Effect Of Packaging Material On The Storage Quaity Of Sudanese Soft Cheese

Abstract

Sudanese white soft cheese was purchsed as traditionally prepared from El Dueim town. The cheese was immediately packed into five different packing meterials, namely metal tin containers, metal tin lined with polyethylene bags, plastic buckets, plastic buckets lined with polyethylene bags and metal gallon, each contained more or less 2.0 kg cheese. All packing materials containing cheese were stored at room temperature (30 ± 5oC) for 6 months (180 days) and examined during storage for changes in proximate composition (protein, fat, total solids, salt, ash and mineral matter), biochemical attributes (pH, acidity), ripening indices (Formol and Schilovish, soluble nitrogen and volatile fatty acids), microbiological features related to safety (e.g. total count, moulds and yeast, coliform, Clostridium spp., Staphylococcus spp. And Salmonella), and organoleptic quality were examined. Total solids, protein and fat content of cheese were fluctuating during storage, where minimum protein content was recorded in non-lined plastic containers up to the end of the storage period. Maximum acidity (2.6% lactic) was found in cheese kept in lined metal tins which lead to a pronouunce decrease in the total count, mould and yeast, and coliform count. Ripening was significantly (P < 0.05) faster in plastic containers and metal gallons as evidenced by significantly (P < 0.05) higher values of Formol ripening index (FRI) and Schilovish ripening index (SRI), soluble nitrogen (SN) and volatile fatty acids (VFA). Lead level was reported in significantly (P < 0.05) higher value in cheese stored in metallic gallons. Such levels reflected disadvantages of packing cheese in such packing materials. Since microbiological features of products decide their safety during storage, the maximum level of moulds yeast and bacteria were reported in cheese stored in plastic and metallic gallon which lead to earlier deterioration of these samples compared to the other packaging materials. The Organoleptic properties were superior after 45 days storage for cheese stored in tin containers, whereas cheese in the plastic container obtained the highest score at the beginning of the storage,and lost such credit towards the end of the storage period.