Modern Food Preservation.pptx

Food preservation

1. M odern Methods for Food Preservation P resented by: Realyn D. Embalado

2. Learning Outcomes: At the end of this lesson, students must be able to: Understand the importance of food preservation; and Identify the modern methods for food preservation

3. W hat is Food Preservation? - Food preservation can be defined as the process of treating and handling food in such a way as to stop or greatly slow down spoilage and prevent foodborne illness while maintaining nutritional value, texture and flavor .

4. History of Food Preservation

5. Modern Methods for Food Preservation 6 . Pascalization 7. Biopreservation 8. Hurdle Technology 9. Nonthermal plasma 10. Modified Atmosphere Pasteurization Freeze Drying Vacuum Packing Irradiation Chemical Food Preservatives

6. Modern Methods for Food Preservation 1. Pasteurization heat-treatment process that destroys pathogenic microorganisms in certain foods and beverages.  Named for the French scientist Louis Pasteur 3 methods : Long temperature long time (LTLT) method High temperature short time (HTST) method Ultra high temperature (UHT) method

7. Advantages The flavor and the texture of the milk have improvised after pasteurizing it. The method kills the pathogens or bacteria present in the raw milk and makes is safe to consume without any health risk. UHT method is the best to apply, as it has less of an adverse effect on milk’s nutritional value and taste. This method may prevent many diseases such as diphtheria, tuberculosis, scarlet fever and brucellosis by killing some of the most harmful bacteria. Disadvantages Milk pasteurized with HTST method is believed to lose 1/3 rd  of the thiamine present in the milk and half of  vitamin B12. The discovery of heat resistant pathogens has increased the risk of the presence of bacteria even after pasteurizing the food. Due to loss of certain enzymes in food during pasteurization, few people consider raw milk a better option to pasteurized milk .

8. Modern Methods for Food Preservation 2. Freeze Drying Freeze drying is a water removal process typically used to preserve perishable materials, with the goal of extending their shelf life and/or preparing them for transport.  Also known as lyophilization

9. 3 Phases Freezing phase - can be done in a freezer, a chilled bath (shell freezer) or on a shelf in the freeze dryer. Primary drying (Sublimation) - pressure is lowered and heat is added to the material in order for the water to sublimate.  Secondary drying (Absorption) - the ironically-bound water molecules are removed.

10. Advantages Great snacks Little to no chemical changes to food Little physical changes to food Nutritional value is almost completely maintained – it is healthy Long-term storage — 20+ years Lightweight food No refrigeration required Disadvantages Water required for reconstitution (except for simple snacks) Slow process — average cycle is 24+ hours Some dislike the dry, Styrofoam texture Not all foods can be freeze dried Airtight containers are required for long-term storage No space savings — the food’s cellular structure is mostly retained Sometimes, normal dehydration is better Production cost

11. Modern Methods for Food Preservation 3. Vacuum Packing “Vacuum packing” is a method of food packaging that removes all air from a food-filled, plastic film package before “sealing” it.  By keeping oxygen out, vacuum packing preserves food by obstructing the growth of fungus, mold and oxygen-induced (aka “obligate’) bacteria including mesophiles , psychrotrophic , thermophiles, and psychrophiles .

12. Advantages Easy to use. The vacuum packaging can be opened easily and safely, when eating, open the bag and eating without heating. Convenient storage and transportation. Vacuum packaging takes up less space, saving storage and transportation costs. Long preservation time, vacuum-packed food, which does not require refrigeration, has a long life and is convenient for long-term use. Disadvantages Everything has two sides, the same with vacuum packaging, the main problem is the lack of high-speed loading equipment, bring some influence to mass production. In the packaging process, inflating and sealing problems are critical, some foods are perishable. In the process of production, transportation and sales, avoid products from mechanical or external extrusion, and such foods are susceptible to moisture and oxidation.

13. Modern Methods for Food Preservation 4. Irradiation Foodstuff is exposed to ionizing radiation either as β- particles or γ- rays. The radiation is capable of killing bacteria, molds and pests among others. The irradiation is also capable of decreasing the ripening of fruits and stops spoilage.

14. Modern Methods for Food Preservation 5 . Chemical Food Preservatives - In processed foods, anti-microbial chemical agents are added to preserve them. These agents are added in smaller amount since these are mostly toxic when consumed in larger amount. Common preservatives are benzoic acid and benzoates which are used in acidic foods such as jams, salad dressing, juices, pickles, carbonated drinks, soy sauce among others.

15. Modern Methods for Food Preservation 6. Pascalization In this technique, foodstuff is pressed inside a vessel exerting very high pressure to the tune of 70,000 lb per square inch. This technique is good since foodstuffs retain their freshness, flavour , texture and nutrients with destruction of microbes.

16. Modern Methods for Food Preservation 7. Biopreservation When natural microbes or antimicrobials are used for preservation and increasing the shelf life of foodstuffs, it is called biopreservation . Lactic acid bacteria have been used as biopreservatives . These bacteria produce lactic acid, acetic acid, bacteriocins and hydrogen peroxide among others which act as antimicrobials.

17. Modern Methods for Food Preservation 8. Hurdle Technology In this technology, more than one approach are applied to inactivate any pathogenic microbe, if present in a food. an intelligent combination of hurdles that secures the safety from microbes and ensures no loss of nutritional quality and economic viability of food.

18. Modern Methods for Food Preservation 9. Nonthermal Plasma In this technology, surface of the foodstuff is exposed to a flame of ionized gas molecules such as nitrogen and helium. It helps in killing the microbes if present on the surface of the food is a cutting-edge technology which has gained much attention during the last decade in the food-processing sector as a promising technology for food preservation and maintenance of food safety.

19. Modern Methods for Food Preservation 10. Modified Atmosphere is a packaging system that involves changing the gaseous atmosphere surrounding a food product inside a pack, and employing packaging materials and formats with an appropriate level of gas barrier to maintain the changed atmosphere at an acceptable level for preservation of the food. Improvement in visual appeal of packed products Decreased risk of food spoilage Prolonged the shelf life of the product

20. THANK YOU!