Abstract

This study aimed at evaluating the effect of storage time on the stability of pineapple products processed by small and medium scale processing enterprises (SMEs) in Rwanda stored at ambient (21 to 25°C) temperatures. Physico-chemical quality characteristics (pH, moisture, fibre, ash, total soluble solids, titratable acidity, sucrose, reducing sugars, total sugars and ethanol) of the sample products were analysed. Changes in the quality were monitored at three and one months interval for syrups, jams and nectars, respectively. Results showed that for nectars, most of the parameters evaluated were stable up to only two months of storage. All nectars, syrups and jams had a pH ranging from 3-5, the normal pH range for fruit products. The levels of titratable acidity of all products were below the maximum limit of 1.35% set by Codex Alimentarius Commission (CAC) Standards. Similarly, their levels of ethanol were less than the maximum of 0.3% recommended by Codex Alimentarius Commission standards. Syrups and jams were stable for most of the parameters up to six months of storage. There was a significant (p<0.05) decrease of sucrose and increase of reducing sugars in syrup and jam samples, specifically from six months of storage. Products from some enterprises exhibited sugar values higher than the maximum recommended by Rwandan, East African and CAC standards. The studied products exhibited significant variations in most of the studied parameters over the storage period with most of the samples not complying with the standards including sugar levels. Processors, therefore, need to be trained on proper fruit processing and the standard requirements for pineapple fruit products.

Key words: Pineapple products, storage stability, chemical properties