Engineering properties of food materials (1).pptx

engineering properties of food materials

1. Engineering properties of food materials Food structuring

2. Content

3. Introduction It is a process involves manipulating ingredients to create specific textures, flavours, and appearances in dishes. The evolution of food structuring reflects the dynamic interplay between tradition and modernity. Traditional methods forming the foundation and contemporary approaches pushing the boundaries of culinary possibilities.

4. Traditional food structuring : Preserving heritage and flavor . Margination – infusing depth and tenderness This age-old technique involves soaking ingredients in a flavourful liquid mixture, often consisting of herbs, spices, oils, and acids. The primary purpose of margination is to imbue the food with layers of taste while simultaneously tenderizing tougher cuts of meat . Across cultures, margination has been a cornerstone of culinary traditions. In Indian cuisine, for instance, the use of yogurt-based marinades, seasoned with spices like cumin, coriander, and turmeric, imparts not only a rich taste but also a tender texture to meats such as chicken or lamb.

5. 2. Smoking : A symphony of Aromas and Textures. Smoking, an ancient preservation method, is deeply ingrained in traditional food structuring. This technique involves exposing food to the smoke produced by burning wood or other aromatic materials. The result is a complex interplay of flavours, aromas, and textures that elevate the culinary experience. In traditional barbeque, meats are slow-cooked over wood or charcoal, absorbing the smoky essence that imparts a distinctive taste and a tantalizing crust

6. 3. Fermentation – The magic of microorganisms It involves the action of microorganisms like bacteria and yeast on ingredients , leading to transformative changes in both flavour and texture. In the world of bread, the fermentation of dough gives rise to the airy, chewy texture of a well baked loaf. The tanginess of fermented pickles, the effervescence of kombucha, and the umami richness of fermented soy products all derive from the intricate of microorganisms during fermentation.

7. 4. Slow cooking This technique is particularly effective for breaking down tough fibres in meats, resulting in dishes that are not only flavourful but also tender and succulent. This method is commonly used for tougher cuts of meat , allowing them to slowly absorb flavours and become fork-tender . Pot roasts and stews, staples in many cuisines, owe their hearty textures to the art of slow cooking.

8. 5 .Pickling Pickling is a traditional preservation method that involves immersing food in a solution of vinegar, salt, and spices . While preservation is the primary goal, pickling also imparts a tangy and sometimes spicy flavour profile to the ingredients. In Asia, pickled ginger and kimchi add zing to dishes, showcasing the versatility of pickling across different culinary traditions.

9. Texture improvement Emulsification Emulsification is a modern structuring technique that involves creating stable mixtures o f two immiscible liquids, typically oil and water. The result is a creamy, unified texture that enhances both the mouth feel and appearance of sauces, dressings, and other culinary creations .example of an emulsion, where egg yolks and oil are blended to create a thick, creamy sauce . The versatility of emulsification extends to salad dressings, aiolis, and various sauce.

10. 2. Gelation Gelation, a modern approach to food structuring, involves the use of gelling agents to create textures ranging from firm gels to delicate foams. Agar-agar, a seaweed-derived gelatin substitute, and gelatin itself are commonly employed to achieve these transformative textures. Foams, achieved through techniques like whipping and aerating , add a light and airy element to dishes, challenging traditional expectations of texture.

11. 3.Sous –vide cooking Sous-vide cooking, a technique that gained popularity in modern gastronomy, involves vacuum-sealing ingredients and cooking them at precise low temperatures in a water bath. This method ensures uniform doneness and optimal retention of flavours, resulting in dishes that are tender, moist, and infused with complexity

12. Approaches to food structuring Food structuring is an intricate dance of art and science, where various techniques shape the textures and stability of our culinary creations. From traditional methods deeply rooted in cultural practices to modern innovations driven by scientific understanding, this comprehensive exploration covers a multitude of facets. We’ll delve into extrusion and spinning as dynamic approaches, the nuanced art of structuring fat products, the delicate balance between structure and stability , the science behind gels and their intricate gelation mechanisms, the creative realm of mixed gels, the microscopic world of gel microstructure, and the profound connections between structure and properties.

13. Extrusion and spinning Food extrusion is a form of extrusion used in food processing. It is a process by which a set of mixed ingredients are forced through an opening in a perforated plate or die with a design specific to the food, and is then cut to a specified size by blades. The machine which forces the mix through the die is an extruder, and the mix is known as the extrudate . The extruder consists of a large, rotating screw tightly fitting within a stationary barrel, at the end of which is the die.

14. Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. Food products manufactured using extrusion usually have a high starch content. These include some pasta, breads (croutons, bread sticks, and flat breads), many breakfast cereals and ready-to-eat snacks, confectionery, pre-made cookie dough, some baby foods, full-fat soy, textured vegetable protein, some beverages, and dry and semi-moist pet foods.

15. Types of extrusion Hot extrusion - Hot extrusion (or extrusion cooking), which is used to produce a wide range of products, including crisp snack foods, sugar confectionery and soya-based weaning foods. Extruder-cookers may be single- or twin- screw machines. Twin-screw machines have approximately twice the capital and maintenance costs of single screw machines and are unlikely to be affordable by most small –scale processors as compared to single- screw extruders. The two factors that control the type and quality of foods that are produced by hot extrusion are the operating conditions in the extruder barrel and the mixture of ingredients that is used.

16. 2. Cold extrusion Cold extrusion, which mixes and shapes foods such as biscuit dough and pasta without cooking them The main application of cold extruders is in pasta production , although similar machines are used to form biscuit dough into different shapes. Different sizes of equipment are available, from small manual machines that are used in micro-scale production and food service outlets, to larger electric machines. The equipment has a mixing chamber, extruder barrel and a die for the desired pasta shape.

17. Effects of extrusion on nutritional quality Destruction of certain naturally occurring toxins Reduction of microorganisms in the final product Slight increase of iron-bioavailability Creation of insulin-desensitizing starches ( a potential risk-factor for developing diabetes) Loss of lysine, an essential amino acid necessary for developmental growth and nitrogen management. Simplification of complex starches, increasing rates of tooth decay Increase of glycemic index of the processed food, as the “extrusion process significantly increased the availability of carbohydrates for digestion” Destruction of Vitamin A (beta-carotene) Denaturation of proteins .

18. Spinning Spinning, a process deeply rooted in textile manufacturing, has extended its reach to the culinary realm. The technique involves the controlled release of liquid droplets through spinning disks or nozzles, creating delicate threads or fibers This method is not only visually appealing but also offers a unique tactile experience. In the world of food, spinning is most commonly associated with the creation of cotton candy, where sugar is melted and extruded through tiny holes, solidifying into fine threads as it cools. This whimsical application of spinning transforms a simple ingredient into an ethereal treat, highlighting the versatility of this approach in the culinary landscape. Together, extrusion and spinning represent a fusion of engineering precision and culinary creativity, offering chefs and food manufacturers an array of tools to sculpt the textures and appearances of diverse food items.