Sourdough Technology—A Traditional Way for Wholesome Foods: A Review Rupesh S. Chavan and Shraddha R. Chavan Abstract: In the present era, consumers wish to have a wide range of foods that are nutritious and flavorful and have long shelf life without added preservatives. Sourdough is an important modern fermentation of cereal flours and water based upon an earlier spontaneous process. The sourdough microflora is dominated by lactic acid bacteria and, along with yeast, they play a key role in the fermentation of bread dough. Factors that affect the quality of sourdough are dough yield, temperature, type of starter culture, acidity of the medium, and the substrate. Sourdough is classified into 3 types (Types I, II, and III); the most widely used for commercial production is Type III. The sourdough fermentation has a number of beneficial effects that include prolonged shelf life, accelerated volume gain, delayed staling, improved bread flavor, and good nutritional value. Sourdough also improves sensory characteristics such as loaf volume, evenness of baking, color, aroma, taste, and texture of breads. Sourdough has been reported to contribute to extended shelf life by inhibiting spoilage bacteria and mold growth. Introduction Bread making is probably one of the oldest technologies known to mankind. Findings suggest that people of Babylon, Egypt, Greece, and Rome used bread as part of their diet long before the A.D. period. Bread is consumed in large quantity in the world in different types and forms depending on cultural habits. Flat breads are the oldest, most diverse, and most popular product in the world. It is estimated that over 1.8 billion people consume various kinds of flat breads all over the world. Bread products and their production techniques differ widely around the world. The objective of bread making is to convert cereal flours into attractive, palatable, and digestible food. The foremost quality characteristics of leavened wheat breads are high volume, soft and elastic crumb structure, good shelf life, and microbiological safety of the product (Cauvain 2003; Chavan and Jana 2008). However, fresh bread is a product with a short shelf life and during its storage, a number of chemical and physical alterations occur known as staling. As a result of these changes, bread quality deteriorates gradually as it loses its freshness and crispiness while crumb firmness and rigidity increase. The pleasant aroma vanishes and flavor assumes a stale feeling (Chavan and Jana 2008). Regardless of the type of tech- nology, a bakery is currently using or willing to use, specific or tailor-made conditioning systems, and technology allows medium and large wholesale bakeries to produce high-quality goods by combining know-how on ingredients and on processing param- eters. Additional technologies have appeared on the market in the early 1990s. While the opportunities for microwave baking of MS 20101216 Submitted 11/3/2010, Accepted 12/9/2010. Author R.S. Chavan is with G.C.M.M.F. Ltd., Anand, Gujarat 388110, India. Author S.R. Chavan is with Dept. of Microbiology, B. A. C. A., A. A.U. Anand, Gujarat 388110, India. Direct inquiries to author Chavan (E-mail: rschavanb_tech@rediffmail.com). (frozen) dough are still being explored, microwaves have entered the baking trade for defrosting and/or reheating purposes. Fresh products were predicted to and did assume a 4% decline in market share versus frozen products by 2006 (Chavan and Chavan 2010). Frozen bakery products are characterized by quick preparation time and affordable price and look and taste as if freshly made and homebaked (Yamauchi and others 2001; Giannou and others 2003). The use of the sourdough process as a means of leavening is one of the oldest biotechnological processes in cereal food production. Sourdough bread is prepared from a mixture of flour and water that is fermented with lactic acid bacteria (LAB), mainly hetero- fermentative strains, elaborating lactic acid, and acetic acid in the mixture and hence causing a pleasant sour-tasting end product. Role of Ingredients in Making Bread Production of bread requires important ingredients such as flour, yeast, and water. Each ingredient used has its own significance both in conventional as well as in sourdough-based product manufac- ture. The roles of such ingredients are highlighted below: Flour Wheat-based foods are major source of nutrients in many re- gions of the world (Fincher and Stone 1986; Hoseney and others 1988). Flour is the most important ingredient in bread making because it modulates the specific characteristics of bakery prod- ucts. It consists of protein, starch and other carbohydrates, ash, fibers, lipids, water, and small amounts of vitamins, minerals, and enzymes. Wheat flour is the most common flour used. Refining of flour greatly affects the protein content as it decreases from 14.2% at 100% extraction to 12.7% at 66% extraction of flour (Pedersen 1994). The 2 basic types of protein that wheat flour 170 Comprehensive Reviews in Food Science and Food Safety  Vol. 10, 2011 c  2011 Institute of Food Technologists ® doi 10.1111/j.1541-4337.2011.00148.x