تاﺛﯿﺮ دﻣﺎي ﻧﮕﻬﺪاري ﺑﺮ ﮐﯿﻔﯿﺖ ﻣﯿﮑﺮوﺑﯽ و ﺧﺼﻮﺻﯿﺎت ﻓﯿﺰﯾﮑﻮﺷﯿﻤﯿﺎﯾﯽ ﭘﻮدر ﻣﯿﮕﻮي ﺗﻮﻟﯿﺪي ﺑﻪ روش ﺧﺸﮏ ﮐﺮدن ﮐﻒ ﭘﻮﺷﯽ

The Effect of Storage Temperature on Microbial and Physicochemical Properties of Shrimp Powder that was Made Using foam Mat Drying

ﺧﺸﮏ ﮐﺮدن ﮐﻒ ﭘﻮﺷﯽ ﻓﺮآﯾﻨﺪي اﺳﺖ ﮐﻪ در آن ﻣﻮاد ﻏﺬاﯾﯽ ﻣﺎﯾﻊ ﺑﻪ وﺳﯿﻠﻪ ﺗﺮﮐﯿﺐ ﮔﺎز ﺑﻪ داﺧﻞ آن ﻫﺎ ﺑﻪ ﮐﻒ ﭘﺎﯾﺪار ﺗﺒﺪﯾﻞ ﺷﺪه، ﺳﭙﺲ در دﻣﺎي ﻧﺴﺒﺘﺎً ﭘﺎﯾﯿﻦ ﺧﺸﮏ ﻣﯽ ﺷﻮﻧﺪ. در اﯾﻦ ﭘﮋوﻫﺶ ﮐﻒ ﻣﯿﮕﻮ ﺑﺎ اﺳﺘﻔﺎده از ﻣﺤﻠﻮل 0/25 درﺻﺪ ﺻﻤﻎ داﻧﻪ ﺷﺎﻫﯽ و رﻗﯿﻖ ﺳﺎزي ﺑﺎ ﻧﺴﺒﺖ 1 ﺑﻪ 4 ﻣﯿﮕﻮ ﺑﻪ آب، ﻃﯽ 4 دﻗﯿﻘﻪ زدن ﺑﻪ دﺳﺖ آﻣﺪ و ﺳﭙﺲ ﮐﻒ ﺗﻮﻟﯿﺪي ﺑﺎ ﺿﺨﺎﻣﺖ 4 ﻣﯿﻠﯽ ﻣﺘﺮ ﺑﺎ اﺳﺘﻔﺎده از ﺧﺸﮏ ﮐﻦ ﺑﺎ دﻣﺎي 70 درﺟﻪ ﺳﺎﻧﺘﯽ ﮔﺮاد ﺧﺸﮏ ﮔﺮدﯾﺪ. در اداﻣﻪ ﺗﺄﺛﯿﺮ دو دﻣﺎي ﻧﮕﻬﺪاري )ﻣﺤﯿﻂ و ﯾﺨﭽﺎل( ﺑﺮ ﻣﺎﻧﺪﮔﺎري ﭘﻮدرﻫﺎي ﻣﯿﮕﻮي ﺗﻮﻟﯿﺪي ﻃﯽ ﻣﺪت 6 ﻣﺎه ﺑﺮرﺳﯽ ﺷﺪ. آزﻣﻮن ﻫﺎ ﺷﺎﻣﻞ داﻧﺴﯿﺘﻪ، ﻓﻌﺎﻟﯿﺖ آﺑﯽ، ﺟﺬب آب، ﺟﺬب روﻏﻦ، ﻧﯿﺘﺮوژن ﻓﺮار، ﺗﯿﻮﺑﺎرﺑﯿﻮﺗﯿﮏ اﺳﯿﺪ، ﭘﺮاﮐﺴﯿﺪ و ﺷﻤﺎرش ﻣﯿﮑﺮوﺑﯽ ﺷﺎﻣﻞ ﮐﻠﯽ ﻓﺮم، ﮐﭙﮏ و ﻣﺨﻤﺮ و ﺷﻤﺎرش ﮐﻠﯽ ﺑﻮد. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺷﻤﺎر ﺑﺎﮐﺘﺮي ﻫﺎي ﻣﺰوﻓﯿﻞ، ﺳﺮﻣﺎﮔﺮا، ﮐﻠﯿﻔﺮم ﮐﻞ، وﯾﺒﺮﯾﻮﻫﺎ، ﮐﭙﮏ و ﻣﺨﻤﺮ ﺑﺎ اﻓﺰاﯾﺶ دوره ﻣﺎﻧﺪﮔﺎري روﻧﺪ اﻓﺰاﯾﺸﯽ داﺷﺘﻨﺪ، از ﻃﺮﻓﯽ ﮐﻠﯿﻔﺮم ﻣﺪﻓﻮﻋﯽ، اﺷﺮﺷﯿﺎ و ﺳﺎﻟﻤﻮﻧﻼ ﻫﻢ در ﻧﻤﻮﻧﻪ ﻫﺎي اوﻟﯿﻪ و ﻫﻢ در ﻃﻮل دوره ﻣﺎﻧﺪﮔﺎري در ﻧﻤﻮﻧﻪ ﻫﺎي ﭘﻮدر ﻣﯿﮕﻮ ﻣﺸﺎﻫﺪه ﻧﺸﺪﻧﺪ. در ﻃﻮل دوره ﻣﺎﻧﺪﮔﺎري، ﺟﺬب آب، ﺟﺬب روﻏﻦ و ﻓﻌﺎﻟﯿﺖ آﺑﯽ روﻧﺪ ﮐﺎﻫﺸﯽ درﺣﺎﻟﯽ ﮐﻪ ﻧﯿﺘﺮوژن ﻓﺮار، ﺗﯿﻮﺑﺎرﺑﯿﻮﺗﯿﮏ اﺳﯿﺪ، ﭘﺮاﮐﺴﯿﺪ و داﻧﺴﯿﺘﻪ روﻧﺪ اﻓﺰاﯾﺸﯽ داﺷﺘﻨﺪ. ﻫﻤﭽﻨﯿﻦ در ﻧﻤﻮﻧﻪ ﻫﺎي ﻧﮕﻬﺪاري ﺷﺪه ﯾﺨﭽﺎل در ﭘﺎﯾﺎن دوره 6 ﻣﺎﻫﻪ ﻧﺴﺒﺖ ﺑﻪ ﻧﻤﻮﻧﻪ ﻫﺎي ذﺧﯿﺮه ﺷﺪه در ﻣﺤﯿﻂ، ﻣﯿﺰان ﻧﯿﺘﺮوژن ﻓﺮار، ﺗﯿﻮﺑﺎرﺑﯿﻮﺗﯿﮏ اﺳﯿﺪ، ﭘﺮاﮐﺴﯿﺪ و ﻓﻌﺎﻟﯿﺖ آﺑﯽ ﮐﻤﺘﺮ ﺑﻮد. در ﮐﻞ، ﭘﻮدر ﻣﯿﮕﻮ در ﺻﻮرت ﮐﻨﺘﺮل ﻓﻌﺎﻟﯿﺖ آﺑﯽ ﻣﺤﯿﻂ ﻣﺎﻧﺪﮔﺎري ﻗﺎﺑﻞ ﻣﻼﺣﻈﻪ اي دارد و ﻣﺎﻧﺪﮔﺎري آن در دﻣﺎي ﯾﺨﭽﺎل ﺑﻪ ﻧﺤﻮ ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ اﻓﺰاﯾﺶ ﻣﯽ ﯾﺎﺑﺪ.

The foam mat drying is a process in which liquid food is converted into stable foam by combining gas into it, and then dried at a relatively low temperature. In current research, shrimp foam was prepared using 0.25% Cress seed gum and dilution with ratio of 1 shrimp to 4 water after 4 min whipping and then foam with 4mm thickness dried in a drier with 70°C. Shelf life of powders for 6 months and two storage temperatures (ambient and refrigerate) were measured. The experiments included density, water activity, water absorption, oil absorption, total volatile base nitrogen (TVB-N), thiobarbituric acid, peroxide and microbial count including coliform bacteria, mold and yeast, and total count. The count of mesophilic, psychrotroph, total coliforms, vibrios, mold and yeast was increasing during shelf-life time. On the other hand, fecal coliform and escherichia coli and Salmonella were not found in shrimp powder samples during shelf-life period. During the shelf-life period of water absorption, oil absorption, water activity, decreasing trend and TVB-N, thiobarbituric acid, peroxide and density were increasing. In refrigerated samples at the end of the 6-month period, there was a lower level of TVB-N, thiobarbituric acid, peroxide and water activity than those stored in the ambient temperature.