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Chemical Spoilage
The most important chemical degradation seen in dried products is fat oxidation.
Undesirable rancid taste and odour caused by oxidation of fats can occur. Oxidation
accelerates in low water activities. The heat, light and oxygen in the air accelerate
the oxidation. The temperature has a significant impact on oxidation, especially during outdoor drying. Oil residues that have remained in the environment before drying also accelerate the oxidation. Contact with metals is another factor that
accelerates the oxidation of the product. For this reason, the products should not be
dried on the metal wires. To prevent oxidation in dried products, the drying
temperature should be kept low, dried in the absence of light and some antioxidants
should be used if possible.
Microbial Spoilage
As is known, the development of microorganisms in low water activities is prevented. Microbial deterioration can also be controlled by controlling the temperature and humidity conditions during the storage of dried products.
Preservation of dried products in suitable packages without moisture permeability is important for preventing microbiological growth.
To protect against oxidative degradation, dried products must be packed in a
vacuum or inert gas with moisture and oxygen non-permeable packing material.
Biede et al. (1982) investigated the quality changes of shrimp sun‐dried, packed
under modified atmosphere and vacuum and stored at 22 °C for 8 months. During
the storage, it was reported that shrimp packaged with both methods decreased
water activity and moisture contents, increased total volatile nitrogen and ammonia
contents and the lowest oxidation determined in shrimps packed under vacuum. In
a previous study, beheaded and dried fresh prawns, Parapenaeopsis stylifera were
packed in polythene bags, and in cans under atmospheres of air, nitrogen, carbon
dioxide and oxygen and then sealed hermetically. At the end of study, it was found
that shelf life of shrimps packed in cans prolonged up to 5 months. However, some
colour and flavour losses were observed in these samples. Lower quality was determined in case of packaging in polyethylene bags (Balachandran 1975).
Dried small marine shrimp was investigated in terms of quality parameter during
the storage at 37 °C. It was determined the increase in trimethylamine (TMA) total
volatile basic nitrogen (TVB-N), thiobarturic acid reactive substances (TBARS),
total viable count (TVC) and sensory scores during the storage. In addition, the
shelf life is reported to be less than 7 days when evaluated for sensory analysis
results (Lu et al. 2011).
2.1.3.7 Smoking of Shrimps/Prawns
Smoking is a traditional process and preservation method used since the early ages.
When the first people begin to consume the animals they hunt on an open wood fire
shortly after discovering the fire, this was an important experience for them to real2.1 Shrimps/Prawns
Chemical Spoilage
The most important chemical degradation seen in dried products is fat oxidation.
Undesirable rancid taste and odour caused by oxidation of fats can occur. Oxidation
accelerates in low water activities. The heat, light and oxygen in the air accelerate
the oxidation. The temperature has a significant impact on oxidation, especially during outdoor drying. Oil residues that have remained in the environment before drying also accelerate the oxidation. Contact with metals is another factor that
accelerates the oxidation of the product. For this reason, the products should not be
dried on the metal wires. To prevent oxidation in dried products, the drying
temperature should be kept low, dried in the absence of light and some antioxidants
should be used if possible.
Microbial Spoilage
As is known, the development of microorganisms in low water activities is prevented. Microbial deterioration can also be controlled by controlling the temperature and humidity conditions during the storage of dried products.
Preservation of dried products in suitable packages without moisture permeability is important for preventing microbiological growth.
To protect against oxidative degradation, dried products must be packed in a
vacuum or inert gas with moisture and oxygen non-permeable packing material.
Biede et al. (1982) investigated the quality changes of shrimp sun‐dried, packed
under modified atmosphere and vacuum and stored at 22 °C for 8 months. During
the storage, it was reported that shrimp packaged with both methods decreased
water activity and moisture contents, increased total volatile nitrogen and ammonia
contents and the lowest oxidation determined in shrimps packed under vacuum. In
a previous study, beheaded and dried fresh prawns, Parapenaeopsis stylifera were
packed in polythene bags, and in cans under atmospheres of air, nitrogen, carbon
dioxide and oxygen and then sealed hermetically. At the end of study, it was found
that shelf life of shrimps packed in cans prolonged up to 5 months. However, some
colour and flavour losses were observed in these samples. Lower quality was determined in case of packaging in polyethylene bags (Balachandran 1975).
Dried small marine shrimp was investigated in terms of quality parameter during
the storage at 37 °C. It was determined the increase in trimethylamine (TMA) total
volatile basic nitrogen (TVB-N), thiobarturic acid reactive substances (TBARS),
total viable count (TVC) and sensory scores during the storage. In addition, the
shelf life is reported to be less than 7 days when evaluated for sensory analysis
results (Lu et al. 2011).
2.1.3.7 Smoking of Shrimps/Prawns
Smoking is a traditional process and preservation method used since the early ages.
When the first people begin to consume the animals they hunt on an open wood fire
shortly after discovering the fire, this was an important experience for them to real2.1 Shrimps/Prawns