Effect of Maturity of Raw Material on Quality of Banana Slices Dried by Microwave
ABSTRACT: The processing characteristics of common banana raw materials were studied, and the quality changes of banana slices in microwave drying equipment were analyzed. The nutritional characteristics of total sugar and starch in banana processing raw materials were determined and their texture and other sensory qualities were evaluated with mature pink banana, banana and banana from Guangdong province.
In the suitable maturity range, the higher the maturity of banana, the better the quality of vacuum microwave dried products, among which banana is more suitable for making crisp chips.
Key words: banana slices microwave drying; varieties; polysaccharides; microwave drying
In some countries and regions, bananas can be used as food substitutes, and FAO has identified them as the fourth largest food after rice, wheat and maize. Banana ranks fourth in total fruit yield in China, next to citrus, apple and pear, and occupies an important position in fresh fruit market. In 2010, the yield of bananas in Guangdong Province was 371.27 *104 t, accounting for 51% of the total national output.
Because banana is a typical respiratory climacteric fruit, it can not bear storage and browning seriously during processing. The pH value of banana is about 5.0, which makes it difficult to sterilize and store. Banana, as an important cash crop in the southern region, is difficult to process. Fruit drying is one of the techniques to prolong fruit storage, such as the drying of grapes and bananas.
In addition, banana slice leisure food is usually commercially produced by deep frying, which may produce acrylamide due to high temperature, and banana products are easy to brown under high temperature drying. Microwave drying technology can help to improve the quality of dehydrated fruit and vegetable dried products and produce new, natural and green expanded leisure food. Banana chips products are chips leisure products processed from ripe bananas.
As the ripeness of banana fruit increases, the original insoluble pectin gradually decomposes into soluble pectin or pectic acid, and the hardness of the fruit decreases. The changes of some chemical substances (such as sugar, acid and starch) in banana fruit are related to the ripeness. In order to determine the suitable microwave processing characteristics of three common bananas and the maturity range of raw materials, the main components of sugar, starch and sensory factors affecting the extrusion process and the quality of banana slices were discussed.
During the ripening process of three kinds of bananas, the sugar content of bananas increased with the decrease of starch content, and the texture of microwave extruded products was brittle. Considering the cost of raw materials, within 48 hours after ripening, bananas were larger than bananas.
Pink banana is more suitable for vacuum microwave extrusion drying.