Effect of some pretreatments before drying on microbial load and sensory acceptability of dried mango slices during storage periods

Abstract

The present study was conducted to assess the effect of some pretreatments, and drying methods on the microbial loads, and sensory acceptability of dried mango slices during storage periods. Four pretreatments (lemon juice, salt solution dips, hot water blanching, and control) and four drying methods (solar, tray, freeze, and fluidized bed drying) were considered and arranged in factorial experimental design. The microbial loads and sensorial acceptance of dried mango slices during storage times were evaluated. The result showed that the pretreatments and drying methods exhibited significant effects on the microbial load and sensory acceptance of the dried mango slices during storage periods. It could be inferred that the total plate count of dried mango slices ranged from 1.4 × 10 2 to 9.6 × 10 3 CFU/g while yeast and mould were 4.2 × 10 1 to 8.2 × 10 1 CFU/g during storage periods; it could be concluded that drying of the mango slices with those pretreatments and drying methods assured the microbial safety of the product for storage periods of 90 days. Generally, the overall acceptance of dried mango slice was good during three months of storage periods on the 7-point Hedonic scale, these indicate that the slices made from mangoes would be accepted when introduced into the market.

Comparison between Quality Traits of Solar-Dried and Freeze-Dried Origanum syriacum L. (Za’atar)

“…Both solar and freeze-drying techniques reduced the total aerobic bacterial count significantly if compared to fresh O. syriacum. Our findings were in agreement with previous studies [31][32][33]. This can be attribute to the fact that removal of moisture makes disturbance and destruction for cell wall as well as for DNA [34].…”

“…It was found that sun-dried ginger had higher content of total bacteria and this was attributed due to contaminants from the surrounded environment [35]. Dereje and Abera [33] found that solar dried mango exhibited higher content fungal count than freeze dried mango. Malmsten et al [32] revealed that freeze-drying was more effective in lowering yeast and mold count than air-drying.…”

Based on quality, energy consumption selecting optimal drying methods of mango slices and kinetics modelling

“…Ripened mangoes are perishable and fresh mangoes are very sensitive to microbial deterioration because of their high-water content. These lead to their short shelf life, and it is a considerable economical and factual issue ( Dereje et al, 2020 , Sehrawat et al, 2018 ). Therefore, deep processing and preservation methods have been extensively pursued to expand the storage and consumption of fresh mangoes.…”

“…Drying is one of the most typical and economic processing methods applied to reduce post-harvest product loss and increase the shelf life of products. This inhibits bacterial growth and hinders putrefaction reactions mainly attributed to the reduced moisture content ( Dereje et al, 2020 , Kumar et al, 2014 , Macedo et al, 2020 ). Traditional drying methods include drying in the sun or shade, which are time-consuming.…”

“…Globally, several studies on mango drying have been conducted ( Dereje et al, 2020 , Malaikritsanachalee et al, 2020 , Mugodo and Workneh, 2021 , Sehrawat et al, 2018 ). However, this study is specific to certain drying conditions and has established the drying kinetics of certain drying methods.…”