Comparative Effects of Silver Nanoparticles, Sucrose and Sodium Chloride as Osmotic Solutions for Tomato Slices: Antioxidant Activity, Microbial Quality and Modelling with Polynomial Regression Model

Abstract

This study has reported comparative effects of silver nanoparticles (AgNPs), sucrose and sodium chloride as osmotic solutions on antioxidant activity and microbial quality of 10 mm tomato slices. 40 g of tomato slices were dehydrated osmotically (OD) at different temperatures (60, 70 and 80°C) and time (30, 60, 90, 120 150 and 180 min). Water loss, solid impregnation, water and solid diffusivities of tomato slices were found to increase with increase in solution temperatures and concentrations with AgNPs having the greatest influence. Antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl increased with increase in solution concentrations but decreased with increase in temperature. Three-way ANOVA (R 2 = 0.998) revealed additive statistically significant effects of osmotic agents, concentrations and temperatures on antioxidant activity; F (8,54) = 67.854, P = 0.00. Polynomial regression analysis with response surface methodology validated experiments such that for each unit increase in concentration and temperature, antioxidant activity increased with good coefficients of determination; sucrose (R 2 = 0.87), NaCl, (R 2 = 0.89) and AgNPs (R 2 = 0.91). Potato dextrose and nutrient agars were used for isolating and identifying microorganisms in OD tomato slices. Tomato slices dehydrated with AgNPs had the highest microbial inhibition of fungi with growth occurring after 7 days, unlike in treatments with sucrose and NaCl where fungal growth appeared after 2 and 5 days, respectively. Aspergillus niger was the most prevalent fungus. It can be concluded that AgNPs may serve as a viable means to dehydrate and preserve tomatoes without loss of antioxidant activity.

Green Nanotechnology in Nigeria: The Research Landscape, Challenges and Prospects

“…In several studies, it has been shown that biosynthesized AgNPs can modulate treated plants to improve their antioxidant activities. Corchorus olitorius grown with different levels of AgNPs increased the DPPH scavenging and ferric reducing abilities of the leaf extract by 1.8 and 4.94 fold respectively(Azeez et al, 2019a) Azeez et al (2019b). also showed that cocoa-bean mediated AgNPs can be used for osmotic dehydration of tomato slices with improved microbial quality and antioxidant properties.…”

Metabolic profiles alteration of Southern Thailand traditional sweet pickled mango during the production process

“…Yu et al ( 27 ) observed the growth of bacteria, yeast, and fungi in osmotically dehydrated blueberries. In addition, Azeez et al ( 28 ) found viable fungi in osmotically dehydrated tomato slices. These indigenous microbiotas, which are usually found on the fruit surface, become the main initiator of spontaneous fermentation because of their adaptive nature to the mango matrix ( 29 ).…”

Responses of Moringa oleifera to alteration in soil properties induced by calcium nanoparticles (CaNPs) on mineral absorption, physiological indices and photosynthetic indicators

“…Metal nanoparticles can be used as nanofertilisers supplying essential minerals or be applied to improve the performance of conventional chemical fertilisers. They are more efficient in supplying nutrients and contribute lesser environmental pollution because of their controllable rates of release thereby reducing the risk of nutrient run-off into water [3,5,[11][12][13][14][17][18][19][20][21].…”