Banana Pseudostem: properties nutritional composition and use as food

Banana pseudostems are crop waste, which cause economic loss and environment issues after harvest. However, pseudostems are rich in dietary fibre and have health benefits. This study explored the chemical composition (proximates, minerals, vitamins) as well as the digestibility and functionality of the carbohydrates. Dietary fibre was estimated using three methods namely the established AOAC method, Gas Chromatography and Nuclear Magnetic Resonance. As fresh banana pseudostems have limited shelf life, drying the stems using cabinet dryer using several conditions such as, drying at 40 °C and 50°C with/ without blanching, were compared with regard to drying time, colour as well as quality of the dried product in terms of the retention of nutrients. Drying at 50 °C without blanching provided the whitest colour and shortest drying time. Thus the optimum condition for drying was established at 50 °C without blanching based on nutrient retention. Musa balbisiana and Musa acuminata banana pseudostems were used in this study. There was no significant difference between protein, fat and carbohydrate content of banana pseudostems dried under different conditions. Moisture content was significantly higher in banana pseudostems dried at 40 °C without blanching; ash content was significantly higher in pseudostems dried at 50 °C without blanching. According to the percentage of total dietary fibre and resistant starch, pseudostem dried at 40 °C with blanching had the lowest digestibility. The neutral sugars in the non-starch polysaccharides were studied and compared with commercially available natural dietary fibre supplements sold in Australia. Pseudostems had higher ratio of soluble dietary fibre to insoluble dietary fibre, as compared to the commercial supplements. The main neutral sugars in the pseudostems were glucose, mannose and xylose, while those in the commercial supplements were xylose, arabinose and mannose, which had different functionality compared to pseudostem fibre. This study is the first to demonstrate that banana pseudostem is a potential dietary fibre supplement, which may bring health benefits to consumers and economic profits to the banana growers