CHEMICAL PROPERTIES OF FOAM MAT-DRIED TOMATO POWDER AS AFFECTED BY PROCESS VARIABLES

This research aimed at studying the optimization of process variables for the production of quality foam mat-dried tomato. The method of drying used for this study is foam mat drying and oven drying which serves as the control.  For this study, Box-Behnken experimental design of response surface methodology (RSM) was used for designing the experiments. The independent variables selected for the foam mat drying were acacia gum (1 - 3 %) as foam stabilizer, temperature (60 -80 oC) and weight of tomato pulp (170, 190 and 210 g/m2). While for the controls were just dried at different temperature ranges of 60, 70 and 80 oC. The fresh ripe tomato was washed, desked, cut into smaller pieces, pulped before adding the foaming agent and stabilizer then whipped for 7 min and dried in a rectangular tray at 60, 70, 80 oC, scarped, milled and packaged in air tight container. Lycopene, total sugar, ascorbic acid, beta-carotene, and total soluble solids ranged from 2.87 – 11.80 mg/100g, 0.0002 – 0.0012 mml/L, 121.01 – 127.50 mgL-1, 1.40 – 2.47 mg, 4.60 – 7.27oBrix respectively and their controls ranged from 6.79 – 9.26 mg/100g, 0.0001 – 0.0008 mml/L, 60.13- 70.81 mgL-1, 0.56 – 0.83 mg and 0.80 – 1.60oBrix respectively. Keywords: Foam Mat Dried Tomato Powder; Process Variables; Chemical Properties; Lycopene; Correlation; Optimization; Face Centered Composite Design. DOI: 10.7176/FSQM/121-06 Publication date: April 30th 2023  

Effect of Addition of Citric Acid and Sodium Benzoate on pH and Microbial Profile of Soymilk

Aim: To study the synergistic effect of chemical preservatives on the keeping quality of soymilk. Study Design: Ten soymilk samples were prepared and treated with different concentrations of citric acid and sodium benzoate and stored at ambient conditions. Place and duration of Study: The present study was conducted at the Department of Food Science and Technology, Nnamdi Azikiwe University, Awka between March 2015 and June 2016 Methodology: Ten (10) soymilk samples were prepared. Soybean seeds (2 kg) that are free of dirt and stones were weighed and steeped in 4 L of tap water, a 12 h steeping regime was adopted. Each soymilk sample was formulated by adding different concentrations of sodium benzoate and citric acid, while the control sample had no treatment. All soymilk samples were then boiled at 75oC for 15 minutes and stored in storage bottles. Standard microbiological techniques were employed in the isolation and enumeration of potential spoilage organisms in soymilk samples. pH analysis was conducted throughout the storage period. Results: There was a decrease in pH of all soymilk samples with increasing storage time. pH at day 0 ranged between 6.2 to 7.2. Isolated bacteria in 10 soymilk samples included Streptococcus sp., Pseudomonas sp., Proteus sp., Bacillus spp., Staphylococcus aureus, Klebsiella sp., Escherichia coli, and Enterobacter species. However, results obtained showed that soymilk could keep up to 7 days at ambient temperature, encouraging the use of citric acid and sodium benzoate as chemical preservatives. Conclusion: In the present study, preservation of soymilk samples from a combination of citric acid and sodium benzoate which are chemical preservatives was found to be more effective than several organic preservatives. Hence, they represent an alternative source of chemical antimicrobial substances for use in food systems to prevent the growth of food borne microorganisms and extend the shelf-life of processed food

Investigation of functional and sensory properties of plantain flour in citric acid

Purpose: This study investigated the effects of process variables on the proximate, functional, and sensory properties of plantain flour. Research Methodology: The plantain fruit was sorted and hand-peeled using kitchen knives. It was then cut into various slices of 2 – 6 mm and steeped in citric acid solutions with concentrations ranging between 1 – 5 %. The steeping time varied between 30 – 120 min. The pretreated plantain slices were processed into flours. Process parameters were analyzed using the response surface methodology of Design Expert software. Results: The proximate parameters of the flour samples showed no significant difference (p > 0.05), but there were significant effects (p< 0.05) on the functional and sensory properties of the flour samples. The functional properties were found to differ significantly. Limitation: This study did not consider the application of other optimization methods such as genetic algorithm and particle swarm optimization in estimating the optimum points. Future studies could focus on these areas. Contribution: The validation of the optimization processes showed success in the application of citric acid in the production of novel plantain flour