of starches are cereal (wheat, corn, rice, barley, oat, sorghum, millet, and rye), legume (lima bean, garbanzo bean, lentil bean, red kidney bean, navy bean, faba bean, mung bean, pinto bean, adzuki bean, field pea, cowpea, beach pea, green pea, grass pea, soybean, and groundnut), some under-utilized legume (sword bean, jack bean, and pigeon pea), root and tuber (cassava, potato, yam, cocoyam, and sweet potato), and unripe fruit (banana, plantain, mango, and pawpaw). Starch granules are mainly found in seeds, roots and tubers, as well as in stems, leaves, fruits and even pollens. The granules occur in all shapes and sizes (spheres, ellipsoids, polygon, platelets, and irregular tubules). The two main components of starch are amylose (AM) and amylopectin (AP) and they differ significantly in their properties and functionality. AM has a high tendency to retrograde and produce tough gels and strong films. In contrast, AP, when dispersed in water, is more stable and produces soft gels and weak films [1]. It is possible for entanglements to occur between AM and AP, along with the presence of minor components (proteins, PLs, and lipids), all also have important impacts on the physicochemical proper- ties of the starches from different botanical origin. The industrial utilization of native starches is limited because of inherent imperfect nature, such as water insolubility and their Correspondence: Adeleke Omodunbi Ashogbon, Faculty of Science, Department of Chemistry and Industrial Chemistry, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria E-mail: ashogbonwale@yahoo.com Fax: þ234-08059225829 Abbreviations: HHP, high hydrostatic pressure; PEF, pulsed electric fields; PGS, pre-gelatinized starches; STMP, sodium trimetaphosphate; STPP, sodium tripolyphosphate; UHP, ultra high pressure DOI 10.1002/star.201300106 Starch/Stärke 2014, 66, 41–57 41 ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.starch-journal.com