Drying rate and quality attributes of foam-mat dried tomato pulp

Abstract

Introduction. Tomato is a short duration fruit that deteriorates easily after harvest, hence the need to process it using foam-mat drying as a technique, to produce tomato with good quality and investigate some process parameters (foaming agent and foam stabilizer concentration) that can influence drying rate and quality of the dried powder.Materials and Methods. Randomized complete block design was used with about 27 samples of tomato pulp using egg white as foaming agent at 3 levels of concentration 5%, 10% and 15% and carboxyl methyl cellulose (CMC) at 0.2%, 0.4% and 0.8% the whipping time at 3 minutes and the samples were dried in a cabinet dryer at 70 °C.Results and Discussion. The result show that the mean for samples treated with foaming agent concentration at 5%, 10% and 15% had drying rates of 19.21 g/hr, 21.53 g/hr and 20.46 g/hr, protein content of 24.66%, 24.72% and 24. 77% and vitamin C content of 1.70%, 1.44% and 1.34% respectively while those treated with CMC concentration at 0.2%, 0.4% and 0.8% had drying rates of 18.74 g/hr, 20.68 g/hr and 21.78 g/hr, protein content of 24.71%, 24.71% and 24.74% and vitamin C content of 1.43%, 1.56% and 1.49% respectively. Analysis of Variance shows that foaming agent and foam stabilizer concentration had no significant effect on drying rate at P≤0.05, but foaming agent had significant effect on protein and vitamin C contents of the sample. Analysis of Variance also shows that the interaction that exist between foaming agent and foam stabilizer had significant effect on the vitamin C and protein content of the sample but had no significant effect on the drying rate at P≤0.05. Furthermore the New Duncan Multiple Range Test (NDMRT) shows the means of protein content 24.66%, 24.72% and 24.77% at foaming agent concentration of 5%, 10% and 15% respectively.Conclusions. Foaming agent concentration is an important parameter that influences the quality attributes of foam-mat dried tomato. In order to achieve maximum retention of the vitamin C content of foam-mat dried tomato pulp, 5% concentration of the foaming agent (egg albumin) is more ideal compared with higher concentrations as this will go a long way to minimize overall cost incurred during foam-mat drying process.

Encapsulated aromatic citronella extract (Cymbopogon nardus) and its responses to protein content, solubility, and water holding capacity of catfish bone powder

“…The foam mat drying method requires foam-forming agents such as tween 80 and egg white. Apart from this, adding fillers such as maltodextrin, xanthan gum, Arabic gum, and cyclodextrin is also required in this method (Olaoye & Obajemihi, 2017). A filler is an agent that can reduce surface tension and facilitate foaming.…”