Thawing fish involves increasing its temperature so that ice crystals melt back into water at around -10C. There are various methods of thawing fish, including refrigeration, cold water, and microwaves. Thawing has merits like increased yield, shorter cooking times, and tenderized texture from ice crystal formation disrupting muscle fibers. However, thawing also has demerits such as weight loss from water leeching out, reduced water holding capacity, and possible color and texture changes from oxidation and rigor mortis. Care must be taken to thaw fish slowly at low temperatures to minimize quality impacts.
General consideration for process design of lyophilized productRajeev Sharma
Lyophilization is commonly used to improve stability and shelf life of injectable drugs like proteins, peptides, and liposomes. It involves three steps: freezing, primary drying where ice sublimates under vacuum, and secondary drying to remove bound water. Key considerations for lyophilization process design include excipient selection, filling container and closure system selection, pre-formulation studies, and ensuring the reconstituted product is suitable for injection. Process parameters like freezing rate and temperature, drying temperature and vacuum level must be optimized. Quality attributes of the lyophilized cake and reconstituted drug product are monitored through analytical testing and stability studies.
How spectacle lenses are made.
In this section you will get the information about lens manufacturing (part 1),i.e, how lens blanks are manufactured and in lens surfacing (part 2) you will get the information about how lenses are surfaced and a finished lens is manufactured.
This document discusses the effects of stabilizers on ice cream properties. Stabilizers increase mix viscosity and prevent wheying off and phase separation. They aid in suspension and produce a stable foam for packaging. Stabilizers also retard ice and crystal growth during storage fluctuations. They slow moisture migration and prevent shrinkage. Stabilizers provide uniformity and resistance to melting, producing a smooth texture. They decrease phase separation and control overrun. Stabilizers inhibit changes in air cells during storage and decrease melting rate by slowing serum drainage. They increase glass transition temperature and affect thermal conductivity. Hydrocolloid type and content influence flavor release and provide better creaminess and texture.
The document discusses the process of freeze concentration. Freeze concentration involves freezing a liquid food which causes ice crystals to form and separate out pure water, leaving a more concentrated liquid product. It can concentrate fruit juices, coffee, tea, beer and wine while better preserving quality and nutrients compared to other concentration methods. Key steps involve nucleation and growth of ice crystals followed by separation of the crystals from the concentrated liquid.
Freezing curve, freezing system & freezing timeMuneeb Vml
The document discusses freezing as an operation to preserve food by lowering its temperature below the freezing point. It describes the freezing process and freezing curve, including nucleation, crystal growth, and how solute concentration changes. It discusses factors that influence freezing time like thermal conductivity and size/shape of food pieces. Methods to calculate freezing time are presented, including Planck's equation and Pham's method. Different freezing systems are outlined like air blast freezers, plate freezers, and fluidized bed freezers.
Thawing fish involves increasing its temperature so that ice crystals melt back into water at around -10C. There are various methods of thawing fish, including refrigeration, cold water, and microwaves. Thawing has merits like increased yield, shorter cooking times, and tenderized texture from ice crystal formation disrupting muscle fibers. However, thawing also has demerits such as weight loss from water leeching out, reduced water holding capacity, and possible color and texture changes from oxidation and rigor mortis. Care must be taken to thaw fish slowly at low temperatures to minimize quality impacts.
General consideration for process design of lyophilized productRajeev Sharma
Lyophilization is commonly used to improve stability and shelf life of injectable drugs like proteins, peptides, and liposomes. It involves three steps: freezing, primary drying where ice sublimates under vacuum, and secondary drying to remove bound water. Key considerations for lyophilization process design include excipient selection, filling container and closure system selection, pre-formulation studies, and ensuring the reconstituted product is suitable for injection. Process parameters like freezing rate and temperature, drying temperature and vacuum level must be optimized. Quality attributes of the lyophilized cake and reconstituted drug product are monitored through analytical testing and stability studies.
How spectacle lenses are made.
In this section you will get the information about lens manufacturing (part 1),i.e, how lens blanks are manufactured and in lens surfacing (part 2) you will get the information about how lenses are surfaced and a finished lens is manufactured.
This document discusses the effects of stabilizers on ice cream properties. Stabilizers increase mix viscosity and prevent wheying off and phase separation. They aid in suspension and produce a stable foam for packaging. Stabilizers also retard ice and crystal growth during storage fluctuations. They slow moisture migration and prevent shrinkage. Stabilizers provide uniformity and resistance to melting, producing a smooth texture. They decrease phase separation and control overrun. Stabilizers inhibit changes in air cells during storage and decrease melting rate by slowing serum drainage. They increase glass transition temperature and affect thermal conductivity. Hydrocolloid type and content influence flavor release and provide better creaminess and texture.
The document discusses the process of freeze concentration. Freeze concentration involves freezing a liquid food which causes ice crystals to form and separate out pure water, leaving a more concentrated liquid product. It can concentrate fruit juices, coffee, tea, beer and wine while better preserving quality and nutrients compared to other concentration methods. Key steps involve nucleation and growth of ice crystals followed by separation of the crystals from the concentrated liquid.
Freezing curve, freezing system & freezing timeMuneeb Vml
The document discusses freezing as an operation to preserve food by lowering its temperature below the freezing point. It describes the freezing process and freezing curve, including nucleation, crystal growth, and how solute concentration changes. It discusses factors that influence freezing time like thermal conductivity and size/shape of food pieces. Methods to calculate freezing time are presented, including Planck's equation and Pham's method. Different freezing systems are outlined like air blast freezers, plate freezers, and fluidized bed freezers.
- The quality of frozen foods is influenced by storage temperature, with quality decreasing as temperatures increase. Maintaining temperatures of -18°C is accepted as safe for extended shelf life.
- Temperature fluctuations during storage can cause recrystallization of ice crystals and reduce quality through increased crystal size.
- Factors like freezer burn, moisture migration, lipid oxidation, protein denaturation, and enzymatic browning can negatively impact the quality of frozen foods during storage and must be controlled. Understanding these factors is key to minimizing quality loss.
This document discusses freeze drying (lyophilization), including its principles, stages of the process, methods of freezing materials, advantages, and applications. Freeze drying works by first freezing the material to be preserved and then removing water by sublimation under a vacuum. This preserves the material's structure and composition while removing moisture. Common applications of freeze drying include preserving pharmaceuticals, foods, and biological materials as it results in materials that can be stored at room temperature for extended periods of time.
Influences of temperature cycled storage on retrogradation and inAtheer Jasim Jandal
Starch gelatinization is a process that disrupts the native molecular orders of starch granules and typically occurs during thermal processing in the presence of water.
Freezing is commonly used to preserve foods by reducing microbial and enzyme activity through lowering temperatures. The rate of freezing and temperature differences between the food and freezing medium impact properties and quality. Very rapid freezing results in significantly different properties than slow freezing due to differences in ice crystal formation within the food structure. Properties of frozen foods like water content and thermal properties affect freezing processes. Ice crystal formation and freezing point depression are important concepts, and controlling recrystallization through consistent low storage temperatures preserves quality. Common freezing equipment includes air blast, plate, and immersion freezers.
Freezing food involves lowering the temperature so that water inside the food freezes into ice crystals. This immobilizes water and reduces water activity to preserve foods. There are different freezing methods like air blast, tunnel, or immersion freezing that allow control over crystal size. Smaller crystals from fast freezing cause less damage to cell structure and texture. Proper frozen storage and thawing are also important to maintain food quality.
Ice cream is a sweetened frozen food made from dairy products like milk and cream that is typically flavored. It is produced by mixing ingredients, homogenizing the mixture to incorporate air, pasteurizing it to kill microorganisms, freezing it while incorporating more air, and then hardening it to a semi-solid form. Major ice cream producers include Unilever, Nestle, and General Mills. Key components like fat, milk solids, sugar, stabilizers, and emulsifiers contribute to ice cream's texture, consistency, flavor, and shelf life.
Carbohydrates play a central role in animal and plant metabolism. Sugars act as preservatives and sweetening agents in foods like jams, jellies, beverages, and frozen desserts. Sugars are hygroscopic and will absorb moisture from the air if not stored in airtight containers. Starches thicken foods when heated in water through a process called gelatinization where the starch granules swell and burst. Different types of starches produce gels with varying properties depending on their amylose and amylopectin content. Colloids form when substances disperse into others without fully dissolving. Common colloidal systems found in foods include gels, sols, foams, and
Discussion about hydrothermal & gel growth method of crystalMostakimRahman1
1.Definition, procedure, advantage, and disadvantage of hydrothermal growth method of crystal.
2.Definition, procedure, advantage, and disadvantage of gel growth method of crystal.
Freezing food involves lowering the temperature so that water inside the food freezes into ice crystals. This process is known as freezing and involves three stages: cooling the food below its freezing point, water changing state to form ice crystals, and further cooling to the freezer temperature for preservation. The rate of freezing impacts crystal size, with fast freezing producing smaller crystals and maintaining food quality better than slow freezing. Proper frozen storage is also important to prevent quality loss from physical, chemical, biochemical, and microbial changes over time. Maintaining temperatures lower than -18°C can help secure food quality and avoid issues like recrystallization according to the time, temperature, tolerance theory of frozen food storage.
This chapter more focused on the reduced temperature processes. Therefore, processes like chilling, freezing, freeze drying and freeze concentration as well as modified or controlled atmosphere storage and packaging are the main lessons covered
This document summarizes the process of freezing fruits and vegetables for preservation. It discusses that freezing stops microbial growth and slows chemical changes by placing foods in temperatures of 0°F or -18°C. The quality of frozen foods depends on factors like the raw materials, pre-treatments like blanching, the freezing method/rate, and storage temperature/time. Freezing inactivates enzymes and microbes and causes small ice crystals to form if done rapidly, minimizing cell damage. Common freezing methods include cold air blasts, plate freezers, and immersing in liquid refrigerants. Frozen foods can be stored for long periods if kept at appropriate temperatures.
Effect of storage conditions on stability of dried milkJ Roopavathy
Dried milk can last 15+ years if stored properly in sealed Mylar bags with oxygen absorbers and desiccants in a cool, dark place below 75 degrees Fahrenheit. However, dried milk stored in warm, moist conditions like cardboard packaging above 104 degrees Fahrenheit will spoil within 30 days. The storage temperature, oxygen levels, packaging, moisture levels, and light exposure all impact the shelf life of dried milk, with non-fat varieties typically lasting longer than full-fat milk, which is not suitable for long-term storage. Browning, clumping, changes in functionality, flavor, and hardening can occur if dried milk is exposed to high heat and moisture over long periods of storage.
There are two main methods of freezing food commercially - fast freezing at temperatures below -25°C which forms small ice crystals, and slow freezing above -24°C which forms larger crystals that can damage the food. Common freezing techniques include air blast, fluidized bed, plate or belt, immersion, and cryogenic freezing using liquid nitrogen or carbon dioxide. The freezing method chosen depends on factors like the food quality desired, type and shape of the food, package used, required flexibility, and costs. Equations can be used to estimate freezing times based on properties of the food and freezing conditions.
This document discusses freezing as a method for food preservation. It describes how freezing works by lowering temperatures to inhibit microorganism growth, outlines different freezing methods like air freezing and immersion freezing, and distinguishes between quick and slow freezing. The document also explains some changes that occur during freezing like chemical changes, textural changes from ice crystal formation, and potential nutrient losses.
Unit 1 Food Processing and Preservation by Low temperature.pptxssuserf7bce8
The document discusses various methods for preserving foods, including refrigeration, freezing, and dehydration. It explains that refrigeration and freezing work by slowing microbial growth and chemical reactions through low temperatures. Freezing is done below 32°F to form ice crystals that prevent further microbial activity. Rapid freezing is best to form small ice crystals and avoid damage to food texture. Common freezing methods include air, contact plate, cryogenic, and fluidized bed freezing. Thawing must also be done carefully to avoid quality losses from drip, oxidation, and texture damage during the phase change from frozen to thawed.
The document discusses the properties, functions, and impact of processing on starch. It covers topics like starch granule structure, gelatinization and pasting behaviors when cooked, retrogradation and crystallization upon cooling, and how physical and chemical modifications can impact properties. The key functional aspects of starch discussed are granule swelling, gelatinization, pasting, and retrogradation in response to heat and water.
A lyophilizer, also known as a freeze dryer, works by freezing materials, reducing the pressure, and adding heat to allow frozen water in the materials to sublimate. The lyophilizer executes a water removal process to preserve perishable materials and extend shelf life by freezing the material and reducing pressure and temperature to allow frozen water to change directly from solid to vapor without passing through the liquid phase. Lyophilizers are used to dry heat-sensitive products, increase shelf life, and reduce weight for storage, shipping and transportation.
- The quality of frozen foods is influenced by storage temperature, with quality decreasing as temperatures increase. Maintaining temperatures of -18°C is accepted as safe for extended shelf life.
- Temperature fluctuations during storage can cause recrystallization of ice crystals and reduce quality through increased crystal size.
- Factors like freezer burn, moisture migration, lipid oxidation, protein denaturation, and enzymatic browning can negatively impact the quality of frozen foods during storage and must be controlled. Understanding these factors is key to minimizing quality loss.
This document discusses freeze drying (lyophilization), including its principles, stages of the process, methods of freezing materials, advantages, and applications. Freeze drying works by first freezing the material to be preserved and then removing water by sublimation under a vacuum. This preserves the material's structure and composition while removing moisture. Common applications of freeze drying include preserving pharmaceuticals, foods, and biological materials as it results in materials that can be stored at room temperature for extended periods of time.
Influences of temperature cycled storage on retrogradation and inAtheer Jasim Jandal
Starch gelatinization is a process that disrupts the native molecular orders of starch granules and typically occurs during thermal processing in the presence of water.
Freezing is commonly used to preserve foods by reducing microbial and enzyme activity through lowering temperatures. The rate of freezing and temperature differences between the food and freezing medium impact properties and quality. Very rapid freezing results in significantly different properties than slow freezing due to differences in ice crystal formation within the food structure. Properties of frozen foods like water content and thermal properties affect freezing processes. Ice crystal formation and freezing point depression are important concepts, and controlling recrystallization through consistent low storage temperatures preserves quality. Common freezing equipment includes air blast, plate, and immersion freezers.
Freezing food involves lowering the temperature so that water inside the food freezes into ice crystals. This immobilizes water and reduces water activity to preserve foods. There are different freezing methods like air blast, tunnel, or immersion freezing that allow control over crystal size. Smaller crystals from fast freezing cause less damage to cell structure and texture. Proper frozen storage and thawing are also important to maintain food quality.
Ice cream is a sweetened frozen food made from dairy products like milk and cream that is typically flavored. It is produced by mixing ingredients, homogenizing the mixture to incorporate air, pasteurizing it to kill microorganisms, freezing it while incorporating more air, and then hardening it to a semi-solid form. Major ice cream producers include Unilever, Nestle, and General Mills. Key components like fat, milk solids, sugar, stabilizers, and emulsifiers contribute to ice cream's texture, consistency, flavor, and shelf life.
Carbohydrates play a central role in animal and plant metabolism. Sugars act as preservatives and sweetening agents in foods like jams, jellies, beverages, and frozen desserts. Sugars are hygroscopic and will absorb moisture from the air if not stored in airtight containers. Starches thicken foods when heated in water through a process called gelatinization where the starch granules swell and burst. Different types of starches produce gels with varying properties depending on their amylose and amylopectin content. Colloids form when substances disperse into others without fully dissolving. Common colloidal systems found in foods include gels, sols, foams, and
Discussion about hydrothermal & gel growth method of crystalMostakimRahman1
1.Definition, procedure, advantage, and disadvantage of hydrothermal growth method of crystal.
2.Definition, procedure, advantage, and disadvantage of gel growth method of crystal.
Freezing food involves lowering the temperature so that water inside the food freezes into ice crystals. This process is known as freezing and involves three stages: cooling the food below its freezing point, water changing state to form ice crystals, and further cooling to the freezer temperature for preservation. The rate of freezing impacts crystal size, with fast freezing producing smaller crystals and maintaining food quality better than slow freezing. Proper frozen storage is also important to prevent quality loss from physical, chemical, biochemical, and microbial changes over time. Maintaining temperatures lower than -18°C can help secure food quality and avoid issues like recrystallization according to the time, temperature, tolerance theory of frozen food storage.
This chapter more focused on the reduced temperature processes. Therefore, processes like chilling, freezing, freeze drying and freeze concentration as well as modified or controlled atmosphere storage and packaging are the main lessons covered
This document summarizes the process of freezing fruits and vegetables for preservation. It discusses that freezing stops microbial growth and slows chemical changes by placing foods in temperatures of 0°F or -18°C. The quality of frozen foods depends on factors like the raw materials, pre-treatments like blanching, the freezing method/rate, and storage temperature/time. Freezing inactivates enzymes and microbes and causes small ice crystals to form if done rapidly, minimizing cell damage. Common freezing methods include cold air blasts, plate freezers, and immersing in liquid refrigerants. Frozen foods can be stored for long periods if kept at appropriate temperatures.
Effect of storage conditions on stability of dried milkJ Roopavathy
Dried milk can last 15+ years if stored properly in sealed Mylar bags with oxygen absorbers and desiccants in a cool, dark place below 75 degrees Fahrenheit. However, dried milk stored in warm, moist conditions like cardboard packaging above 104 degrees Fahrenheit will spoil within 30 days. The storage temperature, oxygen levels, packaging, moisture levels, and light exposure all impact the shelf life of dried milk, with non-fat varieties typically lasting longer than full-fat milk, which is not suitable for long-term storage. Browning, clumping, changes in functionality, flavor, and hardening can occur if dried milk is exposed to high heat and moisture over long periods of storage.
There are two main methods of freezing food commercially - fast freezing at temperatures below -25°C which forms small ice crystals, and slow freezing above -24°C which forms larger crystals that can damage the food. Common freezing techniques include air blast, fluidized bed, plate or belt, immersion, and cryogenic freezing using liquid nitrogen or carbon dioxide. The freezing method chosen depends on factors like the food quality desired, type and shape of the food, package used, required flexibility, and costs. Equations can be used to estimate freezing times based on properties of the food and freezing conditions.
This document discusses freezing as a method for food preservation. It describes how freezing works by lowering temperatures to inhibit microorganism growth, outlines different freezing methods like air freezing and immersion freezing, and distinguishes between quick and slow freezing. The document also explains some changes that occur during freezing like chemical changes, textural changes from ice crystal formation, and potential nutrient losses.
Unit 1 Food Processing and Preservation by Low temperature.pptxssuserf7bce8
The document discusses various methods for preserving foods, including refrigeration, freezing, and dehydration. It explains that refrigeration and freezing work by slowing microbial growth and chemical reactions through low temperatures. Freezing is done below 32°F to form ice crystals that prevent further microbial activity. Rapid freezing is best to form small ice crystals and avoid damage to food texture. Common freezing methods include air, contact plate, cryogenic, and fluidized bed freezing. Thawing must also be done carefully to avoid quality losses from drip, oxidation, and texture damage during the phase change from frozen to thawed.
The document discusses the properties, functions, and impact of processing on starch. It covers topics like starch granule structure, gelatinization and pasting behaviors when cooked, retrogradation and crystallization upon cooling, and how physical and chemical modifications can impact properties. The key functional aspects of starch discussed are granule swelling, gelatinization, pasting, and retrogradation in response to heat and water.
A lyophilizer, also known as a freeze dryer, works by freezing materials, reducing the pressure, and adding heat to allow frozen water in the materials to sublimate. The lyophilizer executes a water removal process to preserve perishable materials and extend shelf life by freezing the material and reducing pressure and temperature to allow frozen water to change directly from solid to vapor without passing through the liquid phase. Lyophilizers are used to dry heat-sensitive products, increase shelf life, and reduce weight for storage, shipping and transportation.
Similar to GLASSY TRANSITION STATE IN FROZEN FOODS (20)
Frozen meat simply means that it's been put into a frozen state (stored at a temperature lower than -18°C) to extend its shelf life. When frozen, the metabolic processes within the meat are drastically slowed, making it last longer.
2. CONTENTS
1. Introduction
2. Understanding glass transition temperature
3. Impact on food quality
4. Controlling Tg in frozen foods
5. Analytical techniques
6. Measuring and interpreting the glass transition in frozen foods and model systems
7. Implications of non-equilibrium states and glass transition in frozen and dried fish and meat products
8. Formation of the glassy phase in frozen foods
9. Solute crystallization
10. Ice recrystallization
3. INTRODUCTION
The glass transition occurs as an
endothermic steps in heat flow, and
the onset temperature of the
maximally freeze-concentrated
unfrozen phase is taken as Tg'. A
single solute may concentrate in
unfrozen phase forms a continuous
matrix around ice crystals .
4. Understanding Glass Transition Temperature (Tg):
• Glass transition temperature (Tg) marks the shift from a hard, glassy state to a rubbery or
viscous state.
• In frozen foods, Tg is crucial as it indicates the change from a rigid, glass-like structure to a
more flexible state.
• Understanding Tg helps predict how frozen foods will behave during storage and thawing.
• Tg is a key factor in maintaining the quality and texture of frozen foods
5. Effects of Temperature
on Food Structure:
• Below Tg: Restricted molecular motion, ice
crystal formation maintains frozen state.
• Near and above Tg: Increased molecular
mobility.
• Tg crossing leads to structural and textural
changes in the food.
6. Impact on Food Quality:
1 Texture Change:
• Near Tg, frozen foods soften, become more elastic, or collapse.
2 Shelf Life Impact:
• Above Tg, increased molecular mobility accelerates spoilage.
3 Recrystallization Effect:
• Close to Tg, ice crystals recrystallize, altering texture.
• Significant in frozen desserts like ice cream.
7. Controlling Tg
in Frozen
Foods:
• Freezing rate determines ice crystal size.
• Slower freezing = larger crystals, impacts
texture.
• Ingredient selection alters Tg for desired
properties.
• Sugars, stabilizers modify Tg, prevent
crystallization.
• Formulation adjustments change Tg, affect
texture.
• Modify water, cryoprotectant levels for Tg
control.
• Adjust fat, protein levels for texture and stability.
8. ANALYTICAL TECHNIQUES
• Analytical Techniques:
• DSC and DMA determine Tg in frozen foods.
• Provide insights into thermal and mechanical properties.
• Importance of Tg:
• Influences texture, stability, and quality.
• Crucial for manufacturers to control.
• Texture and Stability:
• Tg affects texture and accelerates spoilage.
• Quality Control:
• Understanding Tg ensures desirable attributes and longer shelf life.
9. Measuring and
interpreting the glass
transition in frozen foods
and model systems
• Frozen foods have an unfrozen phase due to water removal during freezing.
• Reactions like enzymatic degradation occur in this phase, limiting shelf life.
• Recent research emphasizes viscosity and diffusion rates for stability.
• High viscosities lead to glass formation, slowing diffusion.
• Proper temperatures are crucial for stability.
• Adjusting formulations can enhance shelf life.
10. Implications of Non-Equilibrium
States and Glass Transitions in
Frozen and Dried Fish and
Meat Products
• Frozen and dried foods resist microbial growth but degrade chemically and
physically during storage.
• Issues include enzymatic changes, oxidation, and solute crystallization.
• Desiccated foods benefit from storage in an amorphous glassy state for
prolonged stability.
• Exceeding the glass-transition temperature leads to structural and chemical
alterations.
• Such changes degrade the quality and stability of the food.
11. Formation of the Glassy
Phase in Frozen Foods
• Ice Formation:
• Water crystallizes, concentrating solutes.
• Equilibrium Freezing:
• Solute concentration determines freezing point.
• Glass Transition:
• Below freezing point, solute crystallization slows.
• Viscosity increases, transitioning to a glassy state.
• State Diagram:
• Integrates freezing and glass transition.
• Freeze Concentration:
• Cooling initiates crystallization.
• Water removal depresses freezing point.
• Viscosity rises rapidly.
• UFP becomes a solid glass.
12. SOLUTE CRYSTALLIZATION
• Solute crystallization in frozen foods occurs due
to thermodynamic driving forces toward
equilibrium.
• Common in poorly soluble components like
lactose, especially below -18°C.
• Lactose in ice cream can remain in a glassy
state, preventing gritty texture.
• Crystallization can happen above Tg' due to
supersaturation.
• Lactose's poor solubility at low temperatures
increases the likelihood of crystallization.
• Crystallization rate peaks at a temperature
balancing supersaturation and viscosity.
• Inhibition methods include blending sugars and
using hydrocolloids to increase viscosity.
13. ICE RECRYSTALLIZATION
• Ice Formation and Freezing:
• Rapid freezing crucial for small, numerous ice crystals.
• Initial crystal size determined by nucleation during rapid
cooling.
• Ice Formation and Temperature:
• Ice formation ceases at Tm′ due to water-solute chemical
potential.
• Rapid cooling below unfrozen Tg leads to vitrification;
reheating causes devitrification.
• Recrystallization:
• Modifies ice crystal size and shape post-crystal growth.
• Types: isomass, migratory, accretive.
• Rates depend on temperature, diffusion, and dilution above
Tm′.
• Effects of Recrystallization:
• Larger crystals lower food quality, damage cellular
structures.
• Alters food texture during thawing.
• Impact of Temperature Fluctuations:
• Accelerates quality decline during storage.
• Normal variations cause significant quality loss.
14. CONCLUSION
• GLASS TRANSITION HAVE HIGH IMPACTS
ON STABILITY AND OTHER FOOD QUALITY
PARAMETERS.
• GLASS TRANSITIONS ARE HIGHLY
DEPENDENT ON CONSTITUENTS AND
FREEZING CONDITIONS.
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