**1. Introduction**

 This book focuses on low investment alternative use of dairy by-products. Whey has application in both the pharmacology and nutritional industry. However, three main problems affront cheese makers when they try to process whey: the short half-life, the cost of refrigerating, and transportation cost. All these make the use of whey economically difficult for small and medium manufacturers. Therefore, in most cases, whey ends up as agro-industrial waste. This represents a loss of valuable opportunities and also, as explained below, represents a high environmental impact. In the different chapters, the authors offer alternative biotechnology processes (**Figure 1**). The ultimate goal of the book is to break the paradigm of considering milk by-product as a waste. This introductory chapter provides the global context in which the book was conceived: starts with a historical and current perspective of the consumption of dairy products, continues with the composition of the by-products, followed by our experience of using whey as culture media to produce mineral organic supplement and then isotonic lactosefree beverage, and closes with a general conclusion.

#### **Figure 1.**

*Alternative use of whey and buttermilk discussed in this book.* 
