Kolawole O. Falade

Osmotic Dehydration of Tropical Fruits and Vegetables

Because of the microstructural complexity of plant tissue, osmotic dehydration cannot simply be explained as a pure osmotic process in which cell membranes act as a semipermeable barrier allowing water to pass through. Instead, osmotic dehydration is considered a process in which many simultaneous mechanisms, acting at different levels, are responsible for mass transport. Different compositional and structural profiles are induced in fruits and vegetables, depending on process variables and the tissue microstructure. Compositional-structural profiles that are developed with gas-liquid exchanges in the tissue during osmotic process have a significant impact on physical (optical), textural and chemical properties (e.g., flavour profile) of the final product, which is in part influenced by the differences in the number of cells that are altered and unaltered during the treatment. This review focuses on changes in the physical, chemical, and cellular structure of fruits and vegetables, some technologies commonly applied to increase mass transfer during osmotic dehydration (OD), potentials and industrial applications of OD, and the challenges of osmo-drying technology.

Utilization of Cassava for Food

Cassava (Manihot esculenta Cranz and/or Manihot utillisima Phol) has been processed into food products worldwide for several hundred years. The traditional methods of processing cassava roots into food have been adapted to suit the attributes of the plant such as root yield, spoilage, cyanide content, nutrient content, and process-ability. With increasing population, increasing demand of consumers for better quality foods and increasing new uses for cassava, indigenous methods of cultivation and processing of cassava have been transformed by modern scientific knowledge for use in industrial operations. Cassava is basically made into fermented and unfermented products. Fermented products include cassava bread, fermented cassava flour, fermented starch, fufu, lafun, akyeke (or attieke), agbelima, and gari, whereas the unfermented products include tapioca, cassava chips and pellets, unfermented cassava flour and starch. New food uses of cassava include as flour in gluten free or gluten-reduced products (e.g., bread, biscuits, etc.). This review highlights progress made in the utilization of cassava for food; challenges, process and raw material development issues and improvement achieved in nutritional delivery of cassava foods. Also, progress made in the storage, presentation, packaging, etc., of cassava foods are discussed.

Foam-Mat Drying of Plantain and Cooking Banana (Musa spp.)

Foaming, reconstitution, and sensory attributes of foam-mat-dried plantain and cooking banana were investigated. Plantain and cooking banana pastes mixed with different concentrations (0.005%, 0.01%, 0.015%, and 0.02%) of glyceryl monostearate (GMS) were whipped, and the resulting foams were air dried at 60°C, 70°C, and 80°C. Physical, chemical, and sensory properties of fresh and reconstituted paste from plantain and cooking bananas were determined. Higher GMS concentration and longer whipping time resulted in lower foam densities. Generally, cooking banana foams showed lower foam density compared to plantain foam. Lower drying temperatures and concentration of GMS resulted in longer drying time. pH (4.41–4.80), titratable acidity (0.06–0.08), and water absorption capacity (56.75–64.02%) of the reconstituted pastes varied with commodity, drying temperature, and %GMS concentration. Fresh and reconstituted pastes showed comparable physical and chemical attributes, while the taste and sensory attributes of fresh plantain and cooking banana pastes were significantly (p < 0.05) better than those of reconstituted pastes.