Undersøkelse over effekten av vakuumpakking og lagring i kullsyreatmosfære ved frysing av reker

Abstract

Experiments in freezing of cooked, peeled and unpeeled shrimps have been carried out in order to find out the effect of vacuum-packing and use of carbon dioxide gas in packing of the shrimps during storing at temperatures of -25° and -16°C. Shrimps stored both in vacuum and in carbon dioxide gas maintained quality better than similar samples stored in air at the same temperature. Especially the vacuum-packed samples were definitely better than the others both in colour, taste and texture. The samples stored in carbon dioxide did not keep quite so well, and the samples of shrimps stored in air at the same temperature and in similar packing material were pronounced inferior to the others. Vacuum-packing is therefore considered to be preferable in freezing and storing of shrimps. With a satisfactory vacuum-tight packing it is found possible to store frozen shrimps longer and obtain a higher quality than now is common in commercial freezing of shrimps. The plastic bags used in the experiments were vacuum-tight and strong enough for the packing of peeled shrimps, but the bags were easily penetrated during the packing of unpeeled shrimps. A better method would probably be to freeze unpeeled shrimps in alginate. The experiments also confirmed that the storage temperature is very important in storing of shrimps, and in storing at a temperature of - 25 °C the quality was much better than at a temperature of -16°C.