L 10 Food Preservation Techniques

<p>Fast freezing creates smaller ice crystals and preserves food quality better than slow freezing. (D)</p> Signup and view all the answers

<p>Blanching or scalding the food (B)</p> Signup and view all the answers

<p>To inactivate microorganisms and enzymes (C)</p> Signup and view all the answers

<p>Carotenoids, flavonoids, and phenols (D)</p> Signup and view all the answers

<p>Lack of knowledge regarding its inactivation mechanisms (B)</p> Signup and view all the answers

<p>300-600 MPa (D)</p> Signup and view all the answers

<p>They allow for uniform pressure distribution (D)</p> Signup and view all the answers

<p>Destruction of cellular structures (B)</p> Signup and view all the answers

<p>Intense short flashes of light with varying wavelengths (D)</p> Signup and view all the answers

<p>Inadequate knowledge of critical factors and mechanisms (B)</p> Signup and view all the answers

<p>Water (C)</p> Signup and view all the answers

<p>Discharge of high voltage electric pulses into food (C)</p> Signup and view all the answers

<p>Vegetable and fruit juices (B)</p> Signup and view all the answers

<p>It inactivates enzymes to prolong shelf life (A)</p> Signup and view all the answers

<p>It enhances microbial inactivation and extends shelf life (B)</p> Signup and view all the answers

<p>Inactivating surface microorganisms (C)</p> Signup and view all the answers

<p>Through absorption of UV light leading to DNA mutations (A)</p> Signup and view all the answers

<p>It can alter the color and texture of food (C)</p> Signup and view all the answers

<p>20 kHz (A)</p> Signup and view all the answers

<p>Aging (D)</p> Signup and view all the answers

<p>Degassing (B)</p> Signup and view all the answers

<p>Generating intracellular cavitation (D)</p> Signup and view all the answers

<p>Enhancing evaporation (A)</p> Signup and view all the answers

<p>To keep out microorganisms (B)</p> Signup and view all the answers

<p>Irradiation (B)</p> Signup and view all the answers

<p>Chemical (A)</p> Signup and view all the answers

<p>High temperatures (C)</p> Signup and view all the answers

<p>It shields against microorganisms (D)</p> Signup and view all the answers

<p>To destroy undesirable enzymes and microorganisms (D)</p> Signup and view all the answers

<p>Steam pressure processing (B)</p> Signup and view all the answers

<p>They can prevent growth of most food poisoning microorganisms. (C)</p> Signup and view all the answers

<p>Microbial spoilage can occur due to under processing or leakage. (D)</p> Signup and view all the answers

<p>They sprout and grow significantly. (A)</p> Signup and view all the answers

<p>Boiling (C)</p> Signup and view all the answers

<p>They reduce the activity of microorganisms. (D)</p> Signup and view all the answers

<p>Psychrotrophs (A)</p> Signup and view all the answers

<p>It can kill spoilage organisms quickly. (B)</p> Signup and view all the answers

<p>Vacuuming the headspace before sealing (A)</p> Signup and view all the answers

A non-thermal food preservation technique using high voltage electric pulses to inactivate microbes and enzymes, and enhance extraction of compounds.

PEF improves food safety, extends shelf life, enhances compound extraction (like oils, polyphenols), and speeds up drying.

Combining PEF with gentle heating boosts microbial inactivation and extends food's shelf life.

A technique that uses short, intense UV light pulses to inactivate surface microorganisms.

Pulsed UV light can improve food safety by deactivating microorganisms on surfaces, extending shelf life, and maintaining food quality.

UV light can affect food color and texture, and is often combined with other methods to overcome certain limitations

UV light's germicidal power is linked to DNA mutations from UV absorption by DNA molecules.

Using supercritical carbon dioxide (SCCO2) to treat food. It's effective for killing microbes, enzymes, and extracting valuable compounds.

SCCO2 processing offers benefits like using low temperatures, extracting compounds without harmful solvents, and being environmentally friendly.

Primarily used for surface disinfection, often for liquids flowing in thin films.

Not yet widely used commercially due to lack of understanding about how it works and how to control it.

A food preservation method using extremely high pressure to kill microbes.

High pressure disrupts the cell structure of microbes, making them unable to function.

Food is packaged in flexible containers, placed in a pressure chamber filled with water, and then pressurized.

The effectiveness of HPP depends on the pressure applied, how long the food is pressurized, and the type of microbe and food.

High-frequency sound waves used for various purposes, including degassing, defoaming, filtration, emulsification, food preservation, extraction of active ingredients, and accelerating heat exchange.

Ultrasound waves create cavitation bubbles that collapse, generating shockwaves that disrupt cell membranes and release intracellular components.

Methods used to prevent or delay food spoilage by inhibiting microbial growth, enzymatic reactions, and other degradation processes.

Preventing contamination by microorganisms during food handling and processing. This involves keeping food free of microbes.

Various techniques used to preserve food, including: asepsis, removal of microorganisms, anaerobic conditions, high temperatures, low temperatures, drying, smoking, chemical preservatives, irradiation, and mechanical destruction of microbes.

Some foods have natural barriers that protect them from microbial contamination, such as the shells of nuts and skins of fruits and vegetables.

Wrapping and sealing food in containers to prevent contamination during handling and processing.

Maintaining hygiene during food handling and processing to minimize microbial contamination, especially in industries like dairy.

Creating an environment with minimal oxygen to inhibit the growth of aerobic microorganisms.

Using heat to kill microorganisms in food, like boiling or pasteurization.

Freezing lowers the number of viable microorganisms in food, but it doesn't completely sterilize it. The effectiveness depends on factors like the type of food and the freezing method.

Fast freezing creates smaller ice crystals, reducing damage to food structure and minimizing enzyme inactivation. This also leads to better food quality after thawing.

Drying lowers the water content of food, inhibiting the growth of microorganisms and extending shelf life. The lower the water activity, the slower the spoilage.

Common drying methods include sun drying, freeze drying, spray drying, and smoking. Each method has its own advantages and disadvantages for different food types.

Before drying, food often undergoes treatments like washing, dipping in alkaline solutions, blanching, or adding sugar to reduce microorganisms and preserve quality.

Heating food to around 100°C (212°F) destroys most microbes, but not their tough spores.

Heating food above 100°C (212°F) using steam under pressure kills even the most resistant spores.

Milk is heated to 150°C (302°F) for a very short time, then quickly cooled, ensuring its sterility.

Heating food aims to eliminate pathogens, toxins, spores, and undesirable enzymes to ensure safety and quality.

Canning involves sealing food in containers and applying heat to eliminate microbes for long-term preservation.

Insufficient heat treatment during canning can allow microbes to survive and spoil the food.

Refrigerating food at 6°C (43°F) inhibits the growth of most food poisoning microbes, except for a specific type of botulism.

Certain microbes, like Flavobacterium and Pseudomonas, can still grow at low temperatures, though slowly.