Posts

Showing posts from April, 2015

Caramelization in Cooking - Caramelization Reactions

Image
Food Chemistry: Caramelization Home > Biological Chemistry > Food Chemistry > Food Chemistry: The browning reaction or reactions of amino acids during cooking > Caramelization in Cooking - Caramelization Reactions   Sugar Caramelization Chemistry - Caramelization in Cooking Foods with high carbohydrate and low nitrogen content can be caramelized when heated. It is well known from experience that flavor develops when a food is cooked (heated). There are a number of dishes (such as the cre´me brulees ) where the flavors and color of the caramelization reactions are desirable. The most important reactions, from the prespective of flavor and aroma development , are those that are thermally activated. Amongst these reactions, the Maillard , Strecker and caramelization reactions are largely responsible for the flavors of chocolate and coffee , the caramel flavors of cooked sugars in deserts , on the cr

Weak Acid Weak Base pH calculation solved example

Image
Weak Acid Weak Base pH calculation solved example Home > Weak Acids and Bases – Calculate the pH of a weak acid (a general equation) > Solving Weak Acid and Weak Base pH problems > Weak Acid Weak Base pH calculation solved example Weak Acid Base pH calculation - Solved Example In a previous post entitled “ Weak Acids and Bases – Calculate the pH of a weak acid ” a general equation was derived for a weak acid base pH calculation (mathematical approach). A four-step method was also proposed for weak electrolyte pH calculation ( calculate the pH for a weak acid - calculate the pH for a weak base , chemical approach) (Fig. I.1). Solved examples using the above four-step method were presented in the post “ Solving Weak Acid and Weak Base pH problems ” Some extra solved examples on weak acid (base) chemistry are shown below. The “chemical approach” method is used for the solution.    Fig. I.1: Flowc

Food Preservatives: Sulfites and SO2

Image
Food Chemistry: Sulfites and SO2 as food preservatives Home > Biological Chemistry > Food Chemistry > Food Chemistry: The browning reaction or reactions of amino acids during cooking > Caramelization in Cooking - Caramelization Reactions > Food Chemistry: Antioxidants and Oxidation Reactions in Foods > Food Preservatives: Sulfites and SO 2 Food Chemistry: Sulfites and SO 2 as food preservatives Preservatives or antimicrobial agents play an important role in today's supply of safe and stable foods. Increasing demand for long self-life of processed foods makes the use of chemical food preservatives necessary. The activity of these preserving agents covers yeasts, molds and bacteria. The activity increases with decreasing pH and is mostly derived from undissociated sulfurous acid, which predominates at a pH < 3. The use of sulfites as food preservatives in wine for example dates back to anci