Abstract
Thermal technologies for food preservation prevent the degradation of desired properties of the perishable food items for a longer duration to fulfill the needs of the consumers in the aspects of nutrition, safety, and price. Each freezing method has its distinct characteristics on quality of frozen food products. The major physical and chemical changes observed during the freezing process were freezer burns, recrystallization, protein denaturation, color, flavor, release of enzymes, etc. These will be detailed with appropriate examples. The comparative analysis of the aforementioned thermal technologies based on the quality of food products will be discussed with the recommendations for the selection of appropriate thermal technologies. It will guide the practicing engineers and researchers to understand the drawbacks of conventional thermal technologies and how they affect food qualities along with the advancements made to overcome the drawbacks.
TopObjectives Of Thermal Preservation
The goal of food preservation by thermal technologies is to slow down the growth of microorganisms along with reduction of enzymatic action in the food products by applying external thermal load. Even though thermal food preservation techniques prevent the spoilage of food products but also have an adverse effect on the texture leading to wastage of food products. Several microorganisms could cause detrimental changes in the food products. The main objectives of thermal preservation techniques are to obtain the suitable temperature of the food products to stop the detrimental changes like microbiological, physical, physiological and biochemical within the optimal limit in the food products (Ganguly, 2013; Seetaramaiah, 2011; Leistner, 2000).
Key Terms in this Chapter
Cryo-Mechanical Freezing: The combined method of utilizing the cryogenic freezing technique with the air blast freezing techniques in the single food preservation systems.
Drip Loss: The weight loss in the meat after slaughtering due to dripping of pink proteinaceous fluid in the meat.
Pasteurization: The process of rapid heating followed by rapid cooling for enzymatic inactivation.
Air Blast Freezing: The process of non-contact type of freezing by maintaining the air temperature.
Dehydro-Freezing: Combined method of dehydration of high moisture containing food products before freezing.
Respiratory Climacteric: The exponential change in the respiration rate of the fruits during ripening.
Denaturation: The consequence of cell death under applied external applied load in the food products.