Sugar Concentration

• Sugar concentration - It is a preservation by increased osmotic pressure
• Sugar concentration - Cells placed in solution with high sugar concentration are plasmolyzed, water is withdrawn from the cell, thus, inhibiting the metabolic activities of microorganism.
• Sugar concentration - It uses a similar principle with desiccation or dehydration method of preservation
• History of Sugar Concentration In Europe, earliest cultures of the Europeans involved storing fruits in honey for preservation. In northern climates without sufficient sun to dry foods, preserves are made by heating the fruit with sugar. They got their sugars from sugar canes that came from trades. 
• Importance of sugar concentration of food processing - Sugar content prevents microbial growth and spoilage by increasing the osmotic pressure, which limits microbial growth and makes these foods last longer. (Sugar in Food Preserving (acsedu.co.uk)
• Sugar - It is an organic compound in the form of carbohydrate.  
• Different types of sugar:

  • Simple Sugar
  • Double Sugar
• Simple Sugars known as monosaccharides, which includes glucose (dextrose), fructose (fruit sugar) and galactose. 
• Double Sugar joined by a glycosidic link - 2 monosaccharides joined together are called disaccharides, which includes sucrose (table/granulated sugar). 
• Action of sugar - When sugar is added to foods it binds to the water in the foods reducing the amount of water that is available for the growth of microorganisms. Like salt water also has an osmotic effect i.e., when foods are placed in a concentrated sugar solution water is drawn out of the cells of foods and microorganisms so that microorganisms can no longer survive.
• One way to use sugar is to desiccate fruits by drying them and then packing them with pure sugar. Fruits which are traditionally preserved through this method include ginger, cherries and the peel of citrus fruits. Alternatively, foods may be stored in a sugar syrup or cooked in sugar until they crystalize.
• To produce jams and marmalade, fruits are initially boiled to reduce the water content of fruit and to reduce contaminating microorganisms. Sugar is then added to the fruit to prevent the regrowth of bacteria. Other food preservation techniques involve combining sugar with alcohol to enable the preservation of fruit in alcoholic spirits such as Brandy (alcohol).
• Sugar is also used with salt to preserve certain foods especially fish and meat. Sugar may either be added to salt to create a dry mixture which covers food or may be dissolved in a liquid to make a brine to surround the food. Adding sugar to a salty brine helps to confer a sweetness to meat and fish and also helps to reduce the harsh flavor of salt. 
• Sweetener - White and brown crystalline sugars are used as sweeteners in home cooking and the food industry. Powdered sugars are used as icing sugar in baking and confectionery. Sugar syrups are used in beverages or as a base for fruit sauces, toppings and flavored syrups. Sugars are also used to counter acidic and bitter tastes, e.g. in tomato sauces, mayonnaise or in medical syrups. 
• Texture, volume, and moisture - Sugars play a major role in defining the bulk (volume) and texture (mouthfeel) of foods. For example, sugars provide volume to cakes and biscuits. The combination of sugar with a gelling agent (e.g., pectin) is responsible for the jelly texture of jams. In baked products sugar increases the starch gelatinization temperature, trapping air bubbles and delivering a light texture to cakes.
• Texture, volume, and moisture - Sugar is a humectant (binds water), which is important in food preservation and also affects texture. Sugars also reduce the freezing point, important for producing softer ice creams, and increase the boiling point, which is important in manufacture of sweets. 
• Color - Sugars are responsible for the development of the brown color of many cooked foods, through two processes: the Milliard reaction and caramelization. The golden-brown crust of baked products, such as biscuits and toasted bread, is due to the Milliard reaction, occurring under heat between sugars (predominantly glucose and fructose) and amino acids (proteins). 
• Food preservation - Sugars are also important in food preservation. Marmalades, syrupy fruit desserts, candied fruits and other delicacies were born out of the historical need to preserve fresh produce. The high sugar content prevents microbial growth and spoilage by increasing the osmotic pressure, which limits microbial growth and makes these foods last longer.
• Alcoholic beverages - Sugars are also at the heart of alcoholic fermentation, i.e. the conversion of sugars to ethanol (alcohol) by yeasts, which is used to make alcoholic beverages. Sugars contained in grapes, grains, honey and fruits are used in the production of wine, beer and whisky, mead and ciders respectively.
• Reducing sugar in foods - In light of the high prevalence  of  obesity and overweight, public health efforts are aimed at reducing the number of calories people consume, including reducing the energy density (calories per gram) of processed foods by decreasing total fats and carbohydrates, including sugar.