Pineapple waste is a by-product resulting from canning processing of pineapple that produce about 35% of fruit waste and lead to serious environmental pollution. Pineapple waste contains valuable nutrient components of simple sugar such as sucrose, glucose and fructose. Analysis of sugar content is important for further processing such as fermentation. The aim of this study was to determine the amount of sugar in different parts of pineapple waste (peel, core and crown) from variety N36. The selected pineapple waste for maturity indices 1, 2 and 3 was cut into small pieces before crushed in a food processor. The crushed waste was then filtered through muslin cloth followed by membrane filter 0.45μm to produce pineapple waste extract. Sugar content was determined using High Performance Liquid Chromatography. It was found that fructose content was significantly higher in core (2.24%) followed by peel (2.04%) and crown (0.87%). It was also found that glucose content was significantly higher in core (2.56%) followed by peel (2.18%) and crown (0.53%). Significant difference (p < 0.05) was found for sucrose content between pineapple core and peel extract with the value of 8.92% and 3.87%, respectively. However, sucrose was not detected in pineapple crown. It means that pineapple core extract had the highest values of fructose, glucose and sucrose compared to the other parts of pineapple waste extract. Besides, it was found that sucrose content was significantly higher in pineapple core for index 3 as compared to indices 1 and 2. Glucose and fructose was significantly higher in pineapple core for index 2 compared to indices 1 and 3.
The aim of this study is to determine colour changes during storage and physico- chemical properties of peel, core and crown extracts of pineapple variety N36 for maturity indices of 1, 2 and 3. The L* (lightness), a* (redness) and b* (yellowness) values for peels increased significantly (p ≤ 0.05) at each maturity stage during seven days storage. pH of pineapple peel, core and crown extracts were in the range of 3.24 to 3.84. The titratable acidity, percentage of pulp and Total Soluble Solid (TSS) of pineapple peel, core and crown extracts were in the range of 0.16 to 0.36%, 1.37 to 2.91% and 1.4 to 5.3˚Brix, respectively. Fructose and glucose contents were significantly highest (p ≤ 0.05) in pineapple core extract followed by pineapple peel extract and pineapple crown extract for maturity index 2. Significant difference (p ≤ 0.05) was found in sucrose content between pineapple core and peel extracts with 8.92% and 3.87%, respectively for maturity index 3. However, sucrose was not detected in pineapple crown extract. Pineapple core extract was significantly higher (p ≤ 0.05) amount of total sugar content compared to pineapple peel and crown extracts for all maturity indices.