Plastic wrap has moderate oxygen permeability and non permeability to regulate the oxygen and moisture content around the preserved food. Due to the exchange of oxygen between the inside and outside, it can effectively prevent the growth of anaerobic bacteria and block dust in the air, thereby extending the freshness period of the food. So preservation includes "water retention", "shelf Жыццё "і" абарона пажыўных рэчываў ". Наогул кажучы, ежа, якая правільна загорнутая ў поліэтыленавую плёнку, можа захавацца пры пакаёвай тэмпературы каля тыдня .
